@QT开发自定义控件表盘实例
新建一个QT项目,我的为MyControl,右击MyControl选择Add New,然后按照后面的图片创建一个新的类,最后项目下就出现了dialplate.h,dialplate.cpp,dialplate.ui三个文件。
下面是dialplate.h中的代码:
// An highlighted block
#ifndef DIALPLATE_H
#define DIALPLATE_H
#include <QWidget>
#include<QPainter>
namespace Ui {
class DialPlate;
}
class DialPlate : public QWidget
{
Q_OBJECT
public:
explicit DialPlate(QWidget *parent = nullptr);
~DialPlate();
void paintEvent(QPaintEvent *event);//系统自动调用
int getBigDivided() const;
void setBigDivided(int value);
int getSmallDivided() const;
void setSmallDivided(int value);
int getScale() const;
void setScale(int value);
int getValue() const;
void setValue(int value);
private:
Ui::DialPlate *ui;
double centerRadius;//表盘中心圆半径
double inRadius;//表盘内圆半径
double midRadius;//表盘中间圆半径
double outRadius;//表盘最外圆半径
int bigDivided;//大刻度等分数
int smallDivided;//小刻度等分数
int scale;//倍率
int scaleCount;//scale的位数
int value;//刻度盘的值
void SetParamsInit();
void SetOtherBackground(QPainter *painter);
void DrawPlate(QPainter *painter);
void DrawRing(QPainter *painter,QColor backColor, QColor ringColor,double inRadius,double outRadius);
void DrawScale(QPainter *painter);
void DrawText(QPainter *painter);
void DrawNeedle(QPainter *painter);
void DrawArcRing(QPainter *painter);
void DrawValue(QPainter *painter);
};
#endif // DIALPLATE_H
下面是dialplate.cpp中的代码:程序中的一些具体数字是我根据340*340大小调整出来的,大家也可以自己试着调整自己的比例。
// An highlighted block
#include "dialplate.h"
#include "ui_dialplate.h"
#include"math.h"
#include<QDebug>
#include<cmath>
DialPlate::DialPlate(QWidget *parent) :
QWidget(parent),
ui(new Ui::DialPlate)
{
ui->setupUi(this);
bigDivided=10;
smallDivided=10;
scale=1;
scaleCount=1;
value=0;
}
DialPlate::~DialPlate()
{
delete ui;
}
void DialPlate::paintEvent(QPaintEvent *event)
{
QPainter painter(this);//声明一个画家对象
painter.setRenderHint(QPainter::Antialiasing);//抗锯齿形
//初始化参数设置
this->SetParamsInit();
//填充表盘周围为透明色
this->SetOtherBackground(&painter);
//画表盘
this->DrawPlate(&painter);
}
int DialPlate::getValue() const
{
return value;
}
void DialPlate::setValue(int value)
{
this->value = value;
}
int DialPlate::getScale() const
{
return scale;
}
void DialPlate::setScale(int value)
{
this->scale = value;
}
int DialPlate::getSmallDivided() const
{
return smallDivided;
}
void DialPlate::setSmallDivided(int value)
{
this->smallDivided = value;
}
int DialPlate::getBigDivided() const
{
return bigDivided;
}
void DialPlate::setBigDivided(int value)
{
this->bigDivided = value;
}
//初始化参数设置
void DialPlate::SetParamsInit()
{
centerRadius=(this->width()-290/340.0*this->width())/2;
inRadius=(this->width()-76/340.0*this->width())/2;
midRadius=(this->width()-38/340.0*this->width())/2;
outRadius=(this->width()-14/340.0*this->width())/2;
}
//设置表盘周围为透明色
void DialPlate::SetOtherBackground(QPainter *painter)
{
painter->save();
painter->setBrush(Qt::transparent);
painter->fillRect(this->rect(),QColor(0,0,0,0));
painter->restore();
}
//画表盘
void DialPlate::DrawPlate(QPainter *painter)
{
//画最外环
DrawRing(painter,QColor(240,240,240), QColor(100,100,100),midRadius,outRadius);
//画中间黑环
DrawRing(painter,QColor(240,240,240), QColor(0,0,0),inRadius,midRadius);
//画小环
DrawRing(painter,QColor(240,240,240), QColor(100,100,100),centerRadius,inRadius);
//画刻度
DrawScale(painter);
//画黄色指示条
DrawArcRing(painter);
//画中心点圆
DrawRing(painter,QColor(240,240,240), QColor(233,123,90),0,centerRadius);
//画数字
DrawText(painter);
//画指针
DrawNeedle(painter);
//画值
DrawValue(painter);
}
//画圆环
void DialPlate::DrawRing(QPainter *painter,QColor backColor, QColor ringColor, double inRadius, double outRadius)
