Find a image in code behind

Question

I would like to use the find control method to find a image on the designer and make it visible, but i keep getting a null

This is my Code:

foreach (ImageShow image in imageList)
{
    Image Showimage = (Image)FindControl(image.imageName);
    Showimage.Visible = true;
}

Any help would be much appreciated, Thanks in advance

Can you please add some more code? Maybe both your markup and whole code behind? — Lars Holdgaard, Oct 24 '12 at 12:23
common problem is a fact that FindControl searches only child controls, not their childs — Antonio Bakula, Oct 24 '12 at 12:26
image.imageName is the string value i use to determine what the image id/name is. I get it from a list of string values and then do a foreach to make them all visible — Jacob O'Brien, Oct 24 '12 at 12:27
Your example will work if : Image have ID with imagename and runat="server", and parent must be form or control in witch you are using this code — Antonio Bakula, Oct 24 '12 at 12:38

Antonio Bakula · Accepted Answer · 2012-10-24T13:11:17.283

FindControl does not search throughout a hierarchy of controls, I presume that this is a problem.

try using the following method :

public static T FindControlRecursive<T>(Control holder, string controlID) where T : Control
{
  Control foundControl = null;
  foreach (Control ctrl in holder.Controls)
  {
    if (ctrl.GetType().Equals(typeof(T)) &&
      (string.IsNullOrEmpty(controlID) || (!string.IsNullOrEmpty(controlID) && ctrl.ID.Equals(controlID))))
    {
      foundControl = ctrl;
    }
    else if (ctrl.Controls.Count > 0)
    {
      foundControl = FindControlRecursive<T>(ctrl, controlID);
    }
    if (foundControl != null)
      break;
  }
  return (T)foundControl;
}

Usage:

Image Showimage = FindControlRecursive<Image>(parent, image.imageName);

In your case parent is this, example :

Image Showimage = FindControlRecursive<Image>(this, image.imageName);

You can use it without ID, then will find first occurrence of T :

Image Showimage = FindControlRecursive<Image>(this, string.Empty);

i get an error: Error 5 The non-generic method 'System.Web.UI.Page.FindControl(string)' cannot be used with type arguments — Jacob O'Brien, Oct 24 '12 at 12:52

score 1 · Answer 2 · answered Oct 24 '12 at 12:34

1

foreach (ImageShow image in imageList)
{
    Image showimage = FindControl(image.imageName) as Image;
    if(showimage != null)
    {
         showimage .Visible = true;
    }
}

answered Oct 24 '12 at 12:34

burning_LEGION

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Find a image in code behind

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