How to create a blurred glass effect on a limitless form?

Question

How to make smooth blurry glass on a limitless form? I tried the code specified in Image Processing for Dummies using Page C and GDI + , but I'm sure this is not what I should use. No number of games with him gave any result, which I do after.

This is basically what I'm trying to achieve:

Answer 1

I assume that you are talking about Windows 7 / Vista, and you want to achieve blurry transparent areas that some MS programs have in the same way. In general, you need some kind of image processing that I am not going to cover.

In the case I mentioned above, you should not do it yourself - this is a kind of reinvention of the wheel. Basically, you can use a window manager to achieve this effect (called aero glass) using the methods described in this article: http://msdn.microsoft.com/en-us/magazine/cc163435.aspx

Currently, I only have a Windows 8 machine (in which they by default undoing this blur and transparency), so I do not have a test environment to test this. This week I will go over to it and set up a sample code to do this,

Once you use the desktop window manager, if you just want to blur the top (for example, in your image), use DwmExtendFrameIntoClientArea to enlarge the frame (which by default is blurred by default) in your window. For user area use DwmEnableBlurBehindWindow

So, in case this is really what you are looking for (the solution for Windows 7 / vista is the same as existing MS programs work), tell me and I will update the code later. Otherwise, if you are looking for a general solution (and not just Windows Vista / 7), tell me to save the effort of coding this ...

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EDIT: Given the fact that you decided to manually make an effect, here is some basic code to get you started.

// Code was burrowed from: // http://stackoverflow.com/questions/19867402/how-can-i-use-enumwindows-to-find-windows-with-a-specific-caption-title // http://www.dotnetframework.org/default.aspx/ 4@0 / 4@0 /DEVDIV_TFS/Dev10/Releases/RTMRel/ndp/fx/src/CommonUI/System/Drawing/ NativeMethods@cs /1305376/ NativeMethods@cs // http://stackoverflow.com/questions/7292757/how-to-get-screenshot-of-a-window-as-bitmap-object-in-c // http://stackoverflow.com/questions/798295/how-can-i-use-getnextwindow-in-c */ public static class WinAPI { public delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam); [StructLayout(LayoutKind.Sequential)] public struct RECT { public int left; public int top; public int right; public int bottom; }; public enum GW { GW_HWNDFIRST = 0, GW_HWNDLAST = 1, GW_HWNDNEXT = 2, GW_HWNDPREV = 3, GW_OWNER = 4, GW_CHILD = 5, GW_ENABLEDPOPUP = 6 } [DllImport("User32.dll")] public static extern bool EnumWindows(EnumWindowsProc lpEnumFunc, IntPtr lParam); [DllImport("User32.dll", CharSet = CharSet.Unicode)] public static extern int GetWindowText(IntPtr hWnd, StringBuilder strText, int maxCount); [DllImport("User32.dll")] public static extern int GetWindowTextLength(IntPtr hWnd); [DllImport("User32.dll")] public static extern bool IsWindowVisible(IntPtr hWnd); [DllImport("User32.dll")] public static extern bool IsIconic(IntPtr hWnd); [DllImport("User32.dll")] public static extern bool GetClientRect(IntPtr hWnd, ref RECT lpRect); [DllImport("User32.dll")] public static extern bool GetWindowRect(IntPtr hWnd, ref RECT lpRect); [DllImport("User32.dll")] public static extern IntPtr GetDesktopWindow(); [DllImport("User32.dll")] public static extern IntPtr GetTopWindow(IntPtr hWnd); public static IntPtr GetNextWindow(IntPtr hWnd, GW wCmd) { return GetWindow(hWnd, wCmd); } public static IntPtr GetWindow(IntPtr hWnd, GW wCmd) { return GetWindow(hWnd, (uint)wCmd); } [DllImport("User32.dll")] private static extern IntPtr GetWindow(IntPtr hWnd, uint wCmd); [DllImport("User32.dll")] public static extern bool PrintWindow(IntPtr hWnd, IntPtr hdcBlt, uint nFlags); [DllImport("User32.dll")] public static extern IntPtr GetDC(IntPtr hWnd); [DllImport("Gdi32.dll")] public static extern bool DeleteDC(IntPtr hdc); [DllImport("User32.dll")] public static extern IntPtr GetWindowDC(IntPtr hWnd); [DllImport("User32.dll")] public static extern int ReleaseDC(IntPtr hWnd, IntPtr hdc); [DllImport("User32.dll")] public static extern int GetWindowRgn(IntPtr hWnd, IntPtr hRgn); [DllImport("Gdi32.dll")] public static extern IntPtr CreateCompatibleDC(IntPtr hWnd); [DllImport("Gdi32.dll")] public static extern IntPtr CreateCompatibleBitmap(IntPtr hdc, int width, int height); [DllImport("Gdi32.dll")] public static extern IntPtr CreateBitmap(int width, int height, uint cPlanes, uint cBitsPerPel, IntPtr lpvBits); [DllImport("Gdi32.dll")] public static extern bool DeleteObject(IntPtr hGdiObj); [DllImport("Gdi32.dll")] public static extern bool SelectObject(IntPtr hdc, IntPtr hGdiObj); [DllImport("Gdi32.dll")] public static extern IntPtr CreateRectRgn(int nLeftRect, int nTopRect, int nRightRect, int nBottomRect); public static StringBuilder GetWindowText(IntPtr hWnd) { int length = GetWindowTextLength(hWnd); // Add another place to allow null terminator StringBuilder text = new StringBuilder(length + 1); GetWindowText(hWnd, text, length + 1); return text; } public static bool IsWindowReallyVisible(IntPtr hWnd) { if (!IsWindowVisible(hWnd) || IsIconic(hWnd)) return false; RECT area = new RECT(); if (!GetWindowRect(hWnd, ref area)) return true; if (area.left == area.right || area.bottom == area.top) return false; return true; } public enum RegionFlags { ERROR = 0, NULLREGION = 1, SIMPLEREGION = 2, COMPLEXREGION = 3, } } public class ScreenShot { public static List<IntPtr> GetAllWindows(Func<IntPtr, bool> filter, Func<IntPtr, bool> stop) { List<IntPtr> result = new List<IntPtr>(); WinAPI.EnumWindows((wnd, param) => { bool relevant = filter(wnd); if (relevant) result.Add(wnd); bool shouldStop = stop(wnd); if (shouldStop) Console.WriteLine("Stop"); return !shouldStop; }, IntPtr.Zero); return result; } public static IEnumerable<IntPtr> GetWindowsByOrder(Func<IntPtr, bool> filter) { List<IntPtr> skip = new List<IntPtr>(); List<IntPtr> result = new List<IntPtr>(); IntPtr desktop = WinAPI.GetDesktopWindow(); for (IntPtr wnd = WinAPI.GetTopWindow(IntPtr.Zero); wnd != IntPtr.Zero; wnd = WinAPI.GetNextWindow(wnd, WinAPI.GW.GW_HWNDNEXT)) { if (result.Contains(wnd) || skip.Contains(wnd)) break; else if (filter(wnd)) result.Add(wnd); else skip.Add(wnd); } result.Add(desktop); return result; } public static Image GetScreenshot(IntPtr hWnd) { IntPtr hdcScreen = WinAPI.GetDC(hWnd); IntPtr hdc = WinAPI.CreateCompatibleDC(hdcScreen); WinAPI.RECT area = new WinAPI.RECT(); WinAPI.GetWindowRect(hWnd, ref area); IntPtr hBitmap = WinAPI.CreateCompatibleBitmap(hdcScreen, area.right - area.left, area.bottom - area.top); WinAPI.SelectObject(hdc, hBitmap); WinAPI.PrintWindow(hWnd, hdc, 0); Image resultOpaque = Image.FromHbitmap(hBitmap); WinAPI.DeleteObject(hBitmap); WinAPI.DeleteDC(hdc); IntPtr hRegion = WinAPI.CreateRectRgn(0, 0, 0, 0); WinAPI.RegionFlags f = (WinAPI.RegionFlags) WinAPI.GetWindowRgn(hWnd, hRegion); Region region = Region.FromHrgn(hRegion); WinAPI.DeleteObject(hRegion); Bitmap result = new Bitmap(resultOpaque.Width, resultOpaque.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb); Graphics g = Graphics.FromImage(result); g.Clear(Color.Transparent); if (f != WinAPI.RegionFlags.ERROR) g.SetClip(region, System.Drawing.Drawing2D.CombineMode.Replace); if (f != WinAPI.RegionFlags.NULLREGION) g.DrawImageUnscaled(resultOpaque, 0, 0); g.Dispose(); region.Dispose(); resultOpaque.Dispose(); return result; } /* And now for the actual code of getting screenshots of windows */ var windows = ScreenShot.GetWindowsByOrder(this.WindowFilter).Intersect(ScreenShot.GetAllWindows(this.WindowFilter, (wnd) => false)).ToList(); int index = windows.IndexOf((IntPtr)this.Handle); /* Remove all the windows behind your windows */ if (index != -1) windows.RemoveRange(index, windows.Count - index + 1); windows.Reverse(); /* Get the images of all the windows */ for (int i = 0; i < windows.Count; ++i ) { var window = windows[i]; using (var img = ScreenShot.GetScreenshot(window)) { // Get the actual position of the window // Draw it image overlayed on the other windows 9have an accumulating image) } } 

