New-style PyQt Signals and Slots I was to lazy to take a look at the new-style signal and slot support which was introduced in PyQt 4.5 until yesterday. I did know that there were something called new-style signals and slots but that was the end of the story. For example, a signal&slot for making a signal&slot. App.exec run a loop but not run init over and over again. App.exec is waiting for user input, eventHandler, for example, keyPressEvent, mousePressEvent. Especially, paintEvent for showing the GUI. Init is only called once. The variables of it are allotted into your computer's.
Design multiple windows in designer
The PyQt installer comes with a GUI builder tool called Qt Designer. Using its simple drag and drop interface, a GUI interface can be quickly built without having to write the code. It is however, not an IDE such as Visual Studio. Hence, Qt Designer does not have the facility to debug and build the.
To jump, of course, there must be multiple windows, so we design another window in designer. When we click the login button in the main interface, we will jump to this window.
The method is the same. Drag the control, save it as a. ui file after it is designed, and then convert the. ui file to a. py file.
They are connected by signals and slots
What are signals, slots?
This is a feature of designer. The user will send a signal to guide the slot function to complete the corresponding action. Too abstract, for example.
The code for the main window looks like this.
The above statement to complete the window jump is as follows.
signal
Slot function
So to complete the jump, we have to go through the following steps:
1. Add signals and slots
On the control where you want to add a signal, add a statement. For example, we add a signal to the login button with the object name as the pushButton to connect to the open() slot function, which is used to open a new window.
- self: for UI_ Instantiation object of MainWindow
- pushbutton: the object name of the login button
- Click: signal means to send the signal to the slot function when the user clicks the login button
- Slot and signal connection functions: connect
- open: slot function, that is, after receiving the signal, the function is called.
- Import: is the name of the new window, tiaozhuan.py .
In addition, when opening a new window, we need to close the original login window. In the same way, add a signal on the login button.
signal
Slot function
It is important to note that the close() method must be called with the real instantiated object when closing the window. It can't be replaced by self.
2. Modify the called window
Two modifications are needed:
class Ui_MainWindow(QMainWindow): change the object to QMainWindow
def __init__(self): ා add initialization function super (UI)_ MainWindow,self).__ init__ () self.setupUi (self)
Add initialization function to class
3. Run the main window
Directly run the main window, you can see the heart of the GUI!
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Note: in this case, if you want to run the program, you have to add a file.
Because in the tiaozhuan.py In this window, we introduce three pictures. How to solve this problem, put the resource file in the tiaozhuan.py File in the same directory.
Resource file code link: (put a piece of words, the article is too long to send out... )
https://download.csdn.net/download/leidawangzi/13613277
How to get the resource file? Moving on to the next section, we'll learn how to add pictures to the control.
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Bibliography: Python GUI design (PyQt5 from introduction to practice) - tomorrow Technology
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