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//------------------------------------------------------------------------------
// <copyright file="HtmlInputRadioButton.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
/*
* HtmlInputRadioButton.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.Web;
using System.Web.UI;
using System.Security.Permissions;
/// <devdoc>
/// <para>
/// The <see langword='HtmlInputRadioButton'/> class defines the methods,
/// properties, and events for the HtmlInputRadio control. This class allows
/// programmatic access to the HTML <input type=
/// radio>
/// element on the server.
/// </para>
/// </devdoc>
[
DefaultEvent("ServerChange"),
SupportsEventValidation,
]
public class HtmlInputRadioButton : HtmlInputControl, IPostBackDataHandler {
private static readonly object EventServerChange = new object();
/*
* Creates an intrinsic Html INPUT type=radio control.
*/
public HtmlInputRadioButton() : base("radio") {
}
/*
* Checked property.
*/
/// <devdoc>
/// <para>
/// Gets or sets a value indicating whether a radio button is
/// currently selected or not.
/// </para>
/// </devdoc>
[
WebCategory("Default"),
DefaultValue(""),
DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
]
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;
}
}
/// <devdoc>
/// <para>
/// Gets the value of the HTML
/// Name attribute that will be rendered to the browser.
/// </para>
/// </devdoc>
public override string Name {
get {
string s = Attributes["name"];
return ((s != null) ? s : String.Empty);
}
set {
Attributes["name"] = MapStringAttributeToString(value);
}
}
/// <devdoc>
/// <para>
/// Gets or sets the contents of a text box.
/// </para>
/// </devdoc>
public override string Value {
get {
string val = base.Value;
if (val.Length != 0)
return val;
val = ID;
if (val != null)
return val;
// if specific value is not provided, use the UniqueID
return UniqueID;
}
set {
base.Value = value;
}
}
// Value that gets rendered for the Name attribute
internal override string RenderedNameAttribute {
get {
// For radio buttons, we must make the name unique, but can't just use the
// UniqueID because all buttons in a group must have the same name. So
// we replace the last part of the UniqueID with the group Name.
string name = base.RenderedNameAttribute;
string uid = UniqueID;
int lastColon = uid.LastIndexOf(IdSeparator);
if (lastColon >= 0)
name = uid.Substring(0, lastColon+1) + name;
return name;
}
}
[
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
if (Events[EventServerChange] == null && !Disabled) {
ViewState.SetItemDirty("checked",false);
}
}
/*
* Method used to raise the OnServerChange event.
*/
/// <devdoc>
/// </devdoc>
protected virtual void OnServerChange(EventArgs e) {
EventHandler handler = (EventHandler)Events[EventServerChange];
if (handler != null) handler(this, e);
}
/// <internalonly/>
/// <devdoc>
/// </devdoc>
protected override void RenderAttributes(HtmlTextWriter writer) {
if (Page != null) {
Page.ClientScript.RegisterForEventValidation(Value, RenderedNameAttribute);
}
writer.WriteAttribute("value", Value);
Attributes.Remove("value");
base.RenderAttributes(writer);
}
/*
* Method of IPostBackDataHandler interface to process posted data.
* RadioButton determines the posted radio group state.
*/
/// <internalonly/>
/// <devdoc>
/// </devdoc>
bool IPostBackDataHandler.LoadPostData(string postDataKey, NameValueCollection postCollection) {
return LoadPostData(postDataKey, postCollection);
}
/// <internalonly/>
/// <devdoc>
/// </devdoc>
protected virtual bool LoadPostData(string postDataKey, NameValueCollection postCollection) {
string postValue = postCollection[RenderedNameAttribute];
bool valueChanged = false;
if ((postValue != null) && postValue.Equals(Value)) {
if (Checked == false) {
ValidateEvent(Value, RenderedNameAttribute);
Checked = true;
// only fire change event for RadioButton that is being checked
valueChanged = true;
}
}
else {
if (Checked == true) {
Checked = false;
}
}
return valueChanged;
}
/*
* Method of IPostBackDataHandler interface which is invoked whenever posted data
* for a control has changed. RadioButton fires an OnServerChange event.
*/
/// <internalonly/>
/// <devdoc>
/// </devdoc>
void IPostBackDataHandler.RaisePostDataChangedEvent() {
RaisePostDataChangedEvent();
}
/// <internalonly/>
/// <devdoc>
/// </devdoc>
protected virtual void RaisePostDataChangedEvent() {
OnServerChange(EventArgs.Empty);
}
}
}
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