winform 让事件提早运行
winform 让事件提前运行
今天遇到了一个问题，就是让Winform中的事件提前运行的问题，下面我给出解决方案
Main函数
using System;
using System.Windows.Forms;
namespace FormLoadCompletedDemo
{
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new MainForm());
}
}
}
using System;
using System.Windows.Forms;
namespace FormLoadCompletedDemo
{
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
}
private void ShowChildForm(ChildForm.LoadStyle ls)
{
ChildForm frm = new ChildForm(ls);
frm.ShowDialog();
}
private void btnLoad_Click(object sender, EventArgs e)
{
ShowChildForm(ChildForm.LoadStyle.OnLoad);
}
private void btnShown_Click(object sender, EventArgs e)
{
ShowChildForm(ChildForm.LoadStyle.OnShown);
}
private void btnShownDoEvents_Click(object sender, EventArgs e)
{
ShowChildForm(ChildForm.LoadStyle.OnShownDoEvents);
}
private void btnChildUsingBase_Click(object sender, EventArgs e)
{
ChildFormUsingBase frm = new ChildFormUsingBase();
frm.ShowDialog();
}
}
}
namespace FormLoadCompletedDemo
{
partial class MainForm
{
/// <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.btnShown = new System.Windows.Forms.Button();
this.btnShownDoEvents = new System.Windows.Forms.Button();
this.btnLoad = new System.Windows.Forms.Button();
this.btnChildUsingBase = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// btnShown
//
this.btnShown.Location = new System.Drawing.Point(50, 49);
this.btnShown.Name = "btnShown";
this.btnShown.Size = new System.Drawing.Size(193, 23);
this.btnShown.TabIndex = 1;
this.btnShown.Text = "Open Form Without DoEvents";
this.btnShown.UseVisualStyleBackColor = true;
this.btnShown.Click += new System.EventHandler(this.btnShown_Click);
//
// btnShownDoEvents
//
this.btnShownDoEvents.Location = new System.Drawing.Point(50, 78);
this.btnShownDoEvents.Name = "btnShownDoEvents";
this.btnShownDoEvents.Size = new System.Drawing.Size(193, 23);
this.btnShownDoEvents.TabIndex = 2;
this.btnShownDoEvents.Text = "Open Form *With* DoEvents";
this.btnShownDoEvents.UseVisualStyleBackColor = true;
this.btnShownDoEvents.Click += new System.EventHandler(this.btnShownDoEvents_Click);
//
// btnLoad
//
this.btnLoad.Location = new System.Drawing.Point(50, 20);
this.btnLoad.Name = "btnLoad";
this.btnLoad.Size = new System.Drawing.Size(193, 23);
this.btnLoad.TabIndex = 0;
this.btnLoad.Text = "Do processing in Load event";
this.btnLoad.UseVisualStyleBackColor = true;
this.btnLoad.Click += new System.EventHandler(this.btnLoad_Click);
//
// btnChildUsingBase
//
this.btnChildUsingBase.Location = new System.Drawing.Point(50, 138);
this.btnChildUsingBase.Name = "btnChildUsingBase";
this.btnChildUsingBase.Size = new System.Drawing.Size(193, 23);
this.btnChildUsingBase.TabIndex = 3;
this.btnChildUsingBase.Text = "Open Form derived from BaseForm";
this.btnChildUsingBase.UseVisualStyleBackColor = true;
this.btnChildUsingBase.Click += new System.EventHandler(this.btnChildUsingBase_Click);
//
// MainForm
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(292, 183);
this.Controls.Add(this.btnChildUsingBase);
this.Controls.Add(this.btnLoad);
this.Controls.Add(this.btnShownDoEvents);
this.Controls.Add(this.btnShown);
this.MaximizeBox = false;
this.MinimizeBox = false;
this.Name = "MainForm";
this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
this.Text = "FormLoadCompleteDemo";
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.Button btnShown;
private System.Windows.Forms.Button btnShownDoEvents;
private System.Windows.Forms.Button btnLoad;
private System.Windows.Forms.Button btnChildUsingBase;
}
}
Children form
using System;
using System.Windows.Forms;
namespace FormLoadCompletedDemo
{
public partial class ChildForm : Form
{
public enum LoadStyle
{
OnLoad,
OnShown,
OnShownDoEvents
}
private LoadStyle _ls;
public ChildForm(LoadStyle ls)
{
InitializeComponent();
_ls = ls;
}
private void ChildForm_Load(object sender, EventArgs e)
{
if (_ls == LoadStyle.OnLoad)
LoadList();
}
private void ChildForm_Shown(object sender, EventArgs e)
{
if (_ls == LoadStyle.OnShown)
LoadList();
else if (_ls == LoadStyle.OnShownDoEvents)
{
Application.DoEvents();
LoadList();
}
}
private void LoadList()
{
this.Cursor = Cursors.WaitCursor;
for (int l = 0; l < 50000; l++)
this.listBox1.Items.Add("Item " + l.ToString());
this.Cursor = Cursors.Default;
}
private void ChildForm_FormClosed(object sender, FormClosedEventArgs e)
{
// Without the following, subsequent instances of this form would load
// slower than the 1st call, distorting the time-delay of this demo.
