使用isKindOfClass:我不明白为什么这段代码的表现方式如此

Question

-(void)viewWillAppear:(BOOL)animated
{
   [super viewWillAppear:animated];
   UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
   imageView.image = [UIImage imageNamed:@"Sample.png"];
   [self.view addSubview:imageView];
   NSArray *subviews = [self.view subviews];
   for(id element in subviews) {
      if ([[element class] isKindOfClass:[UIImageView class]]) //check if the object is a UIImageView
      {
         NSLog(@"element is a UIImageView\n");
         [element setCenter:CGPointMake(500., 500.)];
      } else {
         NSLog(@"element is NOT a UIImageView\n");
      }
   }
}

我期望输出为"元素是UIImageView,但实际上元素不是UIImageView.为什么？不是有其他子视图.只有一个.此外,运行时,图像显示为100,100,而不是500,500正如所料.

Answer 1

你的支票错了.你应该调用isKindOfClass:object而不是object类.

[element isKindOfClass:[UIImageView class]]