C# KeyEventArgs.Alt属性代码示例

private void textBox1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
    // Determine whether the key entered is the F1 key. If it is, display Help.
    if(e.KeyCode == Keys.F1 && (e.Alt || e.Control || e.Shift))
    {
        // Display a pop-up Help topic to assist the user.
        Help.ShowPopup(textBox1, "Enter your name.", new Point(textBox1.Bottom, textBox1.Right));
    }
    else if(e.KeyCode == Keys.F2 && e.Modifiers == Keys.Alt)
    {
        // Display a pop-up Help topic to provide additional assistance to the user.
        Help.ShowPopup(textBox1, "Enter your first name followed by your last name. Middle name is optional.",
            new Point(textBox1.Top, this.textBox1.Left));
    }
}

private void treeView1_KeyDown(object sender, KeyEventArgs e)
{
   /* If the 'Alt' and 'E' keys are pressed,
      * allow the user to edit the TreeNode label. */
   if(e.Alt && e.KeyCode == Keys.E)
         
   {
      treeView1.LabelEdit = true;
      // If there is a TreeNode under the mouse cursor, begin editing. 
      TreeNode editNode = treeView1.GetNodeAt(
         treeView1.PointToClient(System.Windows.Forms.Control.MousePosition));
      if(editNode != null)
      { 
         editNode.BeginEdit();
      }
   }
}

private void treeView1_AfterLabelEdit(object sender, NodeLabelEditEventArgs e)
{
   // Disable the ability to edit the TreeNode labels.
   treeView1.LabelEdit = false;
}

//引入命名空间
using System;
   using System.Drawing;
   using System.Collections;
   using System.ComponentModel;
   using System.Windows.Forms;
   using System.Data;

   public class KeyDemo : System.Windows.Forms.Form
   {
      private System.Windows.Forms.Label charLabel;
      private System.Windows.Forms.Label keyInfoLabel;
      public KeyDemo()
      {
         InitializeComponent();
      }

      private void InitializeComponent()
      {
         this.charLabel = new System.Windows.Forms.Label();
         this.keyInfoLabel = new System.Windows.Forms.Label();
         this.SuspendLayout();

         this.charLabel.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F);
         this.charLabel.Location = new System.Drawing.Point(8, 8);
         this.charLabel.Name = "charLabel";
         this.charLabel.Size = new System.Drawing.Size(168, 32);
         this.charLabel.TabIndex = 0;

         this.keyInfoLabel.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F);
         this.keyInfoLabel.Location = new System.Drawing.Point(8, 56);
         this.keyInfoLabel.Name = "keyInfoLabel";
         this.keyInfoLabel.Size = new System.Drawing.Size(168, 136);
         this.keyInfoLabel.TabIndex = 0;

         this.AutoScaleBaseSize = new System.Drawing.Size(15, 37);
         this.ClientSize = new System.Drawing.Size(184, 197);
         this.Controls.AddRange(new System.Windows.Forms.Control[] {this.keyInfoLabel,this.charLabel});
         this.Font = new System.Drawing.Font("Microsoft Sans Serif", 24F);
         this.Name = "Key Demo";
         this.Text = "Key Demo";

         this.KeyDown +=new System.Windows.Forms.KeyEventHandler(this.KeyDemo_KeyDown );
         this.KeyPress +=new System.Windows.Forms.KeyPressEventHandler(this.KeyDemo_KeyPress );
         this.KeyUp +=new System.Windows.Forms.KeyEventHandler(this.KeyDemo_KeyUp );
         
         this.ResumeLayout(false);

      }
      [STAThread]
      static void Main() 
      {
         Application.Run( new KeyDemo() );
      }

      protected void KeyDemo_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e )
      {  
         charLabel.Text = "Key pressed: " + e.KeyChar;
      }

      private void KeyDemo_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e )
      {
         keyInfoLabel.Text = 
            "Alt: " + (e.Alt ? "Yes" : "No") + '\n' +
            "Shift: " + (e.Shift ? "Yes" : "No" ) + '\n' +
            "Ctrl: " + (e.Control ? "Yes" : "No" ) + '\n' + 
            "KeyCode: " + e.KeyCode + '\n' +
            "KeyData: " + e.KeyData + '\n' +
            "KeyValue: " + e.KeyValue;                               
      }
   
      private void KeyDemo_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e )
      {
        Console.WriteLine("Key up");
      }

   }