Getting Null Reference error when trying to set a picture in Telerik Gridview

Question

I'm trying to display pictures in a telerik gridview using the following bit of code:

  foreach (var item in radGridView1.Rows)
        {
            try
            {
                item.Cells["column1"].CellElement.Text = "";
                item.Cells["column1"].CellElement.StretchVertically = true;
                item.Cells["column1"].CellElement.ImageLayout = ImageLayout.Zoom;
                item.Cells["column1"].CellElement.ImageAlignment = ContentAlignment.MiddleCenter;
                item.Cells["column1"].CellElement.Image = Image.FromFile("img/1.jpg");
                pictureBox1.Image = Image.FromFile(item.Cells["Picture"].Value.ToString());
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

But whenever i try to run the application , i get an error message complaining that the

Object reference not set to an instance of an object

What could be possibly wrong with it?!

Answer 1

Sounds like you're dereferencing a null object (eg null.SomeProperty ).

You should put a breakpoint on the line you're getting the error, and see which null object you're dereferencing.

Answer 2

Due to Telerik Virtualization in the controls such as RadGridView CellElements and RowElements can be null.So in order to format certain cells eg in a Telerik RadGridView control we need to use the "CellFormatting" event such as below:

 private void radGridView1_CellFormatting(object sender, CellFormattingEventArgs e)
        {
            try
            {
                if (e.CellElement.ColumnInfo.HeaderText == "Picture") 
                {
                    e.CellElement.Image = pictureBox1.Image;
                }

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }

The same approach is valid for formatting certain rows using RowFormatting event of course.