#include <QFileDialog>
void MainWindow::on_pushButton_clicked()
{
//""记住上次打开
QString fileName1 = QFileDialog::getOpenFileName(this,"打开","","All File(*.*);;Text(*.txt)");
//"."打开根目录
QString fileName2 = QFileDialog::getOpenFileName(this,"打开",".","All File(*.*);;Text(*.txt)");
//"/"返回上一级
QString fileName3 = QFileDialog::getOpenFileName(this,"打开","/","All File(*.*);;Text(*.txt)");
}