I'm doing some simple PySide on 3Dsmax 2015.
This is my error:
python.ExecuteFile "C:\Program Files\Autodesk\3ds Max 2015\scripts\Python\demoUniTest.py"
-- Runtime error: Line 32 <module>()
<type 'exceptions.RuntimeError'> A QApplication instance already exists.
This is my code:
import sys
from PySide.QtCore import *
from PySide.QtGui import *
from math import *
class Form(QDialog):
def __init__(self,parent=None):
super(Form,self).__init__(parent)
self.browser = QTextBrowser()
self.lineedit = QLineEdit("Type an expression and press Enter")
self.lineedit.selectAll()
layout = QVBoxLayout()
layout.addWidget(self.browser)
layout.addWidget(self.lineedit)
self.setLayout(layout)
self.lineedit.setFocus()
self.connect(self.lineedit, SIGNAL("returnPressed()"),self.updateUi)
self.setWindowTitle("Calculate")
def updateUi(self):
try:
text = self.lineedit.text()
self.browser.append("%s = <b>%s</b>" % (text,eval(text)))
except:
self.browser.append("<font color=red>%s is invalid</font>" %text)
app = QApplication(sys.argv)
form = Form()
form.show()
app.exec_()
When I use this code on Picharm dont have any errors. It only appear when I use on 3Dsmax 2015 Listener
Direct citation from the helpfile (Using PySide):
Normally one creates a PySide application object in a script using
QtGui.QApplication(). However, in 3ds Max, there is already a PySide
application running, so you get a handle for that object like this:
QtGui.QApplication.instance()
As a note this has changed somewhat in 3DS Max 2018 and PySide2. I'm just playing around with it myself right now and I was able to get it working after a bit of tinkering. Here's a link to the documentation, though be warned that there is a small typo in the code (at least at the time of writing): http://help.autodesk.com/view/3DSMAX/2018/ENU/?guid=__developer_what_s_new_in_3ds_max_python_api_what_s_new_in_the_3ds_max_2018_p_html
As mentioned in other answers you need to make your UI a child of the main 3DS Max application. The good news is that they have simplified this a bit for you with the function GetQMaxMainWindow(). Use it like this:
from PySide2 import QtWidgets, QtCore, QtGui
import MaxPlus
import os
class SampleUI(QtWidgets.QDialog):
def __init__(self, parent=MaxPlus.GetQMaxMainWindow()):
super(SampleUI, self).__init__(parent)
self.initUI()
def initUI(self):
mainLayout = QtWidgets.QHBoxLayout()
testBtn = QtWidgets.QPushButton("Test!")
mainLayout.addWidget(testBtn)
self.setLayout(mainLayout)
if __name__ == "__main__":
try:
ui.close()
except:
pass
ui = SampleUI()
ui.show()
You're creating an instance of QApplication in the line:
app = QApplication(sys.argv)
And getting that error because there's another instance of QApplication created somewhere before that (presumably somewhere in "3Dsmax 2015 Listener") and you're only allowed one.
See:
QT documentation on QApplication
