//
// System.Web.UI.WebControls.HiddenField.cs
//
// Authors:
// Lluis Sanchez Gual (lluis@novell.com)
//
// (C) 2005 Novell, Inc. (http://www.novell.com)
//
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
#if NET_2_0
using System.Web.UI;
using System.ComponentModel;
namespace System.Web.UI.WebControls{
public class HiddenField : Control, IPostBackDataHandler
{
static readonly object ValueChangedEvent = new object ();
public event EventHandler ValueChanged
{
add { Events.AddHandler (ValueChangedEvent, value); }
remove { Events.RemoveHandler (ValueChangedEvent, value); }
}
[Bindable (true)]
public virtual string Value {
get {
return ViewState.GetString ("Value", "");
}
set {
ViewState ["Value"] = value;
}
}
public override bool EnableTheming {
get {
return false;
}
set {
throw new NotSupportedException ();
}
}
public override string SkinID {
get {
return String.Empty;
}
set {
throw new NotSupportedException ();
}
}
public override void Focus ()
{
throw new NotSupportedException ();
}
protected virtual void OnValueChanged (EventArgs e)
{
EventHandler h = (EventHandler) Events [ValueChangedEvent];
if (h != null)
h (this, e);
}
protected virtual bool LoadPostData (string postDataKey, System.Collections.Specialized.NameValueCollection postCollection)
{
if (Value != postCollection [postDataKey]) {
Value = postCollection [postDataKey];
return true;
}
return false;
}
protected virtual void RaisePostDataChangedEvent ()
{
ValidateEvent (UniqueID, String.Empty);
OnValueChanged (EventArgs.Empty);
}
protected override ControlCollection CreateControlCollection ()
{
return new System.Web.UI.EmptyControlCollection (this);
}
protected internal override void OnPreRender (EventArgs e)
{
base.OnPreRender (e);
}
protected internal override void Render (HtmlTextWriter writer)
{
Page page = Page;
string uniqueid = UniqueID;
if (page != null)
page.ClientScript.RegisterForEventValidation (uniqueid);
writer.AddAttribute (HtmlTextWriterAttribute.Type, "hidden", false);
if (!String.IsNullOrEmpty (ClientID))
writer.AddAttribute (HtmlTextWriterAttribute.Id, ClientID);
if (!String.IsNullOrEmpty (uniqueid))
writer.AddAttribute (HtmlTextWriterAttribute.Name, uniqueid);
if (!String.IsNullOrEmpty (Value))
writer.AddAttribute (HtmlTextWriterAttribute.Value, Value);
writer.RenderBeginTag (HtmlTextWriterTag.Input);
writer.RenderEndTag ();
}
#region IPostBackDataHandler Members
bool IPostBackDataHandler.LoadPostData (string postDataKey, System.Collections.Specialized.NameValueCollection postCollection)
{
return LoadPostData (postDataKey, postCollection);
}
void IPostBackDataHandler.RaisePostDataChangedEvent ()
{
RaisePostDataChangedEvent ();
}
#endregion
}
}
#endif
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