listBox1.Items.Clear();
GC.Collect();
}
}
}
namespace FormLoadCompletedDemo
{
partial class ChildForm
{
/// <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.listBox1 = new System.Windows.Forms.ListBox();
this.comboBox1 = new System.Windows.Forms.ComboBox();
this.comboBox2 = new System.Windows.Forms.ComboBox();
this.comboBox3 = new System.Windows.Forms.ComboBox();
this.groupBox1 = new System.Windows.Forms.GroupBox();
this.groupBox2 = new System.Windows.Forms.GroupBox();
this.comboBox4 = new System.Windows.Forms.ComboBox();
this.comboBox5 = new System.Windows.Forms.ComboBox();
this.groupBox1.SuspendLayout();
this.groupBox2.SuspendLayout();
this.SuspendLayout();
//
// listBox1
//
this.listBox1.FormattingEnabled = true;
this.listBox1.Location = new System.Drawing.Point(6, 59);
this.listBox1.Name = "listBox1";
this.listBox1.Size = new System.Drawing.Size(112, 134);
this.listBox1.TabIndex = 0;
//
// comboBox1
//
this.comboBox1.FormattingEnabled = true;
this.comboBox1.Location = new System.Drawing.Point(6, 59);
this.comboBox1.Name = "comboBox1";
this.comboBox1.Size = new System.Drawing.Size(174, 21);
this.comboBox1.TabIndex = 1;
//
// comboBox2
//
this.comboBox2.FormattingEnabled = true;
this.comboBox2.Location = new System.Drawing.Point(6, 86);
this.comboBox2.Name = "comboBox2";
this.comboBox2.Size = new System.Drawing.Size(174, 21);
this.comboBox2.TabIndex = 2;
//
// comboBox3
//
this.comboBox3.FormattingEnabled = true;
this.comboBox3.Location = new System.Drawing.Point(6, 113);
this.comboBox3.Name = "comboBox3";
this.comboBox3.Size = new System.Drawing.Size(174, 21);
this.comboBox3.TabIndex = 3;
//
// groupBox1
//
this.groupBox1.Controls.Add(this.comboBox5);
this.groupBox1.Controls.Add(this.comboBox4);
this.groupBox1.Controls.Add(this.comboBox3);
this.groupBox1.Controls.Add(this.comboBox1);
this.groupBox1.Controls.Add(this.comboBox2);
this.groupBox1.Location = new System.Drawing.Point(166, 12);
this.groupBox1.Name = "groupBox1";
this.groupBox1.Size = new System.Drawing.Size(193, 199);
this.groupBox1.TabIndex = 4;
this.groupBox1.TabStop = false;
this.groupBox1.Text = "These controls don\'t fully render in form_Shown() unless you call DoEvents() *bef" +
"ore* loading listBox1";
//
// groupBox2
//
this.groupBox2.Controls.Add(this.listBox1);
this.groupBox2.Location = new System.Drawing.Point(12, 12);
this.groupBox2.Name = "groupBox2";
this.groupBox2.Size = new System.Drawing.Size(135, 199);
this.groupBox2.TabIndex = 5;
this.groupBox2.TabStop = false;
this.groupBox2.Text = "This list is loaded with 50k items in order to delay the initial rendering of the" +
" form.";
//
// comboBox4
//
this.comboBox4.FormattingEnabled = true;
this.comboBox4.Location = new System.Drawing.Point(6, 140);
this.comboBox4.Name = "comboBox4";
this.comboBox4.Size = new System.Drawing.Size(174, 21);
this.comboBox4.TabIndex = 4;
//
// comboBox5
//
this.comboBox5.FormattingEnabled = true;
this.comboBox5.Location = new System.Drawing.Point(6, 167);
this.comboBox5.Name = "comboBox5";
this.comboBox5.Size = new System.Drawing.Size(174, 21);
this.comboBox5.TabIndex = 5;
//
// ChildForm
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(374, 224);
this.Controls.Add(this.groupBox1);
this.Controls.Add(this.groupBox2);
this.MaximizeBox = false;
this.MinimizeBox = false;
this.Name = "ChildForm";
this.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent;
this.Text = "ChildForm";
this.Load += new System.EventHandler(this.ChildForm_Load);
this.Shown += new System.EventHandler(this.ChildForm_Shown);
this.FormClosed += new System.Windows.Forms.FormClosedEventHandler(this.ChildForm_FormClosed);
this.groupBox1.ResumeLayout(false);
this.groupBox2.ResumeLayout(false);
