学步园

#region   Hidden   Base   Properties
///   <summary>
///   Hides   the   BorderColor   property,   as   it   not   relevant   on   this   control.
///   </summary>
[
EditorBrowsableAttribute(EditorBrowsableState.Never),
BindableAttribute(BindableSupport.No),
BrowsableAttribute(false),
DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
]
public   override   System.Drawing.Color   BorderColor  
{
get  
{
return   base.BorderColor;
}
set  
{

}
}

///   <summary>
///   Hides   the   BorderStyle   property,   as   it   not   relevant   on   this   control.
///   </summary>
[
EditorBrowsableAttribute(EditorBrowsableState.Never),
BindableAttribute(BindableSupport.No),
BrowsableAttribute(false),
DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
]
public   override   System.Web.UI.WebControls.BorderStyle   BorderStyle  
{
get  
{
return   base.BorderStyle;
}
set  
{

}
}

///   <summary>
///   Hides   the   BorderWidth   property,   as   it   not   relevant   on   this   control.
///   </summary>
[
EditorBrowsableAttribute(EditorBrowsableState.Never),
BindableAttribute(BindableSupport.No),
BrowsableAttribute(false),
DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
]
public   override   System.Web.UI.WebControls.Unit   BorderWidth  
{
get  
{
return   base.BorderWidth;
}
set  
{

}
}

///   <summary>
///   Hides   the   ToolTip   property,   as   it   not   relevant   on   this   control.
///   </summary>
[
EditorBrowsableAttribute(EditorBrowsableState.Never),
BindableAttribute(BindableSupport.No),
BrowsableAttribute(false),
DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
]
public   override   string   ToolTip  
{
get  
{
return   base.ToolTip;
}
set  
{

}
}

///   <summary>
///   Hides   the   Height   property,   as   it   not   relevant   on   this   control.
///   </summary>
[
EditorBrowsableAttribute(EditorBrowsableState.Never),
BindableAttribute(BindableSupport.No),
BrowsableAttribute(false),
DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
]
public   override   Unit   Height  
{
get  
{
return   Unit.Empty;
}
set  
{
base.Height   =   Unit.Empty;
}
}
#endregion

#region   Render   Overrides
///   <summary>
///   Overrides   the   LoadViewState   method.
///   </summary>
protected   override   void   LoadViewState(object   savedState)  
{
base.LoadViewState(savedState);
if   (   this.ViewState[ "-1Saved "]   !=   null   &&   (Boolean)this.ViewState[ "-1Saved "]   )  
{   //   not   really   sure   why   I   have   to   do   this
this.SelectedIndex   =   -1;
}
}

///   <summary>
///   Overrides   the   CreateChildControls   method.
///   </summary>
protected   override   void   CreateChildControls()  
{
container   =   new   WebControl();
container.ID   =   "Container ";
this.Controls.Add(   container   );
                       
text   =   new   TextBox();
text.ID   =   "Text ";
text.Attributes[ "autocomplete "]   =   "off ";
container.Controls.Add(   text   );
text.TextChanged   +=   new   EventHandler(   this.raiseTextChanged   );
                       
button   =   new   WebControl();
button.ID   =   "Button ";
container.Controls.Add(   button   );
}

///   <summary>
///   Overrides   the   OnPreRender   method.
///   </summary>
protected   override   void   OnPreRender(System.EventArgs   e)  
{

base.OnPreRender(e);

if(   this.AutoPostBack   )  
{
this.AutoPostBack   =   false;
this.text.AutoPostBack   =   true;
}
 
       
ResourceManager   manager   =   new   ResourceManager(   this.GetType()   );
ResourceSet   resources   =   manager.GetResourceSet(System.Globalization.CultureInfo.CurrentCulture,   true,   true);

if(   !Page.IsClientScriptBlockRegistered(   "TopWin.WebControls.ComboBox   Library "   )   )  
{
if(   UseReferenceLibrary   )  
{
Page.RegisterClientScriptBlock(   "TopWin.WebControls.ComboBox   Library ",   " <script   language=/ "javascript/ "   src=/ " "   +   ResolveUrl(   ReferenceLibraryUrl   )   +   "/ "> </script> "   );
}  
else  
{
String   script   =   resources.GetString( "ClientScript ");
this.Page.RegisterClientScriptBlock( "TopWin.WebControls.ComboBox   Library ",   script   );
}
}
                       
