32.QT-制作最強電壓電阻表盤,可以自定義陰影效果,漸變顏色,圖標,文字標簽等-附帶demo程序

本文轉載自查看原文 2018-06-30 01:11 3539 4.3 QT學習之路

由於上位機需要繪制電壓電阻表盤,如下圖所示:

后來,在網上找阿找,還是沒找到滿意的,索性自己來畫控件算了,由於第一次畫控件,所以花了我2天時間,才畫好

效果圖如下:

上圖的所有顏色(包括滑動的漸變/單一顏色,以及字體顏色)都可以自定義,包括圖標也可以(上面的電阻圖標,網上沒找到好看的,所以很丑~)

整體效果圖如下所示:

該demo程序放在了提供的源碼地址里了,下載好后,在子文件夾demo1里面

介紹

代碼里添加了自適應設置,根據窗口大小自動改變標簽,圖標,刻度值,中心圓數值等

代碼里集成了定時器,可以通過setTimerType(int msec,int v)成員函數實現表盤指針旋轉快慢,每過多少msec,跑多少值(v),如果msec=0或者v=0,則表示不用定時器,直接跳到終點。

代碼里通過setGradientColorMode(QList<QColor>& Qcolors)成員函數可以自定義一組漸變顏色.

也可以通過setSingleColorMode(QColor color)成員函數自定義單一顏色(上圖2就是設置的單一顏色).

代碼介紹

1.代碼里通過 painter類來繪圖,其中paintEvent()函數如下所示

void Dial::paintEvent(QPaintEvent *)
{
    QPainter painter(this);
    painter.setPen(Qt::NoPen);
    painter.setRenderHint(QPainter::Antialiasing,true);
    painter.setRenderHint(QPainter::SmoothPixmapTransform);
    painter.translate(width()/2,height()/2);
    radius = qMin(width(),height())/2;
    centerR=radius*0.4;       //設置中心圓大小
    drawObkColor(painter);           //外圓盤
    drawScalebkColor(painter);      //畫刻度圓
    drawslideScaleColor(painter);   //畫划過的顏色
    drawShade(painter);            //畫陰影
    drawScaleColor(painter);
    drawbkColor(painter);          //畫內圓
    drawScaleTextColor(painter);   //畫刻度值
    drawPointColor(painter);
    drawCenterColor(painter);      //繪制中心圓
    drawIconValueColor(painter);
    drawlabelColor(painter);
}

2.然后進入drawObkColor()函數,來繪畫外圓盤,函數如下所示

void Dial::drawObkColor(QPainter& paint)      //繪制外圓
{
        paint.save();
        QConicalGradient  Conical(0,0,90);
        Conical.setColorAt(0,oobkColor);
        Conical.setColorAt(0.5,oobkColor);
        Conical.setColorAt(0.12,oobkColor.darker(40));
        Conical.setColorAt(0.88,oobkColor.darker(40));
        Conical.setColorAt(0.4,oobkColor.darker(30));
        Conical.setColorAt(0.6,oobkColor.darker(30));
        Conical.setColorAt(0.25,oobkColor.darker(160));
        Conical.setColorAt(0.75,oobkColor.darker(160));
        Conical.setColorAt(1,oobkColor);
        paint.setBrush(Conical);
        paint.drawEllipse(QPointF(0,0), radius*0.96,radius*0.98);
        Conical.setAngle(270);
        Conical.setColorAt(0,obkColor.darker(40));
        Conical.setColorAt(0.5,obkColor.darker(40));
        Conical.setColorAt(0.25,obkColor.darker(160));
        Conical.setColorAt(0.75,obkColor.darker(160));
        paint.setBrush(Conical);
        paint.drawEllipse(QPointF(0,0), radius*0.93,radius*0.94);
        paint.restore();
}

外圓盤效果如下所示:

3.然后接下來開始畫刻度圓,畫了它后,才能開始畫刻度和划過的顏色等

void Dial::drawScalebkColor(QPainter &paint)        //繪制刻度圓
{
    paint.save();
    paint.setBrush(bkColor);
    paint.drawEllipse(QPointF(0,0), radius*0.90,radius*0.90);

    paint.restore();
}

4.然后接下來開始畫划過的顏色,就是上圖指針划過后都會帶有顏色的那種 (以單色顏色為例)

void Dial::drawslideScaleColor(QPainter &paint)    //畫划過的顏色
{
    /*單一顏色*/  

    int Star_Angle= 210*16-(int)((value/(maxvalue-minvalue))*240*16);

    int spanAngle  =  210*16 - Star_Angle;

    if(spanAngle==0)
        return ;



    qreal SlideBottom =  ((qreal)radius*0.77)/((qreal)radius*0.90);    

    qreal SlideCenterTop = 1-(1-SlideBottom)/3;                        
    qreal SlideCenterBottom = SlideBottom+(1-SlideBottom)/3+0.01;      

    paint.save();

    QColor Tint_SlideColor = SingleSlideColor;


    QRadialGradient Radial(0,0,radius*0.90);


