一、简介

在QGraphicsItem中使用QGraphicsItemAnimation和QTimeLine来实现动画的显示。其中的数据都是测试数据，仅为显示动画效果。

二、详解

1、部分代码

（1）LogMessagesItem.h

#ifndef _LOGMESSAGEITEM_H_#define _LOGMESSAGEITEM_H_#include 
   
    #include 
    
     #include "clusterpagenumber.h"#include "calendarselected.h"class LogContentItem;class LogMessagesItem : public QObject, public QGraphicsItem{    Q_OBJECTpublic:    explicit LogMessagesItem(QGraphicsItem *parent = 0);    QRectF boundingRect() const;    void setSize(const int width, const int height);protected:    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);    bool eventFilter(QObject *obj, QEvent *event);private:    void getLogContents();    void showLogs();    void hideLogItem();private:    int _width;    int _height;    int totalLogs;    int totalPageNumber;    int currentPageNumber;    ClusterPageNumber *pageNumber;    CalendarSelected *calendar;    QList
     
      logItem;    QGraphicsRectItem *rectItem;    bool leftToRight;private slots:    void slotCalendarFinish();    void slotLogPageChange(int index);};class LogContentItem : public QGraphicsItem{public:    explicit LogContentItem(QGraphicsItem *parent = 0);    ~LogContentItem();    QRectF boundingRect() const;    void setData(const QList
      
        &data);protected:    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);private:    QGraphicsTextItem *timeText;    QGraphicsTextItem *typeText;    QGraphicsTextItem *stateText;    QGraphicsTextItem *describeText;};#endif

（2）LogMessagesItem.cpp

#include "LogMessagesItem.h"#define MAXLOGSRPERPAGE 4LogMessagesItem::LogMessagesItem(QGraphicsItem *parent)    : QGraphicsItem(parent)    , totalLogs(0)    , totalPageNumber(1)    , currentPageNumber(1)    , leftToRight(true){    _width = 633;    _height = 437;    logItem.clear();    setFiltersChildEvents(true);    calendar = new CalendarSelected;    QGraphicsProxyWidget *calendarProxy = new QGraphicsProxyWidget(this);    calendarProxy->setWidget(calendar);    calendarProxy->setPos(10, 10);    calendarProxy->show();    calendarProxy->setZValue(1);    connect(calendar, SIGNAL(finish()), this, SLOT(slotCalendarFinish()));    pageNumber = new ClusterPageNumber;    //pageNumber->setBackgroundColor(QColor("#FF0000"));    pageNumber->resize(248, 18);    pageNumber->setTitle(tr("合计日志条数"), 0);    pageNumber->setCurrentAndTotalPage(1, 10);    QGraphicsProxyWidget *pageNumberProxy = new QGraphicsProxyWidget(this);    pageNumberProxy->setWidget(pageNumber);    pageNumberProxy->setPos(633 - 248 -10, 437 - 35);    pageNumberProxy->show();    connect(pageNumber, SIGNAL(currentPageChanged(int)), this, SLOT(slotLogPageChange(int)));    QGraphicsTextItem *title = new QGraphicsTextItem(this);    title->setDefaultTextColor(QColor("#666666"));    title->setFont(QFont("arial", 10, QFont::Normal));    title->setPlainText(tr("按状态："));    title->setPos(460, 10);    QComboBox *logListBox = new QComboBox;    logListBox->resize(100, 23);    logListBox->setStyleSheet("QComboBox{border:1px solid #d7d7d7; border-radius: 3px; padding: 1px 18px 1px 3px;} "                          "QComboBox:editable{ background: white; }"                          "QComboBox:!editable{ background: #fbfbfb; color:#666666}"                          "QComboBox::drop-down{ subcontrol-origin: padding; subcontrol-position: top right; width: 22px; border-left-width: 1px; border-left-color: #c9c9c9; border-left-style: solid; /* just a single line */ border-top-right-radius: 3px; /* same radius as the QComboBox */ border-bottom-right-radius: 3px; }"                          "QComboBox::down-arrow { image: url(:/resources/images/input_drop_down.png); }"                          "QComboBox::down-arrow:on { /* shift the arrow when popup is open */ top: 1px; left: 1px;}"                          "QComboBox QAbstractItemView::item{max-width: 30px;min-height: 20px}");    QListView *listView = new QListView;    listView->setStyleSheet("QListView{font-size: 11px}"                           " QListView::item:!selected{color: #19649f}"                            "QListView::item:selected:active{background-color: #1275c3}"                            "QListView::item:selected{color: white}");    logListBox->setView(listView);    logListBox->addItem(tr("所有日志"));    logListBox->addItem(tr("错误日志"));    logListBox->addItem(tr("警告日志"));    QGraphicsProxyWidget *listBoxrProxy = new QGraphicsProxyWidget(this);    listBoxrProxy->setWidget(logListBox);    listBoxrProxy->setPos(522, 12);    listBoxrProxy->setZValue(1);    listBoxrProxy->show();    rectItem = new QGraphicsRectItem(QRectF(0, 0, 610, 85*4), this);    rectItem->setPos(12, 45);    rectItem->setPen(Qt::NoPen);    rectItem->setFlag(QGraphicsItem::ItemClipsChildrenToShape,true);    getLogContents();}QRectF LogMessagesItem::boundingRect() const{    return QRectF(0,0, _width, _height);}void LogMessagesItem::setSize(const int width, const int height){    _width = width;    _height = height;}void LogMessagesItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget){}bool LogMessagesItem::eventFilter(QObject *obj, QEvent *event){    if (obj != calendar && event->type() == QEvent::MouseButtonPress) {        this->clearFocus();        calendar->setHideQDialog();        return true;    }    if (event->type() == QEvent::Hide) {        calendar->setHideQDialog();    }    if (event->type() == QEvent::Show) {    }    return QObject::eventFilter(obj, event);}void LogMessagesItem::getLogContents(){    for (int i =0; i < 22; i++) {        QList
   
