iOS 设置按钮上图下文的方式

 UIButton*tabBtn = [UIButtonbuttonWithType:UIButtonTypeCustom];

        tabBtn.frame= CGRectMake(tabbarBtn_Width * i, 0, tabbarBtn_Width, 43);
        tabBtn.contentHorizontalAlignment= UIControlContentHorizontalAlignmentCenter;//这是图片和文字的布局居中
        [tabBtn setImage:[UIImageimageNamed:tabbarBtn[i]]forState:UIControlStateNormal];
        [tabBtn setImage:[UIImageimageNamed:tabbarBtn_h[i]]forState:UIControlStateSelected];
        [tabBtn setTintColor:[UIColorwhiteColor]];

        [tabBtnsetTitle:tabarName[i]forState:UIControlStateNormal];

       //设置文字的偏移量，上偏移文字的高度，左偏移图片的宽度，下部和右边不变

        [tabBtnsetTitleEdgeInsets:UIEdgeInsetsMake(tabBtn.imageView.frame.size.height,-tabBtn.imageView.frame.size.width, 0,0)];
        //设置图片的偏移量，上偏移图片的高度，左偏移图片的宽度，下部和右边不变
        [tabBtn setImageEdgeInsets:UIEdgeInsetsMake(- 5,0,0, -tabBtn.titleLabel.bounds.size.width+ 10)];

        tabBtn.titleLabel.font= [UIFontsystemFontOfSize:12.0];