C# 单击某个按钮时弹出拒绝访问消息，具体取决于哪个用户已登录

在登录表单中，当我以医生表中的Jack身份登录时，它将转到第二页。如果单击护士按钮1或护士按钮2，我想弹出一条拒绝访问消息，因为杰克不是护士，而是医生。相反，如果我以护士表中的Mary登录，它将进入第二页。我想在单击医生按钮1或医生按钮2时弹出一条拒绝访问消息，因为玛丽不是医生，而是护士

第二页的按钮名称为BTNDotor1、BTNDotor2、btnNurse1和btnNurse2

**//login Form codes**


    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    using System.Data.SqlClient;
    using System.Configuration;

    namespace GRP_02_03_SACP
    {
        public partial class page_one : Form
        {
            public page_one()
            {
                InitializeComponent();

            }


            private void page_one_Load(object sender, EventArgs e)
            {

            }

            private void btnLogin_Click(object sender, EventArgs e)
            {
                //retrieve connection information info from App.config
                string strConnectionString = ConfigurationManager.ConnectionStrings["sacpConnection"].ConnectionString;
                //STEP 1: Create connection
                SqlConnection myConnect = new SqlConnection(strConnectionString);
                //STEP 2: Create command
                string strCommandtext = "SELECT dUsername, dPassword from DOCTOR";
                // Add a WHERE Clause to SQL statement
                strCommandtext += "   WHERE dUsername=@dname AND dPassword=@dpwd;";
                strCommandtext += "SELECT nUsername, nPassword from NURSE WHERE nUsername=@nname AND nPassword=@npwd;";
                SqlCommand cmd = new SqlCommand(strCommandtext, myConnect);
                cmd.Parameters.AddWithValue("@dname", textUsername.Text);
                cmd.Parameters.AddWithValue("@dpwd", txtPassword.Text);
                cmd.Parameters.AddWithValue("@nname", textUsername.Text);
                cmd.Parameters.AddWithValue("@npwd", txtPassword.Text);


                try
                {
                    // STEP 3: open connection and retrieve data by calling ExecuteReader
                    myConnect.Open();
                    // STEP 4: Access Data
                    SqlDataReader reader = cmd.ExecuteReader();


                    while (reader.Read()) //For Doctor
                    {
                        if (MessageBox.Show("Login Successful") == DialogResult.OK)
                        {
                            page_two form = new page_two();
                            form.Show();
                            return;
                        }                                     
                    } 
                    reader.NextResult();
                    while (reader.Read()) //For Nurse
                    {
                        if (MessageBox.Show("Login Successful") == DialogResult.OK)
                        {
                            page_two form = new page_two();
                            form.Show();
                            return;
                        }
                    }

                    //STEP 5: close connection
                    reader.Close();
                    MessageBox.Show("Invalid username or password");
                }
                catch (SqlException ex)
                {

                }
                finally
                {
                    //STEP 5: close connection
                    myConnect.Close();
                }
            }      
        }
    }

//第二页代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace GRP_02_03_SACP
{
    public partial class page_two : Form
    {
        public page_two()
        {
            InitializeComponent();
        }

        private void btnDoctor1_Click(object sender, EventArgs e)
        {

        }

        private void btnDoctor2_Click(object sender, EventArgs e)
        {

        }

        private void btnNurse1_Click(object sender, EventArgs e)
        {

        }

        private void btnNurse2_Click(object sender, EventArgs e)
        {

        }

    }
}

---

将此添加到您的代码中：

 public Int JobPosition;

在这里，您将定义每个位置的位置

将btnLogin\u上的代码单击更改为：

  private void btnLogin_Click(object sender, EventArgs e)
        {
            //retrieve connection information info from App.config
            string strConnectionString = ConfigurationManager.ConnectionStrings["sacpConnection"].ConnectionString;
            //STEP 1: Create connection
            SqlConnection myConnect = new SqlConnection(strConnectionString);
            //STEP 2: Create command
            string strCommandtext = "SELECT dUsername, dPassword from DOCTOR";
            // Add a WHERE Clause to SQL statement
            strCommandtext += "   WHERE dUsername=@dname AND dPassword=@dpwd;";
            strCommandtext += "SELECT nUsername, nPassword from NURSE WHERE nUsername=@nname AND nPassword=@npwd;";
            SqlCommand cmd = new SqlCommand(strCommandtext, myConnect);
            cmd.Parameters.AddWithValue("@dname", textUsername.Text);
            cmd.Parameters.AddWithValue("@dpwd", txtPassword.Text);
            cmd.Parameters.AddWithValue("@nname", textUsername.Text);
            cmd.Parameters.AddWithValue("@npwd", txtPassword.Text);


            try
            {
                // STEP 3: open connection and retrieve data by calling ExecuteReader
                myConnect.Open();
                // STEP 4: Access Data
                SqlDataReader reader = cmd.ExecuteReader();


                while (reader.Read()) //For Doctor
                {
                    if (MessageBox.Show("Login Successful") == DialogResult.OK)
                    {
                        JobPosition = 1; //Doctor
                        page_two form = new page_two(JobPosition);
                        form.Show();
                        return;
                    }                                     
                } 
                reader.NextResult();
                while (reader.Read()) //For Nurse
                {
                    if (MessageBox.Show("Login Successful") == DialogResult.OK)
                    {

                        JobPosition = 2; //Nurse
                        page_two form = new page_two(JobPosition);
                        form.Show();
                        return;
                    }
                }

                //STEP 5: close connection
                reader.Close();
                MessageBox.Show("Invalid username or password");
            }
            catch (SqlException ex)
            {

            }
            finally
            {
                //STEP 5: close connection
                myConnect.Close();
            }
        }    

在第二页的

code:

 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Linq;
 using System.Text;
 using System.Windows.Forms;

namespace GRP_02_03_SACP
{
public partial class page_two : Form
{
    private Int JopPosition;
    public page_two()
    {
        InitializeComponent();
    }

    public page_two(Int _Position)
    {
        InitializeComponent();
        JopPosition = _Position;
    }

    private void btnDoctor1_Click(object sender, EventArgs e)
    {

    }

    private void btnDoctor2_Click(object sender, EventArgs e)
    {

    }

    private void btnNurse1_Click(object sender, EventArgs e)
    {
        if (JopPosition == 1)
        {
           MessageBox.Show("access denied");
        }
    }

    private void btnNurse2_Click(object sender, EventArgs e)
    {

    }

}

}
虽然这不是最好的解决方案，但如果它是一个小应用程序，而不是复杂的代码，它就可以工作。