Question

您好我是C ++新手并尝试处理托管类ServerApi::Request引发的事件托管类是一个COM接口，我已使用＆＃34;添加引用＆＃34;导入到我的visual studio项目中。用于选择ServerApi.dll文件的工具。所有方法似乎都按预期工作，但事件处理程序onDataReady()永远不会执行。这是我的代码：

//Event receiver
ref class EventReceiver {
public:

    void OnDataReady() {

        cout << "dataReadyHandler called" << endl;

    }

    void AddHandlers(ServerApi::Request^ request) {

        request->DataReady += gcnew DataReadyDelegate(this, &EventReceiver::OnDataReady);
    }

    void RemoveHandlers(ServerApi::Request^ request) {

        request->DataReady -= gcnew DataReadyDelegate(this, &EventReceiver::OnDataReady);

    }

};

void executeEventRequest() {

    ServerApi::RequestManager^ requestManager = gcnew ServerApi::RequestManager();

    ServerApi::Request^ request = requestManager->CreateMethod("...");

    EventReceiver^ eventReceiver = gcnew EventReceiver();
    eventReceiver->AddHandlers(request);
    request->Execute();
    eventReceiver->RemoveHandlers(request);

}

request对象在调用DataReady方法后引发Execute()事件。我知道数据几乎可以立即从轮询中准备好。我错过了什么？

首次修改

这是我在调用request->Execute()后最初等待的方式：

    EventReceiver^ eventReceiver = gcnew EventReceiver();
    eventReceiver->AddHandlers(request);
    request->Execute();
    clock_t beginTime = clock();

    // wait for 2 seconds
    while(clock() < beginTime + 2000) {

        // do nothing

    }

    eventReceiver->RemoveHandlers(request);

立即返回Execute方法控件没有阻塞。

Answer 1

我设法在System::Windows::Forms::Application::DoEvents()方法中使用executeEventRequest()来处理DataReady事件：

EventReceiver^ eventReceiver = gcnew EventReceiver();
eventReceiver->AddHandlers(request);
request->Execute();
clock_t beginTime = clock();

// wait for 2 seconds
while(clock() < beginTime + 2000) {

    System::Windows:Forms::Application::DoEvents() // this line enabled events handling

}

eventReceiver->RemoveHandlers(request);

来自托管对象的事件无法处理

1 个答案: