ios - 响应选择器但抛出错误

- (void)TargetHit:(int)target{

    void (^threadBlock)(void) = ^{
        NSLog(@"respond to selector %d", [self respondsToSelector:@selector(changeImageOfTarget:)]);

        [[NSOperationQueue mainQueue] performSelectorOnMainThread:@selector(changeImageOfTarget:) withObject:[NSNumber numberWithInt:target] waitUntilDone:YES];
        [NSThread sleepForTimeInterval:1.0];
        [[NSOperationQueue mainQueue] performSelectorOnMainThread:@selector(changeImageOfTarget:) withObject:[NSNumber numberWithInt:target] waitUntilDone:YES];
    };

    dispatch_async(dispatch_queue_create(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), threadBlock);
}

我可以理解为什么我的代码返回YES来响应选择器，但是当我尝试执行它时，会收到错误消息，并且应用程序崩溃。

[NSOperationQueue changeImageOfTarget:]: unrecognized selector sent to instance 0x6a39810'

也是一样的

 [[NSThread currentThread] performSelectorOnMainThread:@selector(changeImageOfTarget:) withObject:[NSNumber numberWithInt:target] waitUntilDone:YES];

如何在主线程上执行方法或@selector？

最佳答案

self可能会响应选择器。问题是[NSOperationQueue mainQueue]没有。


  如何在主线程上执行方法或@selector？


只需在要执行操作的对象上调用它即可：

[self performSelectorOnMainThread:@selector(changeImageOfTarget:) withObject:[NSNumber numberWithInt:target] waitUntilDone:YES];

关于ios - 响应选择器但抛出错误，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/11137641/