UIPrintInteractionController无法在iPhone中打印到整页

Question

我正在使用Apple打印文档示例将PDF从iPhone打印到Airprint兼容打印机。但是我没有从iPhone获得整页打印，请看我得到的图片，我需要在全纸张宽度上打印pdf。

下面给出了我用于打印功能的代码，其代码与Apple打印示例应用程序中的代码相同，

    UIPrintInteractionController *controller = [UIPrintInteractionController sharedPrintController];
    if(!controller){
        NSLog(@"Couldn't get shared UIPrintInteractionController!");
        return;
    }

    UIPrintInteractionCompletionHandler completionHandler =
    ^(UIPrintInteractionController *printController, BOOL completed, NSError *error) {
        if(!completed && error){
            NSLog(@"FAILED! due to error in domain %@ with error code %u", error.domain, error.code);
        }
    };

    controller.delegate = self;

    // Obtain a printInfo so that we can set our printing defaults.
    UIPrintInfo *printInfo = [UIPrintInfo printInfo];
    // This application produces General content that contains color.
    printInfo.outputType = UIPrintInfoOutputGeneral;
    // We'll use the URL as the job name.
    printInfo.jobName = [_filePath lastPathComponent];
    // Set duplex so that it is available if the printer supports it. We are
    // performing portrait printing so we want to duplex along the long edge.
    printInfo.duplex = UIPrintInfoDuplexLongEdge;
    // Use this printInfo for this print job.
    controller.printInfo = printInfo;
    controller.printingItem = myData;
    // Be sure the page range controls are present for documents of > 1 page.
    controller.showsPageRange = YES;

    // This code uses a custom UIPrintPageRenderer so that it can draw a header and footer.
    APLPrintPageRenderer *myRenderer = [[APLPrintPageRenderer alloc] init];
//  UIPrintPageRenderer *myRenderer = [[UIPrintPageRenderer alloc] init];
    // The APLPrintPageRenderer class provides a jobtitle that it will label each page with.
//    myRenderer.jobTitle = printInfo.jobName;
    // To draw the content of each page, a UIViewPrintFormatter is used.
    UIViewPrintFormatter *viewFormatter = [docWebView viewPrintFormatter];

#if SIMPLE_LAYOUT

    UIFont *font = [UIFont fontWithName:@"Helvetica" size:HEADER_FOOTER_TEXT_HEIGHT];
    CGSize titleSize = [myRenderer.jobTitle sizeWithFont:font];
    myRenderer.headerHeight = myRenderer.footerHeight = titleSize.height + HEADER_FOOTER_MARGIN_PADDING;
#endif
    [myRenderer addPrintFormatter:viewFormatter startingAtPageAtIndex:0];
    // Set our custom renderer as the printPageRenderer for the print job.
    controller.printPageRenderer = myRenderer;

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
    {
        [controller presentFromBarButtonItem:sender animated:YES completionHandler:completionHandler];  // iPad
    }
    else
    {
        docWebView.hidden = YES;
        [controller presentAnimated:YES completionHandler:completionHandler];  // iPhone
    }

Answer 1

我通过绘制PDFcontext来生成PDF以打印整页。我通过这样的电话进行设置：

NSMutableData *pdfData = [NSMutableData data];
UIGraphicsBeginPDFContextToData(pdfData, CGRectZero, nil);

请注意，因为我已经传入CGRectZero的大小，因此上下文的默认大小为

 /*
  default pdf..
   8.5 X 11 inch
   612 x 792
   */

**这只是72dpi，但它是默认值。我有一个技巧，我在绘图之前缩小以提高分辨率：

for (int page = 0 : page < numberPages : page ++ ){
UIGraphicsBeginPDFPage();
CGContextRef pdfContext = UIGraphicsGetCurrentContext();
CGFloat scaleFactor = 3.0;
CGContextSaveGState(pdfContext);
CGContextScaleCTM(pdfContext, 1.0/scaleFactor, 1.0/scaleFactor);


///draw stuff
/// context size is now (612.0 * 3.0 , 792.0 * 3.0) , i.e. resolution 72.0 * 3.0 dpi..
//


CGContextRestoreGState(pdfContext);

}//page drawing loop


NSString *filePath = [[NSFileManager defaultManager] //etcetc make a path];
BOOL success = [pdfData writeToFile:filePath atomically:YES];

好的，所以现在我的pdf i直接打印到UIPrintInteractionController

NSData *pdfData = [NSData dataWithContentsOfFile:[[self pdfView]filePath]];
   if ([UIPrintInteractionController canPrintData:pdfData]) {

    UIPrintInteractionController *pr = [UIPrintInteractionController sharedPrintController];

    void (^completionHandler)(UIPrintInteractionController *, BOOL, NSError *) =
    ^(UIPrintInteractionController *pic, BOOL completed, NSError *error) {
      if (!completed && error) NSLog(@"Print error: %@", error);
    };

    pr.printingItem = pdfData;
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
      [pr presentFromRect:tool.frame inView:self.view animated:YES completionHandler:completionHandler];
    } else {
      [pr presentAnimated:YES completionHandler:completionHandler];
    } 
  }

请注意，我不会搞乱UIPrintPageRenderer。我没有那门课的经验，我从来不需要研究它。但在我看来，如果它为页眉和页脚腾出空间，那么这些必然会缩小你的文档以便腾出空间。尝试将页眉和页脚合并到文档中。祝你好运

Answer 2

bestPaperForPageSize:withPapersFromArray:

根据给定的页面尺寸和特定于打印机的纸张尺寸可成像区域组合，返回UIKit确定最适合打印作业的打印纸对象。

+ (UIPrintPaper *)bestPaperForPageSize:(CGSize)pageSize withPapersFromArray:(NSArray *)paperList

UIPrintInteractionController的代表可以在UIPrintInteractionControllerDelegate协议中声明的printInteractionController:choosePaper:方法的实现中调用此方法。

Answer 3

而不是 UIViewPrintFormatter * viewFormatter = [docWebView viewPrintFormatter]; 使用 viewPrintFormatter * viewFormatter = [[UIPrintFormatter alloc] init];

不需要pdf和图像的特定格式化程序