Question

后台工作者，传递变量不起作用，在我的例子中我解释了一切，我只放了重要的函数，我有其他函数来自BackgroundWorker。

int TheFunction(unordered_map<std::string,std::string> options, BackgroundWorker^ worker, DoWorkEventArgs ^ e){

    if(options["option1"].compare("options") == 0){
            //...
        }

        return 0;
}

    void backgroundWorker2_DoWork(Object^ sender, DoWorkEventArgs^ e ){
         BackgroundWorker^ worker = dynamic_cast<BackgroundWorker^>(sender);     
        //e->Result = TheFunction( safe_cast<Int32>(e->Argument), worker, e ); //That's how I do to send an integer value and works just fine, but I don't know how to send non-numeric values with safe_cast or something that works, in the function it looks like this: TheFunction(int index, ...) it works fine, I want to know with unordered_map or with strings also would work, I want more than one argument if you can do with std::string
          e->Result = TheFunction(safe_cast<unordered_map<std::string,std::string>>(e->Argument)); //I tried this, and it didn't work

    }


void CallBackgroundWorker(){
         this->backgroundWorker2 = gcnew System::ComponentModel::BackgroundWorker;
         this->backgroundWorker2->WorkerReportsProgress = true;
         this->backgroundWorker2->WorkerSupportsCancellation = true;
         this->backgroundWorker2->DoWork += gcnew DoWorkEventHandler( this, &GUISystem::backgroundWorker2_DoWork );
         this->backgroundWorker2->RunWorkerCompleted += gcnew RunWorkerCompletedEventHandler( this, &GUISystem::backgroundWorker2_RunWorkerCompleted );
         this->backgroundWorker2->ProgressChanged += gcnew ProgressChangedEventHandler( this, &GUISystem::backgroundWorker2_ProgressChanged );


         unordered_map<std::string,std::string>* options = unordered_map<std::string,std::string>();
         options["option1"] = "valor1";
         options["option2"] = "valor2";

         this->backgroundWorker2->RunWorkerAsync(options);
}

那么我该如何发送unordered_map或std :: string（超过1个参数）？

提前谢谢。这会有很大的帮助。

Answer 1

这一行：

unordered_map<std::string,std::string>* options = unordered_map<std::string,std::string>();

即使在标准C ++中，

也不合法。指针需要存储地址，而不是对象。所以你可能想说new使用动态分配（毕竟，对象需要存活直到回调在另一个线程上运行）。

此时，您可以将指针包裹在System::IntPtr内，并在回调中投射ToPointer()的结果。

BackgroundWorker，不能将除数值之外的其他变量发送到函数回调

1 个答案: