ScrollType 继承自： Enum

The kind of scroll notification emitted by ScrollableControl.

示例

import flet as ft


def main(page: ft.Page):
    page.horizontal_alignment = ft.CrossAxisAlignment.CENTER

    counts = {event_type: 0 for event_type in ft.ScrollType}
    count_labels = {
        event_type: ft.Text(f"{event_type.name}: 0") for event_type in ft.ScrollType
    }

    def on_scroll(e: ft.OnScrollEvent):
        counts[e.event_type] += 1
        count_labels[
            e.event_type
        ].value = f"{e.event_type.name}: {counts[e.event_type]}"
        last.value = (
            f"Last event: {e.event_type.name}, pixels={round(e.pixels, 1)}"
            f"{', direction=' if e.direction else ''}"
        )
        for label in count_labels.values():
            label.update()
        last.update()

    page.appbar = ft.AppBar(title="ScrollType Showcase")
    page.add(
        ft.SafeArea(
            content=ft.Column(
                controls=[
                    ft.Text(
                        "Scroll the list to generate start/update/user/end "
                        "notifications."
                    ),
                    last := ft.Text(),
                    ft.Row(
                        wrap=True,
                        spacing=10,
                        controls=[count_labels[t] for t in ft.ScrollType],
                        alignment=ft.MainAxisAlignment.CENTER,
                    ),
                    ft.Container(
                        width=360,
                        height=240,
                        border=ft.Border.all(1, ft.Colors.OUTLINE),
                        border_radius=8,
                        padding=8,
                        content=ft.Column(
                            scroll=ft.ScrollMode.ALWAYS,
                            on_scroll=on_scroll,
                            controls=[
                                ft.Text(f"Scrollable item {i + 1}") for i in range(60)
                            ],
                        ),
                    ),
                ],
            ),
        )
    )


if __name__ == "__main__":
    ft.run(main)

枚举值

名称	类型	默认值	说明
START	—	'start'	Scrolling has started.
UPDATE	—	'update'	Scroll position changed. See scroll_delta.
END	—	'end'	Scrolling has ended.
USER	—	'user'	User scroll direction changed. See direction.
OVERSCROLL	—	'overscroll'	Viewport was overscrolled. See overscroll and velocity are available.