FindControl not working on GridView when inserting bound columns

Question

I have a gridview with several ItemTemplates. The first contains a checkbox the rest contain textboxes.

I then added dynamically some bound controls like this:

BoundField bdfPrivName = new BoundField();
clsUtilities.SetBoundFieldCenter(ref bdfPrivName, "PrivName", "Priv Name");

BoundField bdfDescription = new BoundField();
clsUtilities.SetBoundFieldLeft(ref bdfDescription, "PrivDesc", "Description");

BoundField bdfLive = new BoundField();
clsUtilities.SetBoundFieldCenter(ref bdfLive, "Live","Active?");

grdExisting.Columns.Add(bdfPrivName);
grdExisting.Columns.Add(bdfDescription);
grdExisting.Columns.Add(bdfLive);

I then use FindControl() to locate the checkbox and textboxes and perform my logic based the result

foreach (GridViewRow gvr in grdMissing.Rows)
{ 
    mckbAny = (CheckBox)gvr.FindControl("ckbAdd");
    mtxtApplyDate = (TextBox)gvr.FindControl("txtAddApplyDate");
    mtxtDateToAdd = (TextBox)gvr.FindControl("txtAddDateToAdd");
    mtxtDateToRemove = (TextBox)gvr.FindControl("txtAddDateToRemove");
}

etc.

This all worked fine. I then got a request to put the bound fields as the second, third and fourth columns, after the check box and before the textboxes. I found that this was easy to do by changing the Add’s to Inserts as follows:

grdExisting.Columns.Insert(1, bdfPrivName);
grdExisting.Columns.Insert(2, bdfDescription);
grdExisting.Columns.Insert(3, bdfLive);

It looked fine of the page, but the FindControl(), all of them fail to work.

Please suggest a solution or a workaround.

Thanks in advance.

score 1 · Answer 1 · answered Nov 11 '10 at 14:24

1

It sounds like you have come across this bug:

https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=104994&wa=wsignin1.0

It appears ViewState is not stored (or restored) when a BoundField is inserted into a GridView. So when you do FindControl it doesn't exist.

You could try adding them as you did before and finding some way of re-arranging the columns (I think this is possible).

answered Nov 11 '10 at 14:24

Jamie

988
1
11
19

Just came across this one myself, though that link doesn't work anymore - I did find this: http://connect.microsoft.com/VisualStudio/feedback/details/104994/templatefield-in-a-gridview-doesnt-have-its-viewstate-restored-when-boundfields-are-inserted but no indication as to when it's going to be fixed or what other workarounds are available. – Dylan Nicholson Sep 11 '13 at 00:28

score -1 · Answer 2 · answered Nov 08 '10 at 22:47

I am not sure how it was working for you before, as controls don't belong in row - they are inside cells. Anyways, the issue is that FindControl is not recursive, it will not search entire control tree - only immediate children of the control you run it on. You need to implement your own recursive findcontrol, for example like so:

public static Control FindControlRecursive(Control Root, string Id)
{
  if (Root.ID == Id)
    return Root;
  foreach (Control c in Root.Controls)
  {
    Control fc = FindControlRecursive(c, Id);
    if (fc != null)
      return fc;
  }
  return null;
}

FindControl not working on GridView when inserting bound columns

2 Answers2