QT 如何获知屏幕分辨修改事件

古城微笑少年丶 2022-09-11 07:24 171阅读 0赞

如何获知显示器的屏幕分辨率发生了修改，在QT环境，可以这么做：

### 头文件： ###

#pragma once
    
    #include <QtWidgets/QWidget>
    #include "ui_QtScreenResolutionTest.h"
    
    class QtScreenResolutionTest : public QWidget
    { 
        Q_OBJECT
    
    public:
        QtScreenResolutionTest(QWidget *parent = Q_NULLPTR);
    
    protected:
    	virtual bool nativeEvent(const QByteArray &eventType, void *message, long *result);
    
    private:
        Ui::QtScreenResolutionTestClass ui;
    };

### 实现文件： ###

#include "QtScreenResolutionTest.h"
    #include "windows.h"
    #include <QVBoxLayout>
    #include <QLabel>
    
    QtScreenResolutionTest::QtScreenResolutionTest(QWidget *parent)
        : QWidget(parent)
    { 
        ui.setupUi(this);
    
    	QVBoxLayout * layout = new QVBoxLayout(this);
    	layout->addStretch(1);
    
    	QLabel * label = new QLabel("Current Screen Resolution:");
    	label->setObjectName("lable_screen");
    	label->setAlignment(Qt::AlignCenter);
    	layout->addWidget(label);
    
    	layout->addStretch(1);
    	setLayout(layout);
    
    	int width = GetSystemMetrics(SM_CXSCREEN);
    	int height = GetSystemMetrics(SM_CYSCREEN);
    
    	QString text = QString("Current screen resolution: width=%1, height=%2").arg(width).arg(height);
    	label->setText(text);
    }
    
    bool QtScreenResolutionTest::nativeEvent(const QByteArray &eventType, void *message, long *result)
    { 
    	MSG* msg = reinterpret_cast<MSG*>(message);
    	int msgType = msg->message;
    	switch (msgType)
    	{ 
    	case WM_DISPLAYCHANGE://分辨率修改事件
    	{ 
    		int width = GetSystemMetrics(SM_CXSCREEN);
    		int height = GetSystemMetrics(SM_CYSCREEN);
    
    		QLabel * label = findChild<QLabel *>("lable_screen");
    		if (label)
    		{ 
    			QString text = QString("Current screen resolution: width=%1, height=%2").arg(width).arg(height);
    			label->setText(text);
    		}
    		break;
    	}
    	default:
    		break;
    	}
    
    	return QWidget::nativeEvent(eventType, message, result);
    }

### demo截图 ###

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAaGVsbG9rYW5keQ_size_18_color_FFFFFF_t_70_g_se_x_16_pic_center]

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