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  1. using System;
  2. using System.Drawing;
  3. using System.Drawing.Imaging;
  4. using System.Runtime.InteropServices;
  5. using System.Windows.Forms;
  6.  
  7. namespace alphatest
  8. {
  9.     public class AlphaWindow : Form
  10.     {
  11.         private Timer t;
  12.         private Bitmap b, ob;
  13.         public AlphaWindow(Bitmap bitmap)
  14.         {
  15.             b = bitmap;
  16.             TopMost = true;
  17.             ShowInTaskbar = false;
  18.             Size = bitmap.Size;
  19.             StartPosition = FormStartPosition.CenterScreen;
  20.             Show();			
  21.  
  22.             t = new Timer {Interval = 50};
  23.             t.Tick += t_Tick;
  24.             ob = new Bitmap(b.Width, b.Height);
  25.             t.Start();
  26.         }
  27.  
  28.         private float op = 0.00001f;
  29.         void t_Tick(object sender, EventArgs e)
  30.         {
  31.             Graphics g = Graphics.FromImage(ob);
  32.             if(op<1)op *= 1.2f;
  33.             ColorMatrix m = new ColorMatrix { Matrix33 = op };
  34.  
  35.             ImageAttributes at = new ImageAttributes();
  36.             at.SetColorMatrix(m, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
  37.             g.Clear(Color.Transparent);
  38.             g.DrawImage(b, new Rectangle(0, 0, b.Width, b.Height), 0, 0, b.Width, b.Height, GraphicsUnit.Pixel, at);
  39.             SelectBitmap(ob);
  40.             g.Dispose();
  41.         }
  42.  
  43.         public void SelectBitmap(Bitmap bitmap)
  44.         {
  45.             if (bitmap.PixelFormat != PixelFormat.Format32bppArgb)
  46.             {
  47.                 throw new ApplicationException("The bitmap must be 32bpp with alpha-channel.");
  48.             }
  49.             IntPtr screenDc = APIHelp.GetDC(IntPtr.Zero);
  50.             IntPtr memDc = APIHelp.CreateCompatibleDC(screenDc);
  51.             IntPtr hBitmap = IntPtr.Zero;
  52.             IntPtr hOldBitmap = IntPtr.Zero;
  53.             try
  54.             {
  55.                 // Get handle to the new bitmap and select it into the current device context
  56.                 hBitmap = bitmap.GetHbitmap(Color.FromArgb(0));
  57.                 hOldBitmap = APIHelp.SelectObject(memDc, hBitmap);
  58.  
  59.                 // Set parameters for layered window update
  60.                 APIHelp.Size newSize = new APIHelp.Size(bitmap.Width, bitmap.Height);	// Size window to match bitmap
  61.                 APIHelp.Point sourceLocation = new APIHelp.Point(0, 0);
  62.                 APIHelp.Point newLocation = new APIHelp.Point(Left, Top);		// Same as this window
  63.                 APIHelp.BLENDFUNCTION blend = new APIHelp.BLENDFUNCTION
  64.                                                   {
  65.                                                       BlendOp = APIHelp.AC_SRC_OVER,
  66.                                                       BlendFlags = 0,
  67.                                                       SourceConstantAlpha = 255,
  68.                                                       AlphaFormat = APIHelp.AC_SRC_ALPHA
  69.                                                   };
  70.  
  71.                 // Update the window
  72.                 APIHelp.UpdateLayeredWindow(Handle, screenDc, ref newLocation, ref newSize,
  73.                     memDc, ref sourceLocation, 0, ref blend, APIHelp.ULW_ALPHA);
  74.             }
  75.             finally
  76.             {
  77.                 // Release device context
  78.                 APIHelp.ReleaseDC(IntPtr.Zero, screenDc);
  79.                 if (hBitmap != IntPtr.Zero)
  80.                 {
  81.                     APIHelp.SelectObject(memDc, hOldBitmap);
  82.                     APIHelp.DeleteObject(hBitmap);										// Remove bitmap resources
  83.                 }
  84.                 APIHelp.DeleteDC(memDc);
  85.             }
  86.  
  87.         }
  88.         Point p = new Point(-1, -1);
  89.  
  90.  
  91.         protected override void OnMouseMove(MouseEventArgs e)
  92.         {
  93.             if (e.Button == MouseButtons.Left)
  94.             {
  95.                 if (p.X == -1)
  96.                     p = e.Location;
  97.                 else
  98.                     Location = new Point(Location.X + (e.X - p.X), Location.Y + (e.Y - p.Y));
  99.             }
  100.             else
  101.             {
  102.                 p = new Point(-1, -1);
  103.             }
  104.             base.OnMouseMove(e);
  105.         }
  106.  
  107.         protected override CreateParams CreateParams
  108.         {
  109.             get
  110.             {
  111.                 // Add the layered extended style (WS_EX_LAYERED) to this window
  112.                 CreateParams createParams = base.CreateParams;
  113.                 createParams.ExStyle |= APIHelp.WS_EX_LAYERED;
  114.                 return createParams;
  115.             }
  116.         }
  117.  
