revit 二次开发创建按钮后无法加载

按照教程编写了代码但是加载后 ADDINS里并没有这个 按钮怎么办
namespace JCW
{
[Autodesk.Revit.Attributes.Transaction(Autodesk.Revit.Attributes.TransactionMode.Manual)]
/*public class Class1:IExternalCommand

 {

    public Autodesk.Revit.UI.Result Execute(ExternalCommandData revit, ref string message, ElementSet elements)
     {
         TaskDialog.Show("Revit", "jiechuwanggongcheng");
         return Autodesk.Revit.UI.Result.Succeeded;
     }

 }*/
public class CsAddpanel : IExternalApplication
{

    public Result OnStartup(UIControlledApplication application)
    {
        RibbonPanel ribbonPanel = application.CreateRibbonPanel("ADN class");
        PushButtonData pushButton = new PushButtonData("JCW", "JCW", @"d:\documents\visual studio 2013\Projects\JCW\JCW\bin\Debug\JCW.dll", "JWC.Class1");
        PushButton button = ribbonPanel.AddItem(pushButton) as PushButton;
        return Result.Succeeded;
    }
    public Result OnShutdown(UIControlledApplication application)
    {
        return Result.Succeeded;
    }

}

}

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