问题描述
- QT多线程信号槽没有响应
-
程序逻辑很简单,就是让一个独立线程发送一个信号,UI线程的槽响应,但是运行报错居然是找不到信号
No such signal ,但是编译可以通过,moc文件也有这个信号。大侠们指点一下子,谢谢#include "dialog.h"
#include "ui_dialog.h"Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
connect (&thread,SIGNAL(sendStr(QString)),this,SLOT(MsgStr(QString)),Qt::DirectConnection);
//
}Dialog::~Dialog()
{
delete ui;
}// 启动线程按钮
void Dialog::on_startButton_clicked()
{
thread.start();
ui->startButton->setEnabled(false);
ui->stopButton->setEnabled(true);
}// 终止线程按钮
void Dialog::on_stopButton_clicked()
{
qDebug ()<<"Button";
if (thread.isRunning()) {
thread.stop();
ui->startButton->setEnabled(true);
ui->stopButton->setEnabled(false);
}
}void Dialog::MsgStr(QString &str)
{
qDebug ()<<str;
}/////////////////////////////////////
#ifndef DIALOG_H
#define DIALOG_H#include
#include "mythread.h"
#includenamespace Ui {
class Dialog;
}class Dialog : public QDialog
{
Q_OBJECTpublic:
explicit Dialog(QWidget *parent = 0);
~Dialog();private slots:
void on_startButton_clicked();
void on_stopButton_clicked();
void MsgStr(QString &str);
private:
Ui::Dialog *ui;
CanThread thread;};
#endif // DIALOG_H
////////////////////////////////////////////////////////
#include "mythread.h"
#includeCanThread::CanThread(QObject *parent) :
QThread(parent)
{
stopped = false;
}void CanThread::run()
{
qreal i = 0;
exec ();
while (!stopped) {
// qDebug() << QString("in CanThread: %1").arg(i);
msleep(1000);
QString str = QString("in CanThread: %1").arg(i);
emit sendStr(str);
// exportFun();
i++;
}
stopped = false;
}void CanThread::exportFun()
{
msleep(1000);
}void CanThread::stop()
{
stopped = true;
qDebug ()<<"start 1";
// qDebug ()<<"start 2";
}
////////////////////////////////////////
#ifndef MYTHREAD_H
#define MYTHREAD_H#include
class CanThread : public QThread
{
Q_OBJECT
public:
explicit CanThread(QObject *parent = 0);
void stop();
void exportFun();
protected:
void run();private:
volatile bool stopped;signals:
void sendStr(QString &);
public slots:};
#endif // MYTHREAD_H
解决方案
求求各位大神了,拜托看一眼,信号槽用法应该没有错误,实在没办法,求求大家了
解决方案二:
问题已经解决,问题原因
可能是由于传递的值不可以是局部变量
解决办法信号槽 定义时,不能使用 QString &str 的引用,但是可以这样用const QString &str 或者QString str
解决方案三:
1.一个主界面(主线程),一个次线程,次线程通过信号向主线程传递递增变量,主线程将它显示出来
mythread.h
#include
#include
class Mythread : public QThread
{
Q_OBJECT
public:
Mythread();
protected:
void run();
private:......
答案就在这里:QT 多线程信号与槽(一)
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