Kivy中如何访问GridLayout内动态创建的TextInput内容

Hey there! No worries at all being new to Kivy/Python—we’ve all been there. Let’s break down how to fix your issue with getting text from those dynamically generated TextInputs.

The Core Problem #

Your current code runs into two main issues:

1. Variable Overdue in Loops: The testtext function you define inside the loop doesn’t capture the current extime instance—it ends up referencing the last one created because of how Python handles closures in loops.
2. Duplicate Widgets: Every time you enter the EditWorkoutScreen, setupscreen() adds a new set of widgets without clearing the old ones, which will get messy fast.

Fixes & Modified Code #

Here’s how to adjust your EditWorkoutScreen class to solve both problems, plus add a way to get all input values at once:

class EditWorkoutScreen(Screen):
    def setupscreen(self):
        global exercisedf
        # Clear existing widgets first to avoid duplicates on screen re-entry
        self.ids.exercisestoverify.clear_widgets()
        
        for index, row in exercisedf.iterrows():
            grid = GridLayout(rows=1, spacing=2)
            exname = Label(text=str(row.exercise))
            exfocus = Label(text=str(row.focus))
            exequip = Label(text=str(row.equip))
            extime = TextInput(text=str(row.deftime), size_hint=(None,None), size=(25,30),font_size=11, multiline=False)
            
            # Add a custom attribute to link the TextInput to its exercise
            extime.exercise_name = row.exercise
            
            # Define a callback that uses the TextInput instance directly
            def on_text_validate(instance):
                print(f"Exercise: {instance.exercise_name}, Updated Time: {instance.text}")
            
            extime.bind(on_text_validate=on_text_validate)
            
            grid.add_widget(exname)
            grid.add_widget(exfocus)
            grid.add_widget(exequip)
            grid.add_widget(extime)
            self.ids.exercisestoverify.add_widget(grid)
    
    # Optional: Get all updated workout times at once
    def collect_all_times(self):
        workout_data = {}
        # Loop through each GridLayout in the ScrollView
        for grid in self.ids.exercisestoverify.children:
            # Find the TextInput in each GridLayout
            for widget in grid.children:
                if isinstance(widget, TextInput):
                    workout_data[widget.exercise_name] = widget.text
                    break
        print("All workout times:", workout_data)
        return workout_data

Key Changes Explained #

1. Clear Existing Widgets: self.ids.exercisestoverify.clear_widgets() ensures you don’t stack duplicate training rows every time you open the screen.
2. Custom Attribute for Linking: Adding extime.exercise_name = row.exercise ties each TextInput directly to its corresponding exercise, so you always know which input belongs to which workout.
3. Instance-Based Callback: The on_text_validate function takes the instance parameter (the TextInput that triggered the event), so it always accesses the correct input’s text and linked exercise name—no more variable overlap.

Add a Button to Collect All Values #

To use the collect_all_times function, add a button to your EditWorkoutScreen in the .kv file:

<EditWorkoutScreen>:
    name:'editworkout'
    on_enter: root.setupscreen()
    FloatLayout:
        Label:
            text: 'Verify/Edit Workout'
            pos: 0, 550
            font_size: 20
        Button:
            text: 'Save All Times'
            size_hint: .2, .1
            pos_hint: {"x":.4, "y":.05}
            on_release: root.collect_all_times()
        ScrollView:
            pos_hint: {"x":.160, "y":-.15}
            GridLayout:
                id: exercisestoverify
                size_hint_y: None
                size_hint_x: .80
                orientation: "vertical"
                height: self.minimum_height
                row_default_height: 30
                spacing: 0
                cols:1

This setup will let you either get individual input values when the user presses Enter on a TextInput, or collect all updated times at once with the button.

内容的提问来源于stack exchange，提问作者TKuam