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q
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
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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 BOTTOMLEFT 17 }; 18 19 namespace Ui { 20 class Patchwindow; 21 } 22 23 class Patchwindow : public QWidget 24 { 25 Q_OBJECT 26 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_HView Code
patchwindow.cpp
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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 }View Code
mainwindow.h
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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 QMainWindow 15 { 16 Q_OBJECT 17 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_HView Code
mainwindow.cpp
![](http://img.558idc.com/uploadfile/allimg/boke/ContractedBlock.gif)
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 else 57 { 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 else 69 { 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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