My TextChanged event on a dynamically created textbox in a custom BoundField never fires?

Question

I'm trying to make a custom BoundField (Column) for my custom GridView. I added textboxes to the FooterRow to manage filtering on columns. It displays well, but the TextChanged event is never raised. I guess it is because the textboxes are recreated on each postback, and not persisted.

Here is my code:

public class Column : BoundField
{
    public override void InitializeCell(DataControlFieldCell cell, DataControlCellType cellType, DataControlRowState rowState, int rowIndex)
    {
        base.InitializeCell(cell, cellType, rowState, rowIndex);
        if (cellType == DataControlCellType.Footer)
        {
            TextBox txtFilter = new TextBox();
            txtFilter.ID = Guid.NewGuid().ToString();
            txtFilter.Text = "";
            txtFilter.AutoPostBack = true;
            txtFilter.TextChanged += new EventHandler(txtFilter_TextChanged);
            cell.Controls.Add(txtFilter);
        }
    }

    protected void txtFilter_TextChanged(object sender, EventArgs e)
    {
        // Never get here
    }
}

I tried with a checkbox, and it worked.

you must not change Id property of any control,so that it was not working. It should not be changed in coding — Mudassir, Apr 18 '13 at 13:23

score 1 · Answer 1 · answered Oct 03 '14 at 17:39

I had same problem in a WPF app. It was simply work for me like this way,

 TextBox txtBx = new TextBox();
 txtBx.Width = 300;
 txtBx.TextChanged += txtBox_TextChanged;

And It calls,

private void txtBox_TextChanged(object sender, EventArgs e)
    {
        errorTxt.Text = "Its working";
    }

"errorTxt" is a pre defined TextBlock. Hope this will help some one..

score 0 · Answer 2 · answered Apr 18 '13 at 13:15

Solution:

I finally found the problem, but I don't understand it ! The problem was the ID property, generated with a Guid. Just removing it solved my problem.

public class Column : BoundField
{
    public override void InitializeCell(DataControlFieldCell cell, DataControlCellType cellType, DataControlRowState rowState, int rowIndex)
    {
        base.InitializeCell(cell, cellType, rowState, rowIndex);
        if (cellType == DataControlCellType.Footer)
        {
            TextBox txtFilter = new TextBox();
            // Removing this worked
            //txtFilter.ID = Guid.NewGuid().ToString(); 
            txtFilter.Text = "";
            txtFilter.AutoPostBack = true;
            txtFilter.TextChanged += new EventHandler(txtFilter_TextChanged);
            cell.Controls.Add(txtFilter);
        }
    }

    protected void txtFilter_TextChanged(object sender, EventArgs e)
    {
        // Never get here
    }
}

My TextChanged event on a dynamically created textbox in a custom BoundField never fires?

2 Answers2