“global_asax”在命名空间“ASP”中不明确?

在工程里加入Global.asax,内容如下：
<%@ Application Language="C#" inherits="App_Code.Global, App_Code"%>

具体的实现在 App_Code.Global里面，编译时提示“global_asax”在命名空间“ASP”中不明确?

双击错误提示，进入到出错位置为C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\sls\16185ac4\39e821d7\App_Web_5hcoczk_.3.vb(72,0)

       Protected ReadOnly Property ApplicationInstance() As ASP.global_asax
            Get
                Return CType(Me.Context.ApplicationInstance,ASP.global_asax)
            End Get
        End Property

清除Temporary ASP.NET Files后，问题依旧，高手帮忙解决啊 --------------------编程问答-------------------- global_asax 的名称空间默认是你的web程序集的名称空间，即网站程序集名称；
换一下网站程序集名称；
看一下是否定义了多个global_asax --------------------编程问答-------------------- <%@ Application Language="C#" %>
检查是否存在冲突 --------------------编程问答-------------------- Global_Asax定义如下：

namespace ASP
{
    using System;
    using System.Diagnostics;
    using System.Runtime.CompilerServices;
    using System.Web.Profile;

    [CompilerGlobalScope]
    public class Global_Asax : App_Code.Global
    {
        private static bool __initialized;

        [DebuggerNonUserCode]
        public Global_Asax()
        {
            if (!__initialized)
            {
                __initialized = true;
            }
        }

        protected DefaultProfile Profile
        {
            get
            {
                return (DefaultProfile) base.Context.Profile;
            }
        }
    }
}

--------------------编程问答-------------------- 确认类名没有冲突 --------------------编程问答-------------------- 查找全部 "class Global_Asax", 大小写匹配, 子文件夹, 查找结果 1, "整个解决方案"
  D:\CP\App_global.asax\ASP\Global_Asax.cs(9):    public class Global_Asax : App_Code.Global
  匹配行: 1    匹配文件: 1    合计搜索文件: 2243

--------------------编程问答-------------------- using System;
using System.ComponentModel;
using System.Web;

namespace App_Code
{
    public class Global : HttpApplication
    {
        private IContainer components;
        private Task task;

        public Global()
        {
            this.InitializeComponent();
        }

        protected void Application_AuthenticateRequest(object sender, EventArgs e)
        {
        }

        protected void Application_BeginRequest(object sender, EventArgs e)
        {
        }

        protected void Application_End(object sender, EventArgs e)
        {
            if (this.task != null)
            {
                this.task.Exit();
            }
        }

        protected void Application_EndRequest(object sender, EventArgs e)
        {
        }

        protected void Application_Error(object sender, EventArgs e)
        {
            Exception baseException = base.Server.GetLastError().GetBaseException();
            if (baseException == null)
            {
                base.Server.ClearError();
            }
            else
            {
                string str = "空";
                try
                {
                    str = HttpContext.Current.Request.Url.ToString();
                }
                catch
                {
                }
                string text = "Error, PageName: " + str + "。 ErrorMsg: " + baseException.Message + " Source:" + baseException.Source + "。";
                PublicFunction.WriteException(null, text);
            }
        }

        protected void Application_Start(object sender, EventArgs e)
        {
            this.task = new Task();
            this.task.Run();
        }

        private void InitializeComponent()
        {
            this.components = new Container();
        }

        protected void Session_End(object sender, EventArgs e)
        {
        }

        protected void Session_Start(object sender, EventArgs e)
        {
        }
    }

} --------------------编程问答-------------------- Global 实现如上,设置了断点，也无法调试，运行不到。
找了相关资料，该清理都清理了，也重新生成、发布网站，就是无法执行到。

补充：.NET技术 ,  ASP.NET