wxWidgets GUI應用程序中的多線程？

Question

我在嘗試爲我的wxWidgets GUI應用程序創建一個工作線程時會遇到問題（基本上，我很困惑），它將修改其中一個GUI屬性本身。 （在這種情況下，wxTextCtrl :: AppendText）。目前爲止，我有2個源文件和2個頭文件，用於wx程序本身（不包括我自己的libs，MySQL lib等），說MainDlg.cpp包含一個名爲'MainDlg'的MainForm的派生類wxFrame .cpp其中包含一個叫做'MainForm'的派生類wxApp。

MainForm.cpp

#include "MainHeader.h" // contains multiple header files 

IMPLEMENT_APP(MainForm) 

bool MainForm::OnInit() 
{ 
    MainDlg *Server = new MainDlg(wxT("App Server 1.0"), wxDEFAULT_FRAME_STYLE - wxRESIZE_BORDER - wxMAXIMIZE_BOX); 
    Editor->Show(); 

    return true; 
} 

MainDlg.cpp：

#include "MainHeader.h" 

BEGIN_EVENT_TABLE(MainDlg, wxFrame) 
EVT_BUTTON(6, MainDlg::StartServer) 
EVT_BUTTON(7, MainDlg::StopServer) 
END_EVENT_TABLE() 

CNETServerConnection *cnServCon; 
std::string ServerIP, DBHost, DBUser, DBName, DBPass; 
int UserCapacity, DBPort, ServerPort; 
MYSQL *sqlhnd; 

MainDlg::MainDlg(const wxString &title, long style) : wxFrame(NULL, wxID_ANY, title, wxDefaultPosition, wxSize(301, 230), style) 
{ 
    cnServCon = new CNETServerConnection(100); 
    this->InitializeComponent(); 
} 

void MainDlg::InitializeComponent() 
{ 
    this->SetTitle(wxT("App Server 1.0")); 
    this->SetSize(396, 260); 
    this->SetBackgroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_3DFACE)); 
    this->Centre(); 

    statBox = new wxTextCtrl(this, 4, wxT("Welcome to AppServer 1.0\n\n"), wxPoint(10, 10), wxSize(371, 141), wxTE_MULTILINE | wxTE_READONLY); 

    //................................. 
} 

void MainDlg::StartServer(wxCommandEvent &event) 
{ 
    this->startBtn->Enable(false); 
    this->AppendStatus(wxT("\nLoading server configuration... ")); 

    //................................. 

    this->AppendStatus(wxT("OK\n\nServer ready!\n\n")); 

    // When the server is ready, I need to run a thread 
    // that will update the statBox (through AppendStatus func or wxTextCtrl::AppendText directly) 
    // regularly without interrupting the GUI itself. 
    // Because the thread will contain a while-loop 
    // to make the program keep receiving message from clients. 

    this->startBtn->Hide(); 
    this->stopBtn->Show(); 
    this->cmdBtn->Enable(); 
    this->cmdBox->Enable(); 
} 

void MainDlg::StopServer(wxCommandEvent &event) 
{ 
    //................................... 
} 

void MainDlg::AppendStatus(const wxString &message) 
{ 
    statBox->AppendText(message); 
} 

// Well, here is the function I'd like to run in a new thread 
void MainDlg::ListenForMessages() 
{ 
    int MsgSender = 0; 
    while(1) 
    { 
     if(!cnServCon->GetNewMessage()) 
      continue; 

     if(MsgSender = cnServCon->GetJoiningUser()) 
      this->AppendStatus(wxT("Someone connected to the server.")); 
    } 
} 

我還發現wxThread的使用示例從Simple example of threading in C++：

class MessageThread : public wxThread 
{ 
private: 
    MessageThread(const MessageThread &copy); 
public: 
    MessageThread() : wxThread(wxTHREAD_JOINABLE) 
    { 
    } 

    void *Entry(void) 
    { 
     // My works goes here 
     return; 
    } 
}; 

wxThread *CreateThread() 
{ 
     wxThread *_hThread = new MessageThread(); 

     _hThread->Create(); 
     _hThread->Run(); 

     return _hThread; 
} 

但我不知道如何將其與我的程序相關聯，並使其能夠修改我的GUI屬性（statBox）。

任何形式的幫助，將不勝感激！ :)

謝謝。

Answer 1

最簡單的是創建一個事件類型ID，並使用類型ID使用wxCommandEvent，設置它的串部件（「evt.SetText」），和（使用AddPendingEvent）的事件發送到你的一個窗口。在該事件的處理程序中，您可以使用發送的文本（evt.GetText）在您的控件上調用AppendText，因爲此時您已在GUI線程中。

// in header 
DECLARE_EVENT_TYPE(wxEVT_MY_EVENT, -1) 

// in cpp file 
DEFINE_EVENT_TYPE(wxEVT_MY_EVENT) 

// the event macro used in the event table. id is the window id you set when creating 
// the `wxCommandEvent`. Either use -1 or the id of some control, for example. 
EVT_COMMAND(window-id, event-id, handler-function) 

以下是它的工作原理：Custom Events。