C#把内存里的utf8字符串转成C#内部使用的Unicode_c# 调用c语言库 utf8

传进来内存参数 IntPtr strNameUtf8,int nStrLen

public static string Utf8ToUnicode(IntPtr strNameUtf8, int nStrLen)
{        
    byte[] managedArray = new byte[nStrLen];
    Marshal.Copy(strNameUtf8, managedArray, 0, nStrLen);
    return Encoding.UTF8.GetString(managedArray); ;
}