     data;        data.append("2015-02-13 12:08:57");        data.append("新建系统");        data.append("系统创建完毕");        data.append(tr("成功创建系统(%1)").arg(i + 1));        LogContentItem *contentItem = new LogContentItem(rectItem);        contentItem->setData(data);        contentItem->hide();        logItem.append(contentItem);    }}void LogMessagesItem::showLogs(){    totalLogs = logItem.count();    //totalLogs = 22;    totalPageNumber = 6;    //currentPageNumber = 1;    hideLogItem();    pageNumber->setTitle(tr("合计日志条数"), 22);    pageNumber->setCurrentAndTotalPage(currentPageNumber, 6);    LogContentItem *item = NULL;    int index = (currentPageNumber - 1)*MAXLOGSRPERPAGE;    for(int number = 0; index < totalLogs && index < currentPageNumber*MAXLOGSRPERPAGE; index++, number++) {        item = logItem.at(index);        item->setPos(0, number*85);        item->show();        QGraphicsItemAnimation *animation = new QGraphicsItemAnimation(this);        animation->setItem(item);        QTimeLine *timeLine = new QTimeLine(400);        animation->setTimeLine(timeLine);        if (leftToRight == true) {            animation->setPosAt(0, QPointF( -608, number*85));            animation->setPosAt(1, QPointF(0, number*85));        }        else {            animation->setPosAt(0, QPointF( 608, number*85));            animation->setPosAt(1, QPointF(0, number*85));        }        timeLine->start();    }}void LogMessagesItem::hideLogItem(){    for (int index = 0; index < logItem.count(); index++) {        if (logItem.at(index)) {            logItem.at(index)->hide();        }    }}void LogMessagesItem::slotCalendarFinish(){    showLogs();}void LogMessagesItem::slotLogPageChange(int index){    if (currentPageNumber < index) {        leftToRight = true;    }    else {        leftToRight = false;    }    currentPageNumber = index;    showLogs();}/*****************************LogContentItem********************************/LogContentItem::LogContentItem(QGraphicsItem *parent)    : QGraphicsItem(parent){    timeText = new QGraphicsTextItem(this);    timeText->setDefaultTextColor(QColor("#999999"));    timeText->setFont(QFont("arial", 10, QFont::Normal));    timeText->setPos(boundingRect().right() - 125, boundingRect().top());    typeText = new QGraphicsTextItem(this);    typeText->setDefaultTextColor(QColor("#666666"));    typeText->setFont(QFont("arial", 10, QFont::Normal));    typeText->setPos(boundingRect().left() + 15, boundingRect().top() + 10);    stateText = new QGraphicsTextItem(this);    stateText->setDefaultTextColor(QColor("#666666"));    stateText->setFont(QFont("arial", 10, QFont::Normal));    stateText->setPos(boundingRect().left() + 15, boundingRect().top() + 30);    describeText = new QGraphicsTextItem(this);    describeText->setDefaultTextColor(QColor("#666666"));    describeText->setFont(QFont("arial", 10, QFont::Normal));    describeText->setPos(boundingRect().left() + 15, boundingRect().top() + 50);}LogContentItem::~LogContentItem(){}QRectF LogContentItem::boundingRect() const{    return QRectF(0, 0, 608, 80);}void LogContentItem::setData(const QList
    
