iOS 将“Hello, world”（Helv.Neue Light，180pt）渲染为 PDF？

Question

我想在 UIKit 中动态生成一个最小的 PDF 页面，

所以直接发送到 AirPrint（不涉及文件），

仅包含一行文本，例如，

你好，世界

作为 Helvetica Neue Light 180pt.

TBC 它必须在 PDF 中实际排版，不呈现为图像。

请注意，渲染位图的代码很简单，而且可以广泛使用。示例https://stackoverflow.com/a/6566696/294884

我已经阅读并尝试过，直到我脸色发青。任何人都可以这样做吗？

PS如果你正在阅读这篇文章并且你是一名 Postscript 程序员，那么我专门讨论的是 iPad 中的 PDF 生成系统，例如：https://developer.apple.com/library/mac/documentation/graphicsimaging/conceptual/drawingwithquartz2d/dq_pdf/dq_pdf.html

（我完全不清楚 Quartz 是否是最好的方法——这是一场噩梦。）

顺便说一下，这是使用 html 方法执行此操作的确切代码...

此示例将一些动态 html 直接发送到 AirPrint，不涉及任何文件。

PDF 比较复杂

-(NSString*)_sample
  {
  NSString *r = @"<table border=0 cellpadding=0 cellspacing=0 width=100%>"
        "<tr><td align=right>"
        "<font face=courier size=1>Almost a header!</font>"
        "</tr></td></table>"
        "<br><br><br><br>"

        "<font size=4 face=sans-serif>"
        "Hello"
        "<br><br><br><br>"
        "Some <i>italics</i>."
        "<br><br><br><br>"

        "<table border=1 cellpadding=10 cellspacing=1>"
        "<tr><td align=right>one</td><td>two</td><td>three</td></tr>"
        "</table>"

        "</font>";
  return r;
  }

-(IBAction)printRawHtml:(UIView *)sender
  {
  UIPrintInfo *pif = [UIPrintInfo printInfo];
  pif.outputType = UIPrintInfoOutputGeneral;
  pif.jobName = @"Test HTML-like Job";

  UIMarkupTextPrintFormatter *formatter = [[UIMarkupTextPrintFormatter alloc]
    initWithMarkupText:[self _sample]
    ];

  formatter.startPage = 0;
  formatter.contentInsets = UIEdgeInsetsMake(10, 72.0, 72.0, 72.0);
                               //top,left,bottom,right

  UIPrintInteractionController *pic =
      [UIPrintInteractionController sharedPrintController];
  pic.delegate = self;
  pic.printInfo = pif;
  pic.printFormatter = formatter;
  pic.showsPageRange = NO;
  pic.showsNumberOfCopies = NO;

  void (^cph)(UIPrintInteractionController *, BOOL, NSError *) =
    ^(UIPrintInteractionController
          *printController, BOOL completed, NSError *error)
      {
      if (!completed && error) NSLog(@"print error %@", error);
      };

  if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
    [pic presentFromRect:sender.frame
       inView:self.view animated:YES completionHandler:cph];
  else
    [pic presentAnimated:YES completionHandler:cph];
  }

Answer 1

来自 Apple 开发者网站的代码

- (IBAction)savePDFFile:(id)sender
{
    // Prepare the text using a Core Text Framesetter.
    CFAttributedStringRef currentText = CFAttributedStringCreate(NULL, (CFStringRef)textView.text, NULL);
    if (currentText) {
        CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(currentText);
        if (framesetter) {

            NSString *pdfFileName = [self getPDFFileName];
            // Create the PDF context using the default page size of 612 x 792.
            UIGraphicsBeginPDFContextToFile(pdfFileName, CGRectZero, nil);

            CFRange currentRange = CFRangeMake(0, 0);
            NSInteger currentPage = 0;
            BOOL done = NO;

            do {
                // Mark the beginning of a new page.
                UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, 612, 792), nil);

                // Draw a page number at the bottom of each page.
                currentPage++;
                [self drawPageNumber:currentPage];

                // Render the current page and update the current range to
                // point to the beginning of the next page.
                currentRange = [self renderPageWithTextRange:currentRange andFramesetter:framesetter];

                // If we're at the end of the text, exit the loop.
                if (currentRange.location == CFAttributedStringGetLength((CFAttributedStringRef)currentText))
                    done = YES;
            } while (!done);

            // Close the PDF context and write the contents out.
            UIGraphicsEndPDFContext();

            // Release the framewetter.
            CFRelease(framesetter);

        } else {
            NSLog(@"Could not create the framesetter needed to lay out the atrributed string.");
        }
        // Release the attributed string.
        CFRelease(currentText);
    } else {
            NSLog(@"Could not create the attributed string for the framesetter");
    }
}

这是来自 Apple 的官方文档

https://developer.apple.com/library/ios/documentation/2ddrawing/conceptual/drawingprintingios/GeneratingPDF/GeneratingPDF.html

Answer 2

就像@luser droog 提到的，您可以使用 Quartz2D 在 iOS 中生成 PDF。我自己从未尝试过，但您可以查看this tutorial by Ray Wenderlich。他的教程特别详细介绍了如何以编程方式创建 PDF 以显示简单的“Hello world”字符串。