    Tint_SlideColor.setAlpha(40);
    Radial.setColorAt(1,Tint_SlideColor);
    Radial.setColorAt(SlideBottom-0.005,Tint_SlideColor);
    Radial.setColorAt(0,Qt::transparent);
    Radial.setColorAt(SlideBottom-0.006,Qt::transparent);


    Tint_SlideColor = SingleSlideColor;
    Tint_SlideColor.setAlpha(50);


    Radial.setColorAt(SlideCenterBottom-0.03,Tint_SlideColor);
    Radial.setColorAt(SlideCenterTop+0.03,Tint_SlideColor);

    Tint_SlideColor = SingleSlideColor;
    Tint_SlideColor.setAlpha(50);
    Radial.setColorAt(SlideCenterBottom-0.01,SingleSlideColor.darker(200));
    Radial.setColorAt(SlideCenterTop+0.01,SingleSlideColor.darker(200));

    Radial.setColorAt(SlideCenterBottom,SingleSlideColor);
    Radial.setColorAt(SlideCenterTop,SingleSlideColor);

    paint.setPen(Qt::NoPen);
    paint.setBrush(Radial);

    paint.drawPie(QRectF((qreal)-radius*0.90,(qreal)-radius*0.90,(qreal)radius*1.80,(qreal)radius*1.80),Star_Angle,spanAngle);

    paint.restore();
 


  //... ...  
   
}

效果:

5.然后接下來便開始畫刻度和刻度值,其中比較重要的就是繪制刻度值

由於Painter的rotate()旋轉文字時,也會將文字傾斜了,所以我們需要自定義rotate()函數

具體參考我另一篇rotate函數分析: 31.QPainter-rotate()函數分析-文字旋轉不傾斜,圖片旋轉實現等待

drawScaleTextColor()畫刻度值函數如下所示:

void Dial::drawScaleTextColor(QPainter &paint)    //繪制刻度值
{
    /*繪制文字刻度*/
    paint.save();

    paint.setPen(ScaleColor);

    QString text("%1");

    int size;           //動態計算文字大小

    if(radius<=120)
       size = 10;
    else if((radius>120)&&(radius<500))
       size = 13+(radius-120)/30;
    else if(radius>=500)
       size = 13+(radius-120)/40;

    paint.setFont(QFont("Euphemia",size,QFont::DemiBold));

    QPoint TextPoint(0,radius*0.77-size*0.9);        //設置90°的文字
    TextPoint = CustomRotate(TextPoint,90,240);   //獲取點=210°的文字位置
    qreal TextRotate=210;

     for(int i=0;i<7;i++)              //設置7個刻度值
    {
    
          //... ...

          qreal Current_Value =(qreal)i*((maxvalue-minvalue)/6);

          if((Current_Value>value&&(paint.pen().color()!=ScaleColor)))
          {
              paint.setPen(ScaleColor);

          }
          else if((Current_Value<=value&&(paint.pen().color()!=slideScaleColor)))
          {
              paint.setPen(slideScaleColor);
          }

       paint.drawText(QRect(TextPoint.x()-size*1.5+offest[i].x(),TextPoint.y()-size*1.2+offest[i].y(),size*3,size*2.4),alingns[i],text.arg((maxvalue-minvalue)*i/6));
       TextPoint = CustomRotate(TextPoint,TextRotate,40);   //獲取點=210°的文字位置
       TextRotate-=40;
    }

    paint.restore();
}

效果如下所示:

6.然后接下來開始畫指針

void Dial::drawPointColor(QPainter &paint)          //繪制指針
{

    qreal PointTop;                //動態計算指針頭
    qreal PointBottom;             //動態計算指針底部
    if(radius<=120)
    {
        PointTop = 2;
        PointBottom = 6;
    }
    else if((radius>120)&&(radius<500))
    {
        PointTop = 2 + (radius-120)/100;
        PointBottom = PointTop*3;
    }
    else if(radius>=500)
    {
        PointTop = 2 + (radius-120)/140;
        PointBottom = PointTop*3;
    }

    //指針
    const QPointF  Pointer[4] = {
        QPointF(- PointTop / 2, radius*0.80),
        QPointF(PointTop / 2, radius*0.80),
        QPointF(PointBottom / 2, centerR*0.9),
        QPointF(-PointBottom / 2, centerR*0.9)
    };

    paint.save();


    paint.setBrush(PointerColor);
    paint.setPen(PointerColor.darker(300));


    qreal Current_Angle =60+(int)((value/(maxvalue-minvalue))*240);

    paint.rotate(Current_Angle);

    paint.drawConvexPolygon(Pointer, 4);

    paint.restore();

}

效果如下:

7.然后繼續畫中心圓

void Dial::drawCenterColor(QPainter &paint)      //繪制中心圓
{
    paint.save();

    QRadialGradient Radial(0,0,centerR,0,0);

    Radial.setColorAt(1,centercolor.lighter(170));
    Radial.setColorAt(0.98,centercolor.lighter(150));
    Radial.setColorAt(0.95,centercolor.lighter(130));
    Radial.setColorAt(0.70,centercolor);

    paint.setBrush(Radial);
    paint.drawEllipse(QPointF(0,0), centerR,centerR);

    paint.restore();

}