{
QBrush qbrush(ringColor);
painter->setBrush(qbrush);
painter->drawEllipse(QPointF(this->width()/2.0,this->height()/2.0),outRadius,outRadius);
qbrush.setColor(backColor);
painter->setBrush(qbrush);
painter->drawEllipse(QPointF(this->width()/2.0,this->height()/2.0),inRadius,inRadius);
}
//画刻度
void DialPlate::DrawScale(QPainter *painter)
{
QPen qpen(Qt::white);
double startRadius;//起点半径
double endRadius=midRadius;//终点半径
//绘制刻度
for(int i=0;i<=bigDivided*smallDivided;i++)
{
if(i%smallDivided==0)
{
startRadius=inRadius;//大刻度
qpen.setWidthF(2.5);
}
else
{
startRadius=inRadius+(midRadius-inRadius)/2;//小刻度
qpen.setWidthF(1.5);
}
painter->setPen(qpen);
//起点坐标
double xPosStart=this->width()/2+startRadius*cos(3.14*3/4+i*3.14*3/2/bigDivided/smallDivided);
double yPosStart=this->height()/2+startRadius*sin(3.14*3/4+i*3.14*3/2/bigDivided/smallDivided);
//终点坐标
double xPosEnd=this->width()/2+endRadius*cos(3.14*3/4+i*3.14*3/2/bigDivided/smallDivided);
double yPosEnd=this->height()/2+endRadius*sin(3.14*3/4+i*3.14*3/2/bigDivided/smallDivided);
painter->drawLine(QPointF(xPosStart,yPosStart),QPointF(xPosEnd,yPosEnd));
}
}
//画数字
void DialPlate::DrawText(QPainter *painter)
{
//计算scale是几位数
int scaleCount=1;
int tempScale=scale;
while (tempScale/10)
{
scaleCount++;
tempScale/=10;
}
int fontSize=30-3*scaleCount;
QPen qpen(Qt::green);
qpen.setWidthF(1.0);
painter->setPen(qpen);
QFont font=painter->font();
font.setPixelSize(fontSize);
painter->setFont(font);
double textRadius=inRadius-30;
for(int i=0;i<=bigDivided;i++)
{
double xPosText=this->width()/2+textRadius*cos(3.14*3/4+i*3.14*3/2/bigDivided);
double yPosText=this->height()/2+textRadius*sin(3.14*3/4+i*3.14*3/2/bigDivided);
QRectF textQRect(xPosText-25,yPosText-12,50,24);
painter->drawText(textQRect,Qt::AlignCenter,QString::number(i*scale));
}
}
//画指针
void DialPlate::DrawNeedle(QPainter *painter)
{
double needleRadius=this->width()/2-90/340.0*this->width();
double needleCenterRadius=centerRadius-16/340.0*this->width();
//画指针的圆
DrawRing(painter,Qt::red, Qt::red,0,needleCenterRadius+4);
double biggestValue=bigDivided*scale;
//超出量程则显示为最大值
if(value>biggestValue)
{
value=bigDivided*scale;
}
//指针三角形的三个点坐标
double xPosNeedle0=this->width()/2+needleRadius*cos(3.14*3/4+value/biggestValue*3.14*3/2);
double yPosNeedle0=this->height()/2+needleRadius*sin(3.14*3/4+value/biggestValue*3.14*3/2);
double xPosNeedle1=this->width()/2+needleCenterRadius*cos(3.14*3/4+value/biggestValue*3.14*3/2+3.14/2);
double yPosNeedle1=this->height()/2+needleCenterRadius*sin(3.14*3/4+value/biggestValue*3.14*3/2+3.14/2);
double xPosNeedle2=this->width()/2+needleCenterRadius*cos(3.14*3/4+value/biggestValue*3.14*3/2-3.14/2);
double yPosNeedle2=this->height()/2+needleCenterRadius*sin(3.14*3/4+value/biggestValue*3.14*3/2-3.14/2);
//画三角形
QPen qpen(Qt::red);
QBrush qbrush(Qt::red);
painter->setPen(qpen);
painter->setBrush(qbrush);
QPointF points[3]={QPointF(xPosNeedle0,yPosNeedle0),QPointF(xPosNeedle1,yPosNeedle1),
QPointF(xPosNeedle2,yPosNeedle2)};
painter->drawPolygon(points,3);
}
//画黄色刻度条上的环形指示带(两个扇形相减)
void DialPlate::DrawArcRing(QPainter *painter)
{
//画黄色扇形
QBrush qbrush(QColor(255,255,0,100));
QPen qpen(QColor(255,255,0,100));
painter->setBrush(qbrush);
painter->setPen(qpen);
QRectF outRect(19/340.0*this->width(),19/340.0*this->height(),2*midRadius,2*midRadius);
int startAngle=225*16;
int endAngle=(int)(225+(value/(double)(bigDivided*scale))*270)*16;
int spanAngle=startAngle-endAngle;//角度差(默认为逆时针,负数则为顺时针)
painter->drawPie(outRect,startAngle,spanAngle);
//画减去部分的扇形
