等待线程完成而不冻结MFC中的UI

问题描述

我正在尝试使用AfxBeginThread启动辅助线程，并等待其完成。但是我遇到了一个问题，我可以在没有线程控制的情况下更新UI（显示进度），或者等待线程但UI冻结。我发现了几种获取完成的方法，但是它们都使用WaitForSingleObject。还有其他解决方案吗？这是我的示例代码：

UINT CProgressBarSampleDlg::MyControllingFunction(LPVOID pParam)
{
    CProgressBarSampleDlg* pObject = (CProgressBarSampleDlg*)pParam;

    for (size_t i = 0; i < 10; i++)
    {
        std::this_thread::sleep_for(std::chrono::milliseconds(100)); // simulate long running operation
        
        pObject->m_ProgressBar.StepIt(); // update progress
    }
    
    return 0;
}

void CProgressBarSampleDlg::OnBtnStartClicked()
{
    auto thread = AfxBeginThread(MyControllingFunction,this);
    
    // ... this freezes the UI!
    thread->m_bAutoDelete = FALSE;
    WaitForSingleObject(thread->m_hThread,INFINITE);
    delete thread;
}

解决方法

好吧，在理查德的建议下，我以这种方式解决了这个问题。此外，进度条访问权限已移至消息处理程序中。

UINT CProgressBarSampleDlg::MyControllingFunction(LPVOID pParam)
{
    CProgressBarSampleDlg* pObject = (CProgressBarSampleDlg*)pParam;

    pObject->SendMessage(WM_THREAD_1,(LPARAM)1);
    for (size_t i = 0; i < 10; i++)
    {
        std::this_thread::sleep_for(std::chrono::milliseconds(100)); // simulate long running operation            
        pObject->SendMessage(WM_THREAD_1,(LPARAM)2);
    }
    
    pObject->SendMessage(WM_THREAD_1,(LPARAM)3);
    return 0;
}


void CProgressBarSampleDlg::OnBtnStartClicked()
{
    AfxBeginThread(MyControllingFunction,this);
}

感谢您的想法