QT进度条显示功能的状态 [英] QT Progress bar showing status of a function

问题描述

最近我正在使用QT的点云图书馆项目。

例如，我创建了一个类名系统，其公共函数名为 estimate_normal 。在这个 estimate_normal 内，我从PCL库调用一些函数，在MainWindow.cpp中调用

  system a; 
 a.estimate_normal（）; 
 

我可以通过使用QT进度条看到这个 estimate_normal status？

感谢

解决方案应该在堆上创建类system的对象，并将其移动到一个新的线程，以防止estimate_normal（）阻塞主线程和UI。这可以这样做：

  a = new system（）; 
 QThread * th = new QThread（）; 
 a-> moveToThread（th）; 
 
 QObject :: connect（th，SIGNAL（started（）），a，SLOT（OnStarted（）））; 
 QObject :: connect（th，SIGNAL（finished（）），a，SLOT（OnFinished（）））; 
 
 th-> start（）; 
  

类system中的初始化和终止任务应该在OnStarted（）和OnFinished ）槽。

您应该使用类system中的信号来通知用户界面中进度条的进度条。在你的estimate_normal（）函数中，你应该发出具有适当值的信号。信号如下：

  void progressChanged（int val）; 
  

您还应该将progressChanged（int）信号连接到QProgressBar的setValue 。

最后一点是，在其他线程中，不应直接调用estimate_normal（）。正确的方法是将estimate_normal（）定义为一个插槽，并将信号连接到该插槽，并在您想调用estimate_normal（）时发出信号。

recently I'm working on Point cloud Library project with QT. I'd like to know if I can know the current progress when I use a function.

For example, I create a class name system with a public function named estimate_normal. Inside this estimate_normal, I call some functions from the PCL library, and in MainWindow.cpp I call

system a;
a.estimate_normal();

Can I know the progress by using QT Progress bar to see this estimate_normal status?

Thanks

解决方案

You should create your object of the class "system" on the heap and move it to a new thread in order to prevent estimate_normal() from blocking main thread and the UI. This can be done like:

a = new system();
QThread * th = new QThread();
a->moveToThread(th);

QObject::connect(th,SIGNAL(started()),a,SLOT(OnStarted()));
QObject::connect(th,SIGNAL(finished()),a,SLOT(OnFinished()));

th->start();

Your initialization and termination tasks in the class "system" should be done in OnStarted() and OnFinished() slots respectively.

You should use a signal in the class "system" to notify the progress bar in your user interface of the value for the progress. In your estimate_normal() function you should emit the signal with the appropriate value. The signal is like:

void progressChanged(int val);

You should also connect the progressChanged(int) signal to the setValue(int value) slot of the QProgressBar.

And the last point is that you should not call estimate_normal() directly when it is in an other thread. The correct way is defining estimate_normal() as a slot and connecting a signal to that slot and emitting the signal when you want to call estimate_normal().

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