QRectF inRect(38/340.0*this->width(),38/340.0*this->height(),2*inRadius,2*inRadius);
qbrush.setColor(QColor(100,100,100));
qpen.setColor(QColor(100,100,100));
painter->setBrush(qbrush);
painter->setPen(qpen);
painter->drawPie(inRect,startAngle,spanAngle+(-16));//为了完全减去黄色内部区域,多减一个单位(16)
}
//在表盘上显示数值
void DialPlate::DrawValue(QPainter *painter)
{
//计算scale是几位数
int scaleCount=1;
int tempScale=scale;
while (tempScale/10)
{
scaleCount++;
tempScale/=10;
}
int fontSize=30-3*scaleCount;
QBrush qbrush(Qt::blue);
QPen qpen(Qt::blue);
QFont font=painter->font();
font.setPixelSize(fontSize);
painter->setFont(font);
painter->setBrush(qbrush);
painter->setPen(qpen);
QRectF valueRect(this->width()/2-25,this->height()/2+90/340.0*this->width(),50,30);
painter->drawText(valueRect,Qt::AlignCenter,QString::number(value));
}
然后在mainwindow.h文件中添加如下代码,程序中form不用管,那是另一个自定义控件进度条的程序,
// An highlighted block
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include"form.h"
#include"dialplate.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = nullptr);
~MainWindow();
private:
Ui::MainWindow *ui;
//Form
Form *myForm;
int value=1;
int maxValue=10;
//DialPlate
DialPlate *myDialPlate;
private slots:
//Form
void addValue();
void subValue();
void setMaxValue(int maxValue);
//DialPlate
void setDialPlateValue(int value);
void setBigDivided(int bigDivided);
void setSmallDivided(int smallDivided);
void setScale(int scale);
};
#endif // MAINWINDOW_H
在mainwindow.ui中添加一个widget控件,选择widget控件右击选择提升为,然后根据图片填写类名,再点击添加和提升就可以了。将widget控件的name属性改为dialPlate。再添加几个控制控件。用于控制输入表盘的值,粗刻度数,细刻度数和量程的倍率。它们的name属性分别为:hSlider_dialPlate,spbx_bigDivided,spbx_smallDivided,spbx_scale。
再mainwindow.cpp中添加如下代码,同样不用管Form的代码,只添加DialPlate的代码。
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include<QDebug>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
//Form
connect(this->ui->btn_add,&QPushButton::clicked,this,&MainWindow::addValue);
connect(this->ui->btn_sub,SIGNAL(clicked()),this,SLOT(subValue()));
connect(this->ui->spbx_maxValue,SIGNAL(valueChanged(int)),this,SLOT(setMaxValue(int)));
//DialPlate
connect(this->ui->hSlider_dialPlate,&QSlider::valueChanged,this,&MainWindow::setDialPlateValue);
connect(this->ui->spbx_bigDivided,SIGNAL(valueChanged(int)),this,SLOT(setBigDivided(int)));
connect(this->ui->spbx_smallDivided,SIGNAL(valueChanged(int)),this,SLOT(setSmallDivided(int)));
connect(this->ui->spbx_scale,SIGNAL(valueChanged(int)),this,SLOT(setScale(int)));
}
MainWindow::~MainWindow()
{
delete ui;
}
//Form
void MainWindow::addValue()
{
if(value<this->ui->ProgressBar->getMaxValue())
{
this->ui->ProgressBar->setValue(++value);
//qDebug()<<value;
this->ui->ProgressBar->update();
}
}
void MainWindow::subValue()
{
if(value>0)
{
this->ui->ProgressBar->setValue(--value);
//qDebug()<<value;
this->ui->ProgressBar->update();
}
}
void MainWindow::setMaxValue(int maxValue)
{
this->ui->ProgressBar->setMaxValue(maxValue);
this->ui->ProgressBar->update();
}
//DialPlate
void MainWindow::setDialPlateValue(int value)
{
this->ui->dialPlate->setValue(value);
this->ui->dialPlate->update();//手动调用控件的OnPaint方法
}
void MainWindow::setBigDivided(int bigDivided)
{
this->ui->dialPlate->setBigDivided(bigDivided);
this->ui->dialPlate->update();
}
void MainWindow::setSmallDivided(int smallDivided)
{
this->ui->dialPlate->setSmallDivided(smallDivided);
this->ui->dialPlate->update();
}
void MainWindow::setScale(int scale)
{
this->ui->hSlider_dialPlate->setMaximum(scale*this->ui->dialPlate->getBigDivided());
this->ui->dialPlate->setScale(scale);
this->ui->dialPlate->update();
}
然后点击运行就得到下面的效果啦