Microsoft KB Archive/128637

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HOWTO: How to Draw a Gradient Background

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Q128637

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The information in this article applies to:


 * Microsoft Windows Software Development Kit (SDK) 3.1
 * Microsoft Win32 Application Programming Interface (API)
 * Microsoft Windows 2000 Advanced Server

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SUMMARY
This article provides source code for drawing a gradient background pattern similar to the one used in Microsoft Setup applications. The code will compile and run on Windows version 3.1, Win32s, Windows 95 and Windows NT.

MORE INFORMATION
WARNING: ANY USE BY YOU OF THE CODE PROVIDED IN THIS ARTICLE IS AT YOUR OWN RISK. Microsoft provides this code "as is" without warranty of any kind, either express or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.

  /*************************************************************

*                                                           *   *  DrawBackgroundPattern                                   * *                                                           *   *  Purpose: This function draws a gradient pattern that      * *          transitions between blue and black. This is     * *          similar to the background used in Microsoft      * *          setup programs. *  *                                                            *   *************************************************************/

void DrawBackgroundPattern(HWND hWnd)

{  HDC hDC = GetDC(hWnd);  // Get the DC for the window RECT rectFill;         // Rectangle for filling band RECT rectClient;       // Rectangle for entire client area float fStep;           // How large is each band? HBRUSH hBrush;

int iOnBand; // Loop index

// How large is the area you need to fill?

GetClientRect(hWnd, &rectClient);

// Determine how large each band should be in order to cover the // client with 256 bands (one for every color intensity level)

fStep = (float)rectClient.bottom / 256.0f;

// Start filling bands

for (iOnBand = 0; iOnBand < 256; iOnBand++) {

// Set the location of the current band SetRect(&rectFill,           0,                           // Upper left X            (int)(iOnBand * fStep),      // Upper left Y            rectClient.right+1,          // Lower right X            (int)((iOnBand+1) * fStep)); // Lower right Y

// Create a brush with the appropriate color for this band hBrush = CreateSolidBrush(RGB(0, 0, (255 - iOnBand)));

// Fill the rectangle FillRect(hDC, &rectFill, hBrush);

// Get rid of the brush you created DeleteObject(hBrush);

};

// Give back the DC

ReleaseDC(hWnd, hDC); } Additional query words: 3.00 3.10 4.00 GRADIENT BACKGROUND DITHER

Keywords : kbOSWinNT350 kbOSWinNT351 kbOSWinNT400 kbOSWin2000 kbOSWin95 _IK kbSDKWin16

Issue type : kbhowto

Technology : kbwin2000AdvServ kbwin2000AdvServSearch kbwin2000Search kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinAdvServSearch kbWin32sSearch kbWin32API kbWinSDKSearch kbWinSDK310