经常出现setGeometry: Unable to set geometry

查看调用堆栈如下

查看showEvent函数发现如果没有Qt::WA_Moved属性则会调用adjustPosition函数

void QDialog::showEvent(QShowEvent *event)
{
    if (!event->spontaneous() && !testAttribute(Qt::WA_Moved)) {
        Qt::WindowStates  state = windowState();
        adjustPosition(parentWidget());
        setAttribute(Qt::WA_Moved, false); // not really an explicit position
        if (state != windowState())
            setWindowState(state);
    }
}

解决方案

在调用show(); 以及相似函数前调用
设置Qt::WA_Moved刷卡

setAttribute(Qt::WA_Moved, true);
showMaximized();