自定义按钮 文字在左图片在右

图片宽度：15.f    

    [_titleBtn setTitle:title forState:UIControlStateNormal];

    CGSize titleSize = [title sizeWithAttributes:@{NSFontAttributeName: [UIFont fontWithName:_titleBtn.titleLabel.font.fontName size:_titleBtn.titleLabel.font.pointSize]}];

    [_titleBtn setTitleEdgeInsets:UIEdgeInsetsMake(0, 0, 0, 15)];

    [_titleBtn setImageEdgeInsets:UIEdgeInsetsMake(0, titleSize.width+15, 0, -titleSize.width)];

    [_titleBtn layoutIfNeeded];//刷新，必须加上，不然没有效果