结构体声明如下：

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public struct TPlu
        {
            //[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 36)]
            public string Name;
            public int LFCode;
            //[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 10)]
            public string code;
            public int barcode;

            public int unitprice;
            public int weightunit;
            public int deptment;
            public double tare;
             
            public int shleftime;

            public int packagetype;
            public int packageweight;
            public int tolerance;
            //[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
            public byte message1;

            //[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
            public byte reserved;
            public short reserved1;
            //[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
            public byte message2;
            public byte reserved2;

            //[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
            public byte multilabel;
            //[MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = 1)]
            public byte rebate;
            public int account;
        }

其它INT型的参数都一切正常，唯独shleftime大于3时，下传就报错。0-3下传正常。是否要特殊处理？
文档对于保存期shleftime的说明：宽度 3，默认 15，描述：0~365, 其中 364: 不打印有效期; 365: 有效期和包
装日期均不打印包装日期为零时,包装日期及保鲜日
期均打印。

然而同样写的PB,VB程序则正常。