使用AirPrint在连续纸卷上打印时多余的空白空间

static0886 发表于 Dev

静态的

我正在研究使用票据打印机将票据打印到连续纸卷上的代码。收据类似于您在商店中用信用卡付款时得到的收据。

我正在使用UIMarkupTextPrintFormatter，如下面的代码所示。

但是由于某种原因，我在打印文本的中间和结尾都一直保持空白。（在打印最后一行之后，打印机将继续滚动几英寸的白纸！）

我检查了pageCount属性，它返回2，所以可能这是多余的空白来自哪里。

我还启用了页面范围以显示页面数（用于调试）。我不应该在控制器上获得页面范围。但是我的意思是我的内容超过2页。

您能否指出我的代码不足之处？将HTML内容打印到连续纸上的正确方法是什么？

我的代码可以在打印机模拟器上完美运行。我得到了我想要的确切输出。没有意外的空格。但是在与AirPrint兼容的真实收据打印机上却失败了！

任何建议都非常感谢。

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

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

controller.showsPageRange = YES;
controller.showsPaperSelectionForLoadedPapers = YES;

//  Since the we're using a formatter, explicitly set the other properties to nil
controller.printingItem = nil;
controller.printingItems = nil;
controller.printPageRenderer = nil;


UIMarkupTextPrintFormatter *formatter = [[UIMarkupTextPrintFormatter alloc] initWithMarkupText:[self htmlPrintContent]];
formatter.startPage = 0;
formatter.contentInsets = UIEdgeInsetsZero;
controller.printFormatter = formatter;

// Ask for a print job object and configure its settings to tailor the print request
UIPrintInfo *info = [UIPrintInfo printInfo];

// B&W or color, normal quality output for mixed text, graphics, and images
info.outputType = UIPrintInfoOutputGrayscale;

// Select the job named this in the printer queue to cancel our print request.
info.jobName = @"somejobname";

// Make sure we are printing in a portrait orientation.
info.orientation = UIPrintInfoOrientationPortrait;

// We don't need duplex printing so set it to none explicitly
info.duplex = UIPrintInfoDuplexNone;

// Instruct the printing concierge to use our custom print job settings.
controller.printInfo = info;


// Present the standard iOS Print Panel that allows you to pick the target Printer, number of pages, etc.
[controller presentFromRect:self.printButton.frame inView:self.view animated:YES completionHandler:completionHandler];

静态的

我最终切换到UISimpleTextPrintFormatter而不是UIMarkupTextPrintFormatter。

所有格式化均使用NSAttributedString完成

也已实施

- (CGFloat)printInteractionController:(UIPrintInteractionController *)printInteractionController cutLengthForPaper:(UIPrintPaper *)paper

为了确定我的文字所需的高度。

CGFloat printableWidth = paper.printableRect.size.width;

CGRect attributedStringBoundingRect = [attributedPrintContent boundingRectWithSize:CGSizeMake(printableWidth, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin context:nil];

/* Calculate the margins of the roll */
CGFloat lengthOfMargins = paper.paperSize.height - paper.printableRect.size.height;

/* The cut length is the height of the text, plus margins, plus content insets */
CGFloat cutLength = attributedStringBoundingRect.size.height + lengthOfMargins + formatter.contentInsets.bottom + formatter.contentInsets.top;

希望这可以帮助...

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