/// <summary>
/// 将后面跟有默认行终止符的指定字符串的副本追加到当前 StringBuilder 对象的末尾
/// </summary>
/// <param name="sb"></param>
/// <param name="spaceNum">空格数</param>
/// <param name="text">要追加的字符串</param>
/// <returns></returns>
public static StringBuilder AppendSpaceLine(this StringBuilder sb, int spaceNum, string text)
{
sb.Append(StringHelper.Space(spaceNum));
sb.AppendLine(text);
return(sb);
}