/// <summary>
/// 截取字符串长度，中文默认2个字节
/// </summary>
/// <param name="str">字符串</param>
/// <param name="count">截取的长度</param>
/// <param name="cLen">汉字长度</param>
/// <returns>截取后的字符串</returns>
/// <example>
/// <code lang="c#">
/// <![CDATA[
/// string str1="a中国浙江".GetSubString(3); //返回 "a中";
/// string str2="a中国浙江".GetSubString(3,SingleChineseLen.ONE); //返回 "a中国"
/// ]]>
/// </code>
/// </example>
public static string GetSubString(this string str, int count, SingleChineseLen cLen = SingleChineseLen.TWO)
{
if (string.IsNullOrEmpty(str))
{
return(string.Empty);
}
ASCIIEncoding En = new ASCIIEncoding();
Byte[] B = En.GetBytes(str);
int len = 0;
for (int i = 0; i < B.Length; i++)
{
if (B[i] == 63 && cLen == SingleChineseLen.TWO)//表示是中文
{
len = len + 2;
}
else
{
len = len + 1;
}
if (len >= count)
{
return(str.Substring(0, i + 1));
}
}
return(str);
}
/// <summary>
/// 获取字符串的长度
/// </summary>
/// <param name="str">字符串</param>
/// <param name="cLen">汉字长度，默认一个汉字当2个字符处理</param>
/// <returns>字符串长度</returns>
/// <example>
/// <code lang="c#">
/// <![CDATA[
/// int len1="a中国".GetStringLength(); //返回5;
/// int len2="a中国".GetStringLength(SingleChineseLen.ONE); //返回3
/// ]]>
/// </code>
/// </example>
public static int GetStringLength(this string str, SingleChineseLen cLen = SingleChineseLen.TWO)
{
if (string.IsNullOrEmpty(str))
{
return(0);
}
int len = 0;
if (!string.IsNullOrEmpty(str))
{
ASCIIEncoding En = new ASCIIEncoding();
Byte[] B = En.GetBytes(str.Trim());
for (int i = 0; i < B.Length; i++)
{
if (B[i] == 63 && cLen == SingleChineseLen.TWO)//表示是中文
{
len = len + 2;
}
else
{
len = len + 1;
}
}
}
return(len);
}
