Access cell in DataGrid

drasko · December 18th, 2003, 04:09 AM

Hi all,

In my DataGrid1 I want to read one cell (data type int from database) and put it's value in the TextBox1 control.

    private void DataGrid1_UpdateCommand(object source,
           System.Web.UI.WebControls.DataGridCommandEventArgs e)
    {....
     TextBox1.Text = (Convert.ToInt64((e.Item.Cells[1].Controls[0]))).ToString();
     ....
    }

I got run time error mesage : "Specified cast is not valid."

Can anyone tell me how to do this casting?

Thanks,
Nenad

planoie · December 18th, 2003, 10:14 AM

e.Item.Cells[1].Controls[0] will return you the first control in cell 1. Usually you need to convert that to something explicitly so you can access a property value for that control:

TextBox1.Text = CType(e.Item.Cells[1].Controls[0], TextBox).Text;

However, if you are attempting to just get the value that's in the cell, you can just access the "Text" property of that cell:

e.Item.Cells[1].Text

The method you show here looks like the update handler for the grid so I would believe that you need the first suggestion unless the cell in question is in a readonly column.

When dealing with data grids, you must remember that after the data has been dumped to the grid, all the datatypes are as good as gone. Everything is a string in the grid. So you will always have to convert from a string back into the datatype you want.

Peter
------------------------------------------------------
Work smarter, not harder.

drasko · December 19th, 2003, 09:12 AM

Yes you are right I need the first example, I tried with this:

Code:

TextBox1.Text  = ((TextBox)(e.Item.Cells[4].Controls[0])).Text;

but I still get the same error: Specified cast is not valid ???
Second example works with readonly cols like you said.

I have to solve this urgent

Thanks for your advice

planoie · December 19th, 2003, 10:30 AM

Are you sure you have the right cell index? That index should match based on the columns in the "columns" area of the markup. Do you have any non-visible columns? You must count all columns.

Paste your datagrid markup if you are still having a problem.

Peter
------------------------------------------------------
Work smarter, not harder.

drasko · December 22nd, 2003, 04:45 AM

Finally solution:

Code:

  TextBox1.Text  = ((TextBox)(e.Item.Cells[1].FindControl("txtBox1"))).Text;

because Cells[1] belongs TemplateColumn, and
markup:

Code:

 <EditItemTemplate>
   <asp:TextBox ID="txtBox1" BackColor=#ffcccc Width=50 runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.Kolicina") %>'>
   </asp:TextBox>
</EditItemTemplate>

Thank you Peter you really helped me,

Nenad