qwidget

问题 I basically want to display a rectangle on a dialog window widget. Using another question as reference, I tried to adapt the framework of using a QLabel and painting to it (the process overall seems overly complicated). I started by making a member in the dialog box's class: QLabel* label; In the constructor of the dialog box: label = new QLabel(this); label->setGeometry(20, 50, 50, 100); Just to try and make it work, I gave the dialog box a button to make the "rectangle" created with the

问题 I have a QWidget that contains a QPixmap and a QComboxBox in its Layout. I would like to set the background of the widget transparent (but I want to show the QPixmap and the QComboBox normally). How do I do that? 回答1: It is all well-explained in QWidget documentation: http://doc.qt.io/qt-5/qwidget.html#transparency-and-double-buffering 回答2: You can use the attribute widget->setAttribute(Qt::WA_NoSystemBackground); Qt documentation : Indicates that the widget has no background, i.e. when the

问题 It's now recommended to use QWindow for OpenGL drawing. Is it possible to add a widget to this window? If so, how? If not, how should I go about adding widgets to an OpenGL program using Qt5? 回答1: An application will typically use QWidget or QQuickView for its UI, and not QWindow directly. QWindow is more low level than QWidget . If you want to use QWindow directly, more work is needed to accomplish the job. You should manually do all drawing related things which is not easy. However, if you

问题 I have a custom widget derived from QWidget , which has a minimumSize of (30, 30) and a QLabel as a childWidget : MyWidget::MyWidget (QWidget *parent, QPoint p, QWidget *childWidget) : QWidget (parent) { childWidget = this->childWidget; setAttribute (Qt::WA_DeleteOnClose); this->move (p); verticalLayout = new QVBoxLayout (this); if (childWidget != NULL) { childWidget->setParent (this); childWidget->releaseMouse(); childWidget->setAttribute (Qt::WA_TransparentForMouseEvents, true);

问题 I've used QwtPlot (Qwt 6.0.1) in QML project (Qt 4.8) . i'm wrap it via QDeclarativeItem GraphWidgetQML::GraphWidgetQML(QDeclarativeItem *parent):QDeclarativeItem(parent) { _GraphArea = new GraphWidget; //child of QwtPlot without event handlers overrides QGraphicsProxyWidget *_wiget = new QGraphicsProxyWidget(this); _wiget->setWidget(_GraphArea); _wiget->setFlag(QGraphicsItem::ItemIsFocusable,true); this->setClip(true); } and insert into into QML via code qmlRegisterType<GraphWidgetQML> (

问题 Does anybody has an example how to make a QWidget instance (as toplevel window) override-redirect with the X11 library? the following code doesn't work: QWidget* widget = new QWidget(); XSetWindowAttributes attr; attr.override_redirect = true; XChangeWindowAttributes(display, widget->winId(), CWOverrideRedirect, &attr); widget->show(); Does anybody has an idea? The bigger toplevel-problem i try to solve is the following: QWidget / X11: Prevent window from beeing activated/focussed by mouse

问题 I'm working with Qt 4.7 , I set a QWidget's background-image CSS an image from my qrc. The problem is the image is High res , and only the upper left part of it is showing , I can't get it to scale down to fit. In CSS3 I saw a "background-size : contain" property but I fear it doesn't work in Qt 4.7. Couldn't find a way to make the image fit the window. Any ideas ? I don't mind doing it programmatically . Thanks Solved: http://www.developer.nokia.com/Community/Wiki/Archived:Load,_Resize_image

问题 I want to query a widget's width to carry out some custom layout management. Unfortunately, the following code returns 640 no matter how big or small the widget actually is int myWidth = this->rect().size().width(); // "this" is my class derived from QWidget // myWidth is set to 640 EDIT: int myWidth = this->width() returns the same 640 回答1: Correct place to do special layout management is overridden resizeEvent. At that point size of widget is decided (usually by parent widget's layout,

问题 I'm making a little app for applying various filters on an image using Qt and C++. My question is, is it possible to add multiple widgets on a QDockWidget ? As i want to add buttons for re-applying the last 5 filters on the dock. Here is an example of what i want to achieve. 回答1: It is possible add to multiple QWidget s into any QWidget . It looks like you probably want to do something like this: QDockWidget dock(QLatin1String("Last filters")); QWidget* multiWidget = new QWidget();

问题 Using Qt4.8 on a Mint Linux 12, I implemented a simple window containing a QTableView to show contents of a model. The model data is continually updated (log messages) and the dataChanged() signal is emitted on a regular basis (i.e. every 100ms). The problem I see is stuttering visual updates on the table. I installed an event filter on the window that counts updateRequest -type events, which should trigger a widget repaint (also on child widgets, i.e. the tableView ). These come in with an