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Visual Studio C#Properties.Settings.Default问题

c# visual-studio-2015

Visual Studio C#Properties.Settings.Default问题,c#,visual-studio-2015,excel-addins,excel-automation,C#,Visual Studio 2015,Excel Addins,Excel Automation,我在这里遇到的问题是，我正在为Excel构建一个COM和自动化的组合加载项。尝试访问我创建的自动化加载项类中的Properties.Settings.Default时，通过的值是我为项目设置为默认值的值，即使COM加载项返回通过配置表单保存的值 所有类都在同一项目中，位于同一命名空间下，并且“我的配置表单”、“COM加载项”和“功能区”的类文件都可以访问更新的Properties.Settings.Default值。我的自动化外接程序和静态类（处理所有繁重的工作）无法访问更新的值 COM加载项：

我在这里遇到的问题是，我正在为Excel构建一个COM和自动化的组合加载项。尝试访问我创建的自动化加载项类中的Properties.Settings.Default时，通过的值是我为项目设置为默认值的值，即使COM加载项返回通过配置表单保存的值

所有类都在同一项目中，位于同一命名空间下，并且“我的配置表单”、“COM加载项”和“功能区”的类文件都可以访问更新的Properties.Settings.Default值。我的自动化外接程序和静态类（处理所有繁重的工作）无法访问更新的值

COM加载项：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using Excel = Microsoft.Office.Interop.Excel;
using Office = Microsoft.Office.Core;
using Microsoft.Office.Tools.Excel;
using System.Windows.Forms;

namespace DBLink
{
    public partial class ThisAddIn
    {
        //public Dictionary<string, string> reports;
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
        }

        #region VSTO generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }

        #endregion
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using Microsoft.Office.Tools.Ribbon;
using Excel = Microsoft.Office.Interop.Excel;
using Microsoft.Office.Tools.Excel;

namespace DBLink
{
    public partial class Ribbon1
    {
        private void Ribbon1_Load(object sender, RibbonUIEventArgs e)
        {
            //Even setting the connection string from a class that has
            //access to the correct values fails and says the connection
            //string is not initialised.
            string conString;
            conString = "User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ";
            DataLink.connString = conString;

            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
        }

        private void button1_Click(object sender, RibbonControlEventArgs e)
        {
            Form frm = new Form1();
            frm.ShowDialog();
        }

        private void button2_Click(object sender, RibbonControlEventArgs e)
        {
            try
            {
                DataLink.LoadData(Globals.ThisAddIn.Application.ActiveWorkbook);
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }
        }

        private void button5_Click(object sender, RibbonControlEventArgs e)
        {
            //Do Stuff
        }

        private void button3_Click(object sender, RibbonControlEventArgs e)
        {
            //Do Stuff
        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Windows.Forms;

namespace DBLink
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Properties.Settings.Default.DBServer = textBox1.Text;
            Properties.Settings.Default.DBName = textBox2.Text;
            Properties.Settings.Default.DBUser = textBox3.Text;
            Properties.Settings.Default.DBPassword = textBox4.Text;
            Properties.Settings.Default.Save();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
            try
            {
                con.Open();
                MessageBox.Show("Connected successfully");
                con.Close();
            }
            catch
            {
                MessageBox.Show("There was a problem connecting to the database. Please confirm the details!");
            }
        }
    }
}

using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;

namespace DBLink
{
    [Guid("19C7ACDB-1572-4988-984F-3C56AEF117A5")]
    [ClassInterface(ClassInterfaceType.AutoDual)]
    [ComVisible(true)]

    public partial class MyFunctions2
    {
        string connectionString;
        public MyFunctions2()
        {
        }

        private static string GetSubKeyName(Type type, string subKeyName)
        {
            System.Text.StringBuilder s = new System.Text.StringBuilder();
            s.Append(@"CLSID\{");
            s.Append(type.GUID.ToString().ToUpper());
            s.Append(@"}\");
            s.Append(subKeyName);
            return s.ToString();
        }
        public string MTD(int year, int period, string costCentre, string account)
        {
            connectionString = "User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ";
        return DataLink.MTD(year, period, costCentre, account, connectionString).ToString();
        }

        public double MultiplyNTimes2(double number1, double number2, double timesToMultiply)
        {
            return DataLink.MultiplyNTimes(number1, number2, timesToMultiply);
        }

