{"id":589,"date":"2023-02-18T18:38:38","date_gmt":"2023-02-18T10:38:38","guid":{"rendered":"http:\/\/gjweb.top\/?p=589"},"modified":"2023-02-18T18:38:41","modified_gmt":"2023-02-18T10:38:41","slug":"16-flutter%e5%bc%82%e6%ad%a5","status":"publish","type":"post","link":"https:\/\/gjweb.top\/?p=589","title":{"rendered":"16. Flutter\u5f02\u6b65"},"content":{"rendered":"\n

Dart \u8bed\u8a00\u548c JS \u4e00\u6837\u90fd\u662f\u5355\u7ebf\u7a0b + \u4e8b\u4ef6\u5faa\u73af\u6a21\u5f0f, \u6267\u884c\u65f6\u673a\u4e5f\u548cJS\u7684 event Loop \u4e00\u81f4<\/p>\n\n\n\n

\u8fd4\u56de \u5f02\u6b65\u7684 future<\/h3>\n\n\n\n
Future <String> xxx(
    return Future((){
        return \"xxx\"
    })
)
xxx() async{
    xxx().then((value){print(value)})
}<\/code><\/pre>\n\n\n\n
\u8fd4\u56de\u6307\u5b9a\u7684 Future<\/h2>\n\n\n\n
Future <String> xxx{
    return Future.value(\"hello\")
}<\/code><\/pre>\n\n\n\n
\u8fd4\u56de\u5ef6\u65f6\u7684 Future<\/h2>\n\n\n\n
return Future.delayed(Duration(seconds:3),(){
    return \"Hello\"
})<\/code><\/pre>\n\n\n\n
\u76d1\u542c\u5f02\u5e38<\/h2>\n\n\n\n
.catchError((err){}) \/\/ \u9519\u8bef\u7684\u56de\u8c03
.whenComPlete((){}) \/\/ \u65e0\u8bba\u6210\u529f\u5931\u8d25\u90fd\u4f1a\u89e6\u53d1<\/code><\/pre>\n\n\n\n
async & await<\/h2>\n\n\n\n
xxx() async{
    var res = await xxx()
    print(res)
}<\/code><\/pre>\n\n\n\n
FutureBuilder<\/h2>\n\n\n\n
\u81ea\u52a8\u8ffd\u8e2a Future \u7684\u72b6\u6001\u4fe1\u606f,\u4f1a\u81ea\u52a8\u91cd\u7ed8\u7ec4\u4ef6<\/p>\n\n\n\n
Future <String> loadData()async{
    await Future.delayed(const Duration(secods:2));\/\/ \u7b49\u5f852\u79d2
    return \"this is data\"
}
\u200b
FutureBuild(
    future:loadData(),
    builder:(BUildContext context,AsyncSnapshot<String> snapshot){
        \/\/ \u68c0\u67e5 ConnectionState \u662f\u5426\u672adone
        if(snapshot.connectionState == ConnectionState.done){
            if (snapshot.hasError) {
                return Center(
                    child: Text(\"ERROR: ${snapshot.error}\"),
                );
            }else{
                return Center(child: Text(\"DATA: ${snapshot.data}\"));
            }
        }else{
            return const Center(
                child: CircularProgressIndicator(),
            );
        }
    }
)<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
Dart \u8bed\u8a00\u548c JS \u4e00\u6837\u90fd\u662f\u5355\u7ebf\u7a0b + \u4e8b\u4ef6\u5faa\u73af\u6a21\u5f0f, \u6267\u884c\u65f6\u673a\u4e5f\u548cJS\u7684 event Loop \u4e00\u81f4 \u8fd4 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31],"tags":[],"class_list":["post-589","post","type-post","status-publish","format-standard","hentry","category-flutter"],"_links":{"self":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts\/589","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=589"}],"version-history":[{"count":1,"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts\/589\/revisions"}],"predecessor-version":[{"id":590,"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts\/589\/revisions\/590"}],"wp:attachment":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=589"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=589"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}