ios “接收者类型‘CALayer’例如消息是前向声明”在这里是什么意思？
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What does "Receiver type 'CALayer' for instance message is a forward declaration" mean here?
提问by Jason George
I'm porting a block of code from an iOS4 project to iOS5 and I'm having some troubles with ARC. The code generates a PDF from a screen capture.
我正在将一段代码从 iOS4 项目移植到 iOS5，但我在使用 ARC 时遇到了一些麻烦。该代码从屏幕截图生成 PDF。
PDF Generation Code
PDF生成代码
UIView *captureView;
...
NSMutableData *pdfData = [NSMutableData data];
UIGraphicsBeginPDFContextToData(pdfData, captureView.bounds, nil);
UIGraphicsBeginPDFPage();
CGContextRef pdfContext = UIGraphicsGetCurrentContext();
[captureView.layer renderInContext:pdfContext];
UIGraphicsEndPDFContext();The renderInContext line
renderInContext 行
[captureView.layer renderInContext:pdfContext];generates the following error.
产生以下错误。
Automatic Reference Counting issue
Receiver type 'CALayer' for instance message is a forward declarationAny ideas what is going on here?
任何想法这里发生了什么？
回答by NJones
I was able to duplicate your problem. This is what fixed it for me.
我能够复制你的问题。这就是为我修复它的原因。
Add QuartzCore.framework to your project and this line to your .m file.
将 QuartzCore.framework 添加到您的项目中，并将这一行添加到您的 .m 文件中。
#import <QuartzCore/QuartzCore.h>
