DismissDirection 继承自： Enum

定义用于关闭 SnackBar 所允许的滑动方向。

启用关闭功能后，该方向决定了哪些拖拽手势可以关闭 snack bar。

示例

import flet as ft


def showcase_card(direction: ft.DismissDirection) -> ft.Container:
    status = ft.Text("Swipe the tile", size=12, color=ft.Colors.ON_SURFACE_VARIANT)

    def create_item() -> ft.Dismissible:
        return ft.Dismissible(
            dismiss_direction=direction,
            on_dismiss=lambda _: on_dismiss(),
            background=ft.Container(
                bgcolor=ft.Colors.GREEN_200,
                alignment=ft.Alignment.CENTER_LEFT,
                padding=10,
                content=ft.Icon(ft.Icons.CHECK, color=ft.Colors.GREEN_900),
            ),
            secondary_background=ft.Container(
                bgcolor=ft.Colors.RED_200,
                alignment=ft.Alignment.CENTER_RIGHT,
                padding=10,
                content=ft.Icon(ft.Icons.DELETE, color=ft.Colors.RED_900),
            ),
            content=ft.Container(
                height=52,
                border_radius=8,
                bgcolor=ft.Colors.SURFACE,
                border=ft.Border.all(1, ft.Colors.OUTLINE),
                alignment=ft.Alignment.CENTER,
                content=ft.Text("Dismiss me"),
            ),
        )

    def on_dismiss():
        slot.content = ft.Container(
            height=52,
            border_radius=8,
            bgcolor=ft.Colors.SURFACE,
            border=ft.Border.all(1, ft.Colors.OUTLINE_VARIANT),
            alignment=ft.Alignment.CENTER,
            content=ft.Text("Dismissed"),
        )
        status.value = f"Dismissed via {direction.name}"
        slot.update()
        status.update()

    def reset_item(_):
        slot.content = create_item()
        status.value = "Swipe the tile"
        slot.update()
        status.update()

    slot = ft.Container(content=create_item())

    return ft.Container(
        width=360,
        padding=12,
        border=ft.Border.all(1, ft.Colors.RED),
        border_radius=10,
        bgcolor=ft.Colors.SURFACE_CONTAINER_LOW,
        content=ft.Column(
            spacing=8,
            controls=[
                ft.Text(direction.name, weight=ft.FontWeight.BOLD),
                status,
                slot,
                ft.Button("Reset", on_click=reset_item),
            ],
        ),
    )


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

    page.appbar = ft.AppBar(title="DismissDirection Showcase")
    page.add(
        ft.SafeArea(
            content=ft.Column(
                controls=[
                    ft.Text("Try swipe directions to see which ones are allowed."),
                    ft.Row(
                        wrap=True,
                        spacing=12,
                        expand=True,
                        scroll=ft.ScrollMode.AUTO,
                        alignment=ft.MainAxisAlignment.CENTER,
                        controls=[
                            showcase_card(direction)
                            for direction in ft.DismissDirection
                        ],
                    ),
                ],
            ),
        )
    )


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

枚举值

名称	类型	默认值	说明
NONE	—	'none'	Disables swipe-to-dismiss gestures.
VERTICAL	—	'vertical'	Allows dismissing by swiping vertically. Users can drag either up or down to dismiss.
HORIZONTAL	—	'horizontal'	Allows dismissing by swiping horizontally. Users can drag either left or right to dismiss.
END_TO_START	—	'endToStart'	Allows dismissing toward the end-to-start reading direction. For left-to-right locales this is right-to-left; for right-to-left locales this is left-to-right.
START_TO_END	—	'startToEnd'	Allows dismissing toward the start-to-end reading direction. For left-to-right locales this is left-to-right; for right-to-left locales this is right-to-left.
UP	—	'up'	Allows dismissing only by swiping upward.
DOWN	—	'down'	Allows dismissing only by swiping downward.