2

在尝试将数据编组到我的 DLL 函数并返回到 C# 代码时，我遇到了这个奇怪的错误。我看不到我在哪里传递 null 或读取无效内存，而且这个错误非常模糊。有什么线索吗？？

下面的代码：

FeeCalculation 函数在 DLL 中导出如下：

extern "C" __declspec(dllexport) void __stdcall FeeCalculation(char *cin, 
char *cout, char *flimit, char *frate,
char *fwindow, char *fincrement, char *fbird,
char *fparameter, char *fvalidation, char *fcoupon);

[StructLayout(LayoutKind.Sequential)]
        public struct feeAnswer
        {
            public uint fee;
            public uint tax1;
            public uint tax2;
            public uint tax3;
            public uint tax4;
            public uint surcharge1;
            public uint surcharge2;
            public uint validationFee;
            public uint couponFee1;
            public uint couponFee2;
            public uint couponFee3;
            public uint couponFee4;
            public ushort dstay;
            public ushort mstay;
        };

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        public struct feeRequest
        {
            public byte day;
            public byte month;
            public uint year;
            public byte hour;
            public byte minute;
            public byte rate;
            public byte validation;
            public byte coupon1;
            public byte coupon2;
            public byte coupon3;
            public byte coupon4;
        };

        [DllImport("FeeCalculation.dll", CallingConvention = CallingConvention.StdCall,
           CharSet = CharSet.Ansi)]
        public static extern void FeeCalculation(feeRequest cin,
            out feeAnswer cout, string flimit,
            string frate, string fwindow, string fincrement, string fbird,
            string fparameter, 
            string fvalidation, string fcoupon);

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            feeRequest freq = new feeRequest();
            feeAnswer fans = new feeAnswer();

            string flim = "";
            string frat = "";
            string fwin = "";
            string finc = "";
            string fbir = "";
            string fpar = "";
            string fval = "";
            string fcoup = "";

            freq.day = 26;

            freq.month = 2;

            freq.year = 2010;   //2000 ~ 2099

            freq.hour = 20;

            freq.minute = 47;

            freq.rate = 15;

            freq.validation = 1;

            freq.coupon1 = 2;

            freq.coupon2 = 3;

            freq.coupon3 = 4;

            freq.coupon4 = 5;


            FeeCalculation(freq, out fans, flim, frat, fwin, finc, fbir, fpar, fval, fcoup);

在约翰的建议下：

public static extern void FeeCalculation(feeRequest cin,
            out feeAnswer cout, 
            [MarshalAs(UnmanagedType.LPArray)]
            IntPtr flimit,
           [MarshalAs(UnmanagedType.LPArray)]
            IntPtr frate,
           [MarshalAs(UnmanagedType.LPArray)]
            IntPtr fwindow,
           [MarshalAs(UnmanagedType.LPArray)]
            IntPtr fincrement,
           [MarshalAs(UnmanagedType.LPArray)]
            IntPtr fbird,
           [MarshalAs(UnmanagedType.LPArray)]
            IntPtr fparameter,
           [MarshalAs(UnmanagedType.LPArray)]
            IntPtr fvalidation,
           [MarshalAs(UnmanagedType.LPArray)]
            IntPtr fcoupon);

...

FeeCalculation(freq, out fans, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero);
4

3 回答 3

2

您的问题很可能是您尚未完成互操作声明。正如我之前所说，您的大多数“字符串”参数实际上都是输出字节 [] 参数（或输出结构）

所以你需要做更多这样的事情

    [DllImport("FeeCalculation.dll", CallingConvention = CallingConvention.StdCall,
       CharSet = CharSet.Ansi)]
    public static extern void FeeCalculation(feeRequest cin,
        out feeAnswer cout, 
        [MarshalAs(UnmanagedType.LPArray, SizeConst=100)]
        out byte[] flimit,
        [MarshalAs(UnmanagedType.LPArray, SizeConst=100)]
        out byte[] frate, 
        [MarshalAs(UnmanagedType.LPArray, SizeConst=100)]
        out byte[] fwindow, 
        [MarshalAs(UnmanagedType.LPArray, SizeConst=100)]
        out byte[] fincrement, 
        [MarshalAs(UnmanagedType.LPArray, SizeConst=100)]
        out byte[] fbird,
        [MarshalAs(UnmanagedType.LPArray, SizeConst=100)]
        out byte[] fparameter, 
        [MarshalAs(UnmanagedType.LPArray, SizeConst=100)]
        out byte[] fvalidation, 
        [MarshalAs(UnmanagedType.LPArray, SizeConst=100)]
        out byte[]fcoupon);

您可能不关心其他参数，但该函数仍会尝试写入它们，因此您必须提供虚拟缓冲区并且缓冲区必须足够大以容纳输出。（因此您可能需要更改 SizeConst）。

如果您的函数允许指向输出的 NULL 指针，那么您可以声明您不想要的值IntPtr并传递IntPtr.Zero这些值。

从长远来看，您确实需要声明此函数想要查看的所有结构并将它们全部正确传递。

编辑：好的，你想使用 IntPtr 或 MarshalAs/byte[] 但不能同时使用。

public static extern void FeeCalculation(feeRequest cin,
        out feeAnswer cout, 
        IntPtr flimit,
        IntPtr frate,
        IntPtr fwindow,
        IntPtr fincrement,
        IntPtr fbird,
        IntPtr fparameter,
        IntPtr fvalidation,
        IntPtr fcoupon);

FeeCalculation(freq, out fans, IntPtr.Zero, ...
于 2010-02-27T02:10:30.277 回答
2

为了修复它，我在 .DLL 中try / catch block的代码周围添加了一个。memmove()然后，我必须确保我ref在所有参数上都使用了关键字，否则内存地址没有被正确地引用到 DLL。一旦我这样做了，它现在就可以正常工作了，没有访问冲突。我不需要 MarshalAs 声明，也不需要任何 pack 声明。我只是能够使用LayoutKind.Sequential.

于 2010-03-01T16:54:03.110 回答
0

有时，在使用编组处理非托管代码时，使用editbin !设置堆栈大小可能会有所帮助。尝试设置 16MB 例如运行以下
editbin.exe /stack:16777216 binary_

于 2018-08-26T11:00:31.023 回答