FindControl method get nothing in Gridview with Master Page

Michael YoeH · August 27th, 2009, 06:17 AM

Hi,everybody,
I just encountered a hard problem.First,I create a master page,and add some controls in the master page.Then I created another aspx page using the master page created before.
So,I add a gridview in this aspx page in the ContentPlaceHolder,like before,I did some basic actions,add,update,select etc.The problem is when I edit a row in the gridview,then update it,the cell's content became noting in it.
I try to set the breakpoint in the GridView1_RowUpdating event,and the I followed the sentence,but I got nothing in the cell,code following:

Code:

 using (NorthwindEntities ctx = new NorthwindEntities())
        {
            var categoryid = (int)this.GridView1.DataKeys[e.RowIndex].Value;
            var category = ctx.Categories.First(p => p.CategoryID == categoryid);
            DropDownList ddlUpdateCategory = this.GridView1.Rows[e.RowIndex].Cells[2].FindControl("ddlUpdateCategory") as DropDownList;
            if (ddlUpdateCategory.SelectedItem.Text.Trim() != category.CategoryName)
            {
                Page.ClientScript.RegisterStartupScript(this.GetType(), "MyScript", "alert('Already Exists!');", true);
                return;
            }
            category.CategoryName = ddlUpdateCategory.SelectedItem.Text.Trim();
            category.Description = ((TextBox)this.GridView1.Rows[e.RowIndex].FindControl("txtDes")).Text.Trim();
            ctx.SaveChanges();
        }
        GridView1.EditIndex = -1;
        BindGridView();

What an odd thing! You konw, when I did the same thing in another newly-created aspx page without master page, it worked fine.

I just wonder if it had something with the master page.If I use the master page, the findcontrol() method just conuln't find the textbox control in the EditItemTemplate.

Who can help me? The problem has been bothering me for a couple of hours.
Thanks in advance!

Lee Dumond · August 27th, 2009, 09:17 AM

Code:

category.Description = ((TextBox)this.GridView1.Rows[e.RowIndex].FindControl("txtDes")).Text.Trim();

It looks to me, with the code above, you are looking for the TexBox in the row, which won't work. You first need to locate the appropriate cell in the row, then look for the TextBox in the cell.

Michael YoeH · August 27th, 2009, 08:31 PM

I indeed find the right row and right cell

Code:

TextBox txtDescription = this.GridView1.Rows[e.RowIndex].Cells[3].FindControl("txtDes") as TextBox;

it works fine in the aspx without using masterpage,but it didn't work in the aspx page with masterpage.

Lee Dumond · August 27th, 2009, 09:08 PM

Quote:

Originally Posted by Michael YoeH

I indeed find the right row and right cell

Code:

TextBox txtDescription = this.GridView1.Rows[e.RowIndex].Cells[3].FindControl("txtDes") as TextBox;

it works fine in the aspx without using masterpage,but it didn't work in the aspx page with masterpage.

This is NOT the code you pasted in your original post. Go back and check.

Michael YoeH · August 28th, 2009, 03:42 AM

I know,but both the two segment code didn't work well.
Thanks for your reply