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//------------------------------------------------------------------------------
// <copyright file="HtmlInputCheckBox.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
/*
* HtmlInputCheckBox.cs
*
* Copyright (c) 2000 Microsoft Corporation
*/
namespace System.Web.UI.HtmlControls {
using System.ComponentModel;
using System;
using System.Collections;
using System.Collections.Specialized;
using System.Globalization;
using System.Web;
using System.Web.UI;
using System.Security.Permissions;
/// <devdoc>
/// <para>
/// The <see langword='HtmlInputCheckBox'/> class defines the methods,
/// properties, and events for the HtmlInputCheckBox control. This class allows
/// programmatic access to the HTML <input type=
/// checkbox>
/// element on the server.
/// </para>
/// </devdoc>
[
DefaultEvent("ServerChange"),
SupportsEventValidation,
]
public class HtmlInputCheckBox : HtmlInputControl, IPostBackDataHandler {
private static readonly object EventServerChange = new object();
/*
* Creates an intrinsic Html INPUT type=checkbox control.
*/
/// <devdoc>
/// <para>Initializes a new instance of a <see cref='System.Web.UI.HtmlControls.HtmlInputCheckBox'/> class.</para>
/// </devdoc>
public HtmlInputCheckBox() : base("checkbox") {
}
/*
* Checked property.
*/
/// <devdoc>
/// <para>Gets or sets a value indicating whether the checkbox is
/// currently selected.</para>
/// </devdoc>
[
WebCategory("Default"),
DefaultValue(""),
DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
TypeConverter(typeof(MinimizableAttributeTypeConverter))
]
public bool Checked {
get {
string s = Attributes["checked"];
return((s != null) ? (s.Equals("checked")) : false);
}
set {
if (value)
Attributes["checked"] = "checked";
else
Attributes["checked"] = null;
}
}
/*
* Adds an event handler for the OnServerChange event.
* value: New handler to install for this event.
*/
/// <devdoc>
/// <para>Occurs when </para>
/// </devdoc>
[
WebCategory("Action"),
WebSysDescription(SR.Control_OnServerCheckChanged)
]
public event EventHandler ServerChange {
add {
Events.AddHandler(EventServerChange, value);
}
remove {
Events.RemoveHandler(EventServerChange, value);
}
}
/*
* This method is invoked just prior to rendering.
*/
/// <internalonly/>
/// <devdoc>
/// </devdoc>
protected internal override void OnPreRender(EventArgs e) {
base.OnPreRender(e);
if (Page != null && !Disabled) {
Page.RegisterRequiresPostBack(this);
Page.RegisterEnabledControl(this);
}
// if no change handler, no need to save posted property unless
// we are disabled
if (Events[EventServerChange] == null && !Disabled) {
ViewState.SetItemDirty("checked",false);
}
}
/*
* Method used to raise the OnServerChange event.
*/
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
protected virtual void OnServerChange(EventArgs e) {
// invoke delegates AFTER binding
EventHandler handler = (EventHandler)Events[EventServerChange];
if (handler != null) handler(this, e);
}
/*
* Method of IPostBackDataHandler interface to process posted data.
* Checkbox determines the posted Checked state.
*/
/// <internalonly/>
bool IPostBackDataHandler.LoadPostData(string postDataKey, NameValueCollection postCollection) {
return LoadPostData(postDataKey, postCollection);
}
/// <internalonly/>
protected virtual bool LoadPostData(string postDataKey, NameValueCollection postCollection) {
string post = postCollection[postDataKey];
bool newValue = !String.IsNullOrEmpty(post);
bool valueChanged = (newValue != Checked);
Checked = newValue;
if (newValue) {
ValidateEvent(postDataKey);
}
return valueChanged;
}
protected override void RenderAttributes(HtmlTextWriter writer) {
base.RenderAttributes(writer);
if (Page != null) {
Page.ClientScript.RegisterForEventValidation(RenderedNameAttribute);
}
}
/*
* Method of IPostBackDataHandler interface which is invoked whenever
* posted data for a control has changed. RadioButton fires an
* OnServerChange event.
*/
/// <internalonly/>
void IPostBackDataHandler.RaisePostDataChangedEvent() {
RaisePostDataChangedEvent();
}
/// <internalonly/>
protected virtual void RaisePostDataChangedEvent() {
OnServerChange(EventArgs.Empty);
}
}
}
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