C# 實現窗口透明模糊效果

在之前偶然看見一篇實現Windows窗口透明毛玻璃效果的文章，感覺有意思進去看了一下，原理是通過設置窗口樣式屬性達到透明窗口的目的，在Win10的窗口中仍然存在Win7的Aero效果，但是微軟把它藏起來了，實際上我們仍然能設置它。原篇實現語言是C++，我用C#把它實現了，主要使用 FindWindow、GetWindowLong、SetWindowLong、SetWindowCompositionAttribute 這幾個WinAPI。

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命名空間：

        using System;
        using System.Windows.Forms;
        using System.Runtime.InteropServices;

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聲明方法&構造體：

        public const int GWL_EXSTYLE = -20;
        public const int LWA_ALPHA = 0x00000002;
        public const int WS_EX_LAYERED = 0x00080000;
        [DllImport("user32.dll")]
        public static extern int GetWindowLong(IntPtr hWnd, int nIndex);
        [DllImport("user32")]
        public static extern int SetWindowLong(IntPtr hwnd, int nIndex, int dwNewLong);

        [StructLayout(LayoutKind.Sequential)]
        public struct WindowCompositionAttributeData
        {
            public WindowCompositionAttribute Attribute;
            public IntPtr Data;
            public int SizeOfData;
        }
        public enum WindowCompositionAttribute
        {
            WCA_UNDEFINED = 0,
            WCA_NCRENDERING_ENABLED = 1,
            WCA_NCRENDERING_POLICY = 2,
            WCA_TRANSITIONS_FORCEDISABLED = 3,
            WCA_ALLOW_NCPAINT = 4,
            WCA_CAPTION_BUTTON_BOUNDS = 5,
            WCA_NONCLIENT_RTL_LAYOUT = 6,
            WCA_FORCE_ICONIC_REPRESENTATION = 7,
            WCA_EXTENDED_FRAME_BOUNDS = 8,
            WCA_HAS_ICONIC_BITMAP = 9,
            WCA_THEME_ATTRIBUTES = 10,
            WCA_NCRENDERING_EXILED = 11,
            WCA_NCADORNMENTINFO = 12,
            WCA_EXCLUDED_FROM_LIVEPREVIEW = 13,
            WCA_VIDEO_OVERLAY_ACTIVE = 14,
            WCA_FORCE_ACTIVEWINDOW_APPEARANCE = 15,
            WCA_DISALLOW_PEEK = 16,
            WCA_CLOAK = 17,
            WCA_CLOAKED = 18,
            WCA_ACCENT_POLICY = 19,
            WCA_FREEZE_REPRESENTATION = 20,
            WCA_EVER_UNCLOAKED = 21,
            WCA_VISUAL_OWNER = 22,
            WCA_LAST = 23
        }
        public enum ACCENT_STATE
        {
            ACCENT_DISABLED = 0,
            ACCENT_ENABLE_GRADIENT = 1,
            ACCENT_ENABLE_TRANSPARENTGRADIENT = 2,
            ACCENT_ENABLE_BLURBEHIND = 3,
            ACCENT_ENABLE_ACRYLICBLURBEHIND = 4,
            ACCENT_INVALID_STATE = 5
        }
        [StructLayout(LayoutKind.Sequential)]
        public struct ACCENT_POLICY
        {
            public ACCENT_STATE AccentState;
            public int AccentFlags;
            public int GradientColor;
            public int AnimationId;
        }
        [DllImport("user32.dll")]
        public static extern int SetWindowCompositionAttribute(IntPtr hwnd, ref WindowCompositionAttributeData data);

        [DllImport("user32.dll")]
        public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

 

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功能實現： 

窗口透明效果：

        //設置窗口透明效果
        private void SetWindowTransparent(IntPtr hwnd,int Alpha)
        {
            //IntPtr hwnd = FindWindow(null,"...");
            int OldStyle = GetWindowLong(hwnd,GWL_EXSTYLE);
            SetWindowLong(hwnd,GWL_EXSTYLE, OldStyle | WS_EX_LAYERED);
            SetLayeredWindowAttributes(hwnd, Color.FromArgb(200, Color.Gray).ToArgb(), Alpha,LWA_ALPHA);
        }

窗口模糊效果：

        //設置窗口模糊效果
        private void SetWindowAero(IntPtr hwnd)
        {
                //IntPtr hWnd = FindWindow(null,"...");
                ACCENT_POLICY accent = new ACCENT_POLICY
                {
                    AccentState = ACCENT_STATE.ACCENT_ENABLE_BLURBEHIND,
                    AccentFlags = 0,
                    AnimationId = 0,
                    GradientColor = 0
                };
                var accentStructSize = Marshal.SizeOf(accent);
                var accentPtr = Marshal.AllocHGlobal(accentStructSize);
                Marshal.StructureToPtr(accent, accentPtr, false);
                WindowCompositionAttributeData data = new WindowCompositionAttributeData
                {
                    Attribute = WindowCompositionAttribute.WCA_ACCENT_POLICY,
                    Data = accentPtr,
                    SizeOfData = accentStructSize
                };
                SetWindowCompositionAttribute(hwnd, ref data);
                Marshal.FreeHGlobal(accentPtr);   
        }

 

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調用：

        //查找窗口句柄
        IntPtr hwnd = FindWindow(null,"任務管理器");
        //設置窗口透明，不透明度205
        SetWindowTransparent(hwnd,205);
        //設置窗口模糊
        SetWindowAero(hwnd);

有些窗口在設置后會出現各種各樣的顯示問題，所以不建議所有窗口都設置；另外模糊效果不是很理想，建議只使用透明效果，不透明度測試205最好。