MeasureOverride方法未设置Panel的期望大小

    protected override Size MeasureOverride(Size availableSize)
    {
        Size panelDesiredSize = new Size();
        if ((this.widthWrap) || (this.heightWrap))
        {
            foreach (UIElement elemento in this.Children)
            {
                System.Diagnostics.Debug.WriteLine(\"Measure\" + ((FrameworkElement)elemento).Name);
                ((FrameworkElement)elemento).Measure(new Size(((FrameworkElement)elemento).Width, ((FrameworkElement)elemento).Height));
                System.Diagnostics.Debug.WriteLine(\" child this desireddSIze\" + ((FrameworkElement)elemento).DesiredSize);


                if (this.Orientation.Equals(System.Windows.Controls.Orientation.Vertical))
                {
                    if (this.widthWrap)
                    {
                        //the widest element will determine containers width
                        if (panelDesiredSize.Width < ((FrameworkElement)elemento).Width)
                            panelDesiredSize.Width = ((FrameworkElement)elemento).Width;
                    }
                    //the height of the Layout is determine by the sum of all the elment that it cointains
                    if (this.heightWrap)
                        panelDesiredSize.Height += ((FrameworkElement)elemento).Height;
                }
                else
                {
                    if (this.heightWrap)
                    {
                        //The highest will determine the height of the Layout
                        if (panelDesiredSize.Height < ((FrameworkElement)elemento).Height)
                            panelDesiredSize.Height = ((FrameworkElement)elemento).Height;
                    }

                    //The width of the container is the sum of all the elements widths
                    if (this.widthWrap)
                        panelDesiredSize.Width += ((FrameworkElement)elemento).DesiredSize.Width;
                }
            }
        }

        return panelDesiredSize;
    }

this.Width = finalSize.Width;
this.Height = finalSize.Height;