        [ComRegisterFunctionAttribute]
        public static void RegisterFunction(Type type)
        {
            Registry.ClassesRoot.CreateSubKey(GetSubKeyName(type, "Programmable"));
            RegistryKey key = Registry.ClassesRoot.OpenSubKey(GetSubKeyName(type, "InprocServer32"), true);

            key.SetValue("", System.Environment.SystemDirectory + @"\mscoree.dll", RegistryValueKind.String);
        }

        [ComUnregisterFunctionAttribute]
        public static void UnregisterFunction(Type type)
        {
            Registry.ClassesRoot.DeleteSubKey(GetSubKeyName(type, "Programmable"), false);
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using Microsoft.Office.Tools.Ribbon;
using Excel = Microsoft.Office.Interop.Excel;

namespace DBLink
{
    public static partial class DataLink
    {
        private static string commandText = "select case when ACClass in (2,3,4,5) then SUM(ISNULL(POCredit,0)-ISNULL(PODebit,0)) else SUM(ISNULL(PODebit,0)-ISNULL(POCredit,0)) end as value from Account join Post on ACID = POAccountID left join Segment on SID = POSegmentID join Journal on POJournalID = JID where DatePart(month,JDate) = @month and DatePart(year,JDate) = @year and ACCode = @account and (SName = @seg or @seg = '*') group by ACClass";
        public static string connString="";
        private static SqlConnection con;

        public static void SetConnString(string connection)
        {
            connString = connection;
        }
        public static void LoadData(Excel.Workbook wb)
        {
            //Do stuff... may be deprecated before release.
        }

        public static double MTD(int year, int period, string costCentre, string account, string conString)
        {
            DataTable dt = new DataTable();
            DataSet ds = new DataSet();
            double result = 0;
            int month = period > 6 ? period - 6 : period + 6;
            int actualYear = month > 6 ? year - 1 : year;

            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");

            con = new SqlConnection(connString);
            try
            {
                using (SqlCommand cmd = new SqlCommand(commandText, con))
                {
                    cmd.Parameters.AddWithValue("@month", month);
                    cmd.Parameters.AddWithValue("@year", actualYear);
                    cmd.Parameters.AddWithValue("@account", account);
                    cmd.Parameters.AddWithValue("@seg", costCentre);
                    MessageBox.Show(cmd.CommandText);
                    MessageBox.Show(cmd.Connection.ConnectionString);
                    cmd.Connection.Open();
                    dt.Load(cmd.ExecuteReader());
                    if (dt.Rows.Count > 0)
                    {
                        MessageBox.Show("We have a row");
                        ds.Tables.Add(dt);
                        result = double.Parse(ds.Tables[0].Rows[0].ItemArray[0].ToString());
                    }
                    cmd.Connection.Close();
                    MessageBox.Show(result.ToString());
                }
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }

            return result;
        }
    }
}
表格：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using Excel = Microsoft.Office.Interop.Excel;
using Office = Microsoft.Office.Core;
using Microsoft.Office.Tools.Excel;
using System.Windows.Forms;

namespace DBLink
{
    public partial class ThisAddIn
    {
        //public Dictionary<string, string> reports;
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
        }

        #region VSTO generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }

        #endregion
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using Microsoft.Office.Tools.Ribbon;
using Excel = Microsoft.Office.Interop.Excel;
using Microsoft.Office.Tools.Excel;

namespace DBLink
{
    public partial class Ribbon1
    {
        private void Ribbon1_Load(object sender, RibbonUIEventArgs e)
        {
            //Even setting the connection string from a class that has
            //access to the correct values fails and says the connection
            //string is not initialised.
            string conString;
            conString = "User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ";
            DataLink.connString = conString;

            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
        }

        private void button1_Click(object sender, RibbonControlEventArgs e)
        {
            Form frm = new Form1();
            frm.ShowDialog();
        }

        private void button2_Click(object sender, RibbonControlEventArgs e)
        {
            try
            {
                DataLink.LoadData(Globals.ThisAddIn.Application.ActiveWorkbook);
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }
        }

        private void button5_Click(object sender, RibbonControlEventArgs e)
        {
            //Do Stuff
        }

        private void button3_Click(object sender, RibbonControlEventArgs e)
        {
            //Do Stuff
        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Windows.Forms;

