iphone - UIbutton 宽度和高度为零？

Question

我有这个

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button addTarget:self
              action:@selector(myAction:)
    forControlEvents:UIControlEventTouchDown];

[button setTitle:NSLocalizedString(@"Action", @"")
           forState:UIControlStateNormal];
CGFloat width = button.bounds.size.width;

此时宽度为零...

零？

有什么线索吗？

Answer 1

由于没有设置UIButton的frame，修改代码为

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
button.frame = CGRectMake(20,20,50,50);
[button addTarget:self
              action:@selector(myAction:)
    forControlEvents:UIControlEventTouchDown];

[button setTitle:NSLocalizedString(@"Action", @"")
           forState:UIControlStateNormal];
CGFloat width = button.bounds.size.width; // Now the width of button would be 50