从C+；发送calllback时访问冲突读取位置0x00000004+；代码到C#代码 我正在开发一个Windows 8电话应用程序，其中需要将C++语言的回调事件消息发送到C语言中的UI代码。下面是我创建回调函数并将指针发送到C++代码的C代码。C++代码可以使用这个函数指针向UI发送异步事件消息。

C#代码

public partial class MainPage
{
        public MainPage()
        {
            InitializeComponent();
        }
        public delegate void CallBack([In][MarshalAs(UnmanagedType.LPStr)] string strParam);
        [DllImport("Test.dll", CallingConvention = CallingConvention.StdCall)]
        public static extern void PerformActionWithCallBack(int x);

        void DemonstrateCallBack()
        {
            int x;
            CallBack callback_delegate = new CallBack(CallBackFunction);
            // Converting callback_delegate into a function pointer that can be
            // used in unmanaged code.
            IntPtr intptr_delegate = Marshal.GetFunctionPointerForDelegate(callback_delegate);

            //Getting the pointer into integer value and sending it to C++

            x = (int)intptr_delegate;

            testApp.PerformActionWithCallBack(x);
        }

        //CallBack function in which event messages will be received
        void CallBackFunction([In][MarshalAs(UnmanagedType.LPStr)] string strParam)
        {
            if (Dispatcher.CheckAccess() == false)
            {
                //Updating the text block with the received message
                Dispatcher.BeginInvoke(() => MyTextBlock.Text = strParam);
            }
            else
            {
                MyTextBlock.Text = "Update directly";
            }
        }
}

下面是C++代码，它将发送事件消息到C＜< /p>

---

有了这段代码，我可以成功地获得C#中的事件消息，但在发送650-700个Callback之后，我的应用程序会出现访问冲突异常，在这之后，一切都不起作用。我怀疑我把函数指针从C++传递到C++，但不能解析它。p> 您的问题是，回调\u委托被垃圾回收

说

必须手动防止垃圾收集器从托管代码中收集委托。垃圾收集器不跟踪对非托管代码的引用

试试这个

public partial class MainPage
{
    private CallBack _callBackDelegate = null;
    public MainPage()
    {
        InitializeComponent();
    }
    public delegate void CallBack([In][MarshalAs(UnmanagedType.LPStr)] string strParam);
    [DllImport("Test.dll", CallingConvention = CallingConvention.StdCall)]
    public static extern void PerformActionWithCallBack(int x);

    void DemonstrateCallBack()
    {
        _callBackDelegate = new CallBack(CallBackFunction);
        int x;

        // Converting _callBackDelegate  into a function pointer that can be
        // used in unmanaged code.
        IntPtr intptr_delegate = Marshal.GetFunctionPointerForDelegate(_callBackDelegate );

        //Getting the pointer into integer value and sending it to C++

        x = (int)intptr_delegate;

        testApp.PerformActionWithCallBack(x);
    }

    //CallBack function in which event messages will be received
    void CallBackFunction([In][MarshalAs(UnmanagedType.LPStr)] string strParam)
    {
        if (Dispatcher.CheckAccess() == false)
        {
            //Updating the text block with the received message
            Dispatcher.BeginInvoke(() => MyTextBlock.Text = strParam);
        }
        else
        {
            MyTextBlock.Text = "Update directly";
        }
    }
}

---

当我这样做时，我必须使CallbackFunction保持静态。否则，通过“new CallBack（CallBackFunction）；”初始化CallBackDelegate将返回错误，因为“字段初始值设定项不能引用非静态字段/方法”。如果我将CallbackFunction设置为静态，那么我就无法访问CallbackFunction内部的Dispatcher对象，这会导致错误，因为“非静态字段/方法需要对象引用”。看起来像是死锁。谢谢。@SanjeevKumar对不起，我不是C#程序员，所以我弄错了。您只需在构造函数中或在

void DemonstrateCallback（）

方法中初始化此变量，使其保持在类中而不是静态的。我已经编辑了我的答案，修正了哈斯·克拉夫琴科案，你已经解决了我的问题。它工作得很好。非常感谢你。

public partial class MainPage
{
    private CallBack _callBackDelegate = null;
    public MainPage()
    {
        InitializeComponent();
    }
    public delegate void CallBack([In][MarshalAs(UnmanagedType.LPStr)] string strParam);
    [DllImport("Test.dll", CallingConvention = CallingConvention.StdCall)]
    public static extern void PerformActionWithCallBack(int x);

    void DemonstrateCallBack()
    {
        _callBackDelegate = new CallBack(CallBackFunction);
        int x;

        // Converting _callBackDelegate  into a function pointer that can be
        // used in unmanaged code.
        IntPtr intptr_delegate = Marshal.GetFunctionPointerForDelegate(_callBackDelegate );

        //Getting the pointer into integer value and sending it to C++

        x = (int)intptr_delegate;

        testApp.PerformActionWithCallBack(x);
    }

    //CallBack function in which event messages will be received
    void CallBackFunction([In][MarshalAs(UnmanagedType.LPStr)] string strParam)
    {
        if (Dispatcher.CheckAccess() == false)
        {
            //Updating the text block with the received message
            Dispatcher.BeginInvoke(() => MyTextBlock.Text = strParam);
        }
        else
        {
            MyTextBlock.Text = "Update directly";
        }
    }
}