How to detect when the first column is resized.

[Alex]

I need to know how to detect when the label column of a property grid is resized.

[Yoan]

Hi Alex,

You can try to use ChildrenOfType<>() extension method and find the underlying element. In your case it will be the PropertyGridColumnResizer. Please check the following code snippet for a reference:

var cr = this.propertyGrid.ChildrenOfType<PropertyGridColumnResizer>().FirstOrDefault().ChildrenOfType<Thumb>().FirstOrDefault();

  
cr.DragDelta += new DragDeltaEventHandler(cr_DragDelta);   

 

void cr_DragDelta(object sender, DragDeltaEventArgs e)

{

    

}

Regards,
Yoan
Telerik

[Alex]

.ChildrenOfType<Thumb>() I returning null.

[Yoan]

Hi Alex,

Can you please try to add the above code in RadPropertyGrid's Loaded event:

private void propertyGrid_Loaded(object sender, RoutedEventArgs e)
      {
          var cr = this.propertyGrid.ChildrenOfType<PropertyGridColumnResizer>().FirstOrDefault().ChildrenOfType<Thumb>().FirstOrDefault();
          cr.DragDelta += new DragDeltaEventHandler(cr_DragDelta);
      }

Please let me know about the result.


Regards,
Yoan
Telerik

[Alex]

Still returning null. 

this.pgSpectrums.ChildrenOfType<PropertyGridColumnResizer>().FirstOrDefault().ChildrenOfType<Thumb>().Count()

is returning 

 'this.pgSpectrums.ChildrenOfType<PropertyGridColumnResizer>().FirstOrDefault().ChildrenOfType<Thumb>().Count()' threw an exception of type 'System.ArgumentNullException' int {System.ArgumentNullException}

[Alex]

actually

this.pgSpectrums.ChildrenOfType<PropertyGridColumnResizer>().Count() is 0 so that's the problem.

[Yoan]

Hi Alex,

I've tried to reproduce the problem you report, but to no avail. I have attached my test project for a reference.

Regards,
Yoan
Telerik

[Alex]

I'm using version 2013.1.403.40 your using 2013.2.611.40, could that be the problem?

[Yoan]

Hello Alex,

Indeed, you are right about that. May I ask you to test your project with our latest binaries?

Regards,
Yoan
Telerik

[Alex]

I don't have access to that apparently.  I can only download the one I have.

[Yoan]

Hi Alex,

Actually, you can download our latest binaries from your account :

Products & Subscriptions -> Trial downloads -> RadControls for WPF -> Download -> download a file.

I hope this helps.

Regards,
Yoan
Telerik

[Alex]

I still get the same error.

[Alex]

Figured out the problem, it was calling the load even if it is not shown (which it wasn't').  Fixed that.  Still doesn't do what I want.  Even your example didn't call the function when I changed the width of the label column.

[Alex]

This code isn't working either.  I thought maybe I wasn't using the correct thumb and it's not working

foreach (PropertyGridColumnResizer clsProperty in this.pgSpectrums.ChildrenOfType<PropertyGridColumnResizer>())
                {
                    foreach (Thumb clsThumb in clsProperty.ChildrenOfType<Thumb>())
                    {
                        clsThumb.DragDelta += new DragDeltaEventHandler(cr_DragDelta);
                    }
                }

[Yoan]

Hi Alex,

You can try to subscribe to RadPropertyGrid's FieldLoaded event like so:

private void propertyGrid_FieldLoaded(object sender, FieldEventArgs e)
        {
            Dispatcher.BeginInvoke((Action)(() =>
            {
                var cr = e.Field.ChildrenOfType<PropertyGridColumnResizer>().FirstOrDefault().ChildrenOfType<Thumb>().FirstOrDefault();

         cr.DragDelta += new DragDeltaEventHandler(cr_DragDelta);

            }));
        }

        void cr_DragDelta(object sender, DragDeltaEventArgs e)
        {

        }

Please let me know how it goes.


Regards,
Yoan
Telerik