Qt之QDesktopWidget的使用说明(屏幕个数、屏幕分辩率、屏幕PDI、设置屏幕分辩率)

#include "mainwindow.h" #include "ui_mainwindow.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) , ui(new Ui::MainWindow) { ui->setupUi(this); // 设置标题 setWindowTitle(QStringLiteral("Qt之QDesktopWidget的使用说明(屏幕个数、屏幕分辩率、屏幕PDI、设置屏幕分辩率)")); // 设置界面大小 resize(600, 300); // 为了测试，先把界面放在左100，顶200位置上。 move(100, 200); // 桌面操作作 m_pDeskdop = QApplication::desktop(); move((m_pDeskdop->width() - this->width())/2, (m_pDeskdop->height() - this->height())/2); } MainWindow::~MainWindow() { delete ui; } void MainWindow::on_pushButton_4_clicked() { ui->textEdit->append(QString::number(m_pDeskdop->screenCount())); } void MainWindow::on_pushButton_3_clicked() { ui->textEdit->append(QString::number(m_pDeskdop->numScreens())); } void MainWindow::on_pushButton_2_clicked() { ui->textEdit->append(QString::number(m_pDeskdop->screenNumber())); } void MainWindow::on_pushButton_clicked() { ui->textEdit->append(QString::number(m_pDeskdop->primaryScreen())); } void MainWindow::on_pushButton_5_clicked() { ui->textEdit->append(QString::number(m_pDeskdop->screen()->width())); ui->textEdit->append(QString::number(m_pDeskdop->screen()->height())); } int MainWindow::GetTaskbarInfo() { QRect deskRect = m_pDeskdop->availableGeometry(); QRect screenRect = m_pDeskdop->screenGeometry(); int nLocation = 1; if (deskRect.bottom() != screenRect.bottom()) //任务栏在下 { nLocation = 1; } else if (deskRect.top() != screenRect.top()) //任务栏在上 { nLocation = 2; } else if (deskRect.left() != screenRect.left()) //任务栏在左 { nLocation = 3; } else if (deskRect.right() != screenRect.right()) //任务栏在右 { nLocation = 4; } else //任务栏处于自动隐藏状态 { nLocation = 5; } return nLocation; } void MainWindow::GetTaskbarInfo(int &width, int &height, int &pos) { // 得到被定义的系统数据或者系统配置信息 int wx = GetSystemMetrics(SM_CXSCREEN);// 主显示器屏幕的宽度，以像素为单位。 这是通过调用GetDeviceCaps获得的相同值 int wy = GetSystemMetrics(SM_CYSCREEN);// 主显示器屏幕的高度，以像素为单位。 RECT rtWorkArea; // 函数查询或设置系统级参数 SystemParametersInfo(SPI_GETWORKAREA, 0, &rtWorkArea, 0);// 工作区是指屏幕上不被系统任务条或应用程序桌面工具遮盖的部分 //1.任务栏停靠在左边情况 if (0 != rtWorkArea.left) { width = wx - rtWorkArea.right; height = wy; pos = 0; return; } //2.任务栏停靠在上边情况 if(0!=rtWorkArea.top) { width = wx; height = wy - rtWorkArea.bottom; pos = 1; return; } //3.任务栏停靠在右边情况 if(0==rtWorkArea.left && wx!=rtWorkArea.right) { width = wx - rtWorkArea.right; height = wy; pos = 2; return; } //4.任务栏停靠在下边情况 if(0==rtWorkArea.top && wy!=rtWorkArea.bottom) { width = wx; height = wy - rtWorkArea.bottom; pos = 3; return; } //5.任务栏自动隐藏的情况，这样其宽高都是0 if(0==rtWorkArea.left && 0==rtWorkArea.top && wx==rtWorkArea.right && wy==rtWorkArea.bottom) { width = 0; height =0; pos = 4; return; } } void MainWindow::on_pushButton_7_clicked() { ui->textEdit->append(QString::number(GetTaskbarInfo())); } void MainWindow::on_pushButton_6_clicked() { int w, h, pos; GetTaskbarInfo(w, h, pos); ui->textEdit->append(QStringLiteral("任务栏 宽：%1 高：%2 位置：%3").arg(w).arg(h).arg(pos)); } void MainWindow::on_pushButton_8_clicked() { int nScreenWidth = ::GetSystemMetrics(SM_CXSCREEN); int nScreenHeight = ::GetSystemMetrics(SM_CYSCREEN); HWND hwd = ::GetDesktopWindow(); HDC hdc = ::GetDC(hwd); int width = GetDeviceCaps(hdc, DESKTOPHORZRES); int height = GetDeviceCaps(hdc, DESKTOPVERTRES); double dWidth = (double)width; double dScreenWidth = (double)nScreenWidth; double scale = dWidth / dScreenWidth; ui->textEdit->append(QStringLiteral("nScreenWidth：%1 nScreenHeight：%2 width：%3 height:%4 scale:%5") .arg(nScreenWidth).arg(nScreenHeight) .arg(width).arg(height) .arg(scale)); }