Question

我遇到了问题，我无法在网上找到答案。我想从我的c＃代码中调用c ++函数。 c ++函数声明为：

int read(InfoStruct *pInfo, int size, BOOL flag)

具有以下结构

typedef struct
{
    int ID; 
    char Name[20];
    double value;
    void *Pointer;
    int time;
}InfoStruct;

在我的c＃代码中，我写道：

 public unsafe struct InfoStruct
 {
    public Int32 ID;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 20)]
    public string Name;
    public Double value;
    public void *Pointer;
    public Int32 time;
  };

[DllImport("mydll.dll", SetLastError = true, CharSet = CharSet.Auto, CallingConvention = CallingConvention.Cdecl)]
        public static extern unsafe int read(out MeasurementInfoStruct[] pInfo, int size, bool flag);

我试图运行代码但它崩溃所以我猜我的结构特别是错误*但我无法弄清楚要放什么。它也可能是函数返回一个结构数组的事实，也许我没有正确地调用它。你能帮帮我吗？非常感谢。

Answer 1

我已经创建了一个测试应用程序，代码如下，它工作正常......

// CPP code

typedef struct
{
    int ID; 
    char Name[20];
    double value;
    void *Pointer;
    int time;
}InfoStruct;

int WINAPI ModifyListOfControls(InfoStruct *pInfo, int size, bool flag)
{

    int temp = 10;
    pInfo->ID = 10;
    strcpy(pInfo->Name,"Hi");
    pInfo->value = 20.23;
    pInfo->Pointer = (void *)&temp;
    pInfo->time = 50;
    return 0;
}
/***************************************************/
// This is C# code
[StructLayout(LayoutKind.Sequential)]
public struct InfoStruct
{
    public Int32 ID;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 20)]
    public string Name;
    public Double value;
    public IntPtr Pointer;
    public Int32 time;
};


[DllImport(@"D:\Test\Projects\Release_Build\WeldDll.dll", CallingConvention = CallingConvention.Winapi)]
public static extern int ModifyListOfControls(ref InfoStruct pInfo, int size, bool flag);// ref InfoStruct pi);

public static void Main()
{
    InfoStruct temp = new InfoStruct();

    temp.Pointer = new IntPtr();

    ModifyListOfControls(ref temp, 200, true);

    Console.WriteLine(temp.ID);
    Console.WriteLine(temp.Name);
    Console.WriteLine(temp.time);
    Console.WriteLine(temp.value);


    Console.ReadLine();
}

/ <强> * ** * ** 输出的 * 的** * ** * * 10 你好 50 20.23 的 * ** * ** * ** * ** * ** * ** * * /

如何将包含void *的结构从c ++传递给c＃？

1 个答案: