C#自定义控件教程

.Nt用户自定义控件继承UserControl类，设计很简单的，像平时在窗体上拖控件一样。

操作步骤：
1. 建立一个工程，添加用户控件。

2.在打开的窗体内输入控件名称，如:"ucButton"，按确定按钮。接下来在空白区域拖放3个.Net控件。
如下图：

 

3.代码

 C# code

/// <summary>
/// C#.Net 设计用户自定义控件
/// </summary>
/// </summary>
[ToolboxBitmap(typeof(CustomControl.ucButton), "ucButton.bmp")]
public partial class ucButton : UserControl
{
   private bool _IsFocused = false; //标记按钮是否为焦点状态
  
   public ucButton()
   {
      InitializeComponent();
     
      this.DoHideFocusedTag();
      this.MyCatpionText = this.Name;
   }
  
   private EventHandler _OnButtonClick = null;
  
   private string _MyCatpionText = "ucButton1";
  
   /// <summary>
   /// 按钮标题
   /// </summary>
   [EditorBrowsable(EditorBrowsableState.Always)]
   [Browsable(true)]
   [DefaultValue("ucButton1")]
   public string MyCatpionText
   {
      get { return _MyCatpionText; }
      set { _MyCatpionText = value; lblCaption.Text = _MyCatpionText; }
   }
  
   /// <summary>
   /// 用户自定义Click事件
   /// </summary>
   [EditorBrowsable(EditorBrowsableState.Always)]
   [Browsable(true)]
   public event EventHandler OnButtonClick
   {
      add { _OnButtonClick  = new EventHandler(value); }
      remove { _OnButtonClick -= new EventHandler(value); }
   }
  
   private void lblCaption_Click(object sender, EventArgs e)
   {
      //转移Click事件, 触发用户自定义事件
      if (_OnButtonClick != null) _OnButtonClick(this, e);
   }
  
   private void lblCaption_MouseDown(object sender, MouseEventArgs e)
   {
      if (_IsFocused)
      {
         lblCaption.Font = new Font(lblCaption.Font.FontFamily, lblCaption.Font.Size, FontStyle.Bold);
      }
   }
  
   private void lblCaption_MouseUp(object sender, MouseEventArgs e)
   {
      if (_IsFocused)
      {
         lblCaption.Font = new Font(lblCaption.Font.FontFamily, lblCaption.Font.Size, FontStyle.Regular);
      }
   }
  
   private void ucButton_SizeChanged(object sender, EventArgs e)
   {
      lblUnderLine.Top = this.Height - 1;
      lblUnderLine.Width = this.Width - 15;
   }
  
   /// <summary>
   /// 还原按钮状态
   /// </summary>
   public void DoHideFocusedTag()
   {
      this.pictureBox1.Image = global::vjsdn.CustomControl.Properties.Resources.GrayTag;
      this.lblUnderLine.Visible = false;
      lblCaption.ForeColor = Color.Black;
   }
  
   /// <summary>
   /// 设计按钮为焦点状态
   /// </summary>
   public void DoShowFocusedTag()
   {
      this.pictureBox1.Image = global::vjsdn.CustomControl.Properties.Resources.FosedTag;
      this.lblUnderLine.Visible = true;
      lblCaption.ForeColor = Color.Blue;
   }
  
   private void ucButton_MouseEnter(object sender, EventArgs e)
   {
      if (this.Parent != null)
      {
         foreach (Control c in this.Parent.Controls)
         {
            if (c is ucButton) (c as ucButton).DoHideFocusedTag();
         }
      }
     
      this.DoShowFocusedTag();
      _IsFocused = true;
   }
  
   [EditorBrowsable(EditorBrowsableState.Always)]
   [Browsable(true)]
   [Description("")]
   public Label MyCaption
   {
      get { return lblCaption; }
   }
  
   private void lblCaption_MouseEnter(object sender, EventArgs e)
   {
      this.ucButton_MouseEnter(sender, e);
   }
  
}
4. 按F5编译项目，建立一个测试窗体，在控件工具栏会看到有个齿轮图标的项目。
   在窗体上拖3个ucButton。

5.设置按钮标题及事件。

 

就这么简单，然后按F5运行下程序就可以看到自定义控件的效果了。