WPF GridSplitter - 按比例保存和恢复位置和分割

I am creating a 3-column UI with grid splitters between the columns. I have the requirement to save the sate of the columns so that if the user closes and reopens the app it looks just like they left it. But I am also trying to get the columns to split proportionately - by which I mean if you stretch the window, all three panels grow and if you move the left splitter it changes the division between the left and center columns.I am creating a 3-column UI with grid splitters