Where are there still errors (on my testuite in Windows 8.1)?

• I still have problems with transparency - windows that are translucent inside the clipping area are still painted black.
• I have some unknown black windows (possibly transparent) that still appear
• Taskbar does not display correctly

Answer 2

Winform

Using a Win API such as DwmEnableBlurBehindWindow

  [DllImport("gdi32")] private static extern IntPtr CreateEllipticRgn(int nLeftRect, int nTopRect, int nRightRect, int nBottomRect); [DllImport("dwmapi")] private static extern int DwmEnableBlurBehindWindow(IntPtr hWnd, ref DwmBlurbehind pBlurBehind); public struct DwmBlurbehind { public int DwFlags; public bool FEnable; public IntPtr HRgnBlur; public bool FTransitionOnMaximized; } public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { var hr = CreateEllipticRgn(0, 0, Width, Height); var dbb = new DwmBlurbehind {FEnable = true, DwFlags = 1, HRgnBlur = hr, FTransitionOnMaximized = false}; DwmEnableBlurBehindWindow(Handle, ref dbb); } protected override void OnPaint(PaintEventArgs e) { e.Graphics.FillRectangle(new SolidBrush(Color.Black), new Rectangle(0, 0, Width, Height)); } 

Example 1:

Example 2: you can change the color of a brush (for example: DarkRed) to get nice effects.

It should be noted that you can choose a region where applicable, and you can have more than 1.

Wpf

You can use the same approach .

Wpf has much better shader support, and you can add an effect like blur, but you have more performance. In addition, your image is most likely related to a program created by WPF and Blend.

If I remember correctly, you cannot use shaders such as blur on a solid color brush. Therefore, subsequent ones would not produce the same effect. Set the background to 50% ( Properties of the window Allow transparency = "True" and WindowStyle = "No" )

 <Window.Background> <SolidColorBrush Opacity="0.5" Color="White"/> </Window.Background> 

Native glass windows

Wpf support is described here: http://www.paulrohde.com/native-glass-with-wpf/

I got the following result with a slightly different approach: