QT基于QScrollArea的界面嵌套移动

在实际的应用场景中，经常会出现软件界面战场图大于实际窗体大小，利用QScrollArea可以为widget窗体添加滚动条，可以实现小窗体利用滚动条显示大界面需求。实现如下：

• QT创建一个qWidget界面

       

• 在ui界面中利用QT自带的widget控件布局一个如下图所示的层叠关系，widget_2界面大小需大于widget大小

       

• 界面布局好后，将widget_2提升为类，提升之前需为工程新添加一个设计界面类，添加完之后，将widget_2提升为类类名和前面新添加的设计界面类名一致

       

 

       

• 源码实现如下

　 patchwindow.h

 1 #ifndef PATCHWINDOW_H 2 #define PATCHWINDOW_H 3  4 #include <QDebug> 5 #include <QPainter> 6 #include <QWidget> 7 #include <QMouseEvent> 8 #include <QStyleOption> 9 #include <QPaintEvent>10 11 enum CursorRegion{12     NONE,13     TOPLEFT,14     TOPRIGHT,15     BOTTOMRIGHT,16     BOTTOMLEFT17 };18 19 namespace Ui {20 class Patchwindow;21 }22 23 class Patchwindow : public QWidget24 {25     Q_OBJECT26 27 public:28     explicit Patchwindow(QWidget *parent = 0);29     ~Patchwindow();30     CursorRegion getCursorRegion(QPoint);31 32 public:33     int borderWidth;34     int handleSize;35 36     bool mousePressed;37     QPoint previousPos;38 39 private:40     Ui::Patchwindow *ui;41 42 protected:43     void mousePressEvent(QMouseEvent*);44     void mouseReleaseEvent(QMouseEvent*);45     void mouseMoveEvent(QMouseEvent*);46 47 signals:48     void send_widget_rx_ry(int rx,int ry);49 };50 51 #endif // PATCHWINDOW_H

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 patchwindow.cpp

 1 #include "patchwindow.h" 2 #include "ui_patchwindow.h" 3  4 Patchwindow::Patchwindow(QWidget *parent) : 5     QWidget(parent), 6     ui(new Ui::Patchwindow) 7 { 8     ui->setupUi(this); 9 10     this->setMouseTracking(true);11 12     setFocusPolicy(Qt::StrongFocus);13 14     mousePressed = false;15     borderWidth = 1;16     handleSize = 8;17 18 }19 20 Patchwindow::~Patchwindow()21 {22     delete ui;23 }24 25 26 //设置鼠标形状27 CursorRegion Patchwindow::getCursorRegion(QPoint pos)28 {29     if (pos.x() > 0 && pos.x() < (handleSize + borderWidth) &&30         pos.y() > 0 && pos.y() < (handleSize + borderWidth)  ){31         if (this->hasFocus())32             this->setCursor(QCursor(Qt::SizeFDiagCursor));33         return CursorRegion::TOPLEFT;34     }35 36     if (pos.x() > (this->width() - handleSize - borderWidth) && pos.x() < this->width() &&37         pos.y() > 0 && pos.y() < (handleSize + borderWidth)  ){38         if (this->hasFocus())39             this->setCursor(QCursor(Qt::SizeBDiagCursor));40         return CursorRegion::TOPRIGHT;41     }42 43     if (pos.x() > (this->width() - handleSize - borderWidth) && pos.x() < this->width() &&44         pos.y() > (this->height() - handleSize - borderWidth) && pos.y() < this->height()  ){45         if (this->hasFocus())46             this->setCursor(QCursor(Qt::SizeFDiagCursor));47         return CursorRegion::BOTTOMRIGHT;48     }49 50 51     if (pos.x() > 0 && pos.x() < (handleSize + borderWidth) &&52         pos.y() > (this->height() - handleSize - borderWidth) && pos.y() < this->height()  ){53         if (this->hasFocus())54             this->setCursor(QCursor(Qt::SizeBDiagCursor));55         return CursorRegion::BOTTOMLEFT;56     }57 58     this->setCursor(Qt::ArrowCursor);59     return CursorRegion::NONE;60 }61 62 void Patchwindow::mousePressEvent(QMouseEvent *event)63 {64     mousePressed = true;65     previousPos = this->mapToParent(event->pos());66     //qDebug()<<"previousPos = "<<previousPos;67 }68 69 void Patchwindow::mouseReleaseEvent(QMouseEvent*)70 {71     mousePressed = false;72 }73 74 void Patchwindow::mouseMoveEvent(QMouseEvent *event)75 {76     if (mousePressed){77         QPoint _curPos = this->mapToParent(event->pos());78         QPoint _offPos = _curPos - previousPos;79         previousPos = _curPos;80         //qDebug()<<"_offPos = "<<_offPos;81         //qDebug()<<"_curPos = "<<_curPos;82         emit send_widget_rx_ry(_offPos.rx(),_offPos.ry());83     }84 }

