在iOS开发中，使用UIButton设置title和image，达到tabBarItem的效果，即title在下，image在上：

    目前，我发现有两种比较好的方法：

方法一，使用UIEdgeInsets

    UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];

    [button setFrame:CGRectMake(100, 100, 60, 60)];

    [button setBackgroundColor:[UIColor greenColor]];

    UIImage *image = [UIImage imageNamed:@"index"];

    [button setTitle:@"首页" forState:UIControlStateNormal];

    [button setImage:image forState:UIControlStateNormal];

    // 如果不设置，则默认image在左，title在右，居中显示

    // 如果如下设置，则title和image重叠居中显示

    button.titleEdgeInsets = UIEdgeInsetsMake(0.0, -image.size.width, 0.0, 0.0);

    button.imageEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, 0.0, -

                button.titleLabel.bounds.size.width);

        // 如果如下设置，则title向下移动40个单位，在下，image向上移动20个单位，在上，居中显示

    button.titleEdgeInsets = UIEdgeInsetsMake(40.0, -image.size.width, 0.0, 0.0);

    button.imageEdgeInsets = UIEdgeInsetsMake(-20.0, 0.0, 0.0, -    

                button.titleLabel.bounds.size.width);

    [self.view addSubview:button];

方法二，重写UIButton的layoutSubviews

- (void)layoutSubviews

{

    [super layoutSubviews];

    CGPoint center = self.imageView.center;

    center.x = self.frame.size.width/2;

    center.y = self.imageView.frame.size.height/2;

    self.imageView.center = center;

    CGRect frame = [self titleLabel].frame;

    frame.origin.x = 0;

    frame.origin.y = self.imageView.frame.size.height + 2;

    frame.size.width = self.frame.size.width;

    self.titleLabel.frame = frame;

    self.titleLabel.textAlignment = NSTextAlignmentCenter;

    [self.titleLabel setFont:[UIFont systemFontOfSize:10.0f]];

}