在 Qt 中的 show() 上更改窗口位置

Question

当我从当前窗口（@98​​7654322@）创建窗口对象时，我知道重新定位窗口的过程，如下所示：

QDesktopWidget widget;
QRect screenGeometry = widget.screenGeometry();
int height = screenGeometry.height();
int width = screenGeometry.width();
//set to middle of screen
targetwindow->move((width - targetwindow->width()) / 2.0,
                (height - targetwindow->height()) / 2.0);
targetwindow->show();

currWindow 也有类似的代码。但是我在targetwindow 中有一个后退按钮，它隐藏了targetwindow 和show() 和currWindow。我使用信号槽机制实现了这一点，如下所示：

connect(targetwindow,&TargetWindow::pressTargetWindowGoBackButton,
                                           this,&CurrentWindow::show);

问题是在按下targetwindow 上的返回按钮后，currWindow 显示但没有保持我之前为其设置的位置（即屏幕中间）。我试图通过添加代码来使用此运算符将其定位在绘制事件中来纠正它，但它不起作用：

void currWindow::paintEvent(QPaintEvent *pe)
{

        QDesktopWidget widget;
        QRect screenGeometry = widget.screenGeometry();
        int height = screenGeometry.height();
        int width = screenGeometry.width();
        this->move((width - this->width()) / 2.0,
                        (height - this->height()) / 2.0);
}

我该怎么做？我是否需要覆盖预定义的 show() 函数以及如何？

编辑：添加我的项目的代码。这里 currentwindow -> MainWindow 和 targetwindow->Dialog.

dialog.h

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

signals:
    void goBack();
public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();

private slots:
    void on_pushButton_clicked();

private:
    Ui::Dialog *ui;
};

#endif // DIALOG_H

ma​​inwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "dialog.h"
namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

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

private slots:
    void on_pushButton_clicked();

private:
    Ui::MainWindow *ui;
    Dialog *dia;
};

#endif // MAINWINDOW_H

ma​​in.cpp

#include "mainwindow.h"
#include <QApplication>
#include <QDesktopWidget>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;

    QDesktopWidget widget;
    QRect screenGeometry = widget.screenGeometry();//.availableGeometry(widget.primaryScreen());

    int height = screenGeometry.height();
    int width = screenGeometry.width();
    w.move(-50000,-50000);

    w.move((width - w.width()) / 2.0,
                    (height - w.height()) / 2.0);
    w.show();
    return a.exec();
}

ma​​inwindow.cpp

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


MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    dia=new Dialog;
    connect(dia,&Dialog::goBack,this,&MainWindow::show);
}

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

void MainWindow::on_pushButton_clicked()
{

    QDesktopWidget widget;
    QRect screenGeometry = widget.screenGeometry();//.availableGeometry(widget.primaryScreen());

    int height = screenGeometry.height();
    int width = screenGeometry.width();
    dia->move(-50000,-50000);
//    dia->show();
    dia->move((width - dia->width()) / 2.0,
                    (height - dia->height()) / 2.0);
    dia->show();
    hide();
}

dialog.cpp

#include "dialog.h"
#include "ui_dialog.h"

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
}

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

void Dialog::on_pushButton_clicked()
{
    emit goBack();
    hide();
}

ma​​inwindow.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>900</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <widget class="QPushButton" name="pushButton">
    <property name="geometry">
     <rect>
      <x>150</x>
      <y>90</y>
      <width>201</width>
      <height>141</height>
     </rect>
    </property>
    <property name="text">
     <string>OK</string>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>900</width>
     <height>19</height>
    </rect>
   </property>
  </widget>
  <widget class="QToolBar" name="mainToolBar">
   <attribute name="toolBarArea">
    <enum>TopToolBarArea</enum>
   </attribute>
   <attribute name="toolBarBreak">
    <bool>false</bool>
   </attribute>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>

dialog.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Dialog</class>
 <widget class="QDialog" name="Dialog">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>900</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Dialog</string>
  </property>
  <widget class="QPushButton" name="pushButton">
   <property name="geometry">
    <rect>
     <x>370</x>
     <y>120</y>
     <width>231</width>
     <height>151</height>
    </rect>
   </property>
   <property name="text">
    <string>BACK</string>
   </property>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>

如果您在此执行 OK->Back->OK 循环，您会发现主窗口不断向上移动。

Answer 1

你试过targetwindow的setGeometry()函数吗：

int height = screenGeometry.height();
int width = screenGeometry.width();
int x=(width - w.width()) / 2.0;
int y=(height - w.height()) / 2.0;
w.setGeometry(x,y,w.width(),w.height());
w.show();