为什么我的表单Key_down事件无法调用？ [英] why my form Key_down event can not be invoked?

问题描述

  public   partial   class  Form1：Form 

  private   void  InitializeComponent（）{
  //   ... some控制....  
  //    
  //   Form1  
  //    
  this  .AutoScaleDimensions =  new 系统.Drawing.SizeF（6F，12F）; 
  this  .AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; 
  this  .ClientSize =  new  System.Drawing.Size（ 498 ， 298 ）; 
  this  .Controls.Add（ this  .lwMRU_Projects）; 
  this  .Controls.Add（ this  .cbVS_Versions）; 
  this  .Controls.Add（ this  .lblVS_Versions）; 
  this  .Controls.Add（ this  .toolStrip1）; 
  this  .Controls.Add（ this  .statusStrip1）; 
  this  .MinimumSize =  new  System.Drawing.Size（ 506 ， 332 ）; 
  this  .Name =   Form1< /跨度>; 
  this  .Text =   Editor IV ; 
  this  .Load + =  new  System.EventHandler（此 .Form1_Load）; 
  //   ..................在这里！ ................. //  
  此 .KeyDown  + =  new  System.Windows.Forms.KeyEventHandler（ this  .key_down）; 
 
  this  .statusStrip1.ResumeLayout（ false ）; 
  this  .statusStrip1.PerformLayout（）; 
  this  .toolStrip1.ResumeLayout（ false ）; 
  this  .toolStrip1.PerformLayout（）; 
  this  .ResumeLayout（ false ）; 
  this  .PerformLayout（）; 
  //   ----------无法始终调用------- ------- //  
  private   void  key_down（< span class =code-keyword> object  sender，KeyEventArgs e）
 {
} 
} 

但是 key_down 无法调用事件处理程序（我在开头放了一个断点）。任何提示？

解决方案

重点可能是表单中的控件，而不是表单本身。你可以将 KeyPreview 属性设置为 true ，如果焦点在控件上，你的key_down方法也会被调用形式如下：

 此 .KeyPreview =  true ; 

可能是因为表单包含可以接受用户输入的控件 - 因此他们首先获取它，并且因为它们处理它所以它不会被传递到表单处理程序。



尝试设置 Form.KeyPreview Property [ ^ ]它应该开始工作。

我找到了解决方案！

我需要将表单的 KeyPreview 属性设置为True，以便识别按键事件！

public partial class Form1 : Form

private void InitializeComponent(){
            //...some control....
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(498, 298);
            this.Controls.Add(this.lwMRU_Projects);
            this.Controls.Add(this.cbVS_Versions);
            this.Controls.Add(this.lblVS_Versions);
            this.Controls.Add(this.toolStrip1);
            this.Controls.Add(this.statusStrip1);
            this.MinimumSize = new System.Drawing.Size(506, 332);
            this.Name = "Form1";
            this.Text = "Editor IV";
            this.Load += new System.EventHandler(this.Form1_Load);
            //..................here!.................//
            this.KeyDown += new System.Windows.Forms.KeyEventHandler(this.key_down);

            this.statusStrip1.ResumeLayout(false);
            this.statusStrip1.PerformLayout();
            this.toolStrip1.ResumeLayout(false);
            this.toolStrip1.PerformLayout();
            this.ResumeLayout(false);
            this.PerformLayout();
            //----------cannot invoked always--------------//
            private void key_down(object sender, KeyEventArgs e)
            {
            }
}

but key_down event handler can not be called (I put a breakpoint at beginning). any hint?

解决方案

The focus is probably on a control in the form, not on the form itself. You can set the KeyPreview property to true, then your key_down method will also get called if the focus is on a control in the form:

this.KeyPreview = true;

Probably because the form contains controls which can accept user input - so they get it first, and since they process it it isn't passed to the form handler.

Try setting the Form.KeyPreview Property[^] and it should start to work.

I have found the solution!
I need to set the KeyPreview Property of your Form to True so it will recognize the key press event!

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