I am trying to call the windows API function ExtEscape using the POSTSCRIPT_PASSTHROUGH escape function, and I cannot get it to work. I keep getting an error 87 - ERROR_INVALID_PARAMETER. I have the printer handle, the PS_PASSTHROUGH constant, and then the last two parms are 0 and nil. I can't figure out how to pass the Postscript date that I want to pass to the printer into this function. I've tried:
Length(MyString), @MyString
Length(MyString), PChar(MyString)
sizeof(MyArray), @MyArray //where MyArray is an array of char
sizeof(P), P //where P is a PChar, set to PChar(MyString)
I even tried creating a structure of a Bytes (WORD), MyString (String), and then passing the size of my structure and a pointer to the structure. In all cases, I am still getting Invaild Parameter.
Can anyone tell me how to properly call the ExtEscape API function from Delphi?
