C#与非托管C库之间的互操作

问题描述：

我在DLL中有一个小的C库，我需要调用其中的一些方法.

I have a small C library in a DLL and I need to call a handful of its methods.

它使用指针和一些结构，但否则相当简单.问题是，在.NET与不受管理的世界互操作方面，我不是一个非常了解的人，到目前为止，我的尝试一直在碰到内存访问冲突异常(大概是由于我没有完全正确地指向指针).

It uses pointers and a few structs but is otherwise quite simple. Problem is I'm not terribly knowledgable on .NET's interop with the unmanaged world and my attempts so far keep hitting memory access violation exceptions (presumably due to me not getting the pointers quite right).

有人可以给我一些指导(最好的方法)吗?

Could anyone give me some pointers (ooh a pun!) on the best way to approach this?

谢谢

extern vconfig_t *Pobsopen(Ppoly_t ** obstacles, int n_obstacles);


extern int Pobspath(vconfig_t * config, Ppoint_t p0, int poly0,
            Ppoint_t p1, int poly1,
            Ppolyline_t * output_route);

extern void Pobsclose(vconfig_t * config);

struct vconfig_t {
    int Npoly;
    int N;
    Ppoint_t *P;
    int *start;
    int *next;
    int *prev;
};

typedef struct Ppoly_t {
    Ppoint_t *ps;
    int pn;
} Ppoly_t;

typedef Ppoly_t Ppolyline_t;

typedef struct Pxy_t {
    double x, y;
} Pxy_t;

typedef struct Pxy_t Ppoint_t;
typedef struct Pxy_t Pvector_t;

答

您应该查看文章，它可以将C代码片段转换为C#P/Invoke签名，当然也可以转换为帖子.

You should check out the tool given in this MSDN Magazine article that can translate a C snippet to C# P/Invoke signatures, and of course the post as well.

为您的代码段运行工具可以为您提供:

Running the tool for your code snippet gives you this:

[System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
public struct vconfig_t {

    /// int
    public int Npoly;

    /// int
    public int N;

    /// Ppoint_t*
    public System.IntPtr P;

    /// int*
    public System.IntPtr start;

    /// int*
    public System.IntPtr next;

    /// int*
    public System.IntPtr prev;
}

[System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
public struct Ppoly_t {

    /// Ppoint_t*
    public System.IntPtr ps;

    /// int
    public int pn;
}

[System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
public struct Pxy_t {

    /// double
    public double x;

    /// double
    public double y;
}

public partial class NativeMethods {

    /// Return Type: vconfig_t*
    ///obstacles: Ppoly_t**
    ///n_obstacles: int
    [System.Runtime.InteropServices.DllImportAttribute("<Unknown>", EntryPoint="Pobsopen")]
public static extern  System.IntPtr Pobsopen(ref System.IntPtr obstacles, int n_obstacles) ;


    /// Return Type: int
    ///config: vconfig_t*
    ///p0: Ppoint_t->Pxy_t
    ///poly0: int
    ///p1: Ppoint_t->Pxy_t
    ///poly1: int
    ///output_route: Ppolyline_t*
    [System.Runtime.InteropServices.DllImportAttribute("<Unknown>", EntryPoint="Pobspath")]
public static extern  int Pobspath(ref vconfig_t config, Pxy_t p0, int poly0, Pxy_t p1, int poly1, ref Ppoly_t output_route) ;


    /// Return Type: void
    ///config: vconfig_t*
    [System.Runtime.InteropServices.DllImportAttribute("<Unknown>", EntryPoint="Pobsclose")]
public static extern  void Pobsclose(ref vconfig_t config) ;

}

C#与非托管C库之间的互操作

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