<Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    AllowsTransparency="True" WindowStyle="None"
    >

AllowsTransparency="True" WindowStyle="None"   //设置窗口无边框

C# WPF 设置窗口无边框