[移动开发]如何实现按钮的图片在右边，文字在左边

按钮设置了文字和图片，若宽度足够展开的话，默认都是图片在作，文字在右。想文字在左，图片在右有两种方法。
第一种方法很简单。通过设置setSemanticContentAttribute属性来实现。

       _bgBtn2 = [[UIButton alloc] init];
        [_bgBtn2 setBackgroundColor:[UIColor clearColor]];
        [_bgBtn2 setTitle:@"关注问题(243）" forState:UIControlStateNormal];
        [_bgBtn2.titleLabel setFont:[UIFont systemFontOfSize:12]];
        [_bgBtn2 setTitleColor:DYHighlightColor forState:UIControlStateNormal];
        [_bgBtn2 setImage:[UIImage imageNamed:@"icon_quest31"] forState:UIControlStateNormal];
**[_bgBtn2 setSemanticContentAttribute:UISemanticContentAttributeForceRightToLeft];**

第二种方法是通过设置titleEdgeInsets和setImageEdgeInsets来实现。

        _selectBtn = [[BGSwapButton alloc] initWithTitle:@"排序" titleColor:DEFAULT_TITLE_LIGHT_FRONT_COLOR selectedTitleColor:DYHighlightColor icon:[UIImage imageNamed:@"icon_quest32"] selectedIcon:[UIImage imageNamed:@"icon_quest_sort"] frame:CGRectMake(FULL_WIDTH-40-COMMON_EDGE_DISTANCE, 12+100+12+28+12+8+(45-12.0)/2, 40, 12)];
        _selectBtn.titleLabel.font = BGFont(12);
        **_selectBtn.titleEdgeInsets=UIEdgeInsetsMake(0, -(40 -9)+8,0, 0);//上左下右
        [_selectBtn setImageEdgeInsets:UIEdgeInsetsMake(0, 40-9, 0, 0)];//上左下右**