namespace DBLink
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Properties.Settings.Default.DBServer = textBox1.Text;
            Properties.Settings.Default.DBName = textBox2.Text;
            Properties.Settings.Default.DBUser = textBox3.Text;
            Properties.Settings.Default.DBPassword = textBox4.Text;
            Properties.Settings.Default.Save();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
            try
            {
                con.Open();
                MessageBox.Show("Connected successfully");
                con.Close();
            }
            catch
            {
                MessageBox.Show("There was a problem connecting to the database. Please confirm the details!");
            }
        }
    }
}

using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;

namespace DBLink
{
    [Guid("19C7ACDB-1572-4988-984F-3C56AEF117A5")]
    [ClassInterface(ClassInterfaceType.AutoDual)]
    [ComVisible(true)]

    public partial class MyFunctions2
    {
        string connectionString;
        public MyFunctions2()
        {
        }

        private static string GetSubKeyName(Type type, string subKeyName)
        {
            System.Text.StringBuilder s = new System.Text.StringBuilder();
            s.Append(@"CLSID\{");
            s.Append(type.GUID.ToString().ToUpper());
            s.Append(@"}\");
            s.Append(subKeyName);
            return s.ToString();
        }
        public string MTD(int year, int period, string costCentre, string account)
        {
            connectionString = "User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ";
        return DataLink.MTD(year, period, costCentre, account, connectionString).ToString();
        }

        public double MultiplyNTimes2(double number1, double number2, double timesToMultiply)
        {
            return DataLink.MultiplyNTimes(number1, number2, timesToMultiply);
        }

        [ComRegisterFunctionAttribute]
        public static void RegisterFunction(Type type)
        {
            Registry.ClassesRoot.CreateSubKey(GetSubKeyName(type, "Programmable"));
            RegistryKey key = Registry.ClassesRoot.OpenSubKey(GetSubKeyName(type, "InprocServer32"), true);

            key.SetValue("", System.Environment.SystemDirectory + @"\mscoree.dll", RegistryValueKind.String);
        }

        [ComUnregisterFunctionAttribute]
        public static void UnregisterFunction(Type type)
        {
            Registry.ClassesRoot.DeleteSubKey(GetSubKeyName(type, "Programmable"), false);
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using Microsoft.Office.Tools.Ribbon;
using Excel = Microsoft.Office.Interop.Excel;

namespace DBLink
{
    public static partial class DataLink
    {
        private static string commandText = "select case when ACClass in (2,3,4,5) then SUM(ISNULL(POCredit,0)-ISNULL(PODebit,0)) else SUM(ISNULL(PODebit,0)-ISNULL(POCredit,0)) end as value from Account join Post on ACID = POAccountID left join Segment on SID = POSegmentID join Journal on POJournalID = JID where DatePart(month,JDate) = @month and DatePart(year,JDate) = @year and ACCode = @account and (SName = @seg or @seg = '*') group by ACClass";
        public static string connString="";
        private static SqlConnection con;

        public static void SetConnString(string connection)
        {
            connString = connection;
        }
        public static void LoadData(Excel.Workbook wb)
        {
            //Do stuff... may be deprecated before release.
        }

        public static double MTD(int year, int period, string costCentre, string account, string conString)
        {
            DataTable dt = new DataTable();
            DataSet ds = new DataSet();
            double result = 0;
            int month = period > 6 ? period - 6 : period + 6;
            int actualYear = month > 6 ? year - 1 : year;

            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");

            con = new SqlConnection(connString);
            try
            {
                using (SqlCommand cmd = new SqlCommand(commandText, con))
                {
                    cmd.Parameters.AddWithValue("@month", month);
                    cmd.Parameters.AddWithValue("@year", actualYear);
                    cmd.Parameters.AddWithValue("@account", account);
                    cmd.Parameters.AddWithValue("@seg", costCentre);
                    MessageBox.Show(cmd.CommandText);
                    MessageBox.Show(cmd.Connection.ConnectionString);
                    cmd.Connection.Open();
                    dt.Load(cmd.ExecuteReader());
                    if (dt.Rows.Count > 0)
                    {
                        MessageBox.Show("We have a row");
                        ds.Tables.Add(dt);
                        result = double.Parse(ds.Tables[0].Rows[0].ItemArray[0].ToString());
                    }
                    cmd.Connection.Close();
                    MessageBox.Show(result.ToString());
                }
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }

            return result;
        }
    }
}
自动化：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using Excel = Microsoft.Office.Interop.Excel;
using Office = Microsoft.Office.Core;
using Microsoft.Office.Tools.Excel;
using System.Windows.Forms;

namespace DBLink
{
    public partial class ThisAddIn
    {
        //public Dictionary<string, string> reports;
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
        }

