BTW。 UserControl不使用Visual Studio Designer呈现，但是当您运行应用程序时，该控件可以正常工作。如果您使用“服务器控件”，则在Visual Studio设计器中正确显示该控件时，这是不同的

以下代码非常适用于构建模板化用户控件和模板化服务器控件，但如果要添加绑定功能，则过程略有不同，take a look

Download Source Code

这是创建一个模板的UserControl的代码。

简单输出

模板容器

public class MyTemplateContainer : Control,INamingContainer { }

ASPX代码背后

protected void Page_Load(object sender,EventArgs e)
{
    // just to demonstrate using the contorl
    this.WebUserControl1.Controls.Add(new LiteralControl("<br />new control"));
}

ASPX

<%@ Register src="WebUserControl.ascx" tagname="WebUserControl" tagprefix="uc1" %>

    <uc1:WebUserControl ID="WebUserControl1" runat="server">
        <ContentTemplate>
            My Template<br />
            <asp:Label Text='Hello People' runat="server" ID="lblMessage" />
        </ContentTemplate>
    </uc1:WebUserControl>

ASCX代码落后

public partial class WebUserControl : System.Web.UI.UserControl
{
    [TemplateContainer(typeof(MyTemplateContainer))]
    [TemplateInstance(TemplateInstance.Single)]
    [PersistenceMode(PersistenceMode.InnerProperty)]
    [Browsable(true)]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
    public ITemplate ContentTemplate { get; set; }

    protected void Page_Init(object sender,EventArgs e)
    {
        this.myPlaceHolderTag.Controls.Clear();

        if (this.ContentTemplate != null)
        {
            var container = new MyTemplateContainer();

            this.ContentTemplate.InstantiateIn(container);
            this.myPlaceHolderTag.Controls.Add(container);
        }
        else
        {
            this.myPlaceHolderTag.Controls.Add(new LiteralControl("No template defined"));
        }
    }
}

ASCX

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="WebUserControl.ascx.cs" Inherits="WebUserControl" %>

<asp:PlaceHolder runat="server" ID="myPlaceHolderTag" />

添加模板服务器控件的代码

产量

ASPX

<%@ Register Namespace="MyControls" TagPrefix="my" %>

<my:MyServerControl runat="server" ID="myServerControl">
    <ContentTemplate>
        My Server templated control<br />
        <asp:Label Text="My Label" runat="server" />
    </ContentTemplate>
</my:MyServerControl>

模板容器

namespace MyControls
{
    [ToolBoxItem(false)]
    public class MyTemplateContainer : Control,INamingContainer { } 
}

模板服务器控制

namespace MyControls
{
    [ToolBoxData("<{0}:MyServerControl runat=server >")]
    [ToolBoxItem(true)]
    [ParseChildren(true)]
    // you can inherit from another control if you like,for example from the CompositeControl
    public class MyServerControl : Control,INamingContainer
    {
        [TemplateInstance(TemplateInstance.Multiple)]
        [TemplateContainer(typeof(MyTemplateContainer))]
        [PersistenceMode(PersistenceMode.InnerProperty)]
        [Browsable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        [DefaultValue(null)]
        public ITemplate ContentTemplate { get; set; }

        protected override void CreateChildControls()
        {
            var p = new Panel { ID = "myPanel",BackColor = Color.Silver,Width = new Unit("100%") };

            if (this.ContentTemplate == null)
            {
                p.Controls.Add(new LiteralControl("No content has been specified"));
            }
            else
            {
                var c = new MyTemplateContainer();

                this.ContentTemplate.InstantiateIn(c);
                p.Controls.Add(c);
            }

            this.Controls.Clear();
            this.Controls.Add(p);
        }

        public override void DataBind()
        {
            this.CreateChildControls();
            this.ChildControlsCreated = true;
            base.DataBind();
        }

        public override ControlCollection Controls
        {
            get
            {
                this.EnsureChildControls();
                return base.Controls;
            }
        }
    }
}

参考文献：

> How to: Create Templated ASP.NET User Controls
> Building Templated Custom ASP.NET Server Controls
> Building DataBound Templated Custom ASP.NET Server Controls