windows之MFC进度条

创建UI线程

创建线程类

在vsstudio2019中按快捷键ctrl+shift+x弹出类向导，在类向导中添加MFC类，选择父类为CWinThread。定义类名称点击确定即可。

关联该UI线程对应的对话框

BOOL CProgressThread::InitInstance()
 {
     CProgressDlg dlgprogress;
     m_pMainWnd = &dlgprogress;
     dlgprogress.DoModal();
     return TRUE;
 }

定义线程处理消息及函数

在头文件中定义线程处理消息宏，需要基于WM_USER加上自定义值。如：

#define WM_THREAD_MESSAGES      WM_USER + 8

添加对应的消息处理函数：

 // 头文件中声明
 void OnThreadMessages(WPARAM wParam, LPARAM lParam);

 // cpp文件中建立消息关联
 BEGIN_MESSAGE_MAP(CProgressThread, CWinThread)
     ON_THREAD_MESSAGE(WM_THREAD_MESSAGES, &CProgressThread::OnThreadMessages)
 END_MESSAGE_MAP()

 void CProgressThread::OnThreadMessages(WPARAM wParam, LPARAM lParam)
 {
     CProgressDlg* dlgprogress = ((CProgressDlg*)GetMainWnd());
     const int flag = (int)wParam;
     switch (flag)
     {
     case 0:
         dlgprogress->EndDialog(IDCANCEL); 
         break;
     case 1: {
         const CString tips = *(CString*)lParam;
         dlgprogress->SetTips(tips);
         }
         break;
     case 2:
         break;
     default:
         break;
     }
 }

线程消息处理函数中处理进度条进度位置及信息提示，可自定义wParam及lParam来实现进度、提示传递。

创建关联的对话框

创建一个普通对话框，添加信息提示控件CStatic及进度条控件CProgressCtrl, 设置进度条控件为来回滚动形式而非进度递增新式。这样就不用传递进度信息了。

m_progress_ctrl.SetMarquee(TRUE, 30);

要实现来回滚动的效果需要添加启用通用控件声明, 否则滚动条将不会呈现预期效果：

#if defined _M_IX86
#pragma comment(linker, "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='x86' publicKeyToken='6595b64144ccf1df' language='*'\"")
#elif defined _M_IA64
#pragma comment(linker, "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='ia64' publicKeyToken='6595b64144ccf1df' language='*'\"")
#elif defined _M_X64
#pragma comment(linker, "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='amd64' publicKeyToken='6595b64144ccf1df' language='*'\"")
#else
#pragma comment(linker, "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
#endif

封装对外接口

封装对外接口调用UI线程，隐藏内部进度条实现。


class Progress
{
public:
	Progress();
	~Progress();

	void Start();
	void End();
	void UpdateTips(const CString& tips);


private:
	struct Impl;
	Impl* impl_;

};

在以上声明的Start()接口中创建UI线程：

void Progress::Start()
{
	impl_->thread = AfxBeginThread(RUNTIME_CLASS(CProgressThread));
}

其他接口实现如下：


void Progress::End()
{
	impl_->thread->PostThreadMessage(WM_THREAD_MESSAGES, (WPARAM)0, (LPARAM)0);
}

void Progress::UpdateTips(const CString& tips)
{
	impl_->tips = tips;
	impl_->thread->PostThreadMessage(WM_THREAD_MESSAGES, (WPARAM)1, (LPARAM)&impl_->tips);
}