C# 关闭并释放表单后执行的代码

我有一个Windows窗体应用程序，其运行方式我不理解。为了清晰起见，我创建了一个简单的应用程序，将功能复制到最低逻辑。它有两种形式

表格1： 有一个按钮1，单击该按钮可将行添加到数据表中。 有一个按钮2用于显示表单并将数据表发送到表单

表格2： Form2从datatable创建dataview，并将dataview绑定到listbox。Form2还有一个按钮1，用于在窗体上执行this.Close（）操作。我了解到，使用formName.Show（）打开的任何内容都将在.Close期间被处置

这就是事情变得奇怪的地方。每次清除数据表并再次添加行时，可以反复单击Form1按钮1。单击from1按钮2并显示表单2然后关闭后，返回表单1并单击按钮1将引发错误。错误来自form2（已关闭）列表框1\u SelectedIndexChanged事件

问题是，为什么一个控件的事件在一个窗体上触发？ 我已经找到了几种方法来避免这种情况，但我想了解为什么会发生这种情况，例如设置listbox datasource=null，但我想知道发生了什么。。花了半天的时间想弄明白。所以社区，请在这里教育我

表格1代码

public partial class Form1 : Form
{

    Boolean bInitialLoad = true;
    DataTable dtHardware = new DataTable("Hardware");
    Form2 multiServerView = new Form2();

    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        dtHardware.Clear();

        if (bInitialLoad == true)
        {
            dtHardware.Columns.Add("ServerName", typeof(String));
            dtHardware.Columns.Add("Environment", typeof(String));
        }

        DataRow drNewRow = dtHardware.NewRow();
        drNewRow["ServerName"] = "SomeName";
        drNewRow["Environment"] = "SomeEnvironment";
        dtHardware.Rows.Add(drNewRow);

        drNewRow = dtHardware.NewRow();
        drNewRow["ServerName"] = "SomeName2";
        drNewRow["Environment"] = "SomeEnvironment2";
        dtHardware.Rows.Add(drNewRow);

        bInitialLoad = false;

    }

    private void button2_Click(object sender, EventArgs e)
    {
        OpenMultiServerView();
    }

    private void OpenMultiServerView()
    {
        multiServerView = new Form2(dtHardware);
        this.AddOwnedForm(multiServerView);
        multiServerView.Show();
    }
}

表格1设计师

namespace WindowsFormsApp4
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(308, 390);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(107, 34);
            this.button1.TabIndex = 0;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // button2
            // 
            this.button2.Location = new System.Drawing.Point(437, 296);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(102, 33);
            this.button2.TabIndex = 1;
            this.button2.Text = "button2";
            this.button2.UseVisualStyleBackColor = true;
            this.button2.Click += new System.EventHandler(this.button2_Click);
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(679, 482);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.Button button2;
    }
}

表格2设计师

namespace WindowsFormsApp4
{
    partial class Form2
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.dataGridView1 = new System.Windows.Forms.DataGridView();
            this.listBox1 = new System.Windows.Forms.ListBox();
            this.button1 = new System.Windows.Forms.Button();
            ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).BeginInit();
            this.SuspendLayout();
            // 
            // dataGridView1
            // 
            this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
            this.dataGridView1.Location = new System.Drawing.Point(23, 113);
            this.dataGridView1.Name = "dataGridView1";
            this.dataGridView1.Size = new System.Drawing.Size(749, 287);
            this.dataGridView1.TabIndex = 0;
            // 
            // listBox1
            // 
            this.listBox1.FormattingEnabled = true;
            this.listBox1.Location = new System.Drawing.Point(291, 31);
            this.listBox1.Name = "listBox1";
            this.listBox1.Size = new System.Drawing.Size(171, 69);
            this.listBox1.TabIndex = 1;
            this.listBox1.SelectedIndexChanged += new System.EventHandler(this.listBox1_SelectedIndexChanged);
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(653, 415);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(118, 25);
            this.button1.TabIndex = 2;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // Form2
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(800, 450);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.listBox1);
            this.Controls.Add(this.dataGridView1);
            this.Name = "Form2";
            this.Text = "Form2";
            this.Load += new System.EventHandler(this.Form2_Load);
            ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).EndInit();
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.DataGridView dataGridView1;
        private System.Windows.Forms.ListBox listBox1;
        private System.Windows.Forms.Button button1;
    }
}

