如何使MFC中的控件线程安全 [英] how to make controls thread safe in MFC

问题描述

我在项目中创建了一个线程，并且使用了丰富的编辑控件来显示数据.当我运行应用程序并尝试在Rich edit控件中显示数据时，它将挂起我的窗口.
所以我想使其成为线程安全的.解决方案是什么?

我已经使用以下代码创建了线程.

在h文件中

I have made one thread in my project and I use rich edit control to show data. When i run my appliaction and i try to show data in Rich edit control , It will hang my window.
So I want to make it thread-safe. What is the solution?

I have created thread using below code.

In h file

static unsigned long __stdcall ReadThread1(void *ptr)
{
    ((CSimpleTestDlg*)ptr)->ReadThread();
    return 0;
}

在cpp文件中

In cpp file

void CSimpleTestDlg::OnBnClickedOk()
{
   HANDLE rt;
   DWORD dwReadThread;
   rt = CreateThread(NULL , 0 , (LPTHREAD_START_ROUTINE)ReadThread1 , this , 0, &dwReadThread);
}

void CSimpleTestDlg::ReadThread()
{
    //code
}

推荐答案

规则是:请勿在其他线程中使用UI函数或操作UI对象.

如果您希望线程更新UI对象，则可以发布或发送消息:该消息将由UI线程处理.

例如，假设您在CDialog派生类中创建了一个线程:

在h文件中:

The rule is: never use UI functions or manipulate UI objects in another thread.

If you want a thread to update an UI object, you can for example post or send a message: the message will be handled by the UI thread.

For example, let''s say you created a thread inside a CDialog-derived class:

In h file:

class CYourDialog : public CDialog
{
    ...
    //the thread function
    static DWORD WINAPI YourThread(LPVOID param);
    ...
    //the message handler
    afx_msg LRESULT OnYourMessage(WPARAM wParam, LPARAM lParam);
};

在cpp文件中:

In cpp file:

//define a user message. Replace x by 0, 1, 2, ..., to define different message IDs.
#define WM_YOUR_MESSAGE (WM_USER + x)

BEGIN_MESSAGE_MAP(CYourDialog, CDialog)
    ....
    // map the message ID to the handler
    ON_MESSAGE(WM_YOUR_MESSAGE, OnYourMessage)
END_MESSAGE_MAP()

DWORD WINAPI CYourDialog::YourThread(LPVOID param)
{
    //when you create your thread
    //give this pointer as a parameter so you can get the pointer back here

    //get our dialog pointer
    CYourDialog* pDlg = (CYourDialog*)param;
    
    //SendMessage is synchronous: it will wait that the message is handled before returning
    //be carefull with that function, because it can easily cause deadlocks
    //if you block the main UI thread.
    pDlg->SendMessage(WM_YOUR_MESSAGE, param1, param2);
    //param1 and param2 can be pointers to structures: just cast them in LPARAM in WPARAM
    ...
    return 0;
}

LRESULT	CYourDialog::OnYourMessage(WPARAM wParam, LPARAM lParam)
{
    //here you can cast wParam and lParam back to their real types
    //your are in the UI thread, you can do whatever you want
    return 0;
}

这篇关于如何使MFC中的控件线程安全的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！