Qt自定義控件實(shí)現(xiàn)簡易儀表盤

更新時(shí)間：2019年12月20日 11:46:07 作者：parkchorong

這篇文章主要為大家詳細(xì)介紹了Qt自定義控件實(shí)現(xiàn)簡易儀表盤，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

本文實(shí)例為大家分享了Qt自定義控件實(shí)現(xiàn)簡易儀表盤的具體代碼，供大家參考，具體內(nèi)容如下

Qt自定義控件12：簡易儀表盤（根據(jù)liudianwu大神的界面自己寫的代碼，建議去學(xué)習(xí)劉大神，會受益良多的）

先看效果圖：

思路：畫270度的圓弧，圓弧根據(jù)占比分為兩種顏色，根據(jù)占比在圓弧上畫出一個(gè)圓球作為標(biāo)志，然后就是刻度線和刻度值。刻度線是根據(jù)坐標(biāo)系旋轉(zhuǎn)畫出，刻度值是根據(jù)角度求出x,y坐標(biāo)值構(gòu)造出一個(gè)矩形畫出刻度值（不要用坐標(biāo)系旋轉(zhuǎn)畫刻度值，那樣刻度值的角度也會旋轉(zhuǎn)，寫出的字不是正的，效果不好）。最后就是在中心畫value。

關(guān)鍵代碼：

void CMPassrate5::paintEvent(QPaintEvent *event){
  int width = this->width();
  int height = this->height();
  int side = qMin(width, height);

  QPainter painter(this);
  painter.setRenderHints(QPainter::Antialiasing | QPainter::TextAntialiasing);
  painter.translate(width / 2, height / 2);
  painter.scale(side / 200.0, side / 200.0);

  drawE(&painter);
  drawEPoint(&painter);
  drawLine(&painter);
  drawEText(&painter);
  drawValue(&painter);
}

void CMPassrate5::drawE(QPainter* painter){
  QRect rect(-radius,-radius,2*radius,2*radius);
  painter->save();
  painter->setPen(Qt::NoPen);

  QPainterPath path;
  QPainterPath subPath;
  QPainterPath outPath;
  QPainterPath outPubPath;
  outPath.arcTo(rect,-45,outRange);
  outPubPath.addEllipse(rect.adjusted(side,side,-side,-side));
  outPath -= outPubPath;
  color.setAlpha(100);
  painter->setBrush(color);
  painter->drawPath(outPath);


  path.arcTo(rect,-45+outRange,range);
  subPath.addEllipse(rect.adjusted(4,4,-4,-4));
  path -= subPath;
  color.setAlpha(180);
  painter->setBrush(color);
  painter->drawPath(path);

  painter->restore();
}

void CMPassrate5::drawEPoint(QPainter* painter){
  //圓球位置就在outRange盡頭處
  painter->save();
  color.setAlpha(180);
  painter->setPen(Qt::NoPen);
  painter->setBrush(color);

  float x = (radius-side/2)*qCos((range+135)*3.14/180);
  float y = (radius-side/2)*qSin((range+135)*3.14/180);
  qDebug()<<"x:"<<x<<" y:"<<y;
  painter->drawEllipse(QPoint(x,y),side,side);
  painter->restore();
}

void CMPassrate5::drawLine(QPainter* painter){
  painter->save();
  painter->rotate(135);
  color.setAlpha(100);
  painter->setPen(color);
  QLine line(QPoint(radius-side-lineLength,0),QPoint(radius-side,0));

  for(int i = 0;i<lineCount;i++){
    painter->drawLine(line);
    painter->rotate(270.0/lineCount);
  }
  painter->restore();
}

void CMPassrate5::drawEText(QPainter* painter){
  painter->save();
//  painter->rotate(135);
  painter->setPen(Qt::black);
  float textRange = 270.0/(textCount-1);
  float x,y;
  for(int i = 0;i<=10;i++){
    x = (radius-side-lineLength)*qCos((textRange*i+135)*3.14/180);
    y = (radius-side-lineLength)*qSin((textRange*i+135)*3.14/180);
    if(i<5){
      QRect rect(x,y-4,20,10);
      painter->drawText(rect,Qt::AlignCenter,QString::number(i*10));
    }else if(i ==5){
      QRect rect(x-7,y,20,10);
      painter->drawText(rect,Qt::AlignCenter,QString::number(i*10));
    }else{
      QRect rect(x-20,y-5,20,10);
      painter->drawText(rect,Qt::AlignCenter,QString::number(i*10));
    }

  }
  painter->restore();
}

void CMPassrate5::drawValue(QPainter* painter){
  painter->save();
  QPen pen = painter->pen();
  pen.setColor(color);
  pen.setWidth(2);
  painter->setPen(pen);
  QFont font = painter->font();
  font.setPixelSize(45);
  painter->setFont(font);

  QRect rect(-25,-25,50,50);
  painter->drawText(rect,Qt::AlignCenter,QString::number(value));
  painter->restore();
}

以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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