C# Winform實現炫酷的透明動畫界面

C# Winform實現炫酷的透明動畫界面

做過.NET Winform窗體美化的人應該都很熟悉UpdateLayeredWindow吧，UpdateLayeredWindow可以實現窗體的任意透明，效果很好，不會有毛邊。不過使用這個API之後，會有一個問題就是無法使用普通控件，而且沒有Paint消息。為了解決這個問題，有兩種方法。   一、使用雙層窗體，底層窗體使用UpdateLayeredWindow作為背景，上層窗體用普通窗體，並且可以使用TransparencyKey或者Region來實現去除不需要的窗體內容，讓上層窗體能看到底層的窗體。   二、直接單層窗體，使用控件的DrawToBitmap把控件圖像繪制到UpdateLayeredWindow的窗體上，這樣就可以看到普通控件了。不過這個也有問題：1.控件內容不能自動更新  2.效率低，很多控件使用DrawToBitmap繪制出的圖像不完整，甚至繪制不出圖像。比如TextBox無法顯示光標，WebBrowser無法顯示內容。    三、采用DirectUI技術，重寫所有基礎控件。效果最好，不過工作量巨大。       使用UpdateLayeredWindow時，一般是需要對Bitmap緩存起來，通過設置剪輯區域，局部重繪來提高效率。另外還可以異步重繪，模擬Winform的失效到重繪。       有些人會說為什麼不直接用WPF啊，Wpf和Winform各有優缺點，適應不同的場合。Winform相對於使用更簡單一些，系統要求更低。當然需要看人的習慣了和擅長的。       UpdateLayeredWindow 基本使用方法：   重寫窗體的 CreateParams 屬性    

protected   override  CreateParams CreateParams
           {
              get
                  {
                 CreateParams cp  =   base .CreateParams;
                 cp.ExStyle  |=   0x00080000 ;  //  WS_EX_LAYERED 擴展樣式
                  return  cp;
             }
         }
　　

 

  API調用：  

public   void  SetBitmap(Bitmap bitmap,  byte  opacity)
    {
     if  (bitmap.PixelFormat  !=  PixelFormat.Format32bppArgb)
         throw   new  ApplicationException( "位圖必須是32位包含alpha 通道" );

    IntPtr screenDc  =  Win32.GetDC(IntPtr.Zero);
    IntPtr memDc  =  Win32.CreateCompatibleDC(screenDc);
    IntPtr hBitmap  =  IntPtr.Zero;
    IntPtr oldBitmap  =  IntPtr.Zero;

     try 
         {
        hBitmap  =  bitmap.GetHbitmap(Color.FromArgb( 0 ));   // 創建GDI位圖句柄，效率較低
        oldBitmap  =  Win32.SelectObject(memDc, hBitmap);

        Win32.Size size  =   new  Win32.Size(bitmap.Width, bitmap.Height);
        Win32.Point pointSource  =   new  Win32.Point( 0 ,  0 );
        Win32.Point topPos  =   new  Win32.Point(Left, Top);
        Win32.BLENDFUNCTION blend  =   new  Win32.BLENDFUNCTION();
        blend.BlendOp              =  Win32.AC_SRC_OVER;
        blend.BlendFlags           =   0 ;
        blend.SourceConstantAlpha  =  opacity;
        blend.AlphaFormat          =  Win32.AC_SRC_ALPHA;

        Win32.UpdateLayeredWindow(Handle, screenDc,  ref  topPos,  ref  size, memDc,  ref  pointSource,  0 ,  ref  blend, Win32.ULW_ALPHA);
    }
     finally 
         {
        Win32.ReleaseDC(IntPtr.Zero, screenDc);
         if  (hBitmap  !=  IntPtr.Zero)
              {
            Win32.SelectObject(memDc, oldBitmap);
             
            Win32.DeleteObject(hBitmap);
        }
        Win32.DeleteDC(memDc);
    }
}

 

　　   API聲明：    

class  Win32
    {
     public   enum  Bool
        {
        False  =   0 ,
        True
    } ;


    [StructLayout(LayoutKind.Sequential)]
     public   struct  Point
         {
         public  Int32 x;
         public  Int32 y;

          public  Point(Int32 x, Int32 y) 
          {  this .x  =  x;  this .y  =  y; }
    }


    [StructLayout(LayoutKind.Sequential)]
     public   struct  Size
         {
         public  Int32 cx;
         public  Int32 cy;

          public  Size(Int32 cx, Int32 cy) 
            {  this .cx  =  cx;  this .cy  =  cy; }
    }


    [StructLayout(LayoutKind.Sequential, Pack  =   1 )]
     struct  ARGB
        {
         public   byte  Blue;
         public   byte  Green;
         public   byte  Red;
         public   byte  Alpha;
    }


    [StructLayout(LayoutKind.Sequential, Pack  =   1 )]
     public   struct  BLENDFUNCTION
         {
         public   byte  BlendOp;
         public   byte  BlendFlags;
         public   byte  SourceConstantAlpha;
         public   byte  AlphaFormat;
    }


     public   const  Int32 ULW_COLORKEY  =   0x00000001 ;
     public   const  Int32 ULW_ALPHA  =   0x00000002 ;
     public   const  Int32 ULW_OPAQUE  =   0x00000004 ;

     public   const   byte  AC_SRC_OVER  =   0x00 ;
     public   const   byte  AC_SRC_ALPHA  =   0x01 ;


    [DllImport( " user32.dll " , ExactSpelling  =   true , SetLastError  =   true )]
     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);

    [DllImport( " user32.dll " , ExactSpelling  =   true , SetLastError  =   true )]
     public   static   extern  IntPtr GetDC(IntPtr hWnd);

    [DllImport( " user32.dll " , ExactSpelling  =   true )]
     public   static   extern   int  ReleaseDC(IntPtr hWnd, IntPtr hDC);

    [DllImport( " gdi32.dll " , ExactSpelling  =   true , SetLastError  =   true )]
     public   static   extern  IntPtr CreateCompatibleDC(IntPtr hDC);

    [DllImport( " gdi32.dll " , ExactSpelling  =   true , SetLastError  =   true )]
     public   static   extern  Bool DeleteDC(IntPtr hdc);

    [DllImport( " gdi32.dll " , ExactSpelling  =   true )]
     public   static   extern  IntPtr SelectObject(IntPtr hDC, IntPtr hObject);

    [DllImport( " gdi32.dll " , ExactSpelling  =   true , SetLastError  =   true )]
     public   static   extern  Bool DeleteObject(IntPtr hObject);

    [DllImport( " user32.dll " , EntryPoint  =   " SendMessage " )]
     public   static   extern   int  SendMessage( int  hWnd,  int  wMsg,  int  wParam,  int  lParam);
    [DllImport( " user32.dll " , EntryPoint  =   " ReleaseCapture " )]

     public   static   extern   int  ReleaseCapture();
     public   const   int  WM_SysCommand  =   0x0112 ;
     public   const   int  SC_MOVE  =   0xF012 ;

     public   const   int  SC_MAXIMIZE  =   61488 ;
     public   const   int  SC_MINIMIZE  =   61472 ;
}