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BeginBufferedPaint |
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Description
Begins a buffered paint operation.
C++ Syntax
PowerBASIC Syntax
Parameters
hdcTarget
[in] The handle of the target device context (DC) on which the buffer will be painted.
prcTarget
[in] A pointer to a RECT structure that specifies the area of the target DC in which to paint.
dwFormat
[in] A member of the BP_BUFFERFORMAT enumeration that specifies the format of the buffer.
pPaintParams
[in, opt] A pointer to a BP_PAINTPARAMS structure that defines the paint operation parameters. This value can be NULL.
phdc
[out] When this function returns, points to the handle of the new device context.
Return Value
A handle to a buffered paint animation.
Remarks
A handle to the buffered paint context. If this function fails, the return value is NULL, and phdc is NULL. To get extended error information, call GetLastError.
The returned handle is freed when EndBufferedPaint is called.
An application should call BufferedPaintInit on the calling thread before calling BeginBufferedPaint, and BufferedPaintUnInit before the thread is terminated. Failure to call BufferedPaintInit may result in degraded performance due to internal data being initialized and destroyed for each buffered paint operation.
Function Information
Example
C++
void BufferedPaint(HDC hdc, const RECT *prcPaint)
{ BP_PAINTPARAMS paintParams = {0}; paintParams.cbSize = sizeof(paintParams);
HDC hdcBuffer; HPAINTBUFFER hBufferedPaint = BeginBufferedPaint(hdc, prcPaint, BPBF_COMPATIBLEBITMAP, &paintParams, &hdcBuffer);
if (hBufferedPaint) { // Application specific painting code AppPaint(hdcBuffer, prcPaint); EndBufferedPaint(hBufferedPaint, TRUE); } else { // Error occurred, default to unbuffered painting AppPaint(hdc, prcPaint); } }
PowerBASIC
SUB BufferedPaint(BYVAL hdc AS DWORD, BYREF prcPaint AS RECT)
LOCAL paintParams AS BP_PAINTPARAMS paintParams.cbSize = SIZEOF(paintParams)
LOCAL hdcBuffer AS DWORD LOCAL hBufferedPaint AS DWORD hBufferedPaint = BeginBufferedPaint(hdc, prcPaint, %BPBF_COMPATIBLEBITMAP, paintParams, hdcBuffer)
IF hBufferedPaint THEN ' // Application specific painting code AppPaint(hdcBuffer, prcPaint) EndBufferedPaint(hBufferedPaint, %TRUE) ELSE ' // Error occurred, default to unbuffered painting AppPaint(hdc, prcPaint) END IF
END SUB
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