Question

I have several Silverlight controls on a page and want query all the controls that are of type TextBox and have that working.

Now the Silverlight form I’m working on could have more TextBox controls added. So when I test to see if a TextBox control has a value, I could do:

if (this.TextBox.Control.value.Text() != String.Empty) {     // do whatever } 

but I’d rather have if flexible that I can use this on ANY Silverlight form regardless of the number of TextBox controls I have.

Any ideas on how I would go about doing that?

Answer 1

It sounds like you need a recursive routine like GetTextBoxes below:

void Page_Loaded(object sender, RoutedEventArgs e) {     // Instantiate a list of TextBoxes     List<TextBox> textBoxList = new List<TextBox>();      // Call GetTextBoxes function, passing in the root element,     // and the empty list of textboxes (LayoutRoot in this example)     GetTextBoxes(this.LayoutRoot, textBoxList);      // Now textBoxList contains a list of all the text boxes on your page.     // Find all the non empty textboxes, and put them into a list.     var nonEmptyTextBoxList = textBoxList.Where(txt => txt.Text != string.Empty).ToList();      // Do something with each non empty textbox.     nonEmptyTextBoxList.ForEach(txt => Debug.WriteLine(txt.Text)); }  private void GetTextBoxes(UIElement uiElement, List<TextBox> textBoxList) {     TextBox textBox = uiElement as TextBox;     if (textBox != null)     {         // If the UIElement is a Textbox, add it to the list.         textBoxList.Add(textBox);     }     else     {         Panel panel = uiElement as Panel;         if (panel != null)         {             // If the UIElement is a panel, then loop through it's children             foreach (UIElement child in panel.Children)             {                 GetTextBoxes(child, textBoxList);             }         }     } } 

Instantiate an empty list of TextBoxes. Call GetTextBoxes, passing in the root control on your page (in my case, that’s this.LayoutRoot), and GetTextBoxes should recursively loop through every UI element that is a descendant of that control, testing to see if it’s either a TextBox (add it to the list), or a panel, that might have descendants of it’s own to recurse through.

Hope that helps. 🙂