Question

我有c＃方法ReadBytesInTask，它是从c ++代码调用的，使用Marshal.GetFunctionPointerForDelegate方法获取的函数指针。

ReadBytesInTask获取ptr到非托管的short []数组填充它并发送回非托管代码。在方法内正确地将数组解组为非托管内存，但c ++只获得零填充数组我该怎么办？

[UnmanagedFunctionPointer(CallingConvention.Cdecl, CharSet = CharSet.Auto)]
private delegate int BytesReader([In,Out] IntPtr buffer, int samplesCount, string taskId);

private static readonly BytesReader _readBytesInTask = ReadBytesInTask;

private static int ReadBytesInTask(IntPtr buffer, int samplesCount)
{
    var bufferSize = samplesCount;              
    var samplesToRead = bufferSize <= task.Buffer.Length - task.Offset ? bufferSize : task.Buffer.Length - task.Offset;

    buffer = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(short))*samplesToRead);
    Marshal.Copy(task.Buffer, task.Offset, buffer, samplesToRead);

    task.Offset += samplesToRead;
    if (samplesToRead < bufferSize) task.Offset = 0;
    return samplesToRead;
}

Answer 1

您正在更改指针而不是指向的指针。所以你需要一个指向指针的指针。所以它会是这样的：

private static int ReadBytesInTask(IntPtr* buffer, int samplesCount)

将带有数组的IntPtr返回到c ++

1 个答案: