Qt5气泡式聊天框——QListWidget+QPainter实现

版权声明：本文为博主原创文章，未经博主允许不得转载。作者：沙师弟专栏 https://blog.csdn.net/u014597198/article/details/81505832

目录

由于最近的项目需要，做了些相关IM的工作。所以聊天框也是必不可少的一部分。聊天框的制作分很多种，本文以QListWidget+QPainter绘制的Item做了一个Demo。该Demo只是做一个示例，代码已公布如下，需要的拿去！

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效果图

实现原理

气泡式聊天的显示是由QListWidget作为控件，每个气泡是由QListWidgetItem提升成QWidget来实现的。每个气泡可以理解位是一个QWidget，这样可以自由布置QWidget里面的内容。每个Item保存聊天的对话、发送状态、时间、种类等。

这个QWidget主要是显示一个头像+气泡，气泡里面是聊天的内容等。
气泡是在paintEvent事件中，采用QPainter来绘制的。

调用样例

调用头文件：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QListWidgetItem>
#include "chatmessage/qnchatmessage.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

    void dealMessage(QNChatMessage *messageW, QListWidgetItem *item, QString text, QString time, QNChatMessage::User_Type type);
    void dealMessageTime(QString curMsgTime);
protected:
    void resizeEvent(QResizeEvent *event);
private slots:
    void on_pushButton_clicked();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

调用类源文件：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDateTime>
#include <QDebug>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    resize(600, 800);
}

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

void MainWindow::on_pushButton_clicked()
{
    QString msg = ui->textEdit->toPlainText();
    ui->textEdit->setText("");
    QString time = QString::number(QDateTime::currentDateTime().toTime_t()); //时间戳

    bool isSending = true; // 发送中

    qDebug()<<"addMessage" << msg << time << ui->listWidget->count();
    if(ui->listWidget->count()%2) {
        if(isSending) {
            dealMessageTime(time);

            QNChatMessage* messageW = new QNChatMessage(ui->listWidget->parentWidget());
            QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
            dealMessage(messageW, item, msg, time, QNChatMessage::User_Me);
        } else {
            bool isOver = true;
            for(int i = ui->listWidget->count() - 1; i > 0; i--) {
                QNChatMessage* messageW = (QNChatMessage*)ui->listWidget->itemWidget(ui->listWidget->item(i));
                if(messageW->text() == msg) {
                    isOver = false;
                    messageW->setTextSuccess();
                }
            }
            if(isOver) {
                dealMessageTime(time);

                QNChatMessage* messageW = new QNChatMessage(ui->listWidget->parentWidget());
                QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
                dealMessage(messageW, item, msg, time, QNChatMessage::User_Me);
                messageW->setTextSuccess();
            }
        }
    } else {
        if(msg != "") {
            dealMessageTime(time);

            QNChatMessage* messageW = new QNChatMessage(ui->listWidget->parentWidget());
            QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
            dealMessage(messageW, item, msg, time, QNChatMessage::User_She);
        }
    }
    ui->listWidget->setCurrentRow(ui->listWidget->count()-1);
}

void MainWindow::dealMessage(QNChatMessage *messageW, QListWidgetItem *item, QString text, QString time,  QNChatMessage::User_Type type)
{
    messageW->setFixedWidth(this->width());
    QSize size = messageW->fontRect(text);
    item->setSizeHint(size);
    messageW->setText(text, time, size, type);
    ui->listWidget->setItemWidget(item, messageW);
}

void MainWindow::dealMessageTime(QString curMsgTime)
{
    bool isShowTime = false;
    if(ui->listWidget->count() > 0) {
        QListWidgetItem* lastItem = ui->listWidget->item(ui->listWidget->count() - 1);
        QNChatMessage* messageW = (QNChatMessage*)ui->listWidget->itemWidget(lastItem);
        int lastTime = messageW->time().toInt();
        int curTime = curMsgTime.toInt();
        qDebug() << "curTime lastTime:" << curTime - lastTime;
        isShowTime = ((curTime - lastTime) > 60); // 两个消息相差一分钟
//        isShowTime = true;
    } else {
        isShowTime = true;
    }
    if(isShowTime) {
        QNChatMessage* messageTime = new QNChatMessage(ui->listWidget->parentWidget());
        QListWidgetItem* itemTime = new QListWidgetItem(ui->listWidget);

