1、颜色对话框
connect(ui->actionNew,&QAction::triggered,[=](){
QColor color = QColorDialog::getColor(QColor(255,0,0));
qDebug() <<"RGB:" << color.red() << color.green() << color.blue();
});
2、文件对话框
connect(ui->actionNew,&QAction::triggered,[=](){
QString str = QFileDialog::getOpenFileName(this,"打开文件","E:/","*.txt");
qDebug() << str;
});
3、字体对话框
connect(ui->actionNew,&QAction::triggered,[=](){
bool flag;
QFont font = QFontDialog::getFont(&flag,QFont("宋体",36));
qDebug() << font.family().toUtf8().data() << font.pointSize() << font.bold() << font.italic();
});