namespace WindowsFormsApp4
{
部分类别表格2
{
/// 
///必需的设计器变量。
/// 
private System.ComponentModel.IContainer components=null；
/// 
///清理所有正在使用的资源。
/// 
///如果应释放托管资源，则为true；否则为false。
受保护的覆盖无效处置（布尔处置）
{
if（处理和（组件！=null））
{
组件。Dispose（）；
}
基地。处置（处置）；
}
#区域Windows窗体设计器生成的代码
/// 
///设计器支持所需的方法-不修改
///此方法的内容与代码编辑器一起使用。
/// 
私有void InitializeComponent（）
{
this.dataGridView1=new System.Windows.Forms.DataGridView（）；
this.listBox1=new System.Windows.Forms.ListBox（）；
this.button1=new System.Windows.Forms.Button（）；
（（System.ComponentModel.ISupportInitialize）（this.dataGridView1））.BeginInit（）；
这个.SuspendLayout（）；
// 
//dataGridView1
// 
this.dataGridView1.columnHeadershightSizeMode=System.Windows.Forms.datagridviewColumnHeadershightSizeMode.AutoSize；
this.dataGridView1.Location=新系统.Drawing.Point（23113）；
this.dataGridView1.Name=“dataGridView1”；
this.dataGridView1.Size=新系统.Drawing.Size（749287）；
this.dataGridView1.TabIndex=0；
// 
//列表框1
// 
this.listBox1.FormattingEnabled=true；
this.listBox1.Location=新系统图点（291,31）；
this.listBox1.Name=“listBox1”；
this.listBox1.Size=新系统图尺寸（171,69）；
this.listBox1.TabIndex=1；
this.listBox1.SelectedIndexChanged+=新的System.EventHandler（this.listBox1\u SelectedIndexChanged）；
// 
//按钮1
// 
this.button1.Location=新系统图纸点（653415）；
this.button1.Name=“button1”；
this.button1.Size=新系统图纸尺寸（118,25）；
this.button1.TabIndex=2；
this.button1.Text=“button1”；
this.button1.UseVisualStyleBackColor=true；
this.button1.Click+=新系统.EventHandler（this.button1\u Click）；
// 
//表格2
// 
此.AutoScaleDimensions=新系统.Drawing.SizeF（6F，13F）；
this.AutoScaleMode=System.Windows.Forms.AutoScaleMode.Font；
this.ClientSize=新系统图尺寸（800450）；
this.Controls.Add（this.button1）；
this.Controls.Add（this.listBox1）；
this.Controls.Add（this.dataGridView1）；
this.Name=“Form2”；
this.Text=“Form2”；
this.Load+=new System.EventHandler（this.Form2\u Load）；
（（System.ComponentModel.ISupportInitialize）（this.dataGridView1））.EndInit（）；
此选项为.resume布局（false）；
}
#端区
private System.Windows.Forms.DataGridView dataGridView1；
private System.Windows.Forms.ListBox listBox1；
private System.Windows.Forms.Button按钮1；
}
}
这是因为
Form2
的实例实际上并没有消失。由于调用了
Show
，但垃圾收集器尚未收集它，因此假设它已被释放是正确的。事实上，无法收集它，因为在提供的代码示例中，
Form1
有两个对它创建的
Form2
实例的引用

第一个是
Form1.OwnedForms
。第二个是字段
Form1.multiServerView

您说过有几种方法可以修复它，比如在
Form2
关闭时破坏绑定，但我想我还是放弃这个建议。如果不需要每次显示时都创建一个新的
Form2
实例，您可以在
Form1
的构造函数中创建一个实例，处理
Form2.Closing
并在用户关闭
Form2
时隐藏它

所以，有点像

公共部分类表单1:表单
{
//删除bInitialLoad后，我们将在构造函数中设置数据表。
DataTable dtHardware=新的DataTable（“硬件”）；
Form2 multiServerView；//没有lon
namespace WindowsFormsApp4
{
    partial class Form2
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.dataGridView1 = new System.Windows.Forms.DataGridView();
            this.listBox1 = new System.Windows.Forms.ListBox();
            this.button1 = new System.Windows.Forms.Button();
            ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).BeginInit();
            this.SuspendLayout();
            // 
            // dataGridView1
            // 
            this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
            this.dataGridView1.Location = new System.Drawing.Point(23, 113);
            this.dataGridView1.Name = "dataGridView1";
            this.dataGridView1.Size = new System.Drawing.Size(749, 287);
            this.dataGridView1.TabIndex = 0;
            // 
            // listBox1
            // 
            this.listBox1.FormattingEnabled = true;
            this.listBox1.Location = new System.Drawing.Point(291, 31);
            this.listBox1.Name = "listBox1";
            this.listBox1.Size = new System.Drawing.Size(171, 69);
            this.listBox1.TabIndex = 1;
            this.listBox1.SelectedIndexChanged += new System.EventHandler(this.listBox1_SelectedIndexChanged);
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(653, 415);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(118, 25);
            this.button1.TabIndex = 2;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // Form2
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(800, 450);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.listBox1);
            this.Controls.Add(this.dataGridView1);
            this.Name = "Form2";
            this.Text = "Form2";
            this.Load += new System.EventHandler(this.Form2_Load);
            ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).EndInit();
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.DataGridView dataGridView1;
        private System.Windows.Forms.ListBox listBox1;
        private System.Windows.Forms.Button button1;
    }
}