How to access to ui members from the Designer in the QtCreator?

PowerNow

Hi, I'm just starting with QT Python and only want to access the members of the form.ui file. In the Qt description I find only infos regarding loading the form.ui file.

import sys
import os


from PySide6.QtWidgets import QApplication, QWidget
from PySide6.QtCore import QFile
from PySide6.QtUiTools import QUiLoader


class MainWindow(QWidget):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.load_ui()
        // how to access the QLineEdit element with the name Operant1???

    def load_ui(self):
        loader = QUiLoader()
        path = os.path.join(os.path.dirname(__file__), "form.ui")
        ui_file = QFile(path)
        ui_file.open(QFile.ReadOnly)
        loader.load(ui_file, self)
        ui_file.close()


if __name__ == "__main__":
    app = QApplication([])
    widget = MainWindow()
    widget.show()
    sys.exit(app.exec())

Thanks...

SGaist

Hi and welcome to devnet,

This tutorial, while being written for PyQt, applies as well to PySide2/6.

You'll see there the various way to setup and use your designer based widgets.

Note that you will need to generate Python code out of your .ui files for that.

PowerNow

Thanks, I know this side already, but as I understand there is no description how to access members from a GUI which is directly loaded with the QUiLoader().

Generate a file

$ pyuic5 -o main_window_ui.py ui/main_window.ui

and then access the members via

self.ui = Ui_MainWindow()

Load the GUI via

loader = QUiLoader()

and have no access to the members, because there is no main_window_ui.py

What do I not correctly understand here?

JonB

@PowerNow
If you use the pyuic5 approach to "translate" the .ui file into a .py file --- which indeed I recommend --- you no longer use QUiLoader. They are an either-or approach. With pyuic5 you instead import main_window_ui.py and then access the widgets etc. directly --- have a look at the code generated into that ..._ui.py file.

and have no access to the members, because there is no main_window_ui.py

There is such a file --- it was generated when you ran pyuic5 -o main_window_ui.py ui/main_window.ui.

PowerNow

Sorry for this confusion. Then I will ask again:
How can I access GUI members in python using the QUiLoader()?

@JonB :
"and have no access to the members, because there is no main_window_ui.py"
I related this to "2.Load the GUI via QUiLoader()".

JonB

@PowerNow
If you wish to use QUiLoader() --- which I have never used --- with PySide2, why not Google for that with examples? There are so many hits. For example, one way is https://doc.qt.io/archives/qtforpython-5.12/PySide2/QtUiTools/QUiLoader.html#detailed-description

def loadCustomWidget(parent):
    loader = QUiLoader()

    availableWidgets = loader.availableWidgets()

    if availableWidgets.contains("AnalogClock"):
        myWidget = loader.createWidget("AnalogClock", parent)

    return myWidget

or perhaps what you are looking for is https://stackoverflow.com/questions/20115693/correct-way-to-address-pyside-qt-widgets-from-a-ui-file-via-python

loader = QtUiTools.QUiLoader()
ui = loader.load('filename.ui', parent)
my_widget = ui.my_widget_name

Why not inspect what it is the returned ui in a Python debugger if you want to see what is going on there?

In that stackoverflow post the second answer summarises well

There are two disadvantages of loading UI at run time:

and why that poster and I would recommend preferably the uic approach for development. But up to you.

PowerNow

Thxs, thats it, I could not find that anywhere:

ui = loader.load('filename.ui', parent)

and missunderstand this in the Qt docu

window = loader.load(ui_file)

Yeah, you are right creating the .py is better than loading. But currently I'm trying both for prototyping and sometimes i forgot to create and then couldn't find the fault for ages.