授人以鱼不如授人以渔-圆形刻度盘或者进度条各种计算公式 - QTCN开发网

离线komany

新手上路

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只看楼主倒序阅读楼主发表于: 2017-01-19

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网上实在找不到计算公式，下面是我动手制作过程中摸索出来的，不准的地方望海涵，有了这公式，刻度盘，进度条随你搞，哈哈哈哈！
遇到事情还是要多动手！！！
图片:QQ截图20170119105950.png
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QLabel>
#include <QMainWindow>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
void paintEvent(QPaintEvent *event);
private:
Ui::MainWindow *ui;
QLabel *l1;
QLabel *l2;
QLabel *l3;
};
#endif // MAINWINDOW_H

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#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPainter>
//当前值
const int u =43;
//最大刻度
const int nMax = 100;
//最小刻度
const int nMin = 0;
//旋转角度
const double nPercentRotate = 40;
//
const int nMaxRadus = 200;
const int nMinRadus = 150;
const int nDistance = 50;
//最外面的大圆
const int nDistance2 = 70;
//原点
int nOrgXpos = 0;
int nOrgYpos = 0;
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
nOrgXpos = width() / 2;
nOrgYpos = height() / 2;
l1 = new QLabel(this);
l1->setText(QString("44"));
l1->move(nOrgXpos ,nOrgYpos );
l2 = new QLabel(this);
l3 = new QLabel(this);
l2->setText(QString("Min"));
//这个地方要注意
l2->move(nOrgXpos - nMinRadus, nOrgYpos + nMinRadus );
l3->setText(QString("Max"));
l3->move(nOrgXpos + (nMinRadus ) , nOrgYpos + (nMinRadus ) );
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::paintEvent(QPaintEvent *event)
{
QColor use(112,222,121);
QColor nouse(223,123,111);
QPainter p(this);
double nRotate = (360.0 - 2 * nPercentRotate) / (nMax - nMin);
p.setRenderHint(QPainter::Antialiasing);
p.setRenderHint(QPainter::SmoothPixmapTransform);
p.save();
p.translate(nOrgXpos, nOrgYpos);
p.rotate(nPercentRotate);
p.setPen(use);
for(int i = 0 ; i < u; i++){
p.drawLine(0,nMinRadus,0,nMaxRadus);
p.rotate(nRotate);
}
p.setPen(nouse);
for(int i = u ; i < nMax ; i++){
p.drawLine(0,nMinRadus,0,nMaxRadus);
p.rotate(nRotate);
}
p.restore();
p.setPen(QColor(11,22,33));
p.drawEllipse(nOrgXpos - nMinRadus + nDistance/2 , nOrgYpos - nMinRadus + nDistance/2 , nMinRadus * 2 - nDistance , nMinRadus * 2 - nDistance );
p.restore();
p.setPen(QColor(11,22,33));
p.drawEllipse(nOrgXpos - nMaxRadus - nDistance2/2 , nOrgYpos - nMaxRadus - nDistance2/2 , nMaxRadus * 2 + nDistance2, nMaxRadus * 2 + nDistance2);
}