Ios 响应选择器，但抛出错误

我可以理解为什么我的代码返回

YES

以响应选择器，但当我尝试执行它时，会收到错误消息，应用程序崩溃

- (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);
}

这对我来说也是一样的

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

---

如何在主线程上执行方法或选择器？

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：

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

---

self

可能响应选择器。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：

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