        QSize size = QSize(this->width(), 40);
        messageTime->resize(size);
        itemTime->setSizeHint(size);
        messageTime->setText(curMsgTime, curMsgTime, size, QNChatMessage::User_Time);
        ui->listWidget->setItemWidget(itemTime, messageTime);
    }
}

void MainWindow::resizeEvent(QResizeEvent *event)
{
    Q_UNUSED(event);


    ui->textEdit->resize(this->width() - 20, ui->widget->height() - 20);
    ui->textEdit->move(10, 10);

    ui->pushButton->move(ui->textEdit->width()+ui->textEdit->x() - ui->pushButton->width() - 10,
                         ui->textEdit->height()+ui->textEdit->y() - ui->pushButton->height() - 10);


    for(int i = 0; i < ui->listWidget->count(); i++) {
        QNChatMessage* messageW = (QNChatMessage*)ui->listWidget->itemWidget(ui->listWidget->item(i));
        QListWidgetItem* item = ui->listWidget->item(i);

        dealMessage(messageW, item, messageW->text(), messageW->time(), messageW->userType());
    }
}

实现类

QNChatMessage 头文件：

#ifndef QNCHATMESSAGE_H
#define QNCHATMESSAGE_H

#include <QWidget>

class QPaintEvent;
class QPainter;
class QLabel;
class QMovie;

class QNChatMessage : public QWidget
{
    Q_OBJECT
public:
    explicit QNChatMessage(QWidget *parent = nullptr);

    enum User_Type{
        User_System,//系统
        User_Me,    //自己
        User_She,   //用户
        User_Time,  //时间
    };
    void setTextSuccess();
    void setText(QString text, QString time, QSize allSize, User_Type userType);

    QSize getRealString(QString src);
    QSize fontRect(QString str);

    inline QString text() {return m_msg;}
    inline QString time() {return m_time;}
    inline User_Type userType() {return m_userType;}
protected:
    void paintEvent(QPaintEvent *event);
private:
    QString m_msg;
    QString m_time;
    QString m_curTime;

    QSize m_allSize;
    User_Type m_userType = User_System;

    int m_kuangWidth;
    int m_textWidth;
    int m_spaceWid;
    int m_lineHeight;

    QRect m_iconLeftRect;
    QRect m_iconRightRect;
    QRect m_sanjiaoLeftRect;
    QRect m_sanjiaoRightRect;
    QRect m_kuangLeftRect;
    QRect m_kuangRightRect;
    QRect m_textLeftRect;
    QRect m_textRightRect;
    QPixmap m_leftPixmap;
    QPixmap m_rightPixmap;
    QLabel* m_loading = Q_NULLPTR;
    QMovie* m_loadingMovie = Q_NULLPTR;
    bool m_isSending = false;
};

#endif // QNCHATMESSAGE_H

QNChatMessage 源文件：

#include "qnchatmessage.h"
#include <QFontMetrics>
#include <QPaintEvent>
#include <QDateTime>
#include <QPainter>
#include <QMovie>
#include <QLabel>
#include <QDebug>

QNChatMessage::QNChatMessage(QWidget *parent) : QWidget(parent)
{
    QFont te_font = this->font();
    te_font.setFamily("MicrosoftYaHei");
    te_font.setPointSize(12);
//    te_font.setWordSpacing(0);
//    te_font.setLetterSpacing(QFont::PercentageSpacing,0);
//    te_font.setLetterSpacing(QFont::PercentageSpacing, 100);          //300%,100为默认  //设置字间距%
//    te_font.setLetterSpacing(QFont::AbsoluteSpacing, 0);             //设置字间距为3像素 //设置字间距像素值
    this->setFont(te_font);
    m_leftPixmap = QPixmap(":/img/Customer Copy.png");
    m_rightPixmap = QPixmap(":/img/CustomerService.png");

    m_loadingMovie = new QMovie(this);
    m_loadingMovie->setFileName(":/img/loading4.gif");
    m_loading = new QLabel(this);
    m_loading->setMovie(m_loadingMovie);
    m_loading->resize(16,16);
    m_loading->setAttribute(Qt::WA_TranslucentBackground , true);
    m_loading->setAutoFillBackground(false);
}

void QNChatMessage::setTextSuccess()
{
    m_loading->hide();
    m_loadingMovie->stop();
    m_isSending = true;
}

void QNChatMessage::setText(QString text, QString time, QSize allSize, QNChatMessage::User_Type userType)
{
    m_msg = text;
    m_userType = userType;
    m_time = time;
    m_curTime = QDateTime::fromTime_t(time.toInt()).toString("hh:mm");
    m_allSize = allSize;
    if(userType == User_Me) {
        if(!m_isSending) {
            m_loading->move(m_kuangRightRect.x() - m_loading->width() - 10, m_kuangRightRect.y()+m_kuangRightRect.height()/2- m_loading->height()/2);
            m_loading->show();
            m_loadingMovie->start();
        }
    } else {
        m_loading->hide();
    }

