用鼠标改变QWidget的宽度

Question

我在 QHBoxLayout 中有两个 QWidget。我希望能够通过单击右侧并移动鼠标（例如 Qt Editor 的项目浏览器）来更改左侧 QWidget 的宽度。

Answer 1

您可以使用 eventFilter 并在小部件上使用鼠标移动、输入、离开和鼠标单击。

检查这个例子：我用 QHBoxLayout 制作了两个小部件，并得到了 QEvent::HoverEnter 和 QEvent::MouseButtonPress。

.cpp 文件：

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    widgetOneW = 300;
    widgetTwoW = 300;

    ui->widgetOne->installEventFilter(this);
    ui->widgetTwo->installEventFilter(this);

    ui->widgetOne->setAttribute(Qt::WA_Hover);
    ui->widgetTwo->setAttribute(Qt::WA_Hover);
}

bool MainWindow::eventFilter(QObject *object, QEvent *event)
{
    if ((object == ui->widgetOne) && (event->type() == QEvent::HoverEnter))
    {
        ui->widgetOne->resize(100, ui->widgetOne->height());
        ui->widgetTwo->resize(widgetTwoW, ui->widgetTwo->height());
        return true;
    }
    else if ((object == ui->widgetOne) && (event->type() == QEvent::MouseButtonPress))
    {
        QMouseEvent *keyEvent = static_cast<QMouseEvent *> (event);
        if(keyEvent->button() == Qt::LeftButton)
        {
            ui->widgetOne->resize(100, ui->widgetOne->height());
            ui->widgetTwo->resize(widgetTwoW, ui->widgetTwo->height());
            return true;
        }
    }
    else if ((object == ui->widgetTwo) && (event->type() == QEvent::HoverEnter))
    {
            ui->widgetOne->resize(widgetOneW, ui->widgetOne->height());
            ui->widgetTwo->resize(100, ui->widgetTwo->height());
            return true;
    }
    else if ((object == ui->widgetTwo) && (event->type() == QEvent::MouseButtonPress))
    {
        QMouseEvent *keyEvent = static_cast<QMouseEvent *> (event);
        if(keyEvent->button() == Qt::LeftButton)
        {
            ui->widgetOne->resize(widgetOneW, ui->widgetOne->height());
            ui->widgetTwo->resize(100, ui->widgetTwo->height());
        }
    }
}


MainWindow::~MainWindow()
{
    delete ui;
}

.h 文件：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QKeyEvent>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

    int widgetOneW;
    int widgetTwoW;

public slots:
    bool eventFilter(QObject *object, QEvent *event);

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

.pro 文件：

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = first
TEMPLATE = app


SOURCES += main.cpp\
        mainwindow.cpp

HEADERS  += mainwindow.h

FORMS    += mainwindow.ui

Answer 2

你可以使用 QSplitter 做你想做的事。你可以在这里找到一个完整的例子：

用鼠标改变QWidget的宽度

Changing width of QWidget with mouse

c++

qt

qwidget