I am doing this
ui.label->geometry().setWidth(12);
However the error I get is
Error 1 error C2662: 'QRect::setWidth' : cannot convert 'this' pointer from 'const QRect' to 'QRect &'
Any suggestions on how to resolve this ?
Geometry returns a const QRect reference, so you need to use it like this:
QRect r = ui.label->geometry();
r.setWidth(12);
ui.label->setGeometry(r);
Or you can use resize:
ui.label->resize(12, ui.label->height());
But you can also tell us what are you trying to accomplish and maybe we can find a solution that puts the QLabel into a layout and you won't need to manually resize it.
geometry() returns you const reference to QRect so it can only be used as read-only information.
Not very beautiful way but you may try calling setMinimumWidth(), setMaximumWidth() functions with the same desired value as an argument.
Actually resizing label despite it's contents is very suspicious operation)
Related
I'm trying to put an animated gif into my program.
However, when I follow the proper syntax
QMovie *hit1=new QMovie("BadExplosion.gif");
QLabel *processLabel=new QLabel(this);
processLabel->setMovie(hit1);
hit1->start();
in the
void TestApp::draw()
{
//this code and other drawing code here
}
I run into the error
error C2664: 'QLabel::QLabel(QWidget *, Qt::WindowFlags)' : Cannot convert parameter 1 from 'TestApp *const' to 'QWidget *' on the line
QLabel *processLabel=new QLabel(this);
Any ideas? Thanks!
EDIT: TestApp is a custom class.
If TestApp is a custom class, then it's perfectly normal that this code doesn't work.
Every UI element of Qt may take a parameter at construction, which is the QWidget that will act as a parent. This parent will notably have the responsibility for handling its children deletion. You should read more about this in the Qt Documentation (esp. the doc for QWidget constructor).
In your case, you shouldn't pass this to the QLabel constructor. You must pass another widget that'll become this QLabel parent.
The compiler shows clearly this problem with the message you got. It waits for a QWidget, but got your class instead (which doesn't inherit QWidget at any point).
I have a problem right now with my mini-game I am making. The problem is as follows: I have created an level editor for my game and thus I had to create my own delegate and model, the problem occurs when I try to edit through a shapeeditor ( which more likely creates a painterpath ). I then return the painterpath through data but when I try to paint it with my delegate, qt tells me the following error:
/usr/include/qt4/QtCore/qmetatype.h:169: error: 'qt_metatype_id' is not a member of 'QMetaTypeId<QPainterPath>'
I am not quite sure why I am having this error. For information regarding the source code of the project, I can give if needed. But I am simply thinking the conversion from qvariant to qpainterpath isn't possible. They must be a way to do it.
Note: I tried to do the following
QVariant var = index.model()->data(index, Qt::DecorationRole);
QPainterPath path = var.value<QPainterPath>(); // The error occurs here, this is line 169
But this didn't work >.< Thanks if you can help me
Possible solution, is there anyway to create a pixmap from the painterpath? I could simply return the pixmap instead of the painterpath.
Looks like you need to use Q_DECLARE_METATYPE macro with QPainterPath
Like
Q_DECLARE_METATYPE (QPainterPath)
Here is documentation for the same.
I'm using QVariant to store a object inside of a Qcombobox, This appears to work fine. This is the implementing code:
Add type to QVariant in header:
Q_DECLARE_METATYPE(CDiscRecorder*)
pDiscRecorder Casted as CDiscRecorder:
CDiscRecorder* pDiscRecorder = new CDiscRecorder();
Then stored in the combobox
ui->cbDrives->addItem(QString::fromWCharArray(strName), QVariant::fromValue(pDiscRecorder));
The problem arises when I try to pull it out:
CDiscRecorder* discRecorder = this->ui->cbDrives->itemData(index).value<CDiscRecorder*>;
I receive the error:
error C3867: 'QVariant::value': function call missing argument list; use '&QVariant::value' to create a pointer to member
I tried to implement the hint in the error code to no avail, I have followed the thread Add QObject in the combo box of Qt to implement this behavior, how can get my object back ?
Thanks
The compiler is giving you the hint that the argument list is missing - all you should need to do is add the brackets to tell it that you're trying to call the function. So change it to
CDiscRecorder* discRecorder = this->ui->cbDrives->itemData(index).value<CDiscRecorder*>();
And it should work. That's quite a long line, might be cleaner to break it out
QVariant variant = this->ui->cbDrives->itemData(index);
CDiscRecorder* discRecorder = variant.value<CDiscRecorder*>();
How would I go about passing QSqlQueryModel from a class that connects and queries the database through the control class or QMainWindow in my attempt and back to the widget needing the information?
I thought I could pass the reference location to the QSqlQueryModel object, but this is not working or I am doing something wrong.
I haven't found any examples showing what I am doing on the Qt Developer page.
Looks like these are just compiler errors, nothing specifically to do with Qt.
In short you are getting your pointers and references mixed up.
Error #1:
cardList = new List(sqlModel->getListModel());
You are passing a reference when the List takes a pointer. Fix your return type from getListModel or fix the above line.
Next, you are not specifying the second argument, i.e. the parent QWidget. Either specify your MainWindow as the parent, pass 0, or fix your constructor's signature to provide a default (generally 0).
Error #2:
List::List(QSqlQueryModel *model, QWidget *parent) : ListUI(parent){
setListItems(&model);
}
You receive the model as a pointer and then attempted to take the address of the pointer. I.e. You're making a double pointer. Change the line to
setListItems(model);
Hope that helps.
I'm trying to use the standard icons in Qt for a QToolButton but I have a problem. My code is:
m_buttonZoomPlus->setIcon(QStyle::standardIcon(QStyle::SP_DesktopIcon));
I get the error message :
cannot call member function 'QIcon QStyle::standardIcon(QStyle::StandardPixmap, const QStyleOption*, const QWidget*) const' without object
What does it mean? Do I Have to create an empty QStyle object and call the standardIcon function on it?
Besides, I found a list of standard icons here: http://doc.trolltech.com/main-snapshot/qstyle.html#StandardPixmap-enum
Is this list exhaustive or are there other standard icons? I'm looking for instance for a zoom-in/out icon and I've not yet been able to find it.
Thank you very much for you help.
It means standardIcon is not a static method so you can't call it that way. You need to construct a QStyle and initialize it appropriately then you can use that method to get a specific icon.
Edit: Jeremy is right. If you aren't changing the style or defining your own style you can simply use the following:
QApplication::style()->standardIcon(QStyle::SP_DesktopIcon);
Reference: http://doc.qt.io/qt-5/qstyle.html#standardIcon