    this->update();
}

QSize QNChatMessage::fontRect(QString str)
{
    m_msg = str;
    int minHei = 30;
    int iconWH = 40;
    int iconSpaceW = 20;
    int iconRectW = 5;
    int iconTMPH = 10;
    int sanJiaoW = 6;
    int kuangTMP = 20;
    int textSpaceRect = 12;
    m_kuangWidth = this->width() - kuangTMP - 2*(iconWH+iconSpaceW+iconRectW);
    m_textWidth = m_kuangWidth - 2*textSpaceRect;
    m_spaceWid = this->width() - m_textWidth;
    m_iconLeftRect = QRect(iconSpaceW, iconTMPH, iconWH, iconWH);
    m_iconRightRect = QRect(this->width() - iconSpaceW - iconWH, iconTMPH, iconWH, iconWH);

    QSize size = getRealString(m_msg); // 整个的size

    qDebug() << "fontRect Size:" << size;
    int hei = size.height() < minHei ? minHei : size.height();

    m_sanjiaoLeftRect = QRect(iconWH+iconSpaceW+iconRectW, m_lineHeight/2, sanJiaoW, hei - m_lineHeight);
    m_sanjiaoRightRect = QRect(this->width() - iconRectW - iconWH - iconSpaceW - sanJiaoW, m_lineHeight/2, sanJiaoW, hei - m_lineHeight);

    if(size.width() < (m_textWidth+m_spaceWid)) {
        m_kuangLeftRect.setRect(m_sanjiaoLeftRect.x()+m_sanjiaoLeftRect.width(), m_lineHeight/4*3, size.width()-m_spaceWid+2*textSpaceRect, hei-m_lineHeight);
        m_kuangRightRect.setRect(this->width() - size.width() + m_spaceWid - 2*textSpaceRect - iconWH - iconSpaceW - iconRectW - sanJiaoW,
                                 m_lineHeight/4*3, size.width()-m_spaceWid+2*textSpaceRect, hei-m_lineHeight);
    } else {
        m_kuangLeftRect.setRect(m_sanjiaoLeftRect.x()+m_sanjiaoLeftRect.width(), m_lineHeight/4*3, m_kuangWidth, hei-m_lineHeight);
        m_kuangRightRect.setRect(iconWH + kuangTMP + iconSpaceW + iconRectW - sanJiaoW, m_lineHeight/4*3, m_kuangWidth, hei-m_lineHeight);
    }
    m_textLeftRect.setRect(m_kuangLeftRect.x()+textSpaceRect,m_kuangLeftRect.y()+iconTMPH,
                           m_kuangLeftRect.width()-2*textSpaceRect,m_kuangLeftRect.height()-2*iconTMPH);
    m_textRightRect.setRect(m_kuangRightRect.x()+textSpaceRect,m_kuangRightRect.y()+iconTMPH,
                            m_kuangRightRect.width()-2*textSpaceRect,m_kuangRightRect.height()-2*iconTMPH);

    return QSize(size.width(), hei);
}

QSize QNChatMessage::getRealString(QString src)
{
    QFontMetricsF fm(this->font());
    m_lineHeight = fm.lineSpacing();
    int nCount = src.count("\n");
    int nMaxWidth = 0;
    if(nCount == 0) {
        nMaxWidth = fm.width(src);
        QString value = src;
        if(nMaxWidth > m_textWidth) {
            nMaxWidth = m_textWidth;
            int size = m_textWidth / fm.width(" ");
            int num = fm.width(value) / m_textWidth;
            int ttmp = num*fm.width(" ");
            num = ( fm.width(value) ) / m_textWidth;
            nCount += num;
            QString temp = "";
            for(int i = 0; i < num; i++) {
                temp += value.mid(i*size, (i+1)*size) + "\n";
            }
            src.replace(value, temp);
        }
    } else {
        for(int i = 0; i < (nCount + 1); i++) {
            QString value = src.split("\n").at(i);
            nMaxWidth = fm.width(value) > nMaxWidth ? fm.width(value) : nMaxWidth;
            if(fm.width(value) > m_textWidth) {
                nMaxWidth = m_textWidth;
                int size = m_textWidth / fm.width(" ");
                int num = fm.width(value) / m_textWidth;
                num = ((i+num)*fm.width(" ") + fm.width(value)) / m_textWidth;
                nCount += num;
                QString temp = "";
                for(int i = 0; i < num; i++) {
                    temp += value.mid(i*size, (i+1)*size) + "\n";
                }
                src.replace(value, temp);
            }
        }
    }
    return QSize(nMaxWidth+m_spaceWid, (nCount + 1) * m_lineHeight+2*m_lineHeight);
}

void QNChatMessage::paintEvent(QPaintEvent *event)
{
    Q_UNUSED(event);

