Is there any way to generate PDF file from a XML/H

问题:

I am creating an iPad application, in that i have to use different PDF forms. I got some methods to generate PDF files through code using Quartz2D. But I have to write entire forms through code. I may have to update the PDF forms in future, so again I have to write the code. So I heard that there is a component called iTextSharp for .net pdf creation - is there something similar for iOS? So that I can use some XML templates to create the PDF files. Please help, thanks

回答1:

I do this in my app using the iOS print subsystem and the UIMarkupTextPrintFormatter. The trick is to write your own custom UIPrintPageRenderer that overrides and returns correct values from paperRect and numberOfPages. You'll add your UIMarkupTextPrintFormatter(s) to your custom UIPrintPageRenderer.

Then, you'll need routines similar to this, in the context of your custom UIPrintPageRenderer:

- (CGRect) paperRect
{
    if (!_generatingPdf)
        return [super paperRect];

    return UIGraphicsGetPDFContextBounds();
}

- (CGRect) printableRect
{
    if (!_generatingPdf)
        return [super printableRect];

    return CGRectInset( self.paperRect, 20, 20 );
}

- (NSData*) printToPDF
{
    _generatingPdf = YES;

    NSMutableData *pdfData = [NSMutableData data];

    UIGraphicsBeginPDFContextToData( pdfData, CGRectMake(0, 0, 792, 612), nil );  // letter-size, landscape

    [self prepareForDrawingPages: NSMakeRange(0, 1)];

    CGRect bounds = UIGraphicsGetPDFContextBounds();

    for ( int i = 0 ; i < self.numberOfPages ; i++ )
    {
        UIGraphicsBeginPDFPage();

        [self drawPageAtIndex: i inRect: bounds];
    }

    UIGraphicsEndPDFContext();

    _generatingPdf = NO;

//    NSString* filename = @"/Volumes/Macintosh HD 2/test.pdf";
//    [pdfData writeToFile: filename  atomically: YES];

    return pdfData;
}

回答2:

@TomSwift : agree with his answer but i would like to explain in better way

To be able create PDF from UIWebView is load HTML to yourWebView or there might be case yourWebView can also be hidden to generate PDF but process remains the same

1) Added Category of UIPrintPageRenderer for getting PDF Data as yourWebView.viewPrintFormatter need to be used

@interface UIPrintPageRenderer (PDF)
- (NSData*) printToPDF;
@end

@implementation UIPrintPageRenderer (PDF)
- (NSData*) printToPDF
{
  NSMutableData *pdfData = [NSMutableData data];
  UIGraphicsBeginPDFContextToData( pdfData, self.paperRect, nil );
  [self prepareForDrawingPages: NSMakeRange(0, self.numberOfPages)];
  CGRect bounds = UIGraphicsGetPDFContextBounds();
  for ( int i = 0 ; i < self.numberOfPages ; i++ )
  {
    UIGraphicsBeginPDFPage();
    [self drawPageAtIndex: i inRect: bounds];
  }
  UIGraphicsEndPDFContext();
  return pdfData;
}
@end

2) Add these define for A4 size or any custom size you want

#define kPaperSizeA4 CGSizeMake(595.2,841.8)

3) Process how we can create PDF

//create print renderer
UIPrintPageRenderer *render = [[UIPrintPageRenderer alloc] init];
[render addPrintFormatter:yourWebView.viewPrintFormatter startingAtPageAtIndex:0];

//provide padding ---- increase these values according to your requirement
float topPadding = 10.0f;
float bottomPadding = 10.0f;
float leftPadding = 10.0f;
float rightPadding = 10.0f;

//provide rect for printing and for actual PDF Rect of page
CGRect printableRect = CGRectMake(leftPadding,
                                  topPadding,
                                  kPaperSizeA4.width-leftPadding-rightPadding,
                                  kPaperSizeA4.height-topPadding-bottomPadding);
CGRect paperRect = CGRectMake(0, 0, kPaperSizeA4.width, kPaperSizeA4.height);
[render setValue:[NSValue valueWithCGRect:paperRect] forKey:@"paperRect"];
[render setValue:[NSValue valueWithCGRect:printableRect] forKey:@"printableRect"];

//category created above is used here 
NSData *pdfData = [render printToPDF];
//Save PDF to directory for usage
if (pdfData) {
  [pdfData writeToFile:[NSString stringWithFormat:@"%@/tmp.pdf",NSTemporaryDirectory()] atomically: YES];
}
else
{
  NSLog(@"PDF couldnot be created");
}