NSAttributedString绘制按钮上图下字体

/// 使用图像和文本生成上下排列的属性文本
///
/// @param image      图像
/// @param imageWH    图像宽高
/// @param title      标题文字
/// @param fontSize   标题字体大小
/// @param titleColor 标题颜色
/// @param spacing    图像和标题间距
///
/// @return 属性文本
+ (instancetype)imageTextWithImage:(UIImage *)image imageWH:(CGFloat)imageWH title:(NSString *)title fontSize:(CGFloat)fontSize titleColor:(UIColor *)titleColor spacing:(CGFloat)spacing {
    // 文本字典
    NSDictionary *titleDict = @{NSFontAttributeName : [UIFont systemFontOfSize:fontSize],
                                NSForegroundColorAttributeName : titleColor};
    NSDictionary *spacingDict = @{NSFontAttributeName : [UIFont systemFontOfSize:spacing]};

    // 图片文本
    NSTextAttachment *attachment = [[NSTextAttachment alloc] init];
    attachment.image = image;
    attachment.bounds = CGRectMake(0, 0, imageWH, imageWH);
    NSAttributedString *imageText = [NSAttributedString attributedStringWithAttachment:attachment];

    // 换行文本
    NSAttributedString *lineText = [[NSAttributedString alloc] initWithString:@"\n\n" attributes:spacingDict];

    // 按钮文字
    NSAttributedString *text = [[NSAttributedString alloc] initWithString:title attributes:titleDict];

    // 合并文字
    NSMutableAttributedString *attM = [[NSMutableAttributedString alloc] initWithAttributedString:imageText];
    [attM appendAttributedString:lineText];
    [attM appendAttributedString:text];

    return attM.copy;
}