将数据动态添加到网格视图内的ASP文字控件中

Question

I'm trying to add data to a literal which place inside a gridview. Currently code look like this

protected void GvListingRowDataBound(object sender, GridViewRowEventArgs e)
{
       var query = DisplayAllData();
       Literal info = (Literal)e.Row.FindControl("ltritemInfo");

       if(query != null)
       {
           foreach (var listing in query)
           {
               var list = DisplayListById(listing.id);
               info.Text = "<h3>" + list.title + "</h3>";
               info.Text += "<h4>" + list.description + "</h4>";
           }
       }
}

This will generate an error

Object reference not set to an instance of an object.

If anyone has an idea about this it will be great help

Thanks

Answer 1

Ensure you're only operating on the data rows, and not the header, footer, separator, pager, etc. The enum for this is DataControlRowtype . This is why your info object/reference is null, as it operates on the header first.

• Check that the e.Row.RowType is of type DataRow .
• For safety, also check that your info is not null.

protected void GvListingRowDataBound(object sender, GridViewRowEventArgs e)
{
    if(e.Row.RowType == DataControlRowType.DataRow)
    {        
       var query = DisplayAllData();
       Literal info = (Literal)e.Row.FindControl("ltritemInfo");

       if(query != null && info !=null) 
       {
           foreach (var listing in query)
           {
                var list = DisplayListById(listing.id);
                info.Text = string.Format("<h3>{0}</h3><h4>{1}</h4>",
                               list.title, list.description);    
           }
       }
   }
}