The ExtEscape function allows applications to access capabilities of a particular device that are not available through GDI.
int ExtEscape(
| HDC hdc, | // handle to device context |
| int nEscape, | // escape function |
| int cbInput, | // number of bytes in input structure |
| LPCSTR lpszInData, | // pointer to input structure |
| int cbOutput, | // number of bytes in output structure |
| LPSTR lpszOutData | // pointer to output structure |
| ); |
Parameters
hdc
Identifies the device context.
nEscape
Specifies the escape function to be performed.
cbInput
Specifies the number of bytes of data pointed to by the lpszInData parameter.
lpszInData
Points to the input structure required for the specified escape.
cbOutput
Specifies the number of bytes of data pointed to by the lpszOutData parameter.
lpszOutData
Points to the structure that receives output from this escape. This parameter must not be NULL if ExtEscape is called as a query function. If no data is to be returned in this structure, set cbOutput to 0.
Return Values
The return value specifies the outcome of the function. It is greater than zero if the function is successful, except for the QUERYESCSUPPORT printer escape, which checks for implementation only. The return value is zero if the escape is not implemented. A return value less than zero indicates an error. To get extended error information, call GetLastError.
Remarks
Use this function to pass a driver-defined escape value to a device.
Use the Escape function to pass one of the escape values defined by Windows to a device. ExtEscape might not work properly with the escapes defined by Windows. In particular, escapes in which lpszInData points to a structure that contains a member that is a pointer will fail.
See Also