序言
QT用来做界面程序是真的方便，它本身封装了很多类库，需要的时候直接拿来用就行。
QT的类继承关系网上有很多相关的文章，这里不做赘述。但是简单的界面程序最主要的继承关系还是如下图：
可以将QT的类库分为两个大类，对象和事件。对象之间的信息传递为信号，执行操作的是槽函数。事件的发生则是人机交互的过程，比如鼠标点击、鼠标滚轮滑动、键盘按键等。
算了不多说了，直接上效果图：
太累了，直接上程序程序代码：
#ifndef DRAW_H
#define DRAW_H
#include <QWidget>
#include "map.h"
#include "drawpixmap.h"
#include "coordtrans.h"
#include <QMouseEvent>
#include <QPushButton>
class Draw : public QWidget
{
Q_OBJECT
public:
Draw(Map& rMap);
~Draw();
// Member Funcitons
void mousePressEvent(QMouseEvent *event);
void mouseMoveEvent(QMouseEvent *event);
void mouseReleaseEvent(QMouseEvent *event);
void paintEvent(QPaintEvent *event);
void wheelEvent(QWheelEvent *event);
void setupUi(int iWidth, int iHeight);
// Properties
int _iAction;
QPushButton* _pBtn1;
QPushButton* _pBtn2;
QPushButton* _pBtn3;
QPushButton* _pBtn4;
QWidget* _pWgt;
QPixmap* _pPixmap;
QPixmap* _pPixmap2;
QPainter* _pPainter;
QPoint _beginPos;
QPoint _endPos;
bool _bIsLefButtonDown;
int _iXOffset,_iYOffset;
int _iXAllOffset,_iYAllOffset;
DrawPixmap _pDrawPixmap;
Box* pBox; // 用来调用Box类的成员函数
CoordTrans _Transfer;
Map* pMap;
int _mousePos[4];
QPoint _PointBegin;
QPoint _PointEnd;
public slots:
void frameAmpliffication();
void recover();
void dragMove();
void loadFile();
};
#endif // DRAW_H
这是draw,h头文件，源文件代码如下：
#include "draw.h"
#include <QPainter>
#include <iostream>
#include <QBitmap>
Draw::Draw(Map& rMap) :_pDrawPixmap(&rMap)
{
setupUi(800,600);
this->pMap = &rMap;
_pPixmap = new QPixmap(this->width(), this->height()-30);
_pPixmap->fill(Qt::white);
_Transfer.Initialize(pMap->_dBox, this->width(), this->height()-30);
_pPixmap2=new QPixmap(this->width(),this->height()-30);
_pPixmap2->fill(Qt::transparent);
_iXOffset=0,_iYOffset=0;
_iXAllOffset=0;_iYAllOffset=0;
_iAction=0;
}
Draw::~Draw()
{
}
void Draw::paintEvent(QPaintEvent*)
{
QPainter painter(this);
if(_iAction==1)
{
// 框选放大按钮点击
_pDrawPixmap.update(&_Transfer, _pPixmap,0,0);
painter.drawPixmap(0,30,this->width(),this->height()-30,*_pPixmap/*, -_iXAllOffset, -_iYAllOffset,this->width(),this->height()-30*/);
painter.drawPixmap(0,30,this->width(),this->height()-30,*_pPixmap2);
}
else if(_iAction==0 || _iAction==2)
{
// 初始状态或者恢复按钮点击
_pDrawPixmap.update(&_Transfer, _pPixmap,0,0);
painter.drawPixmap(0,30,this->width(),this->height()-30,*_pPixmap/*, -_iXAllOffset, -_iYAllOffset,this->width(),this->height()-30*/);
}
if(_iAction==3)
{
// 拖拽移动按钮点击
_pPixmap->fill(Qt::white);
_pDrawPixmap.update(&_Transfer, _pPixmap,_iXAllOffset,_iYAllOffset);
painter.drawPixmap(0,30,*_pPixmap );
}
}
void Draw::mousePressEvent(QMouseEvent* event)
{
_beginPos.setX(event->x());
_beginPos.setY(event->y()-30);
_mousePos[0] = event->x();
_mousePos[1] = event->y()-30;
_bIsLefButtonDown=true;
if(_iAction==1)
{
}
else if(_iAction==2)
{
}
else if(_iAction==3)
{
_iXAllOffset+=_iXOffset;
_iYAllOffset+=_iYOffset;
}
}
void Draw::mouseMoveEvent(QMouseEvent *event)
{
_endPos.setX(event->pos().x());
_endPos.setY(event->pos().y()-30);
if(_bIsLefButtonDown)
{
if(_iAction==1)
{
QPainter painter2(_pPixmap2);
_pPixmap2->fill(Qt::transparent);
painter2.drawRect(QRect(_beginPos,_endPos));
update();
}
if(_iAction==3)
{
int tempx=_iXOffset;
int tempy=_iYOffset;
_iXOffset = _endPos.x()-_beginPos.x();
_iYOffset = _endPos.y()-_beginPos.y();
_iXAllOffset += (_iXOffset-tempx);
_iYAllOffset += (_iYOffset-tempy);
update();
}
}
}
void Draw::mouseReleaseEvent(QMouseEvent* event)
{
if(_iAction==1)
{
if(event->button() == Qt::LeftButton)
{
_bIsLefButtonDown=false;
_mousePos[2] = event->x();
_mousePos[3] = event->y()-30;
double dxb,dyb,dxe,dye;
_Transfer.C2M(_mousePos[0],_mousePos[1],dxb,dyb);
_Transfer.C2M(_mousePos[2],_mousePos[3],dxe,dye);
double ChosenArea[4]={
dxb,dyb,dxe,dye};
_Transfer.Initialize(ChosenArea,this->width(),this->height()-30);
_pPixmap->fill(Qt::white);
_pPixmap2->fill(Qt::transparent);
update();
}
}
else if(_iAction==2)
{
}
else if(_iAction==3)
{
}
else if(_iAction==4)
{
}
}
void Draw::wheelEvent(QWheelEvent *event)
{
if(event->delta()>0)
{
}
}
void Draw::setupUi(int iWidth, int iHeight)
{
this->setWindowTitle("MyAPP");
this->resize(iWidth,iHeight);
_pBtn1=new QPushButton("框选放大",this);
_pBtn1->setGeometry(0,0,80,30);
connect(_pBtn1,SIGNAL(clicked()),this,SLOT(frameAmpliffication()));
_pBtn2=new QPushButton("恢复",this);
_pBtn2->setGeometry(85,0,80,30);
connect(_pBtn2,SIGNAL(clicked()),this,SLOT(recover()));
_pBtn3=new QPushButton("拖拽移动",this);
_pBtn3->setGeometry(170,0,80,30);
connect(_pBtn3,SIGNAL(clicked()),this,SLOT(dragMove()));
_pBtn4=new QPushButton("加载文件",this);
_pBtn4->setGeometry(255,0,80,30);
connect(_pBtn4,SIGNAL(clicked()),this,SLOT(loadFile()));
}
void Draw:: frameAmpliffication()
{
this->setCursor(Qt::ArrowCursor);
_iAction=1;
}
void Draw:: recover()
{
_iAction=2;
this->setCursor(Qt::ArrowCursor);
_pPixmap->fill(Qt::white);
_Transfer.Initialize(pMap->_dBox,this->width(),this->height()-30);
update();
}
void Draw:: dragMove()
{
_iAction=3;
if(this->cursor().pos().y()>30)
this->setCursor(Qt::OpenHandCursor);
}
void Draw:: loadFile()
{
_iAction=4;
}
有不懂的留言，我时常来逛。太累了，睡觉了。