C# 调用kernel32.dll 动态链接库的一种使用方式

           /// <summary>
            ///   读取端口
            /// </summary>
            /// <param name="section">要读取的段落名</param>
            /// <param name="key">要读取的键</param>
            /// <param name="defVal">读取异常的情况下的缺省值   </param>
            /// <param name="retVal">key所对应的值，如果该key不存在则返回空值</param>
            /// <param name="size">值允许的大小</param>
            /// <param name="filePath">INI文件的完整路径和文件名</param>
            /// <returns></returns>
            [DllImport("kernel32.dll")]
            public static extern int GetPrivateProfileString(string section, string key, string defVal, StringBuilder retVal, int size, string filePath);