ASP.NET 控件开发教程(一)

找到Button 控件, 然后继续展开Button,

我这里和大家讲讲分别是什么意思就好了 其他的大家自己去看了 不过不理解的 我们可以一起讨论,还可以为你解释一下,那些控件我基本通看了一下 嘿嘿

Base Types 是他的基本类型,Derived Types 是他的派生类,红色的那些图标是她的 方法,带有手的图标是 属性,闪电的图标是 事件 ,.ctor() 就是构造函数 cctor 就是静态构造函数,EventClick ,和 EventCommand 是类成员 .好了 基本就这样了 大家有什么不明白的可以在这里提问,我也会及时回答的.其实 Button 控件包含的意义很深,看明白了 对以后的控件开发有很大的帮助

比如他的
Code
protected override void AddAttributesToRender(HtmlTextWriter writer)
{
bool useSubmitBehavior = this.UseSubmitBehavior;
if (this.Page != null)
{
this.Page.VerifyRenderingInServerForm(this);
}
if (useSubmitBehavior)
{
writer.AddAttribute(HtmlTextWriterAttribute.Type, “submit”);
}
else
{
writer.AddAttribute(HtmlTextWriterAttribute.Type, “button”);
}
PostBackOptions postBackOptions = this.GetPostBackOptions();
string uniqueID = this.UniqueID;
if ((uniqueID != null) && ((postBackOptions == null) || (postBackOptions.TargetControl == this)))
{
writer.AddAttribute(HtmlTextWriterAttribute.Name, uniqueID);
}
writer.AddAttribute(HtmlTextWriterAttribute.Value, this.Text);
bool isEnabled = base.IsEnabled;
string firstScript = string.Empty;
if (isEnabled)
{
firstScript = Util.EnsureEndWithSemiColon(this.OnClientClick);
if (base.HasAttributes)
{
string str3 = base.Attributes["onclick"];
if (str3 != null)
{
firstScript = firstScript + Util.EnsureEndWithSemiColon(str3);
base.Attributes.Remove(“onclick“);
}
}
if (this.Page != null)
{
string postBackEventReference = this.Page.ClientScript.GetPostBackEventReference(postBackOptions, false);
if (postBackEventReference != null)
{
firstScript = Util.MergeScript(firstScript, postBackEventReference);
}
}
}
if (this.Page != null)
{
this.Page.ClientScript.RegisterForEventValidation(postBackOptions);
}
if (firstScript.Length > 0)
{
writer.AddAttribute(HtmlTextWriterAttribute.onclick, firstScript);
if (base.EnableLegacyRendering)
{
writer.AddAttribute(“language”, “javascript”, false);
}
}
if (this.Enabled && !isEnabled)
{
writer.AddAttribute(HtmlTextWriterAttribute.Disabled, “disabled”);
}
base.AddAttributesToRender(writer);
}

AddAttributesToRender这个方法 就很好的展示给大家 ASP.NET 只如何处理INPUT 各种属性的呢.
下面分享我开发工程中的一个控件
这个控件是支持Url 分页的
当然 原理 是利用IList 的索引 取不同”页”的数据 对于偷懒和后台管理很方便,至于前台的分页我想你更喜欢用存储过程 的ROW_NUMBER() 和 IDENTITY 方案来分页吧

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Text.RegularExpressions;
using System.Collections;

namespace YSMV.XWShop1B2C.Control
{
[DefaultProperty("Text")]
[ToolboxData("<{0}:YsmvRepeater runat=\\"server\\" AllowPage=\\"true\\" PageSize=\\"10\\" ShowPage=\\"true\\"></{0}:YsmvRepeater>")]
public class YsmvRepeater : Repeater
{

//Static param
private static readonly Regex RX;
private static readonly object EventPageChanged;

static YsmvRepeater()
{
RX = new Regex(@”^&page=\\d+”, RegexOptions.Compiled);
EventPageChanged = new object();
}

//Static constants
protected const string HTML1 = “<table cellpadding=0 cellspacing=0 class=’inputTable’><tr><td colspan=2>”;
protected const string HTML2 = “</td></tr><tr><td class=paging align=left>”;
protected const string HTML3 = “</td><td align=right class=paging>”;
protected const string HTML4 = “</td></tr></table>”;
private const string LINK_PREV = “<a href=?page={0}><&nbsp;Previous</a>”;
private const string LINK_MORE = “<a href=?page={0}>More&nbsp;></a>”;
private const string KEY_PAGE = “page”;
private const string COMMA = “?”;
private const string AMP = “&”;

protected string emptyText;
private IList dataSource;
private int pageSize = 10;
private int currentPageIndex;
private int itemCount;
private bool allowPage = false;
private bool showPage = true;