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.ListBox listBox1;
private System.Windows.Forms.ComboBox comboBox1;
private System.Windows.Forms.ComboBox comboBox2;
private System.Windows.Forms.ComboBox comboBox3;
private System.Windows.Forms.GroupBox groupBox1;
private System.Windows.Forms.GroupBox groupBox2;
private System.Windows.Forms.ComboBox comboBox5;
private System.Windows.Forms.ComboBox comboBox4;
}
}
using System;
using System.Windows.Forms;
namespace FormLoadCompletedDemo
{
public partial class ChildFormUsingBase : BaseForm
{
public ChildFormUsingBase()
{
InitializeComponent();
}
private void ChildFormUsingBase_LoadCompleted()
{
this.Cursor = Cursors.WaitCursor;
for (int l = 0; l < 50000; l++)
this.listBox1.Items.Add("Item " + l.ToString());
this.Cursor = Cursors.Default;
}
private void ChildFormUsingBase_FormClosed(object sender, FormClosedEventArgs e)
{
// Without the following, subsequent instances of this form would load
// slower than the 1st call, distorting the time-delay of this demo.
listBox1.Items.Clear();
GC.Collect();
}
}
}
namespace FormLoadCompletedDemo
{
partial class ChildFormUsingBase
{
/// <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.listBox1 = new System.Windows.Forms.ListBox();
this.comboBox1 = new System.Windows.Forms.ComboBox();
this.comboBox2 = new System.Windows.Forms.ComboBox();
this.comboBox3 = new System.Windows.Forms.ComboBox();
this.label1 = new System.Windows.Forms.Label();
this.SuspendLayout();
//
// listBox1
//
this.listBox1.FormattingEnabled = true;
this.listBox1.Location = new System.Drawing.Point(12, 12);
this.listBox1.Name = "listBox1";
this.listBox1.Size = new System.Drawing.Size(120, 95);
this.listBox1.TabIndex = 0;
//
// comboBox1
//
this.comboBox1.FormattingEnabled = true;
this.comboBox1.Location = new System.Drawing.Point(192, 21);
this.comboBox1.Name = "comboBox1";
this.comboBox1.Size = new System.Drawing.Size(121, 21);
this.comboBox1.TabIndex = 1;
//
// comboBox2
//
this.comboBox2.FormattingEnabled = true;
this.comboBox2.Location = new System.Drawing.Point(192, 48);
this.comboBox2.Name = "comboBox2";
this.comboBox2.Size = new System.Drawing.Size(121, 21);
this.comboBox2.TabIndex = 2;
//
// comboBox3
//
this.comboBox3.FormattingEnabled = true;
this.comboBox3.Location = new System.Drawing.Point(192, 75);
this.comboBox3.Name = "comboBox3";
this.comboBox3.Size = new System.Drawing.Size(121, 21);
this.comboBox3.TabIndex = 3;
//
// label1
//
this.label1.Location = new System.Drawing.Point(22, 129);
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size(277, 35);
this.label1.TabIndex = 4;
this.label1.Text = "This form performs post-Shown() processing by attaching to BaseForm\'s LoadComplet" +
"ed() event";
//
// ChildFormUsingBase
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(328, 187);
this.Controls.Add(this.label1);
this.Controls.Add(this.comboBox3);
this.Controls.Add(this.comboBox2);
this.Controls.Add(this.comboBox1);
this.Controls.Add(this.listBox1);
this.MaximizeBox = false;
this.MinimizeBox = false;
this.Name = "ChildFormUsingBase";
this.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent;
this.Text = "ChildFormUsingBase";
this.LoadCompleted += new FormLoadCompletedDemo.BaseForm.LoadCompletedEventHandler(this.ChildFormUsingBase_LoadCompleted);
this.FormClosed += new System.Windows.Forms.FormClosedEventHandler(this.ChildFormUsingBase_FormClosed);
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.ListBox listBox1;
private System.Windows.Forms.ComboBox comboBox1;
private System.Windows.Forms.ComboBox comboBox2;
private System.Windows.Forms.ComboBox comboBox3;
private System.Windows.Forms.Label label1;
}
}
下面给出工程，有问题请联系我哦