String   initScript   =   resources.GetString( "InitScript ");
this.Page.RegisterStartupScript( "TopWin.WebControls.ComboBox   Init ",   initScript   );
                       
Page.RegisterArrayDeclaration(   "ComboBoxes ",   " ' "   +   this.ClientID   +   " ' "   );

}

///   <summary>
///   Overrides   the   AddAttributesToRender   method.
///   </summary>
protected   override   void   AddAttributesToRender(   HtmlTextWriter   writer   )  
{

if   (this.Page   !=   null)  
{
this.Page.VerifyRenderingInServerForm(this);
}

writer.AddAttribute(HtmlTextWriterAttribute.Name,   this.UniqueID);
writer.AddAttribute(   HtmlTextWriterAttribute.Onchange,   "ComboBox_SimpleAttach(this,   this.form[ ' "   +   this.text.UniqueID   +   " ']);   "   );
writer.AddAttribute(   "listSize ",   this.Rows.ToString()   );

base.AddAttributesToRender(writer);
}
               
///   <summary>
///   Overrides   the   Render   method.
///   </summary>
protected   override   void   Render(   HtmlTextWriter   writer   )  
{
this.EnsureChildControls();
this.TextControl.ControlStyle.CopyFrom(this.ControlStyle);
this.ContainerControl.ControlStyle.CopyFrom(this.ControlStyle);

this.TextControl.Enabled   =   this.Enabled;
this.ContainerControl.Style[ "POSITION "]   =   this.Style[ "POSITION "];
this.ContainerControl.Style[ "TOP "]   =   this.Style[ "TOP "];
this.ContainerControl.Style[ "LEFT "]   =   this.Style[ "LEFT "];
this.ContainerControl.Style[ "Z-INDEX "]   =   this.Style[ "Z-INDEX "];

base.Render(   getCorrectTagWriter(   writer   )     );
}

///   <summary>
///   Overrides   the   RenderBeginTag   method.
///   </summary>
public   override   void   RenderBeginTag(System.Web.UI.HtmlTextWriter   writer)  
{
container.RenderControl(   writer   );
base.RenderBeginTag(   writer   );
}

///   <summary>
///   Overrides   the   RenderContents   method.
///   </summary>
protected   override   void   RenderContents(System.Web.UI.HtmlTextWriter   writer)  
{
Boolean   oneSelected   =   false;

foreach(   ListItem   item   in   this.Items   )  
{
writer.WriteBeginTag( "option ");
if   (   item.Selected   )  
{
if   (   !oneSelected   )  
{
writer.WriteAttribute(   "selected ",   "selected ",   false   );
}
oneSelected   =   true;
}

writer.WriteAttribute(   "value ",   item.Value,   true   );
writer.Write( "> ");
HttpUtility.HtmlEncode(item.Text,   writer   );
writer.WriteEndTag( "option ");
writer.WriteLine();
}

}

///   <summary>
///   Overrides   the   SaveViewState   method.
///   </summary>
protected   override   object   SaveViewState()  
{
this.ViewState[ "-1Saved "]   =   (   this.SelectedIndex   ==   -1   );   //   not   really   sure   why   I   have   to   do   this
return     base.SaveViewState();
}

#endregion

#region   Util
private   HtmlTextWriter   getCorrectTagWriter(   HtmlTextWriter   writer   )  
{

