C# 刪除字符串中的中文

/// <summary>
/// 刪除字符串中的中文
/// </summary>
public static string Delete中文(string str)
{
    string retValue = str;
    if (System.Text.RegularExpressions.Regex.IsMatch(str, @"[\u4e00-\u9fa5]"))
    {
        retValue = string.Empty;
        var strsStrings = str.ToCharArray();
        for (int index = 0; index < strsStrings.Length; index++)
        {
            if (strsStrings[index] >= 0x4e00 && strsStrings[index] <= 0x9fa5)
            {
                continue;
            }
            retValue += strsStrings[index];
        }
    }
    return retValue;
}