Qt自定义控件实现圆圈加载进度条
时间：2021-01-04 16:13:08 | 栏目：C代码 | 点击：次
本文实例为大家分享了Qt实现圆圈加载进度条的具体代码，供大家参考，具体内容如下
先看效果图：
思路：画一个占270度的圆弧，然后定义一个定时器，定时旋转坐标系，实现旋转的效果。圆弧需要使用渐变色，实现颜色越来越浅的效果
关键代码：CMProcessBar1.cpp
CMProcessBar1::CMProcessBar1(QWidget *parent) :
QWidget(parent),
ui(new Ui::CMProcessBar1)
{
ui->setupUi(this);
QTimer *timer = new QTimer;
connect(timer,QTimer::timeout,this,updaterRotation);// 定时旋转坐标系
timer->start(3);//定时3毫秒
}
CMProcessBar1::~CMProcessBar1()
{
delete ui;
}
void CMProcessBar1::updaterRotation(){ //循环360度旋转坐标系
rotation++;
if(rotation == 360){
rotation = 0;
}
update();
}
void CMProcessBar1::paintEvent(QPaintEvent *event){//根据QPaintPath画出渐变色的圆弧
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);
QConicalGradient gra(QPoint(0,0),0);
gra.setColorAt(0,QColor("#3BB6FE"));
gra.setColorAt(1,QColor("#FFFFFF"));
QBrush brush(gra);
int radis = 40;
int sider = 5;
QRect rect(-radis,-radis,radis*2,radis*2);
QPainterPath path;
path.arcTo(rect,0, 270);
QPainterPath subPath;
subPath.addEllipse(rect.adjusted(sider, sider, -sider, -sider));
path = path-subPath;
painter.setBrush(brush);//QColor("#66CFFF")
painter.setPen(Qt::NoPen);
painter.rotate(rotation);
painter.drawPath(path);
}