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 mainwindow.h

 1 #ifndef MAINWINDOW_H 2 #define MAINWINDOW_H 3  4 #include <QMainWindow> 5 #include <QHBoxLayout> 6 #include <QDebug> 7 #include <QScrollArea> 8  9 10 namespace Ui {11 class MainWindow;12 }13 14 class MainWindow : public QMainWindow15 {16     Q_OBJECT17 18 public:19     explicit MainWindow(QWidget *parent = 0);20     ~MainWindow();21 22     QScrollArea *m_pScroll;23 24 25 private:26     Ui::MainWindow *ui;27 28 private slots:29     void remove_widget(int r_x,int r_y);30 31 32 };33 34 #endif // MAINWINDOW_H

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 mainwindow.cpp

 1 #include "mainwindow.h" 2 #include "ui_mainwindow.h" 3 #include <QPalette> 4  5 #include <QScrollBar> 6  7 MainWindow::MainWindow(QWidget *parent) : 8     QMainWindow(parent), 9     ui(new Ui::MainWindow)10 {11     ui->setupUi(this);12     //this->resize(600,600);13 14     //给父窗体填充颜色15     QPalette palette = ui->widget_2->palette();16     palette.setBrush(QPalette::Window,QBrush(QColor(61,61,61)));17     ui->widget_2->setAutoFillBackground(true);18     ui->widget_2->setPalette(palette);19 20     ui->widget_2->setAttribute(Qt::WA_StyledBackground);21     ui->widget_2->setStyleSheet("QWidget{background: black}");22 23     ui->widget_3->setAttribute(Qt::WA_TransparentForMouseEvents, true);//设置该层鼠标事件透明，可以设置为显示层24 25     m_pScroll = new QScrollArea(ui->widget);26     m_pScroll->setWidget(ui->widget_2);//给widget_2设置滚动条27     //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28 29     QHBoxLayout *pLayout = new QHBoxLayout;30     pLayout->addWidget(m_pScroll);31     pLayout->setMargin(0);32     pLayout->setSpacing(0);33     ui->widget->setLayout(pLayout);34 35     connect(ui->widget_2,&Patchwindow::send_widget_rx_ry,this,&MainWindow::remove_widget);36 37 }38 39 MainWindow::~MainWindow()40 {41     delete ui;42 }43 44 void MainWindow::remove_widget(int r_x,int r_y)45 {46     r_y = m_pScroll->verticalScrollBar()->value()-r_y;47     r_x = m_pScroll->horizontalScrollBar()->value()-r_x;48 49     if((0 < r_y) | (r_y == 0))50     {51         if(r_y > m_pScroll->verticalScrollBar()->maximum())52         {53             r_y = m_pScroll->verticalScrollBar()->maximum();54         }55     }56     else57     {58         r_y = 0;59     }60 61     if((0 < r_x) | (r_x == 0))62     {63         if(r_x > m_pScroll->horizontalScrollBar()->maximum())64         {65             r_x = m_pScroll->horizontalScrollBar()->maximum();66         }67     }68     else69     {70         r_x = 0;71     }72 73     m_pScroll->verticalScrollBar()->setValue(r_y);74     m_pScroll->horizontalScrollBar()->setValue(r_x);75 76 }

View Code

• 最终实现效果如下，可以通过滚轮滚动界面，也可以通过鼠标拖拽来实现界面拖拽效果：

    

    工程源码下载路径：

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