QT widget 添加滚动条

	QVBoxLayout* vLayout = new QVBoxLayout(tasksDetailWidget);
	QLabel* taskNumLabel = new QLabel(QStringLiteral("), tasksDetailWidget);
	//先初始化widget 并设置好布局
	taskListWidget = new QWidget;
	taskListLayout = new QVBoxLayout(taskListWidget);
	taskListLayout->setSpacing(0);
	taskListLayout->setAlignment(Qt::AlignTop);
	taskListWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);

	tasksDetailWidget->resize(1000, 800);
    //基于父widget创建
	QScrollArea* scrollArea = new QScrollArea(tasksDetailWidget);
	scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
	scrollArea->setWidget(taskListWidget); //绑定widget scrollArea成为了widget的父容器
	scrollArea->setWidgetResizable(true);//在widget要显示的内容超出范围时 能够改变widget大小 显示内容

	vLayout->addWidget(taskNumLabel);
	//添加滚动区域
	vLayout->addWidget(scrollArea);