Qt 实现绘制不规则窗口(控件)

相比此方案 ,已有更好的解决方案  https://blog.youkuaiyun.com/qq_33259248/article/details/128222959

项目中要实现类似于下图的一个窗体,里面的红色部分是按钮

 直接上代码

按钮类:

#ifndef MyButton_H
#define MyButton_H

#include <QObject>
#include <QPointer>
#include <QPushButton>
class MyButton : public QPushButton
{
public:
    explicit MyButton(QString flag = "", QWidget *parent = nullptr);
    void setFriendWidget(QWidget *widget);

protected:
    void paintEvent(QPaintEvent *event);
    void mousePressEvent(QMouseEvent *event);

private:
    QString flag_ ;
    QPainterPath path_;
    QPointer< QWidget >friendWidget_;

};

#endif // MyButton_H

#include "mybutton.h"
#include <QPainter>
#include <QBitmap>
#include <QDebug>
#include <QStyleOptionTab>
#include <QMouseEvent>
#include <QApplication>

MyButton::MyButton(QString flag, QWidget *parent):
    QPushButton(parent)
{
    flag_ = flag;
    setWindowFlags(Qt::FramelessWindowHint);
    setAttribute(Qt::WA_TranslucentBackground);//设置背景透明
    QPixmap pixmap(":/view/view/doing1.png");
    setFixedSize(pixmap.size());
}


void MyButton::setFriendWidget(QWidget *widget)
{
    friendWidget_ = widget;
}

void MyButton::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);
    QBrush brush(QColor(255, 0, 0), Qt::SolidPattern);
    painter.setBrush(brush);

    QPainterPath path;
    path.moveTo(0, 0);
    path.lineTo(98, 0);
    path.lineTo(118, 19);
    path.lineTo(98, 38);
    path.lineTo(0, 38);
    path.lineTo(20, 19);
    path.closeSubpath();
    QFont font;
    font.setPixelSize(16);
    path.addText(40, 20, font, flag_);
    painter.setPen(Qt::NoPen);
    painter.drawPath(path);

    path_ = path;
}


void MyButton::mousePressEvent(QMouseEvent *event)
{
    if (this->parent() && (event->buttons() & Qt::LeftButton))
    {
        qDebug() << flag_ << event->pos().rx() << event->pos().ry();
        if (path_.contains(event->pos()))
        {
            qDebug() << flag_ << "按钮内部" ;
            QPushButton::mousePressEvent(event);
        }
        else
        {
            qDebug() << flag_ << "按钮外部" << friendWidget_ ;
            this->setAttribute(Qt::WA_TransparentForMouseEvents, true);
            //将点击事件在当前部件的坐标转换为在父窗口坐标系中的坐标
            QPoint point = this->mapToGlobal(event->pos());
            if (friendWidget_ != nullptr)
            {
                //将当前部件在父窗口的坐标转为在当前部件自己的坐标系中的坐标
                QPoint  point1 = friendWidget_->mapFromGlobal(point);
                QMouseEvent *mouseEvent = new QMouseEvent(event->type(), point1, event->button(), event->buttons(), event->modifiers());
                QApplication::postEvent(friendWidget_, mouseEvent);
            }
            this->setAttribute(Qt::WA_TransparentForMouseEvents, false);
        }
    }
}

主界面

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPainter>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    button1_ = new MyButton("button1", this);
    button2_ = new MyButton("button2", this);
    button3_ = new MyButton("button3", this);

    button2_->setFriendWidget(button1_);
    button3_->setFriendWidget(button2_);

    connect(button1_, &MyButton::pressed, this, &MainWindow::slotButton1);
    connect(button2_, &MyButton::pressed, this, &MainWindow::slotButton2);
    connect(button3_, &MyButton::pressed, this, &MainWindow::slotButton3);

    button1_->move(100, 100);
    button2_->move(button1_->pos() + QPoint(-30 + button1_->width(), 0));
    button3_->move(button2_->pos() + QPoint(-30 + button2_->width(), 0));
}

MainWindow::~MainWindow()
{
    delete ui;
}
void MainWindow::slotButton1()
{
    ui->lineEdit->setText("1");
}
void MainWindow::slotButton2()
{
    ui->lineEdit->setText("2");
}
void MainWindow::slotButton3()
{
    ui->lineEdit->setText("3");
}

解释:

1. 按钮中通过重写paintEvent 绘制出按钮形状. 显示如图
2. 但是此时按钮的鼠标点击事件触发范围,如下图所示,三个按钮的触发范围分别为 黑色框,蓝色框,绿色框,和我们想要的不符合.我们想要的点击范围为三个宽箭头形状
3. 重写 mousePressEvent,判断鼠标点击点是否在 path范围内,如果在正常触发事件, 如果不在,则当前按钮忽略此事件,这样就不会在点击空白处时误触发(如上图1处)  . 然后将此事件发给 friendWidget
4. 按钮new的顺序是,1,2,3, 所以button2盖住了button1的一部分(上图2处), 此时点击2处实际触发的是button.我把button1 作为friendwidget给button2,如果button2鼠标点击事件不在path范围内, 则把点击事件发给button1,button1判断点是否在当前path范围内,如果不在则忽略, 如果在则说明点击到上图2处,触发button1的事件

 借鉴: Qt 鼠标点击事件穿透_jupeiii的博客-优快云博客_qt 点击事件