Elm:获取图像的大小

import Browser
import Html exposing (div, text)
import Task exposing (Task)
import Image exposing (size)

-- 定义一个Msg类型
type Msg = ImageSize (Maybe (Int, Int))

-- 更新函数
update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
    case msg of
        ImageSize maybeSize ->
            -- 处理图像大小
            let
                newSize =
                    case maybeSize of
                        Just (width, height) ->
                            "图像宽度：" ++ toString width ++ "，图像高度：" ++ toString height

                        Nothing ->
                            "无法获取图像大小"
            in
            ( { model | imageSize = newSize }, Cmd.none )

-- 视图函数
view : Model -> Html Msg
view model =
    div [] [ text model.imageSize ]

-- 初始化函数
init : () -> (Model, Cmd Msg)
init _ =
    ( { imageSize = "等待获取图像大小..." }, Task.attempt ImageSize (size "https://example.com/image.jpg") )

-- 主函数
main =
    Browser.sandbox { init = init, update = update, view = view }

-- 模型类型
type alias Model =
    { imageSize : String }