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How to get the current QApplication in pyQt?
I am trying to get a reference to the current QApplication object with pyQt5, but couldn't find the function. My search about "pyQt get current QApplication" shows results about how to create an QApplication. So my question is:
Is there a global QApplication object, and if so how can get a reference to an existing (the current) application.
The reason I ask, is that I want to test if a debugging code is running within a Qt GUI application. Then, I'd like to bring up a QMessagebox to show error messages if the function is used in a Qt application; or print out a message to stdout otherwise.
python pyqt5
asked Nov 20 '18 at 6:56
tinlyxtinlyx
10.7k1856108
add a comment |
I am trying to get a reference to the current QApplication object with pyQt5, but couldn't find the function. My search about "pyQt get current QApplication" shows results about how to create an QApplication. So my question is:
Is there a global QApplication object, and if so how can get a reference to an existing (the current) application.
The reason I ask, is that I want to test if a debugging code is running within a Qt GUI application. Then, I'd like to bring up a QMessagebox to show error messages if the function is used in a Qt application; or print out a message to stdout otherwise.
python pyqt5
asked Nov 20 '18 at 6:56
tinlyxtinlyx
10.7k1856108
add a comment |
I am trying to get a reference to the current QApplication object with pyQt5, but couldn't find the function. My search about "pyQt get current QApplication" shows results about how to create an QApplication. So my question is:
Is there a global QApplication object, and if so how can get a reference to an existing (the current) application.
The reason I ask, is that I want to test if a debugging code is running within a Qt GUI application. Then, I'd like to bring up a QMessagebox to show error messages if the function is used in a Qt application; or print out a message to stdout otherwise.
python pyqt5
asked Nov 20 '18 at 6:56
tinlyxtinlyx
10.7k1856108
I am trying to get a reference to the current QApplication object with pyQt5, but couldn't find the function. My search about "pyQt get current QApplication" shows results about how to create an QApplication. So my question is:
Is there a global QApplication object, and if so how can get a reference to an existing (the current) application.
The reason I ask, is that I want to test if a debugging code is running within a Qt GUI application. Then, I'd like to bring up a QMessagebox to show error messages if the function is used in a Qt application; or print out a message to stdout otherwise.
python pyqt5
python pyqt5
asked Nov 20 '18 at 6:56
tinlyxtinlyx
10.7k1856108
asked Nov 20 '18 at 6:56
tinlyxtinlyx
10.7k1856108
asked Nov 20 '18 at 6:56
tinlyxtinlyx
10.7k1856108
asked Nov 20 '18 at 6:56
tinlyxtinlyx
10.7k1856108
asked Nov 20 '18 at 6:56
tinlyxtinlyx
10.7k1856108
10.7k1856108
add a comment |
add a comment |
1 Answer
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there should only be one QApplication, and if we want to obtain the existing one, you must use instance(), a common approach is to use the following technique:
app = QtWidgets.QApplication.instance()
if app is None:
# if it does not exist then a QApplication is created
app = QtWidgets.QApplication()
answered Nov 20 '18 at 6:59
eyllanesceyllanesc
75.8k103156
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
there should only be one QApplication, and if we want to obtain the existing one, you must use instance(), a common approach is to use the following technique:
app = QtWidgets.QApplication.instance()
if app is None:
# if it does not exist then a QApplication is created
app = QtWidgets.QApplication()
answered Nov 20 '18 at 6:59
eyllanesceyllanesc
75.8k103156
add a comment |
there should only be one QApplication, and if we want to obtain the existing one, you must use instance(), a common approach is to use the following technique:
app = QtWidgets.QApplication.instance()
if app is None:
# if it does not exist then a QApplication is created
app = QtWidgets.QApplication()
answered Nov 20 '18 at 6:59
eyllanesceyllanesc
75.8k103156
add a comment |
there should only be one QApplication, and if we want to obtain the existing one, you must use instance(), a common approach is to use the following technique:
app = QtWidgets.QApplication.instance()
if app is None:
# if it does not exist then a QApplication is created
app = QtWidgets.QApplication()
answered Nov 20 '18 at 6:59
eyllanesceyllanesc
75.8k103156
there should only be one QApplication, and if we want to obtain the existing one, you must use instance(), a common approach is to use the following technique:
app = QtWidgets.QApplication.instance()
if app is None:
# if it does not exist then a QApplication is created
app = QtWidgets.QApplication()
answered Nov 20 '18 at 6:59
eyllanesceyllanesc
75.8k103156
answered Nov 20 '18 at 6:59
eyllanesceyllanesc
75.8k103156
answered Nov 20 '18 at 6:59
eyllanesceyllanesc
75.8k103156
answered Nov 20 '18 at 6:59
eyllanesceyllanesc
75.8k103156
75.8k103156
add a comment |
add a comment |
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