没有数据时如何显示错误消息？

Question

I'm Working with Asp .net MVC3,Following is my controller method,

      public ActionResult TravelReadyAdminDownloadInvoke(int intId, int intMonth)
    {
        TravelReadyAdminModel objTravelReadyAdminModel = new TravelReadyAdminModel();
        try
        {
            if (intId == 3)
            {
                objTravelReadyAdminModel = objTravelReadyAdminModel.GetTravelReadyAdminRawExport(intId, intMonth);
                if (objTravelReadyAdminModel.lstRawDataEntities == null)
                {

                }
                else
                {
                    objTravelReadyAdminModel.ExportTravelReadyAdmin("TRAdminRawData", objTravelReadyAdminModel.lstRawDataEntities);
                }
            }
        }
        catch (Exception ex)
        {
            ILogManager LogManager = new LogManager();
            var frame = new StackFrame(0);
            LogManager.CallLogging(frame, ex.Message, ex.StackTrace);
            return RedirectToAction("Error", "Common");
        }
        return View();
    }

what code i need to give inside if condition to show the error message box?

Answer 1

Create an _MessageBox partial like this (I'm using bootstrap alert here):

 if (TempData.ContainsKey("warning"))
 {
     <div class="alert alert-danger">
         <button type="button" class="close" data-dismiss="alert">x</button>
         @TempData["warning"]
     </div>
 }

In your layout folder add this somewhere:

@Html.Partial("_MessageBox")

In your controller add this (I prefer to call it in base controller that I can re-use):

protected void Alert(string message)
{
            // Check to see if it exists already and removes it
    if (TempData.ContainsKey("warning"))
        TempData.Remove("warning");
    TempData.Add("warning", message);

}

Then call it like this in your controller:

catch (Exception ex)
{
    ILogManager LogManager = new LogManager();
    var frame = new StackFrame(0);
    LogManager.CallLogging(frame, ex.Message, ex.StackTrace);
    Alert("Warning message");
}