My Window overlaps taskbar when windowsstyle = none and transparency = true (WPF)

Hello

I've create my own Windows Border in my Wpf Project (Windowsstyle=none,allowtransparency=true) , but when my window is Maximized it overlapps the Taskbar. I've solved this Problem, but only if the Taskbar is on the bottom and has its normal size. How can I handle this problem? And how does this work with multiple Displays and the Taskbar has a custom size and position?

Thanks for Help.