How to Print a PDF File Using Cocoa

连接：http://www.danandcheryl.com/2010/05/how-to-print-a-pdf-file-using-cocoa

Mac OS X is well known for its great support for PDF files. You can create a PDF file from anything you can print. I thought that using Apple’s PDFKit framework would make it easy to program a way to print an existing PDF file. That turned out not to be the case.

Sending a file to a printer using the lp command is easy. However, this approach does not work for PDF files formatted for landscape printing. You can specify landscape orientation, but I wanted a way to detect the orientation automatically.

PDFKit has a PDFView object that has a printWithInfo:autoRotate: method. However, adding aPDFDocument to a PDFView and telling it to print doesn’t work. I eventually stumbled onto the fact thatPDFDocumenthas a secret method that makes printing easy. So here is the code:

#import <Quartz/Quartz.h>- (void)printPDF:(NSURL *)fileURL {    // Create the print settings.    NSPrintInfo *printInfo = [NSPrintInfo sharedPrintInfo];    [printInfo setTopMargin:0.0];    [printInfo setBottomMargin:0.0];    [printInfo setLeftMargin:0.0];    [printInfo setRightMargin:0.0];    [printInfo setHorizontalPagination:NSFitPagination];    [printInfo setVerticalPagination:NSFitPagination];    // Create the document reference.    PDFDocument *pdfDocument = [[[PDFDocument alloc] initWithURL:fileURL] autorelease];    // Invoke private method.    // NOTE: Use NSInvocation because one argument is a BOOL type. Alternately, you could declare the method in a category and just call it.    BOOL autoRotate = YES;    NSMethodSignature *signature = [PDFDocument instanceMethodSignatureForSelector:@selector(getPrintOperationForPrintInfo:autoRotate:)];    NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:signature];    [invocation setSelector:@selector(getPrintOperationForPrintInfo:autoRotate:)];    [invocation setArgument:&printInfo atIndex:2];    [invocation setArgument:&autoRotate atIndex:3];    [invocation invokeWithTarget:pdfDocument];    // Grab the returned print operation.    NSPrintOperation *op = nil;    [invocation getReturnValue:&op];    // Run the print operation without showing any dialogs.    [op setShowsPrintPanel:NO];    [op setShowsProgressPanel:NO];    [op runOperation];}

I consider this code to be in the public domain. Please feel free to copy and paste. And let me know if you find any problems or have suggestions.