Non-resizeable QDialog with fixed size in Qt?

Question

I have a Qt dialog application. Now I dont want that dialog to be resizeable. I am not sure how to achieve this. I tried a bunch of things but still when the dialog launches this dialog can be resized.

What is the property that i should set to disable the dialog/Widget resize.

I also tried

setSizePolicy(QSizePolicy::Fixed);

But i get an error saying..

source\nimcac_settingsMain.cpp(36) : error C2248:
**'QSizePolicy::QSizePolicy' : cannot access private member declared in class 'QSizePolicy'**
        p:\ThirdPartyExports\Qt\export\4.3\4.3.1f14\include\QtGui\../../src\gui\
kernel\qsizepolicy.h(177) : see declaration of 'QSizePolicy::QSizePolicy'
        p:\ThirdPartyExports\Qt\export\4.3\4.3.1f14\include\QtGui\../../src\gui\
kernel\qsizepolicy.h(34) : see declaration of 'QSizePolicy'

Kindly help me out with this.

score 119 · Answer 1 · edited Oct 29 '15 at 13:42

119

The compile error you get is because you try to pass a QSizePolicy::Policy to setSizePolicy(QSizePolicy), but there's no implicit conversion from QSizePolicy::Policy (which is the policy for one dimension) to QSizePolicy (which is a class containing, among other things, one Policy per dimension (height, width)). QSizePolicy doesn't work on top-level widgets (windows) anyway, though.

setFixedSize() only works if you know the size of the dialog in advance (and usually you don't, what with changing font sizes and languages). You can do

window()->setFixedSize( window()->sizeHint() );

but it's much better to use

window->layout()->setSizeConstraint( QLayout::SetFixedSize );

That lets the layout determine the size of the dialog, but doesn't allow resizing, which I assume is what you were asking for.

edited Oct 29 '15 at 13:42

Steve Lorimer

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answered Jul 20 '09 at 05:42

Marc Mutz - mmutz

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`window->layout()->setSizeConstraint( QLayout::SetFixedSize );` is almost what I need because it updates with changing font etc. But I would like to fix only the height but not the width. Is this possible? – HiFile.app - best file manager Feb 09 '18 at 22:34
You're the MVP. This makes my QDialog not user-resizable, but it still resizes whenever its content changes size. – i know nothing Nov 14 '19 at 13:12

score 55 · Accepted Answer · edited Jun 03 '14 at 08:05

55

I don't know if you already tried it, but QWidget::setFixedSize should do what you want

edited Jun 03 '14 at 08:05

NG_

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answered Mar 30 '09 at 14:37

Caotic

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It seems to me that although this avoids resizing, you must know beforehand the window dimensions (and this don't always obey font changes, screen scaling and so on). – Berin do CD Apr 04 '19 at 18:17

score 26 · Answer 3 · edited Apr 12 '13 at 19:01

26

this->setFixedSize(this->width(),this->height());

edited Apr 12 '13 at 19:01

ollo

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answered Oct 14 '09 at 03:18

Samir

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Or simply `this->setFixedSize(this->size());` – Daniel Saner Jan 24 '13 at 15:54
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Or even simpler :) `setFixedSize(size());` – lapis Aug 15 '13 at 16:13

score 9 · Answer 4 · edited Apr 20 '15 at 08:28

9

You need to change the windowFlags of the dialog and set it to Qt::MSWindowsFixedSizeDialogHint.

This only works in windows.

For more information please see this example: http://doc.qt.digia.com/4.5/widgets-windowflags.html

edited Apr 20 '15 at 08:28

mavroprovato

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answered Mar 30 '09 at 07:33

Jesus Fernandez

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Please don't provide windows-specific solutions when portable solutions exist… – Salamandar Mar 22 '19 at 20:48

score 8 · Answer 5 · answered Jun 06 '14 at 12:44

8

On QT Creator, in the UI editor, click on the top object in the properties window, then scroll at the bottom in the Layout part. You should see the layoutSizeConstraint property.

Set the layoutSizeConstraint to SetFixedSize.

answered Jun 06 '14 at 12:44

jlguenego

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score 4 · Answer 6 · edited Nov 02 '12 at 21:39

4

If you use QtCreator (of course you are) you can set the property HorizontalsizePolicy to fixed and Vertical Policy also to Fixed. Then you can set the maximumSize to the dimensions you want. The window will not maximise again.

edited Nov 02 '12 at 21:39

Mario S

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answered Nov 02 '12 at 21:18

etsoft

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score 2 · Answer 7 · answered Feb 01 '14 at 00:54

In code you can do something like this,

Dialog->resize(581, 292);
QSizePolicy sizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
sizePolicy.setHorizontalStretch(0);
sizePolicy.setVerticalStretch(0);
sizePolicy.setHeightForWidth(WaterLevelEditorDialog->sizePolicy().hasHeightForWidth());
Dialog->setSizePolicy(sizePolicy);
Dialog->setMinimumSize(QSize(581, 292));
Dialog->setMaximumSize(QSize(581, 292));
Dialog->setSizeGripEnabled(false);

In QtCreator do as follows,

Select the dialog box widget
Locate the dialog box widget in Object Window
In Object Window, right click on dialog box object to popup a menu
Select "Size Constraints" -> "Set Maximum Size" from the menu
Right click again on dialog object to popup a menu
Select "Size Constraints" -> "Set Minimum Size"
In Property Window,
- ensure "sizePolicy"->"Horizontal Policy" has value "Fixed"
- ensure "sizePolicy"->"Vertical Policy" has value "Fixed"
- ensure "sizeGripEnabled" is not checked

score 1 · Answer 8 · answered Sep 02 '21 at 20:43

1

An easier way is to set the maxium size to 0.

this->setMaxiumSize(QSize(0, 0));

answered Sep 02 '21 at 20:43

Patitotective

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score 1 · Answer 9 · edited Apr 12 '13 at 19:01

1

From the Qt documentation, setSizePolicy() method either takes zero argument or two arguments but cannot be one argument. That's why you get this compilation error. From my experiment, if you don't set the fixed size. This method has no use. The window can still be resizable.

edited Apr 12 '13 at 19:01

ollo

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answered Mar 08 '12 at 11:36

PixelsTech

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score 0 · Answer 10 · edited Feb 10 '13 at 22:58

0

In case you are designing UI in QML and launching using QDeclarativeView, try the below code.

QScopedPointer<QmlApplicationViewer> viewer(QmlApplicationViewer::create());
.
.
.
//To make the window non-resizable
viewer->setFixedSize(viewer->width(),viewer->height());

Here QmlApplicationViewer is derived from QDeclarativeView.

edited Feb 10 '13 at 22:58

ollo

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answered Oct 19 '12 at 09:48

Akaanthan Ccoder

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Non-resizeable QDialog with fixed size in Qt?

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