QT中的滚动条QScrollArea

QT里的滚动条操作&＃xff0c;
我理解的QScrollArea对象的使用为&＃xff0c;把某个widget绑定到该QScrollArea对象&＃xff0c;scrol->setWidget(widget);
绑定的widget对象的长宽超过边界时&＃xff0c;会有滚动条的效果。

#include
#include
#include
#include
#include
void ScrollArea_test::Init()
{ root_widget_ &＃61; new QWidget(this);setCentralWidget(root_widget_);QVBoxLayout* root_layout &＃61; new QVBoxLayout(root_widget_);setLayout(root_layout);QWidget* widget &＃61; new QWidget();QVBoxLayout* layout &＃61; new QVBoxLayout(widget);setLayout(layout);QPushButton* btn_1 &＃61; new QPushButton();btn_1->setText("zhangsan");btn_1->setFixedSize(600, 600);QPushButton* btn_2 &＃61; new QPushButton();btn_2->setText("zhangsan");btn_2->setFixedSize(600, 600);layout->addWidget(btn_1);layout->addWidget(btn_2);QScrollArea* scrol &＃61; new QScrollArea();scrol->setWidget(widget);scrol->setWidgetResizable(1);scrol->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOn);scrol->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);root_layout->addWidget(scrol);QPushButton* btn_3 &＃61; new QPushButton();btn_3->setText("lisi");btn_3->setFixedSize(100, 100);root_layout->addWidget(btn_3);}

显示效果为&＃xff1a;