把某个asp.net 控件替换成自定义控件的方法

<pages>
<tagMapping>
<add
tagType=
"System.Web.UI.WebControls.WebParts.WebPartManager"
mappedTagType=
"Microsoft.Sharepoint.WebPartPartManager,
MSPS.Web.dll, Version='2.0.0.0'"
/>
</tagMapping>
</pages>

<form id="form1" runat="server">
<div>
<asp:Label ID="lb1" runat="server" Text="lb"></asp:Label>
</div>
</form>

<form name="form1" method="post" action="Default.aspx" id="form1">
<div>
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="/wEPDwULLTE1ODYxMzExNjlkZIRGtA8oGwNrNQd7V9ZkX3zxcLan" />
</div>

<div>
<span id="lb1">lb</span>
</div>
</form>

<tagMapping>
<add tagType="System.Web.UI.WebControls.Label" mappedTagType="CJQ.Web.MyLabel" />
</tagMapping>

namespace CJQ.Web
{
public class MyLabel : System.Web.UI.WebControls.Label
{
protected override void RenderContents(System.Web.UI.HtmlTextWriter writer)
{
writer.Write("接收：");
base.RenderContents(writer);
}

}
}

<form name="form1" method="post" action="Default.aspx" id="form1">
<div>
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="/wEPDwULLTE1ODYxMzExNjlkZIRGtA8oGwNrNQd7V9ZkX3zxcLan" />
</div>

<div>
<span id="lb1">接收：lb</span>
</div>
</form>