使用QPainter 画饼图

具体如图所示：

当单击不同的tab标签时，根据表中的数据显示不同的饼图。

具体部分代码如下所示：

//根据数据绘制饼图

void ProTeam::paintEvent(QPaintEvent *)

{

    QPainter painter(this);

    painter.fillRect(510,420,10,10,Qt::red);

    painter.fillRect(510,440,10,10,Qt::blue);

    painter.fillRect(510,460,10,10,Qt::yellow);

    painter.fillRect(510,480,10,10,Qt::green);

    double first=ui->lineFirst->text().toDouble();

    double second=ui->lineSecond->text().toDouble();

    double third=ui->lineThird->text().toDouble();

    double fourth=ui->lineFour->text().toDouble();

    double sum=first+second+third+fourth;

    QPainter painter2(this);//四种信号量的饼状图绘制

    painter2.setBrush(Qt::red);

    painter2.setPen(Qt::NoPen);

    painter2.drawPie(400,400,100,100,0,360*16*first/sum);

    painter2.setBrush(Qt::blue);

    painter2.drawPie(400,400,100,100,360*16*first/sum,360*16*second/sum);

    painter2.setBrush(Qt::yellow);

    painter2.drawPie(400,400,100,100,360*16-360*16*third/sum-360*16*fourth/sum,360*16*third/sum);

    painter2.setBrush(Qt::green);

    painter2.drawPie(400,400,100,100,360*16-360*16*fourth/sum,360*16*fourth/sum);

}

//当lineEdit框中的内容发生改变时，所画的饼图也跟着改变

void ProTeam::on_lineFirst_textChanged(const QString &arg1)

{

    update();

}

void ProTeam::on_lineSecond_textChanged(const QString &arg1)

{

    update();

}

void ProTeam::on_lineThird_textChanged(const QString &arg1)

{

    update();

}

void ProTeam::on_lineFour_textChanged(const QString &arg1)

{

    update();

}

当单击不同的tab标签时，传递标签下面所对应的表格的数据。

void ProTeam::on_tabWidget_tabBarClicked(int index)

{

    if(index==0)

    {

       int row=ui->tableWidget->rowCount()-1;

       ui->lineFirst->setText(ui->tableWidget->item(row,3)->text());

       ui->lineSecond->setText(ui->tableWidget->item(row,4)->text());

       ui->lineThird->setText(ui->tableWidget->item(row,5)->text());

       ui->lineFour->setText(ui->tableWidget->item(row,6)->text());

       ui->label->setText(codeChange("已完成任务"));

       ui->label_2->setText(codeChange("未完成任务"));

       ui->label_3->setText(codeChange("过期任务"));

       ui->label_4->setText(codeChange("关闭任务"));

    }

    else if(index==1)

    {

        int row=ui->tableWidget_2->rowCount()-1;

        ui->lineFirst->setText(ui->tableWidget_2->item(row,2)->text());

        ui->lineSecond->setText(ui->tableWidget_2->item(row,3)->text());

        ui->lineThird->setText(ui->tableWidget_2->item(row,4)->text());

        ui->lineFour->setText(ui->tableWidget_2->item(row,5)->text());

        ui->label->setText(codeChange("已修正BUG"));

        ui->label_2->setText(codeChange("未修正BUG"));

        ui->label_3->setText(codeChange("保留BUG"));

        ui->label_4->setText(codeChange("关闭BUG"));

    }

    else if(index==2)

    {

        int row=ui->tableWidget_3->rowCount()-1;

        ui->lineFirst->setText(ui->tableWidget_3->item(row,3)->text());

        ui->lineSecond->setText(ui->tableWidget_3->item(row,4)->text());

        ui->lineThird->setText(ui->tableWidget_3->item(row,5)->text());

        ui->lineFour->setText(ui->tableWidget_3->item(row,6)->text());

        ui->label->setText(codeChange("已测试"));

        ui->label_2->setText(codeChange("未测试"));

        ui->label_3->setText(codeChange("已关闭测试"));

        ui->label_4->setText(codeChange("过期测试"));

    }

}

//编码转换

QString ProTeam::codeChange(const QByteArray &str){

    QTextCodec* codec = QTextCodec::codecForName("gb2312");

    QString s;

    s = codec->toUnicode(str);

    return s;

    }

 //使表格处于不可编辑状态代码如下：

    ui->tableWidget->setEditTriggers(QAbstractItemView::NoEditTriggers);