huobazi/1

## 1
---
layout: post
title: Scroll Page 表单提交后页面重新滚回原来滚动条所在位置
comments: true
date: 2004-09-20 13:55
categories:
- ASP.NET
- 前端开发
- Asp.net
---

<p>作者<span style="text-decoration: underline;"><span style="color: #800080;"><a href="http://scottwater.com/">scottwater</a><br /></span></span>原文地址：<a href="http://scottwater.com/articles/ScrollPage">http://scottwater.com/articles/ScrollPage</a><br />感谢<a href="http://scottwater.com/">scottwater</a>先生！<br />我做了一点修改，使其支持横向滚动条位置的记忆</p>

```
using System;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
using System.Web.UI;

namespace ShangGu.XaTaxi.Components
{
 /// <summary>
/// Summary description for ScrollPage.
/// </summary>
public class ScrollPage : System.Web.UI.Page
 {
public ScrollPage()
 {

}

private bool _useScrollPersistence = true;
 /// <summary>
/// There could be PostBack senarios where we do not want to remember the scroll position. Set this property to false
/// if you would like the page to forget the current scroll position
/// </summary>
public bool UseScrollPersistence
 {
 get {return this._useScrollPersistence;}
set {this._useScrollPersistence = value;}
}

private string _bodyID;
/// <summary>
/// Some pages might already have the ID attribute set for the body tag. Setting this property will not render the ID or change
/// the existing value. It will simply update the javascript written out to the browser.
/// </summary>
public string BodyID
 {
 get {return this._bodyID;}
 set {this._bodyID = value;}
}


//Last chance. Do we want to maintain the current scroll position
protected override void OnPreRender(EventArgs e)
 {
if(UseScrollPersistence)
 {
RetainScrollPosition();
}
base.OnPreRender (e);
}

protected override void Render(HtmlTextWriter writer)
 {
//No need processing the HTML if the user does not want to maintain scroll position or already has
//set the body ID value
if(UseScrollPersistence)
 {
TextWriter tempWriter = new StringWriter();
base.Render(new HtmlTextWriter(tempWriter));
if(BodyID == null)
 {
writer.Write(Regex.Replace(tempWriter.ToString(),"<body","<body id="thebody" ",RegexOptions.IgnoreCase));
}
//=++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//
//2004－9－16 武眉博 修正了因BodyID不空时造成javascript错误的bug
//
//=++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
else
 {
writer.Write(Regex.Replace(tempWriter.ToString(),"<body","<body id=""+BodyID+"" ",RegexOptions.IgnoreCase));

}
}
else
 {
base.Render(writer);
}
}

//=++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//
//2004－9－20 武眉博 增加了隐藏文本域"__SCROLLPOS_LEFT"，以增加对横向滚动条位置的记忆功能
//
//=++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
private static string saveScrollPosition = "<script language='javascript'>function saveScrollPosition() {{document.forms[0].__SCROLLPOS_TOP.value = {0}.scrollTop;document.forms[0].__SCROLLPOS_LEFT.value = {0}.scrollLeft ;}}{0}.onscroll=saveScrollPosition;</script>";
private static string setScrollPosition = "<script language='javascript'>function setScrollPosition() {{{0}.scrollTop ="{1}"; {0}.scrollLeft ="{2}"}}{0}.onload=setScrollPosition;</script>";

//Write out javascript and hidden field
private void RetainScrollPosition()
 {
RegisterHiddenField("__SCROLLPOS_TOP", "0");
RegisterHiddenField("__SCROLLPOS_LEFT", "0");
string __bodyID = BodyID == null ? "thebody" : BodyID;
RegisterStartupScript("saveScroll", string.Format(saveScrollPosition,__bodyID));

if(Page.IsPostBack)
 {
RegisterStartupScript("setScroll", string.Format(setScrollPosition,__bodyID, Request.Form["__SCROLLPOS_TOP"],Request.Form["__SCROLLPOS_LEFT"]));
}
}
}
}
```

## 2
---
layout: post
title: 自定义控件实现广告内容后期加载，以及NamingContainer层次的应用
comments: true
date: 2007-08-05 13:49
categories:
- ASP.NET
- Asp.net
- 自定义控件
- NamingContainer
---

<p>自定义控件：广告内容后期加载。以及NamingContainer层次的应用<br />网站上的广告内容可能会因加载过慢而导致整个网页加载过慢<br />我们可以考虑将广告内全部放在网页最底部，等整个页面加载完毕後<br />再采用javascript使其显示，考虑给控件一个TargetContainerID标识<br />控件广告内容将要被显示的容器ID，然后从控件自己所处的 开始向上查找该ID<br />所指定的控件，(我们只向上找而没有向下找，并且没有处理某层次的<br />子NamingContainer,所以不一定能够找到，这里没有考虑从Page对象向下递归查找<br />主要考虑为了提高性能),如果没有找到，则考虑给用户一个事件让用户自己处理TargetContainer</p>
<p>下面的自定义控件对此实现了封装:</p>
<p><!--more--></p>


```
//------------------------------------------------------------------------------
//
// Copyright (c) www.AspxBoy.com All rights reserved.
