[PyQt] QQmlApplicationEngine and QGuiApplication
Jérôme Godbout
jerome at bodycad.com
Thu Feb 25 22:56:37 GMT 2016
Sound like you are missing the plugin and module path maybe. You can add
this function to your new MyQmlApplication class:
def loadPluginPath(self):
for i in os.environ['QT_PLUGIN_PATH'].split(';'):
self._engine.addPluginPath(i)
You can also add the following before creating the application object:
os.environ['QML2_IMPORT_PATH'] = ';'.join(['.', r"qml"])
os.environ['QT_PLUGIN_PATH'] = ';'.join(['.', r"plugins"])
Add any required path to both depending on your use case. Call the
app.loadPluginPath() before the app.showAndExec()
This way the QQmlEngine will known where the module and plugin can be
found. Make sure you have the Qt modules and plugin available inside those
path list.
Also on another note, Try to remove the ApplicationWindow from the script
and try a simple script that only display a simple Item like this, you may
have some Qml errors preventing the application from launching:
TestMain.qml:
import QtQuick 2.5
Rectangle
{
color: 'red'
width: 500
height: 500
}
On Thu, Feb 25, 2016 at 4:25 PM, Daniel Krause <madakr at web.de> wrote:
> Thank you for your suggestions.
>
> @Jerome
> I used you code "as is", but for the last lines: I changed them to
>
> if __name__ == '__main__':
> app = MyQmlApplication("MyAppTitle", sys.argv)
> app.showAndExec(QUrl("main.qml"))
>
> The code executes, but the Window is empty.
>
> [image: Inline-Bild 1]
>
> @Miguel:
> I changed additionally the name "MainForm" to "Rectangle" as you
> suggested. But still, the window is empty...
>
> I have the feeling, that the qml-file is not found / loaded. If I change
> the file name to "Main.qml" (which does not exist), the window looks the
> same...
> Could it be an OS-problem, as I am working on windows?
>
> Any ideas would be welcome.
>
> Daniel
>
> 2016-02-25 18:37 GMT+01:00 Jérôme Godbout <jerome at bodycad.com>:
>
>> No sure what is wrong with yours, but I'm using a QQuickView inside a
>> QApplication and it work well.
>>
>> import sys
>>
>> from PyQt5.QtCore import QSettings, QUrl, QRect, pyqtSignal, pyqtSlot
>> from PyQt5.QtWidgets import QApplication
>> from PyQt5.QtQuick import QQuickView, QQuickWindow
>>
>> class MyQmlApplication(QApplication):
>> _application_name = "UNDEFINED"
>> _qquickview = None
>> _engine = None
>> _settings = None
>>
>> def __init__(self, title, args):
>> QApplication.__init__(self, args)
>> self._qquickview = QQuickView()
>> self._qquickview.setTitle(title)
>> self._qquickview.setResizeMode(QQuickView.SizeRootObjectToView)
>> self._qquickview.setGeometry(QRect(100,100,600,800))
>> self._engine = self._qquickview.engine()
>>
>> def showAndExec(self, qml_url):
>> self._qquickview.setSource(qml_url)
>> self._qquickview.show()
>> return self.exec_()
>>
>> app = BodycadQmlApplication("MyAppTitle", sys.argv)
>> app.showAndExec(QUrl("Main.qml"))
>>
>>
>> On Thu, Feb 25, 2016 at 10:43 AM, Daniel Krause <madakr at web.de> wrote:
>>
>>> Hello,
>>>
>>> I am new to PyQt and having trouble to include QML-Code into an python
>>> application.
>>>
>>> The QML-File (main.qml) I can build in a project in QtCreator (a Qt
>>> Quick Application was used to create the project).
>>>
>>> import QtQuick 2.5
>>> import QtQuick.Controls 1.4
>>> import QtQuick.Dialogs 1.2
>>> import QtQml.Models 2.1
>>>
>>> ApplicationWindow {
>>> visible: true
>>> width: 640
>>> height: 480
>>> title: qsTr("Hello World")
>>>
>>> menuBar: MenuBar {
>>> Menu {
>>> title: qsTr("File")
>>> MenuItem {
>>> text: qsTr("&Open")
>>> onTriggered: console.log("Open action triggered");
>>> }
>>> MenuItem {
>>> text: qsTr("Exit")
>>> onTriggered: Qt.quit();
>>> }
>>> }
>>> }
>>>
>>> MainForm {
>>> id: mainForm1
>>> anchors.fill: parent
>>>
>>> SplitView {
>>> id: splitView1
>>> width: 100
>>> anchors.left: parent.left
>>> anchors.leftMargin: 36
>>> anchors.bottom: parent.bottom
>>> anchors.bottomMargin: 8
>>> anchors.top: parent.top
>>> anchors.topMargin: 8
>>> orientation: Qt.Vertical
>>>
>>>
>>> Button {
>>> id: btn_welcome
>>> x: 49
>>> y: 21
>>> text: qsTr("Welcome")
>>> }
>>>
>>> Button {
>>> id: btn_database
>>> x: 49
>>> y: 50
>>> text: qsTr("Database")
>>> }
>>>
>>> MouseArea {
>>> id: mouseArea1
>>> x: 0
>>> y: 191
>>> width: 100
>>> height: 100
>>> }
>>> }
>>> }
>>> }
>>>
>>> It results in the following window:
>>>
>>>
>>> To create the application in Python I tried to use QGuiApplication
>>> and QQmlApplicationEngine.
>>> main.py and main.qml are located in the same directory:
>>>
>>> import sys
>>> from PyQt5.QtQml import QQmlApplicationEngine
>>> from PyQt5.QtGui import QGuiApplication
>>>
>>> if __name__ == '__main__':
>>> app = QGuiApplication(sys.argv)
>>> engine = QQmlApplicationEngine("main.qml")
>>> print(engine)
>>> sys.exit(app.exec_())
>>>
>>> The print()-statement is never executed, no window is appearing.
>>>
>>> What did I miss?
>>>
>>> Thanks in advance
>>>
>>> Daniel
>>>
>>> _______________________________________________
>>> PyQt mailing list PyQt at riverbankcomputing.com
>>> https://www.riverbankcomputing.com/mailman/listinfo/pyqt
>>>
>>
>>
>
> _______________________________________________
> PyQt mailing list PyQt at riverbankcomputing.com
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