  118.         // Let Windows drag this window for us (thinks its hitting the title bar of the window)
  119.         //protected override void WndProc(ref Message message)
  120.         //{
  121.         //    if (message.Msg == APIHelp.WM_NCHITTEST)
  122.         //    {
  123.         //        // Tell Windows that the user is on the title bar (caption)
  124.         //        //message.Result = (IntPtr)APIHelp.HTCAPTION;
  125.         //    }
  126.         //    /*else if(message.Msg == 3)
  127.         //    {
  128.         //        return;
  129.         //    }*/
  130.         //    else
  131.         //    {
  132.         //        base.WndProc(ref message);
  133.         //    }
  134.         //}
  135.         private void InitializeComponent()
  136.         {
  137.             SuspendLayout();
  138.             // 
  139.             // AlphaWindow
  140.             // 
  141.             AutoValidate = AutoValidate.EnablePreventFocusChange;
  142.             ClientSize = new Size(284, 262);
  143.             FormBorderStyle = FormBorderStyle.None;
  144.             Name = "AlphaWindow";
  145.             ShowInTaskbar = false;
  146.             Load += Splash_Load;
  147.             MouseDown += AlphaWindow_MouseDown;
  148.             MouseMove += AlphaWindow_MouseMove;
  149.             ResumeLayout(false);
  150.  
  151.         }
  152.  
  153.         private void Splash_Load(object sender, EventArgs e)
  154.         {
  155.  
  156.         }
  157.  
  158.         protected override void OnClick(EventArgs e)
  159.         {
  160.             base.OnClick(e);
  161.             //Close();
  162.         }
  163.  
  164.         private void AlphaWindow_MouseDown(object sender, MouseEventArgs e)
  165.         {
  166.             OnDragOver(null);
  167.         }
  168.  
  169.         private void AlphaWindow_MouseMove(object sender, MouseEventArgs e)
  170.         {
  171.         }
  172.  
  173.     }
  174.  
  175.     // Class to assist with Win32 API calls
  176.     class APIHelp
  177.     {
  178.         // Required constants
  179.         public const Int32 WS_EX_LAYERED = 0x80000;
  180.         public const Int32 HTCAPTION = 0x02;
  181.         public const Int32 WM_NCHITTEST = 0x84;
  182.         public const Int32 ULW_ALPHA = 0x02;
  183.         public const byte AC_SRC_OVER = 0x00;
  184.         public const byte AC_SRC_ALPHA = 0x01;
  185.  
  186.         public enum Bool
  187.         {
  188.             False = 0,
  189.             True = 1
  190.         }
  191.  
  192.         [StructLayout(LayoutKind.Sequential)]
  193.         public struct Point
  194.         {
  195.             public Int32 x;
  196.             public Int32 y;
  197.  
  198.             public Point(Int32 x, Int32 y) { this.x = x; this.y = y; }
  199.         }
  200.  
  201.         [StructLayout(LayoutKind.Sequential)]
  202.         public struct Size
  203.         {
  204.             public Int32 cx;
  205.             public Int32 cy;
  206.  
  207.             public Size(Int32 cx, Int32 cy) { this.cx = cx; this.cy = cy; }
  208.         }
  209.  
  210.         [StructLayout(LayoutKind.Sequential, Pack = 1)]
  211.         struct ARGB
  212.         {
  213.             public byte Blue;
  214.             public byte Green;
  215.             public byte Red;
  216.             public byte Alpha;
  217.         }
  218.  
  219.         [StructLayout(LayoutKind.Sequential, Pack = 1)]
  220.         public struct BLENDFUNCTION
  221.         {
  222.             public byte BlendOp;
  223.             public byte BlendFlags;
  224.             public byte SourceConstantAlpha;
  225.             public byte AlphaFormat;
  226.         }
  227.  
  228.         [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
  229.         public static extern Bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref Point pptDst, ref Size psize, IntPtr hdcSrc, ref Point pprSrc, Int32 crKey, ref BLENDFUNCTION pblend, Int32 dwFlags);
  230.  
  231.         [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
  232.         public static extern IntPtr CreateCompatibleDC(IntPtr hDC);
  233.  
  234.         [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
  235.         public static extern IntPtr GetDC(IntPtr hWnd);
  236.  
  237.         [DllImport("user32.dll", ExactSpelling = true)]
  238.         public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);
  239.  
  240.         [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
  241.         public static extern Bool DeleteDC(IntPtr hdc);
  242.  
  243.         [DllImport("gdi32.dll", ExactSpelling = true)]
  244.         public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
  245.  
  246.         [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
  247.         public static extern Bool DeleteObject(IntPtr hObject);
  248.  
  249.     }
  250. }
  251.  
Compilation error #stdin compilation error #stdout 0s 0KB
comments ()
stdin 
Standard input is empty
compilation info 
prog.cs(5,22): error CS0234: The type or namespace name `Forms' does not exist in the namespace `System.Windows'. Are you missing `System.Windows.Forms' assembly reference?
prog.cs(9,32): error CS0246: The type or namespace name `Form' could not be found. Are you missing an assembly reference?
prog.cs(11,17): error CS0246: The type or namespace name `Timer' could not be found. Are you missing `System.Threading' or `System.Timers' using directive?
prog.cs(91,45): error CS0246: The type or namespace name `MouseEventArgs' could not be found. Are you missing an assembly reference?
prog.cs(107,28): error CS0246: The type or namespace name `CreateParams' could not be found. Are you missing an assembly reference?
prog.cs(158,33): error CS0115: `alphatest.AlphaWindow.OnClick(System.EventArgs)' is marked as an override but no suitable method found to override
prog.cs(164,59): error CS0246: The type or namespace name `MouseEventArgs' could not be found. Are you missing an assembly reference?
prog.cs(169,59): error CS0246: The type or namespace name `MouseEventArgs' could not be found. Are you missing an assembly reference?
Compilation failed: 8 error(s), 0 warnings
stdout 
Standard output is empty
https://ideone.com/sxJprO
language:
C# (gmcs 5.20.1)
created:
8 years ago
visibility:
public

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