WPF 设置窗口在屏幕中央显示

在 InitializeComponent(); 之前添加 WindowStartupLocation = WindowStartupLocation.CenterScreen;

 /// 

    /// Interaction logic for MainWindow.xaml
    /// 
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            WindowStartupLocation = WindowStartupLocation.CenterScreen;
            InitializeComponent();
        }
        ...
}