qt的moveToThread将一个类放入线程中后即使不将thread->start(),函数的信号槽就已经无法使用
时间: 2024-04-06 14:32:42 浏览: 62
是的,当你使用`moveToThread`函数将一个类对象放入一个线程中后,如果你不调用`thread->start()`来启动该线程,则该对象的事件循环将无法运行,也就无法处理信号和槽。因此,你需要在将对象放入线程之后,手动调用`thread->start()`函数来启动线程,从而让对象可以正常运行。同时,需要注意的是,在线程执行完成后,你需要调用`thread->quit()`和`thread->wait()`函数来结束线程,避免出现内存泄漏的问题。
相关问题
在userwindow.class类中的void onGetProtocolData()函数中调用AddDataToList()函数,调用AddDataToList函数时候,使用movetothread多线程,要怎么实现?AddDataToList函数如下: void UserWindow::AddDataToList(QStringList strList) { if(!ui->checkBox_4->checkState()) return; int row = ui->tableWidget->rowCount(); ui->tableWidget->insertRow(row); for(int i = 0; i < strList.count();i ++) { QTableWidgetItem *item = new QTableWidgetItem(strList.at(i),0); ui->tableWidget->setItem(row, i, item); if(i != strList.count() - 1) ui->tableWidget->item(row,i)->setTextAlignment(Qt::AlignCenter | Qt::AlignHCenter); } ui->tableWidget->scrollToBottom(); }
要在`onGetProtocolData()`函数中调用`AddDataToList()`函数,并使用`moveToThread`实现多线程,可以按照以下步骤进行操作:
1. 创建一个新的线程对象,并将其设置为`AddDataToList`函数的父对象。这将确保在新线程中执行`AddDataToList`函数。
```cpp
QThread* thread = new QThread(this);
```
2. 创建一个新的对象来执行`AddDataToList`函数。这个对象应该是继承自`QObject`类,并且实现了`AddDataToList`函数的逻辑。
```cpp
class DataProcessor : public QObject
{
Q_OBJECT
public:
explicit DataProcessor(QObject* parent = nullptr) : QObject(parent) {}
public slots:
void AddDataToList(QStringList strList)
{
if(!ui->checkBox_4->checkState())
return;
int row = ui->tableWidget->rowCount();
ui->tableWidget->insertRow(row);
for(int i = 0; i < strList.count();i ++)
{
QTableWidgetItem *item = new QTableWidgetItem(strList.at(i),0);
ui->tableWidget->setItem(row, i, item);
if(i != strList.count() - 1)
ui->tableWidget->item(row,i)->setTextAlignment(Qt::AlignCenter | Qt::AlignHCenter);
}
ui->tableWidget->scrollToBottom();
}
};
```
3. 将新对象移动到新线程中。
```cpp
DataProcessor* dataProcessor = new DataProcessor();
dataProcessor->moveToThread(thread);
```
4. 连接`onGetProtocolData()`函数和`AddDataToList()`函数。这将确保当`onGetProtocolData()`函数被调用时,`AddDataToList()`函数将在新线程中执行。
```cpp
connect(this, &UserWindow::onGetProtocolData, dataProcessor, &DataProcessor::AddDataToList);
```
5. 启动新线程。
```cpp
thread->start();
```
最后,在`onGetProtocolData()`函数中,通过发送信号来调用`AddDataToList()`函数。
```cpp
emit onGetProtocolData(strList);
```
这样,当调用`onGetProtocolData()`函数时,`AddDataToList()`函数将在新线程中执行。请注意,如果在`AddDataToList()`函数中有与GUI相关的操作,需要使用适当的方式进行跨线程通信,以确保线程安全。
void fetchFiles(const QString &path) { emit started(); QThread *thread = new QThread; FileSystemWorker *worker = new FileSystemWorker; worker->moveToThread(thread); connect(thread, &QThread::started, worker, [this, worker, path]() { worker->fetchFiles(path); }); connect(worker, &FileSystemWorker::fileFound, this, &CustomSysmodel::fileFound); connect(worker, &FileSystemWorker::finished, thread, &QThread::quit); connect(worker, &FileSystemWorker::finished, worker, &FileSystemWorker::deleteLater); connect(thread, &QThread::finished, thread, &QThread::deleteLater); connect(worker, &FileSystemWorker::finished, this, &CustomSysmodel::finished); thread->start(); thread->wait(); delete thread; delete worker;} wait()函数阻塞主线程, 改写为用Qt::QueuedConnection实现功能
改写后的代码如下:
```
void fetchFiles(const QString &path) {
emit started();
QThread *thread = new QThread;
FileSystemWorker *worker = new FileSystemWorker;
worker->moveToThread(thread);
connect(thread, &QThread::started, worker, [this, worker, path]() {
worker->fetchFiles(path);
});
connect(worker, &FileSystemWorker::fileFound, this, &CustomSysmodel::fileFound);
connect(worker, &FileSystemWorker::finished, thread, &QThread::quit);
connect(worker, &FileSystemWorker::finished, worker, &FileSystemWorker::deleteLater);
connect(thread, &QThread::finished, thread, &QThread::deleteLater);
connect(worker, &FileSystemWorker::finished, this, &CustomSysmodel::finished);
thread->start();
// 使用 Qt::QueuedConnection 将 wait() 改为槽函数
QMetaObject::invokeMethod(thread, &QThread::wait, Qt::QueuedConnection);
}
```
使用 Qt::QueuedConnection 将 wait() 函数改为槽函数,以避免阻塞主线程。当线程执行完成时,wait() 函数会被调用,等待线程结束。
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