.net控件编程-事件

完成事件功能有两种方法：“冒泡”和“包含”

具体实现代码如下：

 

  1using System;
  2using System.Collections.Generic;
  3using System.Text;
  4using System.Web.UI;
  5using System.Web.UI.WebControls;
  6using System.ComponentModel;
  7using System.ComponentModel.Design;
  8
  9namespace OnClick
 10{
 11    public class OnClick : CompositeControl
 12    {
 13        private Button _button;
 14        private TextBox _textBox;
 15        //定义事件
 16         private static readonly object EventSubmitKey = new object();
 17        [
 18        Bindable(true), Category("Appearance"), DefaultValue(""), Description("")
 19        ]
 20        public string ButtonText {
 21            get {
 22                EnsureChildControls();
 23                return _button.Text;
 24            }
 25            set {
 26                EnsureChildControls();
 27                _button.Text = value;
 28            }
 29        }
 30        [
 31        Bindable(true), Category("Appearance"), DefaultValue(""), Description("")
 32        ]
 33        public string Text {
 34            get {
 35                EnsureChildControls();
 36                return _textBox.Text;
 37            }
 38            set {
 39                EnsureChildControls();
 40                _textBox.Text = value;
 41            }
 42        }
 43        //定义事件属性
 44        public event EventHandler Submit
 45        {
 46            add {
 47                Events.AddHandler(EventSubmitKey, value);
 48            }
 49            remove {
 50                Events.AddHandler(EventSubmitKey, value);
 51            }
 52        }
 53        //定义事件接受方
 54        protected virtual void OnSubmit(EventArgs e) {
 55            EventHandler SubmitHandler = (EventHandler)Events[EventSubmitKey];
 56            if (SubmitHandler != null)
 57                SubmitHandler(this, e);
 58        }
 59        /**///// 实现Submit事件引发的事件处理程序 
 60        //private void _button_Click(Object source, EventArgs e)
 61        //{
 62        //    OnSubmit(EventArgs.Empty);
 63        //}
 64        // 重写OnBubbleEvent方法，执行事件冒泡，响应用户操作发起事件
 65        protected override bool OnBubbleEvent(object source, EventArgs e)
 66        {
 67            bool handled = false;
 68            if (e is CommandEventArgs)
 69            {
 70                CommandEventArgs ce = (CommandEventArgs)e;
 71                if (ce.CommandName == "Submit")
 72                {
 73                    OnSubmit(EventArgs.Empty);
 74                    handled = true;
 75                }
 76            }
 77            return handled;
 78        }
 79　　    // 重写ICompositeControlDesignerAccessor接口的RecreateChildContrls方法
 80        protected override void RecreateChildControls()
 81        {
 82            EnsureChildControls();
 83        }
 84
 85　　    //重写CreateChildControls方法，将子控件添加到复合控件中 
 86
 87        protected override void CreateChildControls()
 88        {
 89            Controls.Clear();
 90            _button = new Button();
 91            _textBox = new TextBox();
 92            _button.ID = "btn";
 93            //_button.Click += new EventHandler(_button_Click);
 94            _button.CommandName = "Submit";
 95            this.Controls.Add(_button);
 96            this.Controls.Add(_textBox);
 97        }
 98
 99　　    //重写Render方法，呈现控件中其他的HTML代码 

        protected override void Render(HtmlTextWriter output)
        {
            output.AddAttribute(HtmlTextWriterAttribute.Border, "0px");
            output.AddAttribute(HtmlTextWriterAttribute.Cellpadding, "5px");
            output.AddAttribute(HtmlTextWriterAttribute.Cellspacing, "0px");
            output.RenderBeginTag(HtmlTextWriterTag.Table);
                output.RenderBeginTag(HtmlTextWriterTag.Tr);
                    output.RenderBeginTag(HtmlTextWriterTag.Td);
                    _textBox.RenderControl(output);
                    output.RenderEndTag();
                    output.RenderBeginTag(HtmlTextWriterTag.Td);
                    _button.RenderControl(output);
                    output.RenderEndTag();
                output.RenderEndTag();
            output.RenderEndTag();
        }
    }
}