Switch theme mode

[Anubizzx]

Question

How can i change the theme with a switch, i tried to fix it and none of that works, i tried to google and i haven't found anything. Pls help me.

Code sample

import flet as ft
def main(page: ft.Page):

    setting1 = ft.Switch(label="Light theme", value=False)

    page.window.height = 400
    page.window.width = 800

    if setting1.value == False:

        ft.ThemeMode.DARK
        page.update()

    elif setting1.value == True:

        ft.ThemeMode.LIGHT
        page.update()

    page.title = "test"
    page.add(setting1)

ft.app(main)

Error message

No response

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• I have searched for answers to my question both in the issues and in previous discussions.

[ndonkoHenri]

Example 1 - Predefined Theme mode

import flet as ft


def main(page: ft.Page):
    page.title = "Switch Theme Mode"
    page.theme_mode = ft.ThemeMode.DARK

    def handle_theme_change(e):
        if s.value is True:
            page.theme_mode = ft.ThemeMode.LIGHT
        else:
            page.theme_mode = ft.ThemeMode.DARK
        page.update()

    s = ft.Switch(label="Light theme", value=False, on_change=handle_theme_change)
    page.add(s)


ft.app(main)

Example 2 - Derived Theme mode (from platform settings)

import flet as ft


def main(page: ft.Page):
    page.title = "Switch Theme Mode"
    page.theme_mode = ft.ThemeMode(page.platform_brightness.value)

    def handle_theme_change(e):
        if s.value is True:
            page.theme_mode = ft.ThemeMode.LIGHT
        else:
            page.theme_mode = ft.ThemeMode.DARK
        page.update()

    s = ft.Switch(
        label="Light theme",
        value=page.theme_mode == ft.ThemeMode.LIGHT,
        on_change=handle_theme_change,
    )
    page.add(s)


ft.app(main)