如何在 dart/Flutter 中使用 SplayTreeMap on Firebase 快照字典？

Question

我已通过 StreamBuilder 成功取回数据，需要对其进行排序。如何按键对快照数据的地图进行排序？此外，如果您举一个这样做的例子，我的价值也会有所帮助。我想我想做一个SplayTreeMap，但如果有更好的方法请提供。这是我的字典...

{Vid2: {imageString: https://i.ytimg.com/vi/Amq-qlqbjYA/mqdefault.jpg, title: BLACKPINK - '마지막처럼 (AS IF IT'S YOUR LAST)' M/V, rank: 2, videoID: Amq-qlqbjYA}, Vid10: {imageString: https://i.ytimg.com/vi/KSH-FVVtTf0/mqdefault.jpg, title: EXO 엑소 'Monster' MV, rank: 10, videoID: KSH-FVVtTf0}, Vid6: {imageString: https://i.ytimg.com/vi/BVwAVbKYYeM/mqdefault.jpg, title: [MV] BTS(방탄소년단) _ DOPE(쩔어), rank: 6, videoID: BVwAVbKYYeM}, Vid3: {imageString: https://i.ytimg.com/vi/m8MfJg68oCs/mqdefault.jpg, title: [MV] BTS(방탄소년단) _ Boy In Luv(상남자), rank: 3, videoID: m8MfJg68oCs}, Vid4: {imageString: https://i.ytimg.com/vi/9pdj4iJD08s/mqdefault.jpg, title: BLACKPINK - '불장난 (PLAYING WITH FIRE)' M/V, rank: 4, videoID: 9pdj4iJD08s}, Vid1: {imageString: https://i.ytimg.com/vi/3s1jaFDrp5M/mqdefault.jpg, title: EPIK HIGH - 'BORN HATER' M/V, rank: 1, videoID: 3s1jaFDrp5M}, Vid8: {imageString: https://i.ytimg.com/vi/3QAcvc4Ysl0/mqdefault.jpg, title: LONNI - LA KPOP 2, rank: 8, videoID: 3QAcvc4Ysl0}, Vid5: {imageString: https://i.ytimg.com/vi/2ips2mM7Zqw/default.jpg, title: BIGBANG - 뱅뱅뱅 (BANG BANG BANG) M/V, rank: 5, videoID: 2ips2mM7Zqw}}

我想通过按键显示它... 视频 1、视频 2、视频 3...

或按排名等值，即... Vid1:rank“1”，Vid2：排名“2”，Vid3：排名“3”...

Answer 1

如果源是地图，这应该可以满足您的要求：

final sorted = new SplayTreeMap<String,dynamic>.from(map, (a, b) => a.compareTo(b));

DartPad example

如何在 dart/Flutter 中使用 SplayTreeMap on Firebase 快照字典？

How to use a SplayTreeMap on Firebase snapshot dictionary in dart/Flutter?

sorting

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splay-tree

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