      &data){    timeText->setPlainText(data.at(0));    typeText->setPlainText(QObject::tr("类型：%1").arg(data.at(1)));    stateText->setPlainText(QObject::tr("状态：%1").arg(data.at(2)));    describeText->setPlainText(QObject::tr("描述：%1").arg(data.at(3)));}void LogContentItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget){    painter->setPen(QPen(QColor("#BBBBBB")));    painter->setBrush(QColor("#FFFFFF"));    painter->drawRect(0, 0, 608, 80);}

（3）LogMessagesView.h

#ifndef LOGMESSAGESVIEW_H#define LOGMESSAGESVIEW_H#include 
   
    #include 
    
     #include 
     
      #include 
      
       #include 
       
        class LogMessagesView : public QGraphicsView{    Q_OBJECTpublic:    LogMessagesView(QWidget *parent = 0);    ~LogMessagesView();protected:    void mousePressEvent ( QMouseEvent * event);    void mouseMoveEvent(QMouseEvent *event);    void mouseReleaseEvent(QMouseEvent *event);private:    QPoint dragPosition;    bool bPressFlag;};#endif // LOGMESSAGESVIEW_H

（4）LogMessagesView.cpp

#include "LogMessagesView.h"#include "LogMessagesItem.h"LogMessagesView::LogMessagesView(QWidget *parent)    : QGraphicsView(parent)    , bPressFlag(false){    QTextCodec *codec = QTextCodec::codecForName("System");    QTextCodec::setCodecForLocale(codec);    QTextCodec::setCodecForCStrings(codec);    QTextCodec::setCodecForTr(codec);    int width = 633;    int height = 437;    setWindowFlags(Qt::Widget |Qt::FramelessWindowHint);    //setStyleSheet("background:transparent;border:0px");    this->setBackgroundBrush(QBrush(QColor("#EEF7FD")));    QGraphicsScene *scene = new QGraphicsScene(this);    scene->setSceneRect(-width/2,-height/2,width,height);    setSceneRect(2, 2, width - 4, height - 4);    setScene(scene);    setCacheMode(QGraphicsView::CacheBackground);    setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);    LogMessagesItem *item = new LogMessagesItem;    this->installEventFilter(item);    scene->addItem(item);}LogMessagesView::~LogMessagesView(){}void LogMessagesView::mousePressEvent ( QMouseEvent * event){    bPressFlag = true;    dragPosition = event->pos();    QGraphicsView::mousePressEvent(event);}void LogMessagesView::mouseMoveEvent(QMouseEvent *event){    if (bPressFlag) {        QPoint relaPos(QCursor::pos() - dragPosition);        move(relaPos);    }    QGraphicsView::mouseMoveEvent(event);}void LogMessagesView::mouseReleaseEvent(QMouseEvent *event){    bPressFlag = false;    QGraphicsView::mouseReleaseEvent(event);}