        #region VSTO generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }

        #endregion
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using Microsoft.Office.Tools.Ribbon;
using Excel = Microsoft.Office.Interop.Excel;
using Microsoft.Office.Tools.Excel;

namespace DBLink
{
    public partial class Ribbon1
    {
        private void Ribbon1_Load(object sender, RibbonUIEventArgs e)
        {
            //Even setting the connection string from a class that has
            //access to the correct values fails and says the connection
            //string is not initialised.
            string conString;
            conString = "User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ";
            DataLink.connString = conString;

            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
        }

        private void button1_Click(object sender, RibbonControlEventArgs e)
        {
            Form frm = new Form1();
            frm.ShowDialog();
        }

        private void button2_Click(object sender, RibbonControlEventArgs e)
        {
            try
            {
                DataLink.LoadData(Globals.ThisAddIn.Application.ActiveWorkbook);
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }
        }

        private void button5_Click(object sender, RibbonControlEventArgs e)
        {
            //Do Stuff
        }

        private void button3_Click(object sender, RibbonControlEventArgs e)
        {
            //Do Stuff
        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Windows.Forms;

namespace DBLink
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Properties.Settings.Default.DBServer = textBox1.Text;
            Properties.Settings.Default.DBName = textBox2.Text;
            Properties.Settings.Default.DBUser = textBox3.Text;
            Properties.Settings.Default.DBPassword = textBox4.Text;
            Properties.Settings.Default.Save();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
            try
            {
                con.Open();
                MessageBox.Show("Connected successfully");
                con.Close();
            }
            catch
            {
                MessageBox.Show("There was a problem connecting to the database. Please confirm the details!");
            }
        }
    }
}

using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;

namespace DBLink
{
    [Guid("19C7ACDB-1572-4988-984F-3C56AEF117A5")]
    [ClassInterface(ClassInterfaceType.AutoDual)]
    [ComVisible(true)]

    public partial class MyFunctions2
    {
        string connectionString;
        public MyFunctions2()
        {
        }

        private static string GetSubKeyName(Type type, string subKeyName)
        {
            System.Text.StringBuilder s = new System.Text.StringBuilder();
            s.Append(@"CLSID\{");
            s.Append(type.GUID.ToString().ToUpper());
            s.Append(@"}\");
            s.Append(subKeyName);
            return s.ToString();
        }
        public string MTD(int year, int period, string costCentre, string account)
        {
            connectionString = "User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ";
        return DataLink.MTD(year, period, costCentre, account, connectionString).ToString();
        }

        public double MultiplyNTimes2(double number1, double number2, double timesToMultiply)
        {
            return DataLink.MultiplyNTimes(number1, number2, timesToMultiply);
        }

        [ComRegisterFunctionAttribute]
        public static void RegisterFunction(Type type)
        {
            Registry.ClassesRoot.CreateSubKey(GetSubKeyName(type, "Programmable"));
            RegistryKey key = Registry.ClassesRoot.OpenSubKey(GetSubKeyName(type, "InprocServer32"), true);

            key.SetValue("", System.Environment.SystemDirectory + @"\mscoree.dll", RegistryValueKind.String);
        }

        [ComUnregisterFunctionAttribute]
        public static void UnregisterFunction(Type type)
        {
            Registry.ClassesRoot.DeleteSubKey(GetSubKeyName(type, "Programmable"), false);
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using Microsoft.Office.Tools.Ribbon;
using Excel = Microsoft.Office.Interop.Excel;

namespace DBLink
{
    public static partial class DataLink
    {
        private static string commandText = "select case when ACClass in (2,3,4,5) then SUM(ISNULL(POCredit,0)-ISNULL(PODebit,0)) else SUM(ISNULL(PODebit,0)-ISNULL(POCredit,0)) end as value from Account join Post on ACID = POAccountID left join Segment on SID = POSegmentID join Journal on POJournalID = JID where DatePart(month,JDate) = @month and DatePart(year,JDate) = @year and ACCode = @account and (SName = @seg or @seg = '*') group by ACClass";
        public static string connString="";
        private static SqlConnection con;

        public static void SetConnString(string connection)
        {
            connString = connection;
        }
        public static void LoadData(Excel.Workbook wb)
        {
            //Do stuff... may be deprecated before release.
        }

        public static double MTD(int year, int period, string costCentre, string account, string conString)
        {
            DataTable dt = new DataTable();
            DataSet ds = new DataSet();
            double result = 0;
            int month = period > 6 ? period - 6 : period + 6;
            int actualYear = month > 6 ? year - 1 : year;