[Browsable(true)
, Category("Appearance"),
DefaultValue(true),
Description("是否显示翻页链接")
]
public bool ShowPage
{
get { return showPage; }
set { showPage = value; }
}
[Browsable(true),
Category("Appearance"),
DefaultValue(true),
Description("是否允许分页")]
public bool AllowPage
{
get { return allowPage; }
set { allowPage = value; }
}
[Browsable(true),
Category("Appearance"),
DefaultValue(10),
Description("每页显示的数量")
]
public int PageSize
{
get { return pageSize; }
set { pageSize = value; }
}
[Browsable(true),
Category("Appearance"),
DefaultValue(""),
Description("无记录时候显示的内容")]
public string EmptyText
{
set { emptyText = value; }
}
override public object DataSource
{
set
{
//This try catch block is to avoid issues with the VS.NET designer
//The designer will try and bind a datasource which does not derive from ILIST
try
{
dataSource = (IList)value;
ItemCount = dataSource.Count;
}
catch
{
dataSource = null;
ItemCount = 0;
}
}
}
protected int PageCount
{
get { return (ItemCount – 1) / pageSize; }
}

virtual public int ItemCount
{
get { return itemCount; }
set
{itemCount = value;}
}

virtual public int CurrentPageIndex
{
get { return currentPageIndex; }
set { currentPageIndex = value; }
}

public void SetPage(int index)
{
//OnPageIndexChanged(new DataGridPageChangedEventArgs(null, index));
OnPageIndexChanged(new GridViewPageEventArgs(index));
}

override protected void OnLoad(EventArgs e)
{
if (Visible)
{
string page = Context.Request[KEY_PAGE];
int index = (page != null) ? int.Parse(page) : 0;
SetPage(index);
}
}

/// <summary>
/// Overriden method to control how the page is rendered
/// </summary>
/// <param name=”writer”></param>
override protected void Render(HtmlTextWriter writer)
{

//Check there is some data attached
string page = Context.Request[KEY_PAGE];
int index = (page != null) ? int.Parse(page) : 0;
if (ItemCount == 0)
{
writer.Write(emptyText);
return;
}
//Mask the query
string query = Context.Request.Url.Query.Replace(COMMA, AMP);
query = RX.Replace(query, string.Empty);

// Write out the first part of the control, the table header
writer.Write(HTML1);

// Call the inherited method
base.Render(writer);

// Write out a table row closure
writer.Write(HTML2);

//Determin whether next and previous buttons are required
//Previous button?
if (currentPageIndex > 0)
{
if (ShowPage)
writer.Write(string.Format(LINK_PREV, (currentPageIndex – 1) + query));
}

//Close the table data tag
writer.Write(HTML3);

//Next button?
if (currentPageIndex < PageCount)
{
if (ShowPage)
writer.Write(string.Format(LINK_MORE, (currentPageIndex + 1) + query));
}

//Close the table
writer.Write(HTML4);
}

override protected void OnDataBinding(EventArgs e)
{
if (!allowPage)
{
base.DataSource = dataSource;
base.OnDataBinding(e);
return;
}
//Work out which items we want to render to the page
int start = CurrentPageIndex * pageSize;
int size = Math.Min(pageSize, ItemCount – start);

IList page = new ArrayList();

//Add the relevant items from the datasource
for (int i = 0; i < size; i++)
page.Add(dataSource[start + i]);

//set the base objects datasource
base.DataSource = page;
base.OnDataBinding(e);

}

//public event DataGridPageChangedEventHandler PageIndexChanged;
public event GridViewPageEventHandler PageIndexChanged
{
add
{
Events.AddHandler(EventPageChanged, value);
}
remove
{
Events.RemoveHandler(EventPageChanged, value);
}
}
virtual protected void OnPageIndexChanged(GridViewPageEventArgs e)
{
GridViewPageEventHandler pagehandler = (GridViewPageEventHandler)Events[EventPageChanged];
if (pagehandler != null)
pagehandler(this, e);
}
}
}
代码已经加了注释,细心的朋友 可能发现和 PETSHOP 中的控件很相似 ,对,我是用那个修改的,我优化了他的事件private static readonly object EventPageChanged; 呵呵 ,好的 大家期待我的下个作品吧.