给QWidget添加滚动条（QScrollArea）

Qt版本：Qt 5.2.0

#include "widget.h"
#include "ui_widget.h"

#include <QPalette>
#include <QScrollArea>

Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
this->resize(200,200);

//给父窗体填充颜色
QPalette palette = ui->widget_2->palette();
palette.setBrush(QPalette::Window,QBrush(QColor(61,61,61)));
ui->widget_2->setAutoFillBackground(true);
ui->widget_2->setPalette(palette);

QScrollArea *m_pScroll = new QScrollArea(ui->widget);
m_pScroll->setWidget(ui->widget_2);//给widget_2设置滚动条
ui->widget_2->setMinimumSize(1500,1000);//这里注意，要比主窗体的尺寸要大，不然太小的话会留下一片空白

QHBoxLayout *pLayout = new QHBoxLayout;
pLayout->addWidget(m_pScroll);
pLayout->setMargin(0);
pLayout->setSpacing(0);
ui->widget->setLayout(pLayout);
}

Widget::~Widget()
{
delete ui;
}