近期由于工作不忙，就来做做自定义控件，做的不好，请给建议，以后会改。
那就直接本入正题吧：
头文件：
#ifndefMAINWINDOW_H
#define MAINWINDOW_H #include <QMainWindow> #include<QPainter> #include<QVector> namespace Ui { class MainWindow; } class MainWindow : public QMainWindow { Q_OBJECT protected: virtual void paintEvent(QPaintEvent *event); public: explicit MainWindow(QWidget *parent = 0); ~MainWindow(); protected slots: void move(int); private: Ui::MainWindow *ui; int value; private: //绘画初始化 void painter_init(QPainter&); //绘制圆环1 void draw_Ellipse(QVector<double>&,QVector<double>&,QPainter &); //重载draw_Ellipse()函数，用于绘制圆环2 void draw_Ellipse(QVector<double>&,QVector<double>&,QPainter &,QRadialGradient &); //绘画扇形 void draw_pie(QPainter &); //绘制文本和刻度 void draw_text_line(QPainter&); //绘制指针 void draw_point(QPainter&); }; #endif // MAINWINDOW_H 源文件：#include"mainwindow.h"
#include "ui_mainwindow.h" #include <QPainterPath> #include<QDebug> MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); value=0; ui->horizontalSlider->setRange(0,100); QObject::connect(ui->horizontalSlider,SIGNAL(valueChanged(int)),this,SLOT(move(int))); } MainWindow::~MainWindow() { delete ui; } void MainWindow::paintEvent(QPaintEvent *event) { QPainter paint(this); painter_init(paint); //[1]获取圆环 QVector<double> num={200,200,300,300}; QVector<double> num1={220,220,260,260}; draw_Ellipse(num, num1,paint); [2]获取圆环 QVector<double> num2={220,220,260,260}; QVector<double> num3={260,260,180,180}; QRadialGradient radgrient(220,220,90,260,260); draw_Ellipse(num2,num3,paint,radgrient); [3]获取扇形，并重叠。 draw_pie(paint); paint.setBrush(QBrush(Qt::darkRed,Qt::SolidPattern)); QVector<double> num4={320,320,60,60}; QVector<double> num5={327.5,327.5,45,45}; draw_Ellipse(num4,num5,paint); paint.setBrush(QBrush(Qt::gray,Qt::SolidPattern)); QPainterPath big4; big4.addEllipse(327.5,327.5,45,45); //[4]显示刻度以及文本 draw_text_line(paint); //【5】显示指针 draw_point(paint); } void MainWindow::move(int num) { value=num; qDebug()<<value; update(); } void MainWindow::painter_init(QPainter &paint) { paint.setRenderHint(QPainter::Antialiasing,true); paint.setBrush(QBrush(Qt::darkBlue,Qt::SolidPattern)); } void MainWindow::draw_Ellipse(QVector<double> &num, QVector<double> &num1,QPainter &paint) { QPainterPath big; big.addEllipse(num.at(0),num.at(1),num.at(2),num.at(3)); QPainterPath small; big.addEllipse(num1.at(0),num1.at(1),num1.at(2),num1.at(3)); QPainterPath path; path=big-small; paint.drawPath(path); } void MainWindow::draw_Ellipse(QVector<double> &num, QVector<double> &num1, QPainter &paint, QRadialGradient &radgrient) { radgrient.setColorAt(0.0,Qt::darkGray); radgrient.setColorAt(0.2,Qt::white); radgrient.setColorAt(0.5,Qt::darkGray); paint.setBrush(QBrush(Qt::gray,Qt::SolidPattern)); paint.setPen(Qt::NoPen); draw_Ellipse(num,num1,paint); } void MainWindow::draw_pie(QPainter &paint) { paint.setBrush(QBrush(Qt::darkGreen,Qt::SolidPattern)); // 扇形起始角度 int startAngle = -40*16 ; // 扇形覆盖范围（120度的） int spanAngle = 260*16; QRectF rect_top(260,260, 180.0, 180.0); QRectF rect_top1(280,280, 140.0, 140.0); QRectF rect_top2(260,260, 180.0, 180.0); paint.drawPie(rect_top, startAngle, spanAngle); paint.setBrush(QBrush(Qt::gray,Qt::SolidPattern)); paint.drawPie(rect_top1, startAngle, spanAngle); paint.drawPie(rect_top2, 220*16, 100*16); } void MainWindow::draw_text_line(QPainter &paint) { paint.translate(350,350); paint.setPen(Qt::black); for(int i=0;i<=25;i++) { if(i%5==0) { paint.drawLine(0,-90,0,-100); switch(i/5) { case 0:paint.drawText(-5,-103, tr("%1").arg(50));break; case 1:paint.drawText(-5,-103, tr("%1").arg(60));break; case 2:paint.drawText(-5,-103, tr("%1").arg(70));break; case 3:paint.drawText(-5,-103, tr("%1").arg(80));break; case 4:paint.drawText(-5,-103, tr("%1").arg(90));break; case 5:paint.drawText(-5,-103, tr("%1").arg(100));break; } } else { paint.drawLine(0,-95,0,-100); } paint.rotate(5.2); } paint.rotate(100-5.2); for(int i=0;i<=25;i++) { if(i%5==0) { paint.drawLine(0,-90,0,-100); switch(i/5) { case 0:paint.drawText(-5,-103, tr("%1").arg(0));break; case 1:paint.drawText(-5,-103, tr("%1").arg(10));break; case 2:paint.drawText(-5,-103, tr("%1").arg(20));break; case 3:paint.drawText(-5,-103, tr("%1").arg(30));break; case 4:paint.drawText(-5,-103, tr("%1").arg(40));break; } } else { paint.drawLine(0,-95,0,-100); } paint.rotate(5.2); } } void MainWindow::draw_point(QPainter &paint) { QPoint hand[3]={ QPoint(0,-90), QPoint(4,-25), QPoint(-4,-25), }; QColor handcolor(200,10,10,200); paint.setBrush(handcolor); paint.save(); paint.restore(); paint.drawText(-6,3,tr("%1").arg(value)); paint.rotate(220+5.2); paint.save(); paint.rotate(value*2.6); paint.drawConvexPolygon(hand,3); paint.restore(); }