    QPainter painter(this);
    painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);//消锯齿
    painter.setPen(Qt::NoPen);
    painter.setBrush(QBrush(Qt::gray));

    if(m_userType == User_Type::User_She) { // 用户
        //头像
//        painter.drawRoundedRect(m_iconLeftRect,m_iconLeftRect.width(),m_iconLeftRect.height());
        painter.drawPixmap(m_iconLeftRect, m_leftPixmap);

        //框加边
        QColor col_KuangB(234, 234, 234);
        painter.setBrush(QBrush(col_KuangB));
        painter.drawRoundedRect(m_kuangLeftRect.x()-1,m_kuangLeftRect.y()-1,m_kuangLeftRect.width()+2,m_kuangLeftRect.height()+2,4,4);
        //框
        QColor col_Kuang(255,255,255);
        painter.setBrush(QBrush(col_Kuang));
        painter.drawRoundedRect(m_kuangLeftRect,4,4);

        //三角
        QPointF points[3] = {
            QPointF(m_sanjiaoLeftRect.x(), 30),
            QPointF(m_sanjiaoLeftRect.x()+m_sanjiaoLeftRect.width(), 25),
            QPointF(m_sanjiaoLeftRect.x()+m_sanjiaoLeftRect.width(), 35),
        };
        QPen pen;
        pen.setColor(col_Kuang);
        painter.setPen(pen);
        painter.drawPolygon(points, 3);

        //三角加边
        QPen penSanJiaoBian;
        penSanJiaoBian.setColor(col_KuangB);
        painter.setPen(penSanJiaoBian);
        painter.drawLine(QPointF(m_sanjiaoLeftRect.x() - 1, 30), QPointF(m_sanjiaoLeftRect.x()+m_sanjiaoLeftRect.width(), 24));
        painter.drawLine(QPointF(m_sanjiaoLeftRect.x() - 1, 30), QPointF(m_sanjiaoLeftRect.x()+m_sanjiaoLeftRect.width(), 36));

        //内容
        QPen penText;
        penText.setColor(QColor(51,51,51));
        painter.setPen(penText);
        QTextOption option(Qt::AlignLeft | Qt::AlignVCenter);
        option.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
        painter.setFont(this->font());
        painter.drawText(m_textLeftRect, m_msg,option);
    }  else if(m_userType == User_Type::User_Me) { // 自己
        //头像
//        painter.drawRoundedRect(m_iconRightRect,m_iconRightRect.width(),m_iconRightRect.height());
        painter.drawPixmap(m_iconRightRect, m_rightPixmap);

        //框
        QColor col_Kuang(75,164,242);
        painter.setBrush(QBrush(col_Kuang));
        painter.drawRoundedRect(m_kuangRightRect,4,4);

        //三角
        QPointF points[3] = {
            QPointF(m_sanjiaoRightRect.x()+m_sanjiaoRightRect.width(), 30),
            QPointF(m_sanjiaoRightRect.x(), 25),
            QPointF(m_sanjiaoRightRect.x(), 35),
        };
        QPen pen;
        pen.setColor(col_Kuang);
        painter.setPen(pen);
        painter.drawPolygon(points, 3);

        //内容
        QPen penText;
        penText.setColor(Qt::white);
        painter.setPen(penText);
        QTextOption option(Qt::AlignLeft | Qt::AlignVCenter);
        option.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
        painter.setFont(this->font());
        painter.drawText(m_textRightRect,m_msg,option);
    }  else if(m_userType == User_Type::User_Time) { // 时间
        QPen penText;
        penText.setColor(QColor(153,153,153));
        painter.setPen(penText);
        QTextOption option(Qt::AlignCenter);
        option.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
        QFont te_font = this->font();
        te_font.setFamily("MicrosoftYaHei");
        te_font.setPointSize(10);
        painter.setFont(te_font);
        painter.drawText(this->rect(),m_curTime,option);
    }
}

代码分享

码云地址：https://gitee.com/sand_teacher_younger_brother/Demo_MessageChat

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