我有一个关于Objective-C中的块的问题。
例如,我有以下代码:
__block int count = 0;
void (^someFunction)(void) = ^(void){
count = 4;
};
count +=2;
如何正确编写相同的代码,使计数变为6而不是2?
谢谢!
我应该展示实际的代码,因为我的上一个问题不够清晰。
__block CMTime lastTime = CMTimeMake(-1, 1);
__block int count = 0;
[_imageGenerator generateCGImagesAsynchronouslyForTimes:stops
completionHandler:^(CMTime requestedTime, CGImageRef image, CMTime actualTime,
AVAssetImageGeneratorResult result, NSError *error)
{
if (result == AVAssetImageGeneratorSucceeded)
{
NSImage *myImage = [[NSImage alloc] initWithCGImage:image size:(NSSize){50.0,50.0}];
[arrOfImages addObject:myImage];
}
if (result == AVAssetImageGeneratorFailed)
{
NSLog(@"Failed with error: %@", [error localizedDescription]);
}
if (result == AVAssetImageGeneratorCancelled)
{
NSLog(@"Canceled");
}
if (arrOfImages.count > 5)
{
NSLog(@"here");
}
count++;
}];
int f = count+1;
进行了10次迭代后,计数器为0...为什么?!?!