Qt记住上次窗口的位置和状态

void MainWindow::showEvent(QShowEvent * event) {
    restoreGeometry(_config->IniRead(QStringLiteral("MainWindow/geometry")).toByteArray()); // 读取位置
    restoreState(_config->IniRead(QStringLiteral("MainWindow/state")).toByteArray());       // 读取状态
}

void MainWindow::closeEvent(QCloseEvent * event) {
    _config->IniWrite(QStringLiteral("MainWindow/geometry"), saveGeometry());   // 记住位置
    _config->IniWrite(QStringLiteral("MainWindow/state"), saveState());     // 记住状态
}