/// <summary>
/// 通用版：從 "Key:Value" 這種字串中解析出 Value，並轉成 T 回傳。
/// </summary>
/// <typeparam name="T">
/// 目標型別，只要能用 Convert.ChangeType 轉換就行（數值、string…）
/// </typeparam>
/// <param name="line">形如 "SomeKey:123.45" 或 "Foo:ABC" 的字串</param>
private T ReadValueFromFile<T>(string line)
{
    // 1) 切兩段
    var parts = line.Split(':', 2);
    if (parts.Length < 2)
        throw new FormatException($"無法解析 '{line}'，必須包含 ':'");

    string valStr = parts[1];

    // 2) 如果是字串，就直接回傳
    if (typeof(T) == typeof(string))
        return (T)(object)valStr;

    // 3) 其他型別交給 Convert.ChangeType
    return (T)Convert.ChangeType(valStr, typeof(T));
}

UInt16 u16 = ReadValueFromFile<UInt16>("ParamA:65535");
int    i32 = ReadValueFromFile<int>(     "ParamB:-12345");
float  f   = ReadValueFromFile<float>(   "ParamC:3.14159");
ulong  u64 = ReadValueFromFile<ulong>(   "ParamD:9876543210");
string s   = ReadValueFromFile<string>(  "ParamE:Hello!");

        private UInt16 ReadValueFromFileUint16(String para_line)
        {
            string[] astringee = null;
            UInt16 i;

            astringee = para_line.Split(':');
            i = Convert.ToUInt16(astringee[1]);
            return i;
        }

        private Single ReadValueFromFileSingle(String para_line)
        {
            string[] astringee = null;
            Single i;

            astringee = para_line.Split(':');
            i = Convert.ToSingle(astringee[1]);
            return i;
        }

        private ulong ReadValueFromFileUint64(String para_line)
        {
            string[] astringee = null;
            UInt64 i;

            astringee = para_line.Split(':');
            i = Convert.ToUInt64(astringee[1]);
            return (ulong)i;
        }

        private long ReadValueFromFileInt64(String para_line)
        {
            string[] astringee = null;
            Int64 i;

            astringee = para_line.Split(':');
            i = Convert.ToInt64(astringee[1]);
            return (long)i;
        }

        private int ReadValueFromFileInt32(String para_line)
        {
            Int32 _outValue;
            string[] astringee = null;

            astringee = para_line.Split(':');
            _outValue = Convert.ToInt32(astringee[1]);

            return (int)(_outValue);
        }

        private UInt32 ReadValueFromFileUint32(String para_line)
        {
            UInt32 _outValue;
            string[] astringee = null;

            astringee = para_line.Split(':');
            _outValue = Convert.ToUInt32(astringee[1]);

            return (uint)_outValue;
        }

        private Int16 ReadValueFromFileInt16(String para_line)
        {
            Int16 _outValue;
            string[] astringee = null;

            astringee = para_line.Split(':');
            _outValue = Convert.ToInt16(astringee[1]);

            return _outValue;
        }

        private float ReadValueFromFileFloat(String para_line)
        {
            Double _outValue;
            string[] astringee = null;

            astringee = para_line.Split(':');
            _outValue = Convert.ToDouble(astringee[1]);

            return (float)_outValue;
        }

        private byte ReadValueFromFileByte(String para_line)
        {
            byte _outValue;
            string[] astringee = null;

            astringee = para_line.Split(':');
            _outValue = Convert.ToByte(astringee[1]);

            return _outValue;
        }

        private String ReadValueFromFileString(String para_line)
        {
            String _outValue;
            string[] astringee = null;

            astringee = para_line.Split(':');
            _outValue = astringee[1];

            return _outValue;
        }