(较难)模拟树的用法

<ext:DropDownList Label="指定类别" AutoPostBack="true" Required="true" EnableSimulateTree="true" ShowRedStar="true" runat="server" ID="ddlBox"

OnSelectedIndexChanged="ddlBox_SelectedChange" >
</ext:DropDownList>

try
{
　　DataTable dt = Govaze.SQLServerDAL.Factory.getDataXmlDAL().ProcDataTable("<root><Type>simulate_tree2</Type><AID>" + TreeID.Text + "</AID></root>", "DataXmlProject");

　　ddlBox.DataTextField = "Name";
　　ddlBox.DataValueField = "Id";
　　ddlBox.DataSimulateTreeLevelField = "Level";
　　ddlBox.DataEnableSelectField = "EnableSelect";
　　ddlBox.EnableSimulateTree = dt.Rows.Count <= 1 ? false : true;
　　ddlBox.DataSource = dt;
　　ddlBox.DataBind();

}
catch { }

 ddlBox.SelectedValue = TreeID.Text;

数据库中的写法

ELSE IF @Type='simulate_tree2'
BEGIN

SELECT @AID=@Text1.value('(root/AID)[1]', 'Int');

SELECT @HID=HID FROM dbo.ProjectSub WHERE AID=@AID
-- SELECT @HID=@HID.GetAncestor(@HID.GetLevel()-3).ToString()
--【参数】[ProjectSub 中 HID 的级别] {@TreeID=> dbo.ProjectSub.AID => dbo.ProjectSub.HID => @HID.GetAncestor(@HID.GetLevel()-3).ToString() }

SELECT AID AS Id
,ObjectName AS Name
--,(CASE HLevel WHEN 3 THEN HID.ToString() ELSE HID.GetAncestor(1).ToString() END ) AS Level
,HLevel-4 AS Level
, 'True' AS EnableSelect

FROM dbo.ProjectSub WHERE HID.IsDescendantOf(@HID)=1
ORDER BY HID
END