服务器控件之组合控件(用户登录)完成于2004-10-21

using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebFrame
{
 [
 DefaultEvent("Login"),
 DefaultProperty("Name")
 ]
 public class CompositeLogin : WebControl, INamingContainer
 {
  private Button _button;
  private TextBox _nameTextBox;
  private Label _nameLabel;
  private TextBox _passwordTextBox;
  private Label _passwordLabel;
  private RequiredFieldValidator _nameValidator;
  private RequiredFieldValidator _passwordValidator;

  private static readonly object EventLogin = new object();

  #region 重載System.Web.UI.Control類的Controls屬性
  //獲取ControlCollection對象,該對象表示UI層次結構中指定的服務器控的子控件
  public override ControlCollection Controls
  {
   get
   {
    //確定服務器控件是否包含子控件，如果不包含，則創建子控件
    EnsureChildControls();
    return base.Controls;
   }
  }
  #endregion

  public string ButtonText
  {
   get
   {
    EnsureChildControls();
    return _button.Text;
   } 
   set
   {
    EnsureChildControls();
    _button.Text = value;
   }
  }

  public string Name
  {
   get
   {
    EnsureChildControls();
    return _nameTextBox.Text;
   }
   set
   {
    EnsureChildControls();
    _nameTextBox.Text = value;
   }
  }

  public string NameErrorMessage
  {
   get
   {
    EnsureChildControls();
    return _nameValidator.ErrorMessage;
   }
   set
   {
    EnsureChildControls();
    _nameValidator.ErrorMessage = value;
    _nameValidator.ToolTip = value;
   }
  }

  public string NameLabel
  {
   get
   {
    EnsureChildControls();
    return _nameLabel.Text;
   }
   set
   {
    EnsureChildControls();
    _nameLabel.Text = value;
   }
  }

  public string PassWord
  {
   get
   {
    EnsureChildControls();
    return _passwordTextBox.Text;
   }
  }

  public string PassWordErrorMessage
  {
   get
   {
    EnsureChildControls();
    return _passwordValidator.ErrorMessage;
   }
   set
   {
    EnsureChildControls();
    _passwordValidator.ErrorMessage = value;
    _passwordValidator.ToolTip = value;
   }
  }

  public string PassWordLabel
  {
   get
   {
    EnsureChildControls();
    return _passwordLabel.Text;
   }
   set
   {
    EnsureChildControls();
    _passwordLabel.Text = value;
   }
  }

  public event EventHandler Login
  {
   add
   {
    Events.AddHandler(EventLogin,value);
   }
   remove
   {
    Events.AddHandler(EventLogin,value);
   }
  }

  protected virtual void OnLogin(EventArgs e)
  {
   EventHandler loginHandler = (EventHandler)Events[EventLogin];
   if(loginHandler!=null)
    loginHandler(this,e);
  }

  protected override bool OnBubbleEvent(object source, EventArgs e)
  {
   bool handled = false;
   if(e is CommandEventArgs)
   {
    CommandEventArgs ce = (CommandEventArgs)e;
    if(ce.CommandName =="Login")
    {
     OnLogin(EventArgs.Empty);
     handled = true;
    }
   }
   return handled;
  }

  #region 動態創建子控件

  protected override void CreateChildControls()
  {
   Controls.Clear();

   _nameLabel = new Label();

   _nameTextBox = new TextBox();
   _nameTextBox.ID = "nameTextBox";

   _nameValidator = new RequiredFieldValidator();
   _nameValidator.ID = "validator1";
   _nameValidator.ControlToValidate = _nameTextBox.ID;
   _nameValidator.Text = "*";
   _nameValidator.Display = ValidatorDisplay.Dynamic;

   _passwordLabel = new Label();

   _passwordTextBox = new TextBox();
   _passwordTextBox.ID = "passwordTextBox";

   _passwordValidator = new RequiredFieldValidator();
   _passwordValidator.ID = "validator2";
   _passwordValidator.ControlToValidate = _passwordTextBox.ID;
   _passwordValidator.Text = "*";
   _passwordValidator.Display = ValidatorDisplay.Dynamic;

   _button = new Button();
   _button.ID = "button1";
   _button.CommandName = "Login";

   this.Controls.Add(_nameLabel);
   this.Controls.Add(_nameTextBox);
   this.Controls.Add(_nameValidator);
   this.Controls.Add(_passwordLabel);
   this.Controls.Add(_passwordTextBox);
   this.Controls.Add(_passwordValidator);
   this.Controls.Add(_button);
  }

  #endregion

  #region 控件輸出　

  protected override void Render(HtmlTextWriter writer)
  {
   //將需要呈現的Html屬性與樣式添加到指定的System.Web.UI.HtmlTextWriter中
   AddAttributesToRender(writer);
   writer.AddAttribute(HtmlTextWriterAttribute.Cellpadding,"1",false);
   writer.RenderBeginTag(HtmlTextWriterTag.Table);
   writer.RenderBeginTag(HtmlTextWriterTag.Tr);
   writer.RenderBeginTag(HtmlTextWriterTag.Td);
   _nameLabel.RenderControl(writer);
   writer.RenderEndTag();
   writer.RenderBeginTag(HtmlTextWriterTag.Td);
   _nameTextBox.RenderControl(writer);
   writer.RenderEndTag();
   writer.RenderBeginTag(HtmlTextWriterTag.Td);
   _nameValidator.RenderControl(writer);
   writer.RenderEndTag();
   writer.RenderEndTag();
   writer.RenderBeginTag(HtmlTextWriterTag.Tr);
   writer.RenderBeginTag(HtmlTextWriterTag.Td);
   _passwordLabel.RenderControl(writer);
   writer.RenderEndTag();
   writer.RenderBeginTag(HtmlTextWriterTag.Td);
   _passwordTextBox.RenderControl(writer);
   writer.RenderEndTag();
   writer.RenderBeginTag(HtmlTextWriterTag.Td);
   _passwordValidator.RenderControl(writer);
   writer.RenderEndTag();
   writer.RenderEndTag();
   writer.RenderBeginTag(HtmlTextWriterTag.Tr);
   writer.AddAttribute(HtmlTextWriterAttribute.Colspan,"3");
   writer.AddAttribute(HtmlTextWriterAttribute.Align,"right");
   writer.RenderBeginTag(HtmlTextWriterTag.Td);
   _button.RenderControl(writer);
   writer.RenderEndTag();
   writer.RenderEndTag();
   writer.RenderEndTag();
  }

  #endregion

 }
}