WPF 玻璃窗口，无边框且无焦点调整大小

Question

我正在尝试使用 DmwAPI 中的 DwmEnableBlurBehindWindow 方法创建 Aero 玻璃 无边框 和 不可调整大小 WPF 窗口。但是，由于某种奇怪的原因，此窗口的玻璃颜色看起来好像窗口失焦。正如您在接下来的三张图片中看到的那样，带有边框的普通窗口（例如图 1 和 2）工作得很好并且反应如预期（深蓝色聚焦，失焦时发白（= 非活跃））。

允许调整大小的无边框窗口显示相同的行为：

不可调整大小的无边框窗口在处于活动状态时总是看起来好像失焦（您可以在最后一个图 3 中看到）并且不活跃。它总是看起来发白：

这是我如何设置玻璃样式的一些示例代码：

public MainWindow()
{
    InitializeComponent();

    WindowStyle = WindowStyle.None;
    ResizeMode = ResizeMode.NoResize;

    Height = 200;

    Background = Brushes.Transparent;
    Loaded += MainWindow_Loaded;
}
void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
    var windowInteropHelper = new WindowInteropHelper(this);
    var handle = windowInteropHelper.Handle;
    var mainWindowSrc = HwndSource.FromHwnd(handle);

    if (mainWindowSrc != null)
        if (mainWindowSrc.CompositionTarget != null)
            mainWindowSrc.CompositionTarget.BackgroundColor = Color.FromArgb(0, 0, 0, 0);
    var glassParams = new DwmApi.DwmBlurbehind
    {
        dwFlags = DwmApi.DwmBlurbehind.DWM_BB_ENABLE,
        fEnable = true,
        hRegionBlur = IntPtr.Zero
    };

    IntPtr dis = new IntPtr(2);
    DwmApi.DwmSetWindowAttribute(mainWindowSrc.Handle,
                DwmApi.DwmWindowAttribute.DWMWA_LAST,
                dis,
                sizeof(uint));

    DwmApi.DwmEnableBlurBehindWindow(
        handle,
        glassParams
        );
}

我尝试聚焦窗口，但这似乎不会影响行为。关于如何解决这个问题的任何想法或指示？

Answer 1

我在 dwm apis 上工作不多，所以我可能错了，但我认为默认的 dwm 渲染策略是使用 WindowStyle 来计算渲染。如果您禁用该策略，它的行为将与您预期的一样。

添加以下位来修复你的忧郁 xD

const int DWMWA_NCRENDERING_POLICY = 2;
int DWMNCRP_DISABLED = 2;

DwmSetWindowAttribute(hwnd, DWMWA_NCRENDERING_POLICY, ref DWMNCRP_DISABLED, sizeof(int));

有关此巫术的详细信息，请查看以下资源：

DwmSetWindowAttribute function

DWMWINDOWATTRIBUTE enumeration

MainWindow.xaml

<Window x:Class="dwm.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525"/>

MainWindow.xaml.cs

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media;

namespace dwm
{
    public partial class MainWindow
    {
        [DllImport("dwmapi.dll", PreserveSig = false)]
        public static extern void DwmEnableBlurBehindWindow(IntPtr hwnd, ref DwmBlurbehind blurBehind);

        [DllImport("dwmapi.dll", PreserveSig = true)]
        private static extern int DwmSetWindowAttribute(IntPtr hwnd, int attr, ref int attrValue, int attrSize);

        public MainWindow()
        {
            InitializeComponent();
        }

        protected override void OnSourceInitialized(EventArgs e)
        {
            base.OnSourceInitialized(e);

            var bb = new DwmBlurbehind
            {
                dwFlags = CoreNativeMethods.DwmBlurBehindDwFlags.DwmBbEnable,
                Enabled = true
            };

            WindowStartupLocation = WindowStartupLocation.CenterScreen;
            Background = Brushes.Transparent;
            ResizeMode = ResizeMode.NoResize;
            WindowStyle = WindowStyle.None;

            Focus();

            var hwnd = new WindowInteropHelper(this).Handle;

            HwndSource.FromHwnd(hwnd).CompositionTarget.BackgroundColor = Colors.Transparent;

            DwmEnableBlurBehindWindow(hwnd, ref bb);

            const int dwmwaNcrenderingPolicy = 2;
            var dwmncrpDisabled = 2;

            DwmSetWindowAttribute(hwnd, dwmwaNcrenderingPolicy, ref dwmncrpDisabled, sizeof(int));
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct DwmBlurbehind
        {
            public CoreNativeMethods.DwmBlurBehindDwFlags dwFlags;
            public bool Enabled;
            public IntPtr BlurRegion;
            public bool TransitionOnMaximized;
        }

        public static class CoreNativeMethods
        {
            public enum DwmBlurBehindDwFlags
            {
                DwmBbEnable = 1,
                DwmBbBlurRegion = 2,
                DwmBbTransitionOnMaximized = 4
            }
        }
    }
}

焦点屏幕截图

没有焦点的屏幕截图

测试环境

操作系统：Windows 8 - x64

主题：标准窗口