xcode iOS 5 需要 ARC 桥接转换
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iOS 5 requires ARC bridged cast
提问by BillyRay
Im following a tutorial and I'm not sure how to convert this code to get it to run free without errors with ARC enabled.
我正在学习教程，但我不确定如何转换此代码以使其在启用 ARC 的情况下自由运行而不会出错。
- (void)setHourHandImage:(CGImageRef)image
{
if (image == NULL) {
hourHand.backgroundColor = [UIColor blackColor].CGColor;
hourHand.cornerRadius = 3;
}else{
hourHand.backgroundColor = [UIColor clearColor].CGColor;
hourHand.cornerRadius = 0.0;
}
hourHand.contents = (id)image;
The only part that is giving me an error is the (id)image;
唯一给我一个错误的部分是（id）图像；
Also
还
w = CGImageGetWidth((CGImageRef)hourHand.contents);
(CGImageRef)minHand.contents); gives me an error
(CGImageRef)minHand.contents); 给我一个错误
Thanks
谢谢
回答by Lily Ballard
You need a __bridgecast.
你需要一个__bridge演员。
hourHand.contents = (__bridge id)image;
and
和
w = CGImageGetWidth((__bridge CGImageRef)hourHand.contents);
The __bridgecast tells ARC that this cast doesn't affect the ownership of the object in any way. The alternatives are __bridge_retainedand __bridge_transfer, which are generally used via the CFBridgingRetain()and CFBridgingRelease()functions.
该__bridge铸告诉ARC这一投不以任何方式影响对象的所有权。替代方法是__bridge_retainedand __bridge_transfer，它们通常通过CFBridgingRetain()andCFBridgingRelease()函数使用。
