Generating multi-page PDF from single UIView w/ subviews

Question

I'm having trouble breaking my PDF out into multiple pages from a single UIView. I'm trying to keep this as simple as possible. I have a UIScrollView that can vary in height. As of right now, I can get the first page to display correctly, but nothing after that. I'm pretty stumped at this point. Here's what I have:

NSMutableData *pdfData = [NSMutableData data];

UIGraphicsBeginPDFContextToData(pdfData, CGRectZero, nil);

CGContextRef pdfContext = UIGraphicsGetCurrentContext();
NSInteger    pageHeight = 867;

for (int originY = 0; originY < self.scrollView.contentSize.height; originY += pageHeight) {

    // Start a new page.
    UIGraphicsBeginPDFPageWithInfo(CGRectMake(0,originY,768,pageHeight), nil);

    [self.scrollView.layer renderInContext:pdfContext];

    for (UIView *subview in self.scrollView.subviews) {
        [subview.layer renderInContext:pdfContext];
    }

}

UIGraphicsEndPDFContext();

I'm trying to traverse this single UIScrollView and pick out the "pages" based on this frame, but that's not exactly working. Any help would be appreciated. I have read the apple docs on this topic and had problems translating that into my own application.

Answer 1

This worked pretty well for me. Make your life easier and just call on CGContextTranslateCTM.

NSInteger pageHeight = 792; // Standard page height - adjust as needed
NSInteger pageWidth = 612; // Standard page width - adjust as needed

/* CREATE PDF */
NSMutableData *pdfData = [NSMutableData data];
UIGraphicsBeginPDFContextToData(pdfData, CGRectMake(0,0,pageWidth,pageHeight), nil);
CGContextRef pdfContext = UIGraphicsGetCurrentContext();
for (int page=0; pageHeight * page < scrollView.frame.size.height; page++)
{
    UIGraphicsBeginPDFPage();
    CGContextTranslateCTM(pdfContext, 0, -pageHeight * page);
    [scrollView.layer renderInContext:pdfContext];
}

UIGraphicsEndPDFContext();