//
//------------------------------------------------------------------------------
namespace HBZ.Ads.Controls
{
using System;
using System.ComponentModel;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using HBZ.Ads;
using System.Collections.Generic;
using System.Text;
[Designer( typeof( HBZ.Ads.Controls.AdRotatorDesigner ) )]
public class AdRotator : WebControl
{
private Dictionary findControlHelperCacheList = new Dictionary( );
private readonly string scriptFormat = " var {0}_target = document.getElementById(\"{0}\"); var {1}_base = document.getElementById(\"{1}\"); if ({0}_target) {{ {0}_target.innerHTML = {1}_base.innerHTML; {1}_base.innerHTML = \"\"; }}";
private static readonly object eventObj = new object( );
public event FindTargetContainerEventHandler FindTargetContainer
{
add
{
Events.AddHandler( eventObj , value );
}
remove
{
Events.RemoveHandler( eventObj , value );
}
}
public AdRotator( )
: base( HtmlTextWriterTag.Span )
{
}
[TypeConverter( typeof( ValidatedControlConverter ) )]
[DefaultValue( "" ) , Category( "Data" ) , Description( "广告位后期加载后显示的位置的控件ID" )]
[IDReferenceProperty]
public string TargetContainerID
{
get
{
return (string)this.ViewState[ "TargetContainerID" ] ?? string.Empty;
}
set
{
this.ViewState[ "TargetContainerID" ] = value;
}
}
[Bindable( true ) , Category( "Data" ) , DefaultValue( "" ) , Description( "广告位的默认内容" )]
public string DefaultContent
{
get
{
return (string)this.ViewState[ "DefaultContent" ] ?? "广告位招租";
}
set
{
this.ViewState[ "DefaultContent" ] = value;
}
}
protected override void OnPreRender( EventArgs e )
{
base.OnPreRender( e );
if ( !string.IsNullOrEmpty( TargetContainerID ) )
{
this.Style.Add( HtmlTextWriterStyle.Display , "none" );
ClientScriptManager cs = Page.ClientScript;
if ( !cs.IsStartupScriptRegistered( this.ClientID ) )
{
cs.RegisterStartupScript( this.GetType( ) , this.ClientID , GetLazyLoadingScript( ) , true );
}
}
}
protected virtual string GetLazyLoadingScript( )
{
Control target = FindControlHelper( TargetContainerID );
if ( target == null )
{
throw new TargetContainerNotFoundException( );
}
StringBuilder sb = new StringBuilder( );
sb.AppendFormat( scriptFormat , target.ClientID , this.ClientID );
return sb.ToString( );
}
protected virtual void RenderAdvertisement( Advertisement ad , HtmlTextWriter writer )
{
// 广告内容
}
protected override void RenderContents( HtmlTextWriter writer )
{
// call RenderAdvertisement method
}
protected Control FindControlHelper( string id )
{
Control c = null;
if ( findControlHelperCacheList.ContainsKey( id ) )
{
c = findControlHelperCacheList[ id ];
}
else
{
c = base.FindControl( id ); // 注意：我们从自己开始向上沿NamingContainer层次查找
Control nc = NamingContainer;
while ( ( null == c ) && ( null != nc ) )
{
c = nc.FindControl( id );
nc = nc.NamingContainer;
}
if ( null == c )
{
// 因为我们是从自己开始向上沿NamingContainer层次查找，而没有向下找，
// 并且没有找每一层NamingContainer内的其他NamingContainer,
