Qt 重叠同级 Widget 定制化穿透点击

先来先看效果，三个部分重叠的正方形，每个正方形中间有个小正方形，希望点击其中一个小正方形时，不被上方的 Widget 遮挡，选中时小正方形变色。

大体思路是：
1.在主 Widget 捕获点击事件，遍历子Widget，看子Widget中的小正方形是否位于鼠标下；

2.如果子 Widget 的小正方形位于鼠标下，子 Widget 就给 小正方形发送事件，使其变色（小正方形中也捕获点击事件）。

3.如果点击在了最上层的子 Widget 的小正方形上，则直接触发了小正方形的事件。

具体实现细节见代码，UI 都是代码手写的，所以可以复制粘贴直接运行，有用的话赞点一点，复制点一点：

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QString>
class MainWindow;
class BaseWidget:public QWidget{QString name;
public:QString Name();void SetName(QString name);bool IsWidget(QString name);BaseWidget(QWidget*parent);
};
class CenterRect:public BaseWidget{
public:CenterRect(QWidget*parent);void mousePressEvent(QMouseEvent* mouseEvent);
};
class EventWidget:public BaseWidget{
public:CenterRect* centerRect;MainWindow*Parent = nullptr;EventWidget(QWidget*parent,QColor color);//判断pos是否在centerRect里bool InRect(QPoint pos);//TryActivebool TryActive(QPoint pos,QEvent *e);//把事件转发给centerRectvoid TransEvent(QEvent *e);//进行激活操作void Active(QEvent *e);void ResetCenterRectColor();void ClearOtherSelection();
};class MainWindow : public QWidget
{Q_OBJECTpublic:QList<EventWidget*> EventWidgetList;MainWindow(QWidget *parent = nullptr);void mousePressEvent(QMouseEvent* mouseEvent);~MainWindow();void Clear();
};
#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include <QMouseEvent>
#include <QDebug>
#include <QApplication>
void SetWidgetColor(QColor color, QWidget* dstWidget)
{QPalette pal(dstWidget->palette());pal.setColor(QPalette::Background, color);dstWidget->setAutoFillBackground(true);dstWidget->setPalette(pal);
}QString BaseWidget::Name()
{return name;
}void BaseWidget::SetName(QString name)
{this->name = name;
}bool BaseWidget::IsWidget(QString name)
{return this->name == name;
}BaseWidget::BaseWidget(QWidget *parent):QWidget(parent)
{//写一些通用的属性
}
CenterRect::CenterRect(QWidget *parent):BaseWidget(parent)
{SetName("CenterRect");
}void CenterRect::mousePressEvent(QMouseEvent *mouseEvent)
{((EventWidget*)parent())->ClearOtherSelection();SetWidgetColor(QColor(0,200,200),this);
}
EventWidget::EventWidget(QWidget *parent,QColor color):BaseWidget(parent)
{this->resize(400,400);Parent = (MainWindow*)parent;SetWidgetColor(color,this);centerRect = new CenterRect(this);centerRect->resize(50,50);centerRect->move(200-25,200-25);SetName("EventWidget");SetWidgetColor(QColor(200,200,0),centerRect);
}bool EventWidget::InRect(QPoint pos)
{QPoint p = mapFromParent(pos);CenterRect*rect = (CenterRect*)childAt(p);if(!rect)return false;if(!rect->IsWidget("CenterRect"))return false;return true;
}bool EventWidget::TryActive(QPoint pos,QEvent *e)
{if(InRect(pos)){Active(e);return true;}return false;
}void EventWidget::TransEvent(QEvent *e)
{QApplication::sendEvent(centerRect,e);
}void EventWidget::Active(QEvent *e)
{raise();TransEvent(e);
}void EventWidget::ResetCenterRectColor()
{SetWidgetColor(QColor(200,200,0),centerRect);
}void EventWidget::ClearOtherSelection()
{Parent->Clear();
}MainWindow::MainWindow(QWidget *parent):QWidget(parent){EventWidget*ew1 = new EventWidget(this,QColor(200,0,0,50));ew1->move(0,0);EventWidget*ew2 = new EventWidget(this,QColor(0,200,0,50));ew2->move(50,50);EventWidget*ew3 = new EventWidget(this,QColor(0,0,200,50));ew3->move(100,100);EventWidget*ew4 = new EventWidget(this,QColor(0,0,200,50));ew4->move(200,100);EventWidget*ew5 = new EventWidget(this,QColor(0,0,200,50));ew5->move(800,100);EventWidgetList.push_back(ew1);EventWidgetList.push_back(ew2);EventWidgetList.push_back(ew3);EventWidgetList.push_back(ew4);EventWidgetList.push_back(ew5);ew2->raise();}void MainWindow::mousePressEvent(QMouseEvent *event){QPoint pos = event->pos();EventWidget * widget = (EventWidget*)this->childAt(pos);if(!widget)return;if(!widget->IsWidget("EventWidget"))return;for(EventWidget*widget:EventWidgetList){widget->TryActive(pos,event);}
}MainWindow::~MainWindow()
{
}void MainWindow::Clear()
{for(EventWidget*widget:EventWidgetList){widget->ResetCenterRectColor();}
}