QT的常用对话框的应用

QMessageBox类提供了常用的弹出式对话框：提示、警告、错误、询问、关于对话框

需要添加头文件

#include <QMessageBox>

MESSAGE  是要是显示的字符串

    void Dialog::criticalMessage()
    {
        QMessageBox::StandardButton reply;
        reply = QMessageBox::critical(this, tr("QMessageBox::critical()"),
                                        MESSAGE,
                                        QMessageBox::Abort | QMessageBox::Retry | QMessageBox::Ignore);
        if (reply == QMessageBox::Abort)
            criticalLabel->setText(tr("Abort"));
        else if (reply == QMessageBox::Retry)
            criticalLabel->setText(tr("Retry"));
        else
            criticalLabel->setText(tr("Ignore"));
    }  

    void Dialog::informationMessage()
    {
        QMessageBox::StandardButton reply;
        reply = QMessageBox::information(this, tr("QMessageBox::information()"), MESSAGE);
        if (reply == QMessageBox::Ok)
            informationLabel->setText(tr("OK"));
        else
            informationLabel->setText(tr("Escape"));
    }  

    void Dialog::questionMessage()
    {
        QMessageBox::StandardButton reply;
        reply = QMessageBox::question(this, tr("QMessageBox::question()"),
                                        MESSAGE,
                                        QMessageBox::Yes | QMessageBox::No | QMessageBox::Cancel);
        if (reply == QMessageBox::Yes)
            questionLabel->setText(tr("Yes"));
        else if (reply == QMessageBox::No)
            questionLabel->setText(tr("No"));
        else
            questionLabel->setText(tr("Cancel"));
    }  

    void Dialog::warningMessage()
    {
        QMessageBox msgBox(QMessageBox::Warning, tr("QMessageBox::warning()"),
                           MESSAGE, 0, this);
        msgBox.addButton(tr("Save &Again"), QMessageBox::AcceptRole);
        msgBox.addButton(tr("&Continue"), QMessageBox::RejectRole);
        if (msgBox.exec() == QMessageBox::AcceptRole)
            warningLabel->setText(tr("Save Again"));
        else
            warningLabel->setText(tr("Continue"));  

    }