// 所以这种查找有可能出现没有找到id对应的控件
// 当没此时有找到时，激发FindTargetContainer事件交给用户自己设定Target Container Control
FindTargetContainerEventArgs args = new FindTargetContainerEventArgs( id );
OnFindTargetContainer( args );
c = args.Control;
}
if ( null != c )
{
findControlHelperCacheList[ id ] = c;
}
}
return c;
}
protected virtual void OnFindTargetContainer( FindTargetContainerEventArgs e )
{
FindTargetContainerEventHandler hander = Events[ eventObj ] as FindTargetContainerEventHandler;
if ( hander != null )
{
hander( this , e );
}
}
}
public delegate void FindTargetContainerEventHandler( object src , FindTargetContainerEventArgs e );
public class FindTargetContainerEventArgs : EventArgs
{
private string controlID;
private Control control;
public FindTargetContainerEventArgs( string controlId )
{
controlID = controlId;
}
public string ControlID
{
get
{
return controlID;
}
}
public Control Control
{
get
{
return control;
}
set
{
control = value;
}
}
}
public class TargetContainerNotFoundException : Exception
{
string exceptionMessage = string.Empty;
public TargetContainerNotFoundException( )
: this( "TargetContainerID所指定的控件没有找到！您或许应该处理一下FindTargetContainer事件" )
{
}
public TargetContainerNotFoundException( string message )
: base( message )
{
this.exceptionMessage = message;
}
public override string Message
{
get
{
if ( exceptionMessage != null )
{
return exceptionMessage;
}
return base.Message;
}
}
}
}
```
	---
	layout: post
	title: Scroll Page 表单提交后页面重新滚回原来滚动条所在位置
	comments: true
	date: 2004-09-20 13:55
	categories:
	- ASP.NET
	- 前端开发
	- Asp.net
	---

	<p>作者<span style="text-decoration: underline;"><span style="color: #800080;"><a href="http://scottwater.com/">scottwater</a><br /></span></span>原文地址：<a href="http://scottwater.com/articles/ScrollPage">http://scottwater.com/articles/ScrollPage</a><br />感谢<a href="http://scottwater.com/">scottwater</a>先生！<br />我做了一点修改，使其支持横向滚动条位置的记忆</p>

	```
	using System;
	using System.IO;
	using System.Text;
	using System.Text.RegularExpressions;
	using System.Web.UI;

	namespace ShangGu.XaTaxi.Components
	{
	/// <summary>
	/// Summary description for ScrollPage.
	/// </summary>
	public class ScrollPage : System.Web.UI.Page
	{
	public ScrollPage()
	{

	}

	private bool _useScrollPersistence = true;
	/// <summary>
	/// There could be PostBack senarios where we do not want to remember the scroll position. Set this property to false
	/// if you would like the page to forget the current scroll position
	/// </summary>
	public bool UseScrollPersistence
	{
	get {return this._useScrollPersistence;}
	set {this._useScrollPersistence = value;}
	}

	private string _bodyID;
	/// <summary>
	/// Some pages might already have the ID attribute set for the body tag. Setting this property will not render the ID or change
	/// the existing value. It will simply update the javascript written out to the browser.
