qt 窗体间通信

利用qt的信号和槽，可以完成窗体间的通信，下面列出父子窗口利用信号和槽的相关代码。

parent窗口：

//parent.h

#ifndef PARENT_H
#define PARENT_H

#include <QMainWindow>
#include "child.h"

namespace Ui {
class Parent;
}

class Parent : public QMainWindow
{
    Q_OBJECT

public:
    explicit Parent(QWidget *parent = 0);
    ~Parent();

signals:
    //打开子窗口的信号
    void childOpen(const QString &message);

private slots:
    //打开子窗口
    void on_pushButtonParent_clicked();
    //接收子窗口关闭的信号的槽
    void on_child_closed(const QString &message);

private:
    Ui::Parent *ui;
};

#endif // PARENT_H

//parent.cpp

#include "parent.h"
#include "ui_parent.h"

Parent::Parent(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::Parent)
{
    ui->setupUi(this);
}

Parent::~Parent()
{
    delete ui;
}

void Parent::on_pushButtonParent_clicked()
{
    Child *child = new Child();
    //向子窗口发送信号
    connect(this, SIGNAL(childOpen(QString)), child, SLOT(on_open(QString)));
    emit childOpen("子窗口打开,父窗口传递消息到子窗口");

    //连接子窗口关闭的信号
    connect(child, SIGNAL(closed(QString)), this, SLOT(on_child_closed(QString)));
    child->exec();
    //注意,需要关闭,否则到时打开几次子窗口就会触发几次窗口打开信号
    disconnect(this, SIGNAL(childOpen(QString)), child, SLOT(on_open(QString)));
}


void Parent::on_child_closed(const QString &message)
{
    QMessageBox::information(NULL, "父窗口", message);
}

 

child窗体:

//child.h

#ifndef CHILD_H
#define CHILD_H

#include <QDialog>
#include <QMessageBox>

namespace Ui {
class Child;
}

class Child : public QDialog
{
    Q_OBJECT

public:
    explicit Child(QWidget *parent = 0);
    ~Child();
public slots:
    //接收窗口打开信号的槽
    void on_open(const QString &message);
    //关闭窗口
    void on_pushButtonChild_clicked();
signals:
    //窗口关闭的信号
    void closed(const QString &message);

private:
    Ui::Child *ui;
};

#endif // CHILD_H

//child.cpp

#include "child.h"
#include "ui_child.h"

Child::Child(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Child)
{
    ui->setupUi(this);
}

Child::~Child()
{
    delete ui;
}

void Child::on_open(const QString &message)
{
    QMessageBox::information(NULL, "子窗口", message);
}

void Child::on_pushButtonChild_clicked()
{
    this->close();
    emit closed("子窗口关闭,向父窗口发送消息");
}

结果截图：