            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");

            con = new SqlConnection(connString);
            try
            {
                using (SqlCommand cmd = new SqlCommand(commandText, con))
                {
                    cmd.Parameters.AddWithValue("@month", month);
                    cmd.Parameters.AddWithValue("@year", actualYear);
                    cmd.Parameters.AddWithValue("@account", account);
                    cmd.Parameters.AddWithValue("@seg", costCentre);
                    MessageBox.Show(cmd.CommandText);
                    MessageBox.Show(cmd.Connection.ConnectionString);
                    cmd.Connection.Open();
                    dt.Load(cmd.ExecuteReader());
                    if (dt.Rows.Count > 0)
                    {
                        MessageBox.Show("We have a row");
                        ds.Tables.Add(dt);
                        result = double.Parse(ds.Tables[0].Rows[0].ItemArray[0].ToString());
                    }
                    cmd.Connection.Close();
                    MessageBox.Show(result.ToString());
                }
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }

            return result;
        }
    }
}
最后，静态类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using Excel = Microsoft.Office.Interop.Excel;
using Office = Microsoft.Office.Core;
using Microsoft.Office.Tools.Excel;
using System.Windows.Forms;

namespace DBLink
{
    public partial class ThisAddIn
    {
        //public Dictionary<string, string> reports;
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
        }

        #region VSTO generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }

        #endregion
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using Microsoft.Office.Tools.Ribbon;
using Excel = Microsoft.Office.Interop.Excel;
using Microsoft.Office.Tools.Excel;

namespace DBLink
{
    public partial class Ribbon1
    {
        private void Ribbon1_Load(object sender, RibbonUIEventArgs e)
        {
            //Even setting the connection string from a class that has
            //access to the correct values fails and says the connection
            //string is not initialised.
            string conString;
            conString = "User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ";
            DataLink.connString = conString;

            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
        }

        private void button1_Click(object sender, RibbonControlEventArgs e)
        {
            Form frm = new Form1();
            frm.ShowDialog();
        }

        private void button2_Click(object sender, RibbonControlEventArgs e)
        {
            try
            {
                DataLink.LoadData(Globals.ThisAddIn.Application.ActiveWorkbook);
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }
        }

        private void button5_Click(object sender, RibbonControlEventArgs e)
        {
            //Do Stuff
        }

        private void button3_Click(object sender, RibbonControlEventArgs e)
        {
            //Do Stuff
        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Windows.Forms;

namespace DBLink
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Properties.Settings.Default.DBServer = textBox1.Text;
            Properties.Settings.Default.DBName = textBox2.Text;
            Properties.Settings.Default.DBUser = textBox3.Text;
            Properties.Settings.Default.DBPassword = textBox4.Text;
            Properties.Settings.Default.Save();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");
            try
            {
                con.Open();
                MessageBox.Show("Connected successfully");
                con.Close();
            }
            catch
            {
                MessageBox.Show("There was a problem connecting to the database. Please confirm the details!");
            }
        }
    }
}

using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;

namespace DBLink
{
    [Guid("19C7ACDB-1572-4988-984F-3C56AEF117A5")]
    [ClassInterface(ClassInterfaceType.AutoDual)]
    [ComVisible(true)]

    public partial class MyFunctions2
    {
        string connectionString;
        public MyFunctions2()
        {
        }

        private static string GetSubKeyName(Type type, string subKeyName)
        {
            System.Text.StringBuilder s = new System.Text.StringBuilder();
            s.Append(@"CLSID\{");
            s.Append(type.GUID.ToString().ToUpper());
            s.Append(@"}\");
            s.Append(subKeyName);
            return s.ToString();
        }
        public string MTD(int year, int period, string costCentre, string account)
        {
            connectionString = "User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ";
        return DataLink.MTD(year, period, costCentre, account, connectionString).ToString();
        }

        public double MultiplyNTimes2(double number1, double number2, double timesToMultiply)
        {
            return DataLink.MultiplyNTimes(number1, number2, timesToMultiply);
        }

