UIPrintInteractionController presentFromRect问题 [英] UIPrintInteractionController presentFromRect issue

问题描述

我使用presentFromRect方法显示来自UIButton的AirPrint选项，一切都按预期工作，但如果我一直按下按钮足够快，我的应用程序会崩溃EXC_BAD_ACCESS，可能是因为popover没有被释放。

Im showing the AirPrint options from a UIButton using the presentFromRect method, everything is working as expected, but if i keep pressing the button fast enough my app crashes with EXC_BAD_ACCESS, probably because of the popover not being release.

我在启用ARC的情况下使用Xcode 4.2。

Im using Xcode 4.2 with ARC enabled.

任何帮助都会很棒！

更新2：问题只发生在iOS 5模拟器上，iPad 4.3模拟器按预期工作。

更新：

这是真正的问题：

*由于未捕获的异常'NSGenericException'而终止应用程序，原因：' - [UIPopoverController dealloc]到达，而popover仍然可见。'

* Terminating app due to uncaught exception 'NSGenericException', reason: '-[UIPopoverController dealloc] reached while popover is still visible.'

这是代码：

这里我正在调用我的方法：

Here I'm calling my method:

PrintUtils* printUtils = [[PrintUtils alloc] init];
printUtils.delegate = self;
[printUtils setHeader:@"Header"];
[printUtils print:self.webView fromRect:self.myButton.frame inView:self.menuView];

我的方法：

- (void)print:(UIWebView *)webView fromRect:(CGRect)rect inView:(UIView *)view
{

    printController = [UIPrintInteractionController sharedPrintController];
    [printController setDelegate:self];


    if(!printController){

        NSError* error = [[NSError alloc] initWithDomain:@"Print unavailable!" code:0 userInfo:nil];

        [self showError:error];
        return;
    }

    UIPrintInteractionCompletionHandler completionHandler = 
    ^(UIPrintInteractionController *printController, BOOL completed, NSError *error) {
        if(!completed && error){
            [self showError:error];
        }
    };

    UIPrintInfo* printInfo = [UIPrintInfo printInfo];
    [printInfo setJobName:header];
    [printInfo setDuplex:UIPrintInfoDuplexLongEdge];
    [printInfo setOutputType:UIPrintInfoOutputGeneral];

    UIPrintFormatter* viewFormatter = [webView viewPrintFormatter];

    CustomPrintPageRenderer *pageRenderer = [[CustomPrintPageRenderer alloc] init];    
    [pageRenderer setJobTitle:[printInfo jobName]];

    UIFont* font = [UIFont fontWithName:@"Helvetica" size:HEADER_FOOTER_TEXT_HEIGHT]; 
    CGSize titleSize = [pageRenderer.jobTitle sizeWithFont:font];
    pageRenderer.headerHeight = pageRenderer.footerHeight = titleSize.height + HEADER_FOOTER_MARGIN_PADDING;


    [pageRenderer addPrintFormatter:viewFormatter startingAtPageAtIndex:0];

    [printController setPrintPageRenderer:pageRenderer];
    [printController setPrintInfo:printInfo];    
    [printController setPrintFormatter:viewFormatter];
    [printController setShowsPageRange:YES];    
    [printController presentFromRect:rect inView:view animated:YES completionHandler:completionHandler];

}

我尝试解决实现UIPrintInteractionControllerDelegate方法的问题：

My attempt to fix the problem implementing the UIPrintInteractionControllerDelegate Method:

- (void)printInteractionControllerWillPresentPrinterOptions:(UIPrintInteractionController *)printInteractionController
{

    if (visible) {
        [printController dismissAnimated:YES];
    }
}

推荐答案

你有没有想过这个？问题是你没有检查设备是iPad还是iPhone。 iPhone不支持presentFromRect：但iPad确实如此。这就是为什么你在iPhone上运行它时会遇到错误的访问。

Did you ever figure this out? The problem is that you´re not checking if the device is an iPad or iPhone. iPhone does not support presentFromRect: but iPad does. That's why you get the bad access when you run it on iPhone.

这是你需要做的：

if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {

    [printController presentFromFromBarButtonItem:sender animated:YES completionHandler:completionHandler];

} else {

    [printController presentAnimated:YES completionHandler:completionHandler];

}

这篇关于UIPrintInteractionController presentFromRect问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！