HtmlTextWriter   tagWriter   =   writer;

if   (   writer   is   System.Web.UI.Html32TextWriter   )  
{
HttpBrowserCapabilities   browser   =   this.Page.Request.Browser;
if(   browser.W3CDomVersion.Major   >   0   )  
{
tagWriter   =     new   HtmlTextWriter(   writer.InnerWriter   );
}  
else   if   (   String.Compare(   browser.Browser,   "netscape ",   true   )   ==   0   )  
{
if   (   browser.MajorVersion   > =   5   )  
{
tagWriter   =   new   HtmlTextWriter(   writer.InnerWriter   );
}
}
}

return   tagWriter;
}

private   void   raiseTextChanged(   Object   sender,   EventArgs   e   )
{
OnTextChanged(   e   );
}

///   <summary>
///   The   container   control   of   ComboBox 's   controls.
///   </summary>
///   <remarks>
///   This   is   used   by   the   designer.
///   </remarks>
protected   internal   WebControl   ContainerControl  
{
get  
{
EnsureChildControls();
return   container;
}
}

///   <summary>
///   The   button   which   activates   the   dropdownlist   portion   of   the   ComboBox.
///   </summary>
///   <remarks> This   is   used   by   the   designer. </remarks>
protected   internal   WebControl   ButtonControl  
{
get  
{
EnsureChildControls();
return   button;
}
}

///   <summary>
///   The   text   area   of   the   ComboBox.
///   </summary>
///   <remarks> This   is   used   by   the   designer. </remarks>
protected   internal   TextBox   TextControl  
{
get  
{
EnsureChildControls();
return   text;
}
}

private   WebControl   container;
private   WebControl   button;
private   TextBox   text;

private   Boolean   isLoaded   =   false;
#endregion

///   <summary>
///   Overrides   <see   cref= "ListControl.SelectedIndex "/> .
///   </summary>
public   override   int   SelectedIndex  
{
get  
{
return   base.SelectedIndex;
}
set  
{
base.SelectedIndex   =   value;
if   (   this.isLoaded   )  
{
if   (   this.SelectedItem   !=   null   )  
{
this.Text   =   this.SelectedItem.Text;
}  
else  
{
this.Text   =   String.Empty;
}
}
}
}

///   <summary>
///   Overrides   <see   cref= "Control.OnLoad "/>
///   </summary>
protected   override   void   OnLoad(System.EventArgs   e)  
{
this.isLoaded   =   true;
base.OnLoad(e);
}

}
///   <summary>
///   The   designer   for   the   <see   cref= "ComboBox "/> .
///   </summary>
public   class   ComboBoxDesigner:   ListControlDesigner  
{

///   <summary>
///   Overrides   <see   cref= "ListControlDesigner.GetDesignTimeHtml "/> .
///   </summary>
public   override   String   GetDesignTimeHtml()  
{
try  
{
combo.TextControl.Visible   =   false;
combo.TextControl.BackColor   =   combo.BackColor;
combo.ContainerControl.Visible   =   false;

Int32   oldSelectedIndex   =   -1;
if   (   combo.Text   !=   String.Empty   )  
{
oldSelectedIndex   =   combo.SelectedIndex;
combo.Items.Insert(   0,   new   ListItem(   combo.Text,   combo.Text   )   );
combo.SelectedIndex   =   0;
}
String   result   =   base.GetDesignTimeHtml();
if   (   combo.Text   !=   String.Empty   )  
{
combo.Items.RemoveAt(0);
combo.SelectedIndex   =   oldSelectedIndex;
}

combo.TextControl.Visible   =   true;
combo.ContainerControl.Visible   =   true;
return   result;
}  
catch   (   Exception   ex   )  
{
return   this.GetErrorDesignTimeHtml(ex);
}
}

///   <summary>
///   Overrides   <see   cref= "ListControlDesigner.Initialize "/> .
///   </summary>
public   override   void   Initialize(System.ComponentModel.IComponent   component)  
{
base.Initialize(   component   );
this.combo   =   (ComboBox)component;
}

///   <summary>
///   The   ComboBox   for   this   designer.
///   </summary>
protected   ComboBox   combo;
}
}
合并起来编译。

控件名字教Combobox，用法跟winform的一样。