1.让UIButton的图片跟按钮大小不一致。

[button setImage:[UIImage imageNamed:@"buttonImage"] forState:UIControlStateNormal];
button.imageEdgeInsets = UIEdgeInsetsMake(10,20,10,20);

2.ios7在某个controller中让statusbar消失。

- (BOOL)prefersStatusBarHidden {
    return YES;
}