Qt的信号和槽的使用方法练习

通过实现两个对话框互相发送消息的功能来熟悉Qt的信号和槽。具体功能：程序为单对话框程序，点击其上的打开按钮可以再次打开一个对话框，两个对话框都有发送消息按钮、输入消息文本框和编辑消息文本框，并实现互发消息功能。

主对话框头文件：

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

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

private:
    Ui::Dialog *ui;
private slots:
    void openDialog();
    void receiveMessage(QString message);
    void pushButtonSendMessage_click();
signals:
void sendMessage(QString);

};

#endif // DIALOG_H

主对话框实现文件：

#include "dialog.h"
#include "ui_dialog.h"
#include "dialogother.h"

namespace {
    DialogOther* other;
}
Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);

    other=new DialogOther();
    connect(ui->pushButton,SIGNAL(clicked(bool)),this,SLOT(openDialog()));
    connect(ui->pushButtonSendMessage,SIGNAL(clicked(bool)),this,SLOT(pushButtonSendMessage_click()));
    connect(this,SIGNAL(sendMessage(QString)),other,SLOT(receiveMessage(QString)));
    connect(other,SIGNAL(sendMessage(QString)),this,SLOT(receiveMessage(QString)));
}

Dialog::~Dialog()
{
    delete ui;
    delete other;
}


void Dialog::openDialog()
{
    other->show();
}

void Dialog::receiveMessage(QString message)
{
    ui->textEdit->setText(nullptr);
    ui->textEdit->setText(message);
}

void Dialog::pushButtonSendMessage_click()
{
    emit sendMessage(ui->lineEdit->text());
}

另一个对话框头文件：

#ifndef DIALOGOTHER_H
#define DIALOGOTHER_H

#include <QDialog>

namespace Ui {
class DialogOther;
}

class DialogOther : public QDialog
{
    Q_OBJECT

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

private:
    Ui::DialogOther *ui;
public slots:
    void receiveMessage(QString message);
    void pushButtonSendMessage_Click();
signals:
    void sendMessage(QString);
};

#endif // DIALOGOTHER_H

另一个对话框实现文件：

#include "dialogother.h"
#include "ui_dialogother.h"

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

    connect(ui->pushButton,SIGNAL(clicked(bool)),this,SLOT(pushButtonSendMessage_Click()));
}

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

void DialogOther::receiveMessage(QString message)
{
    ui->textEdit->setText(nullptr);
    ui->textEdit->setText(message);
}

void DialogOther::pushButtonSendMessage_Click()
{
    emit sendMessage(ui->lineEdit->text());
}