自定义面板上的WPF DataGrid

Question

I create a custom panel :

public class TowColumnWrapPanel : Panel
{
  //Here have Dependency Properties: RowSpacing, ColumnSpacing, ColumnsCount

    protected override Size ArrangeOverride(Size arrangeSize)
    {
        List<int> shownChildIndexes = new List<int>();
        for (int i = 0; i < VisualChildrenCount; i++)
        {
            if (Children[i].Visibility == System.Windows.Visibility.Visible)
                shownChildIndexes.Add(i);
        }
        if (shownChildIndexes.Count == 1)
        {
           //on my example I use the code below:

            var child = Children[shownChildIndexes[0]];
            var r = new Rect(0, 0, arrangeSize.Width, arrangeSize.Height);
            if (child as FrameworkElement != null)
                (child as FrameworkElement).MaxWidth = arrangeSize.Width; 
            child.Arrange(r);
        }
        else
        {
           //Some functionality here for lot childs!! 
        }
        return base.ArrangeOverride(arrangeSize);
    }
}

Meaning of the above class is that all children will have the same size, and will be stretched on one column / two column (optional to the user)

Everything works well!

Except of course for the DataGrid !!!!

When I have a DataGrid on my custom panel. It looks like this:

Before resize (it's fine):

After Resize: (Somehow adds infinite column)

I don't understand why is happened, a little help would help!

Answer 1

I missed this function: MeasureOverride - can be seen at the link below:

http://www.codeproject.com/Articles/238307/A-Two-Column-Grid-for-WPF

This is what caused the problems in the DG.