	/// </summary>
	public string BodyID
	{
	get {return this._bodyID;}
	set {this._bodyID = value;}
	}


	//Last chance. Do we want to maintain the current scroll position
	protected override void OnPreRender(EventArgs e)
	{
	if(UseScrollPersistence)
	{
	RetainScrollPosition();
	}
	base.OnPreRender (e);
	}

	protected override void Render(HtmlTextWriter writer)
	{
	//No need processing the HTML if the user does not want to maintain scroll position or already has
	//set the body ID value
	if(UseScrollPersistence)
	{
	TextWriter tempWriter = new StringWriter();
	base.Render(new HtmlTextWriter(tempWriter));
	if(BodyID == null)
	{
	writer.Write(Regex.Replace(tempWriter.ToString(),"<body","<body id="thebody" ",RegexOptions.IgnoreCase));
	}
	//=++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	//
	//2004－9－16 武眉博修正了因BodyID不空时造成javascript错误的bug
	//
	//=++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	else
	{
	writer.Write(Regex.Replace(tempWriter.ToString(),"<body","<body id=""+BodyID+"" ",RegexOptions.IgnoreCase));

	}
	}
	else
	{
	base.Render(writer);
	}
	}

	//=++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	//
	//2004－9－20 武眉博增加了隐藏文本域"__SCROLLPOS_LEFT"，以增加对横向滚动条位置的记忆功能
	//
	//=++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
	private static string saveScrollPosition = "<script language='javascript'>function saveScrollPosition() {{document.forms[0].__SCROLLPOS_TOP.value = {0}.scrollTop;document.forms[0].__SCROLLPOS_LEFT.value = {0}.scrollLeft ;}}{0}.onscroll=saveScrollPosition;</script>";
	private static string setScrollPosition = "<script language='javascript'>function setScrollPosition() {{{0}.scrollTop ="{1}"; {0}.scrollLeft ="{2}"}}{0}.onload=setScrollPosition;</script>";

	//Write out javascript and hidden field
	private void RetainScrollPosition()
	{
	RegisterHiddenField("__SCROLLPOS_TOP", "0");
	RegisterHiddenField("__SCROLLPOS_LEFT", "0");
	string __bodyID = BodyID == null ? "thebody" : BodyID;
	RegisterStartupScript("saveScroll", string.Format(saveScrollPosition,__bodyID));

	if(Page.IsPostBack)
	{
	RegisterStartupScript("setScroll", string.Format(setScrollPosition,__bodyID, Request.Form["__SCROLLPOS_TOP"],Request.Form["__SCROLLPOS_LEFT"]));
	}
	}
	}
	}
	```
	---
	layout: post
	title: 自定义控件实现广告内容后期加载，以及NamingContainer层次的应用
	comments: true
	date: 2007-08-05 13:49
	categories:
	- ASP.NET
	- Asp.net
	- 自定义控件
	- NamingContainer
	---

	<p>自定义控件：广告内容后期加载。以及NamingContainer层次的应用<br />网站上的广告内容可能会因加载过慢而导致整个网页加载过慢<br />我们可以考虑将广告内全部放在网页最底部，等整个页面加载完毕後<br />再采用javascript使其显示，考虑给控件一个TargetContainerID标识<br />控件广告内容将要被显示的容器ID，然后从控件自己所处的开始向上查找该ID<br />所指定的控件，(我们只向上找而没有向下找，并且没有处理某层次的<br />子NamingContainer,所以不一定能够找到，这里没有考虑从Page对象向下递归查找<br />主要考虑为了提高性能),如果没有找到，则考虑给用户一个事件让用户自己处理TargetContainer</p>
	<p>下面的自定义控件对此实现了封装:</p>
	<p><!--more--></p>


	```
	//------------------------------------------------------------------------------
	//
	// Copyright (c) www.AspxBoy.com All rights reserved.
	//
	//------------------------------------------------------------------------------
	namespace HBZ.Ads.Controls
	{
	using System;
	using System.ComponentModel;
	using System.Web;
	using System.Web.UI;
	using System.Web.UI.WebControls;
	using HBZ.Ads;
	using System.Collections.Generic;
	using System.Text;
	[Designer( typeof( HBZ.Ads.Controls.AdRotatorDesigner ) )]
	public class AdRotator : WebControl
	{
	private Dictionary findControlHelperCacheList = new Dictionary( );
	private readonly string scriptFormat = " var {0}_target = document.getElementById(\"{0}\"); var {1}_base = document.getElementById(\"{1}\"); if ({0}_target) {{ {0}_target.innerHTML = {1}_base.innerHTML; {1}_base.innerHTML = \"\"; }}";
	private static readonly object eventObj = new object( );
