编组C＃结构，C ++使用StructureToPtr [英] Marshalling C# structure to C++ Using StructureToPtr

问题描述

我有C＃类：

namespace Models
{
    [StructLayout(LayoutKind.Explicit, Size = 120, CharSet = CharSet.Unicode)]
    public struct DynamicState
    {
        [FieldOffset(0)]
        public double[] Position;

        [FieldOffset(24)]
        public double[] Velocity;

        [FieldOffset(48)]
        public double[] Acceleration;

        [FieldOffset(72)]
        public double[] Attitude;

        [FieldOffset(96)]
        public double[] AngularVelocity;
    }
}

和C ++ / CLI方式：

and C++/CLI method:

Models::DynamicState SomeClassClr::DoSomething(Models::DynamicState ds)
{
    int struct_size = Marshal::SizeOf(ds);
    System::IntPtr ptr = Marshal::AllocHGlobal(struct_size);
    DynamicStateStruct ds_struct;
    struct_size = sizeof(ds_struct);

    Marshal::StructureToPtr(ds, ptr, false);
    ds_struct = *(DynamicStateStruct*)ptr.ToPointer();

    Models::DynamicState returnVal;
    mpSomeClass->doSomething(ds_struct);

    return returnVal;
}

其中DynamicStateStruct是本地C ++类：

where DynamicStateStruct is a native C++ class:

struct DynamicStateStruct
{
    double mPosition[3];
    double mVelocity[3];
    double mAcceleration[3];
    double mAttitude[3];
    double mAngularVelocity[3];
};

当我恢复结构（ ds_struct ）在本地C ++，我没有得到正确的价值观，任何想法与我缺少的是什么

When I recover the struct (ds_struct) in native C++ I am not getting the correct values, any ideas with what I am missing?

推荐答案

请尝试以下变量：<？ / p>

Try the following variant:

public struct DynamicState
{
    [MarshalAs (UnmanagedType.ByValArray, SizeConst=3)]
    public double[] Position;

    [MarshalAs (UnmanagedType.ByValArray, SizeConst=3)]
    public double[] Velocity;

    [MarshalAs (UnmanagedType.ByValArray, SizeConst=3)]
    public double[] Acceleration;

    [MarshalAs (UnmanagedType.ByValArray, SizeConst=3)]
    public double[] Attitude;

    [MarshalAs (UnmanagedType.ByValArray, SizeConst=3)]
    public double[] AngularVelocity;
}

另一种方法是使用固定阵列提供不安全的代码：

Another option is to use fixed array available in unsafe code:

public unsafe struct DynamicState
{
    public fixed double Position[3];

    public fixed double Velocity[3];

    public fixed double Acceleration[3];

    public fixed double Attitude[3];

    public fixed double AngularVelocity[3];
}

P.S。在.NET互操作程序一个很好的指南可以在这里找到： http://www.mono-project.com/Interop_with_Native_Libraries

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