如何在用户输入时立即获取PyQT中QLineEdit的信息？

Hey there! To get input from your QLineEdit widgets as the user types (instead of waiting for a button click), you can leverage PyQt's signal-slot system. The QLineEdit class provides a textChanged signal that triggers immediately whenever the text in the input box changes—whether from typing, pasting, or any other user action.

Step-by-Step Implementation: #

1. Define a slot function that will receive the updated text whenever the input changes. You can create separate slots for each input box or a single generic one, depending on your needs.
2. Connect the textChanged signal of each QLineEdit to your slot function.

Here's how to modify your code:

from PyQt5.QtWidgets import QLineEdit, QWidget

class YourWidget(QWidget):
    def __init__(self):
        super().__init__()
        
        # Your original input boxes
        self.datestartbox = QLineEdit(self)
        self.dateendbox = QLineEdit(self)
        
        # Connect signals to slots
        self.datestartbox.textChanged.connect(self.on_start_date_updated)
        self.dateendbox.textChanged.connect(self.on_end_date_updated)
    
    # Slot for start date input changes
    def on_start_date_updated(self, new_text):
        print(f"Start date changed to: {new_text}")
        # Do whatever you need with the new text here
    
    # Slot for end date input changes
    def on_end_date_updated(self, new_text):
        print(f"End date changed to: {new_text}")
        # Handle the end date input here

Alternative: Generic Slot for Multiple Inputs #

If you want to use a single slot for both input boxes, you can check which widget emitted the signal using self.sender():

def on_input_updated(self, new_text):
    sender = self.sender()
    if sender == self.datestartbox:
        print(f"Start date: {new_text}")
    elif sender == self.dateendbox:
        print(f"End date: {new_text}")

Then connect both signals to this slot:

self.datestartbox.textChanged.connect(self.on_input_updated)
self.dateendbox.textChanged.connect(self.on_input_updated)

Key Note: textChanged vs textEdited #

• textChanged triggers every time the text changes, including when you set it programmatically (e.g., self.datestartbox.setText("2024-01-01")).
• If you only want to react to user-initiated changes, use the textEdited signal instead—it won't trigger when the text is set via code.

That's it! Now you'll get the input text immediately as the user types.

内容的提问来源于stack exchange，提问作者Markus T