	public event FindTargetContainerEventHandler FindTargetContainer
	{
	add
	{
	Events.AddHandler( eventObj , value );
	}
	remove
	{
	Events.RemoveHandler( eventObj , value );
	}
	}
	public AdRotator( )
	: base( HtmlTextWriterTag.Span )
	{
	}
	[TypeConverter( typeof( ValidatedControlConverter ) )]
	[DefaultValue( "" ) , Category( "Data" ) , Description( "广告位后期加载后显示的位置的控件ID" )]
	[IDReferenceProperty]
	public string TargetContainerID
	{
	get
	{
	return (string)this.ViewState[ "TargetContainerID" ] ?? string.Empty;
	}
	set
	{
	this.ViewState[ "TargetContainerID" ] = value;
	}
	}
	[Bindable( true ) , Category( "Data" ) , DefaultValue( "" ) , Description( "广告位的默认内容" )]
	public string DefaultContent
	{
	get
	{
	return (string)this.ViewState[ "DefaultContent" ] ?? "广告位招租";
	}
	set
	{
	this.ViewState[ "DefaultContent" ] = value;
	}
	}
	protected override void OnPreRender( EventArgs e )
	{
	base.OnPreRender( e );
	if ( !string.IsNullOrEmpty( TargetContainerID ) )
	{
	this.Style.Add( HtmlTextWriterStyle.Display , "none" );
	ClientScriptManager cs = Page.ClientScript;
	if ( !cs.IsStartupScriptRegistered( this.ClientID ) )
	{
	cs.RegisterStartupScript( this.GetType( ) , this.ClientID , GetLazyLoadingScript( ) , true );
	}
	}
	}
	protected virtual string GetLazyLoadingScript( )
	{
	Control target = FindControlHelper( TargetContainerID );
	if ( target == null )
	{
	throw new TargetContainerNotFoundException( );
	}
	StringBuilder sb = new StringBuilder( );
	sb.AppendFormat( scriptFormat , target.ClientID , this.ClientID );
	return sb.ToString( );
	}
	protected virtual void RenderAdvertisement( Advertisement ad , HtmlTextWriter writer )
	{
	// 广告内容
	}
	protected override void RenderContents( HtmlTextWriter writer )
	{
	// call RenderAdvertisement method
	}
	protected Control FindControlHelper( string id )
	{
	Control c = null;
	if ( findControlHelperCacheList.ContainsKey( id ) )
	{
	c = findControlHelperCacheList[ id ];
	}
	else
	{
	c = base.FindControl( id ); // 注意：我们从自己开始向上沿NamingContainer层次查找
	Control nc = NamingContainer;
	while ( ( null == c ) && ( null != nc ) )
	{
	c = nc.FindControl( id );
	nc = nc.NamingContainer;
	}
	if ( null == c )
	{
	// 因为我们是从自己开始向上沿NamingContainer层次查找，而没有向下找，
	// 并且没有找每一层NamingContainer内的其他NamingContainer,
	// 所以这种查找有可能出现没有找到id对应的控件
	// 当没此时有找到时，激发FindTargetContainer事件交给用户自己设定Target Container Control
	FindTargetContainerEventArgs args = new FindTargetContainerEventArgs( id );
	OnFindTargetContainer( args );
	c = args.Control;
	}
	if ( null != c )
	{
	findControlHelperCacheList[ id ] = c;
	}
	}
	return c;
	}
	protected virtual void OnFindTargetContainer( FindTargetContainerEventArgs e )
	{
	FindTargetContainerEventHandler hander = Events[ eventObj ] as FindTargetContainerEventHandler;
	if ( hander != null )
	{
	hander( this , e );
	}
	}
	}
	public delegate void FindTargetContainerEventHandler( object src , FindTargetContainerEventArgs e );
	public class FindTargetContainerEventArgs : EventArgs
	{
	private string controlID;
	private Control control;
	public FindTargetContainerEventArgs( string controlId )
	{
	controlID = controlId;
	}
	public string ControlID
	{
	get
	{
	return controlID;
	}
	}
	public Control Control
	{
	get
	{
	return control;
	}
	set
	{
	control = value;
	}
	}
	}
	public class TargetContainerNotFoundException : Exception
	{
	string exceptionMessage = string.Empty;
	public TargetContainerNotFoundException( )
	: this( "TargetContainerID所指定的控件没有找到！您或许应该处理一下FindTargetContainer事件" )
	{
	}
	public TargetContainerNotFoundException( string message )
	: base( message )
	{
	this.exceptionMessage = message;
	}
	public override string Message
	{
	get
	{
	if ( exceptionMessage != null )
	{
	return exceptionMessage;
	}
	return base.Message;
	}
	}
	}
	}
	```