adjustSize在顯示過程中可能存在展示不完全的問題,產生場景:
子widget大小超過父widget,同時子widget大於當前屏幕分辨率的2/3。
對adjustSize應源碼如下:
QSize QWidgetPrivate::adjustedSize() const
{
Q_Q(const QWidget);
QSize s = q->sizeHint();
if (q->isWindow()) {
Qt::Orientations exp;
if (layout) {
if (layout->hasHeightForWidth())
s.setHeight(layout->totalHeightForWidth(s.width()));
exp = layout->expandingDirections();
} else
{
if (q->sizePolicy().hasHeightForWidth())
s.setHeight(q->heightForWidth(s.width()));
exp = q->sizePolicy().expandingDirections();
}
if (exp & Qt::Horizontal)
s.setWidth(qMax(s.width(), 200));
if (exp & Qt::Vertical)
s.setHeight(qMax(s.height(), 100));
#if 0 // Used to be included in Qt4 for Q_WS_X11
QRect screen = QApplication::desktop()->screenGeometry(q->x11Info().screen());
#else // all others
QRect screen = QApplication::desktop()->screenGeometry(q->pos());
#endif
s.setWidth(qMin(s.width(), screen.width()*2/3));
s.setHeight(qMin(s.height(), screen.height()*2/3));
if (QTLWExtra *extra = maybeTopData())
extra->sizeAdjusted = true;
}
if (!s.isValid()) {
QRect r = q->childrenRect(); // get children rectangle
if (r.isNull())
return s;
s = r.size() + QSize(2 * r.x(), 2 * r.y());
}
return s;
}
可以看出最後計算:
s.setWidth(qMin(s.width(), screen.width()*2/3));
s.setHeight(qMin(s.height(), screen.height()*2/3));
會取縮放後的大小與分辨率2/3進行對比,取更小的尺寸,從而導致該現象發生
解決方式:
在調用adjustSize之後,進行子widget與父widget進行對比,如果子widget的尺寸大於父widget則父widget重新resize即可