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根据Qt中的显示/屏幕大小定位动态QDialog

screen position dialog qt

NESHOM · 技术社区 · 8 年前

我想定位并显示一个关于显示器的对话框。该对话框有一个标签。该对话框将根据标签的大小展开。

下面是我不工作的代码。它尝试在屏幕中央显示对话框(默认情况下,对话框显示在中央,此代码仅用于评估):

QDialog splash;
QVBoxLayout *laySplash = new QVBoxLayout(&splash);
QLabel *lblText = new QLabel;
laySplash->addWidget(lblText);
lblText->setText("hello world! hello world! hello world! hello world! hello world! ");

int intScreenHeight = QApplication::desktop()->screenGeometry().height();
int intScreenWidth = QApplication::desktop()->screenGeometry().width();

splash.layout()->update();
splash.layout()->activate();

int intSplashLeft = (intScreenWidth / 2) - (splash.width() / 2);
int intSplashTop = (intScreenHeight /2) - (splash.height() / 2);
splash.move(intSplashLeft, intSplashTop);

splash.exec();

我做错了什么?

(我在Linux中使用Qt5)

2 回复 | 直到 8 年前

eyllanesc 8 年前

您案例中的问题是,布局只会在小部件可见后更新其大小,一种可能的解决方案是通过调用该方法强制它 adjustSize() 的 QDialog .

有几种方法可以使小部件居中:

第一种形式:

QDialog splash;
QVBoxLayout *laySplash = new QVBoxLayout(&splash);
QLabel *lblText = new QLabel;
laySplash->addWidget(lblText);
lblText->setText("hello world! hello world! hello world! hello world! hello world! ");
splash.adjustSize();

splash.setGeometry(
    QStyle::alignedRect(
        Qt::LeftToRight,
        Qt::AlignCenter,
        splash.size(),
        qApp->desktop()->availableGeometry()
    )
);

splash.exec();

第二种形式:

QDialog splash;
QVBoxLayout *laySplash = new QVBoxLayout(&splash);
QLabel *lblText = new QLabel;
laySplash->addWidget(lblText);
lblText->setText("hello world! hello world! hello world! hello world! hello world! ");
splash.adjustSize();
QPoint p = QApplication::desktop()->geometry().center()-splash.rect().center();
splash.move(p);

splash.exec();

第三种形式(您的方法):

QDialog splash;
QVBoxLayout *laySplash = new QVBoxLayout(&splash);
QLabel *lblText = new QLabel;
laySplash->addWidget(lblText);
lblText->setText("hello world! hello world! hello world! hello world! hello world! ");

splash.adjustSize();
int intScreenHeight = QApplication::desktop()->screenGeometry().height();
int intScreenWidth = QApplication::desktop()->screenGeometry().width();

int intSplashLeft = (intScreenWidth / 2) - (splash.width() / 2);
int intSplashTop = (intScreenHeight /2) - (splash.height() / 2);
splash.move(intSplashLeft, intSplashTop);

splash.exec();

Gurushant GeneCode 8 年前

试试我的代码创建一个名为set geometry的函数,并传递QDialog指针和相对于屏幕的大小百分比。如果希望对话框的大小为总屏幕的50%,则通过50

void setGeometry(QDialog *dialogBox, int PercentageOfScreen)
{
    int x, y, w, h;
    QRect rect = QApplication::desktop()->screenGeometry();
    int screen_width = rect.width();
    int screen_height = rect.height();

    //Represent Percentage in decimals
    float PercentageOfScreenFloat = (float)PercentageOfScreen/100;

    //Calculate w and h
    w = (PercentageOfScreenFloat * screen_width);
    h = (PercentageOfScreenFloat * screen_height);

    //Check for max and min size hints
    int minW = dialogBox->minimumWidth();
    int minH = dialogBox->minimumHeight();

    int maxW = dialogBox->maximumWidth();
    int maxH = dialogBox->maximumHeight();

    if(w<minW || h<minH)
    {
        w = minW;
        h = minH;
    }
    else if(w>maxW || h>maxH)
    {
        w = maxW;
        h = maxH;
    }

    //Now Calculate x and y
    x = screen_width / 2;
    x = x - w / 2;

    y = screen_height / 2;
    y = y - h / 2;

    dialogBox->setGeometry(x, y, w, h);

}