Qt保存QPlanTextEdit内容到文件

void SerialPortShell::SaveDate()
{
    QFileDialog dlg(this);
    //获取内容的保存路径
    QString fileName = dlg.getSaveFileName(this, tr("Save As"), "./", tr("Text File(*.txt)"));
    if( fileName == "" )
    {
        return;
    }
    //内容保存到路径文件
    QFile file(fileName);
    //以文本方式打开
    if( file.open(QIODevice::WriteOnly | QIODevice::Text) )
    {
        QTextStream out(&file); //IO设备对象的地址对其进行初始化
        out << ui->plainTextEdit_recevieMessage->toPlainText() << endl; //输出
        QMessageBox::warning(this, tr("Finish"), tr("Successfully save the file!"));
        file.close();
    }
    else
    {
        QMessageBox::warning(this, tr("Error"), tr("File to open file!"));
    }
}