/// <summary>
/// 隐藏敏感信息
/// </summary>
/// <param name="info">信息实体</param>
/// <param name="left">左边保留的字符数</param>
/// <param name="right">右边保留的字符数</param>
/// <param name="basedOnLeft">当长度异常时，是否显示左边 
/// <code>true</code>显示左边，<code>false</code>显示右边
/// </param>
/// <returns></returns>
public static string HideSensitiveInfo(string info, int left, int right, bool basedOnLeft=true)
{
if (String.IsNullOrEmpty(info))
{
return "";
}
StringBuilder sbText = new StringBuilder();
int hiddenCharCount = info.Length - left - right;
if (hiddenCharCount > 0)
{
string prefix = info.Substring(0, left), suffix = info.Substring(info.Length - right);
sbText.Append(prefix);
for (int i = 0; i < hiddenCharCount; i++)
{
sbText.Append("*");
}
sbText.Append(suffix);
}
else
{
if (basedOnLeft)
{
if (info.Length > left && left > 0)
{
sbText.Append(info.Substring(0, left) + "****");
}
else
{
sbText.Append(info.Substring(0, 1) + "****");
}
}
else
{
if (info.Length > right && right > 0)
{
sbText.Append("****" + info.Substring(info.Length - right));
}
else
{
sbText.Append("****" + info.Substring(info.Length - 1));
}
}
}
return sbText.ToString();
}

/// <summary>
/// 隐藏敏感信息
/// </summary>
/// <param name="info">信息实体</param>
/// <param name="left">左边保留的字符数</param>
/// <param name="right">右边保留的字符数</param>
/// <param name="basedOnLeft">当长度异常时，是否显示左边 
/// <code>true</code>显示左边，<code>false</code>显示右边
/// <returns></returns>
public static string HideSensitiveInfo1(string info, int left, int right, bool basedOnLeft = true)
{
if (String.IsNullOrEmpty(info))
{
return "";
}
StringBuilder sbText = new StringBuilder();
int hiddenCharCount = info.Length - left - right;
if (hiddenCharCount > 0)
{
string prefix = info.Substring(0, left), suffix = info.Substring(info.Length - right);
sbText.Append(prefix);
sbText.Append("****");
sbText.Append(suffix);
}
else
{
if (basedOnLeft)
{
if (info.Length > left && left >0)
{
sbText.Append(info.Substring(0, left) + "****");
}
else
{
sbText.Append(info.Substring(0, 1) + "****");
}
}
else
{
if (info.Length > right && right>0)
{
sbText.Append("****" + info.Substring(info.Length - right));
}
else
{
sbText.Append("****" + info.Substring(info.Length - 1));
}
}
}
return sbText.ToString();
}

/// <summary>
/// 隐藏敏感信息
/// </summary>
/// <param name="info">信息</param>
/// <param name="sublen">信息总长与左子串（或右子串）的比例</param>
/// <param name="basedOnLeft">当长度异常时，是否显示左边，默认true，默认显示左边
/// <code>true</code>显示左边，<code>false</code>显示右边
/// <returns></returns>
public static string HideSensitiveInfo(string info,int sublen = 3,bool basedOnLeft = true)
{
if (String.IsNullOrEmpty(info))
{
return "";
}
if (sublen<=1)
{
sublen = 3;
}
int subLength = info.Length / sublen;
if (subLength > 0 && info.Length > (subLength*2) )
{
string prefix = info.Substring(0, subLength), suffix = info.Substring(info.Length - subLength);
return prefix + "****" + suffix;
}
else
{
if (basedOnLeft)
{
string prefix = subLength > 0 ? info.Substring(0, subLength) : info.Substring(0, 1);
return prefix + "****";
}
else
{
string suffix = subLength > 0 ? info.Substring(info.Length-subLength) : info.Substring(info.Length-1);
return "****"+suffix;
}
}
}

/// <summary>
/// 隐藏手机号详情
/// </summary>
/// <param name="phone">手机号</param>
/// <param name="left">左边保留字符数</param>
/// <param name="right">右边保留字符数</param>
/// <returns></returns>
public static string HideTelDetails(string phone, int left = 3, int right = 4)
{
return HideSensitiveInfo(phone, left, right);
}

/// <summary>
/// 隐藏手机号详情
/// </summary>
/// <param name="phone">手机号</param>
/// <param name="left">左边保留字符数</param>
/// <param name="right">右边保留字符数</param>
/// <returns></returns>
public static string HideTelDetails(string phone, int left = 3, int right = 4)
{
return HideSensitiveInfo1(phone, left, right);
}

/// <summary>
/// 隐藏右键详情
/// </summary>
/// <param name="email">邮件地址</param>
/// <param name="left">邮件头保留字符个数，默认值设置为3</param>
/// <returns></returns>
public static string HideEmailDetails(string email, int left = 3)
{
if (String.IsNullOrEmpty(email))
{
return "";
}
if (System.Text.RegularExpressions.Regex.IsMatch(email, @"\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"))//如果是邮件地址
{
int suffixLen =email.Length - email.LastIndexOf('@');
return HideSensitiveInfo(email, left, suffixLen,false);
}
else
{
return HideSensitiveInfo(email);
}
}