        [ComRegisterFunctionAttribute]
        public static void RegisterFunction(Type type)
        {
            Registry.ClassesRoot.CreateSubKey(GetSubKeyName(type, "Programmable"));
            RegistryKey key = Registry.ClassesRoot.OpenSubKey(GetSubKeyName(type, "InprocServer32"), true);

            key.SetValue("", System.Environment.SystemDirectory + @"\mscoree.dll", RegistryValueKind.String);
        }

        [ComUnregisterFunctionAttribute]
        public static void UnregisterFunction(Type type)
        {
            Registry.ClassesRoot.DeleteSubKey(GetSubKeyName(type, "Programmable"), false);
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using Microsoft.Office.Tools.Ribbon;
using Excel = Microsoft.Office.Interop.Excel;

namespace DBLink
{
    public static partial class DataLink
    {
        private static string commandText = "select case when ACClass in (2,3,4,5) then SUM(ISNULL(POCredit,0)-ISNULL(PODebit,0)) else SUM(ISNULL(PODebit,0)-ISNULL(POCredit,0)) end as value from Account join Post on ACID = POAccountID left join Segment on SID = POSegmentID join Journal on POJournalID = JID where DatePart(month,JDate) = @month and DatePart(year,JDate) = @year and ACCode = @account and (SName = @seg or @seg = '*') group by ACClass";
        public static string connString="";
        private static SqlConnection con;

        public static void SetConnString(string connection)
        {
            connString = connection;
        }
        public static void LoadData(Excel.Workbook wb)
        {
            //Do stuff... may be deprecated before release.
        }

        public static double MTD(int year, int period, string costCentre, string account, string conString)
        {
            DataTable dt = new DataTable();
            DataSet ds = new DataSet();
            double result = 0;
            int month = period > 6 ? period - 6 : period + 6;
            int actualYear = month > 6 ? year - 1 : year;

            MessageBox.Show("User ID = " + Properties.Settings.Default.DBUser + "; Password = " + Properties.Settings.Default.DBPassword + "; Data Source = " + Properties.Settings.Default.DBServer + "; Initial Catalog = " + Properties.Settings.Default.DBName + "; ");

            con = new SqlConnection(connString);
            try
            {
                using (SqlCommand cmd = new SqlCommand(commandText, con))
                {
                    cmd.Parameters.AddWithValue("@month", month);
                    cmd.Parameters.AddWithValue("@year", actualYear);
                    cmd.Parameters.AddWithValue("@account", account);
                    cmd.Parameters.AddWithValue("@seg", costCentre);
                    MessageBox.Show(cmd.CommandText);
                    MessageBox.Show(cmd.Connection.ConnectionString);
                    cmd.Connection.Open();
                    dt.Load(cmd.ExecuteReader());
                    if (dt.Rows.Count > 0)
                    {
                        MessageBox.Show("We have a row");
                        ds.Tables.Add(dt);
                        result = double.Parse(ds.Tables[0].Rows[0].ItemArray[0].ToString());
                    }
                    cmd.Connection.Close();
                    MessageBox.Show(result.ToString());
                }
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }

            return result;
        }
    }
}
我所能想到的是，不知何故，正在创建2个或更多的设置实例。如果有人对如何解决这个问题有任何想法，那就太好了

编辑：再多玩一点，COM加载项似乎只在加载时看到保存的值，然后才看到原始值。功能区可以始终查看设置

编辑2:已经解决了这个问题，并将答案放入将来的参考中，一旦2天限制到期，将标记为答案。

好的，因此我找到了一个解决方案，因为所有内容都加载到不同的AppDomain中

步骤1：调用
this.Application.Evaluate（“=MTD（）”）在ThisAddIn\u启动方法中。这意味着我的COM和自动化加载项都在同一AppDomain下运行

步骤2：在ThisAddIn_启动方法中将连接字符串传递给我的DataLink类


大量的谷歌搜索发现：
设置是否在用户范围内？配置文件在程序集旁边吗？@LeiYang是的，设置在用户范围内（很久以前在另一个项目中遇到过该问题）。DBLink.dll.config.deploy文件位于Visual Studio使用“发布”选项时生成的版本控制应用程序文件文件夹中的DBLink.dll.deploy文件旁边。如果使用Build，则会在DBLink.dll旁边得到一个DBLink.dll.config文件。