This function allows applications to access capabilities of a particular device that are not available through the graphics display interface (GDI). The device capabilities this function accesses must be implemented by an OEM.
int ExtEscape( HDC hdc, int nEscape, int cbInput, LPCSTR lpszInData, int cbOutput, LPSTR lpszOutData );
[in] Handle to the device context.
[in] Specifies the escape function to be performed.
[in] Specifies the number of bytes of data pointed to by the lpszInData parameter.
[in] Long pointer to the input structure required for the specified escape.
[in] Specifies the number of bytes of data pointed to by the lpszOutData parameter.
[out] Long pointer 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.
A value greater than zero indicates success.
A value less than zero indicates an error.
The QUERYESCSUPPORT printer escape, which checks for implementation only, returns zero when the escape is not implemented.
To get extended error information, call GetLastError.
Use this function to pass a driver-defined escape value to a device.
The escape values passed in to this function are driver-defined.
Windows Embedded CE does not support system-defined escape values.
When using QUERYESCSUPPORT to find out whether a device supports an escape value, set the nEscape parameter to QUERYESCSUPPORT and point to the escape value in question with the lpszInData parameter.