我正在制作一个正在播放广播电台的应用程序，但出现错误，我不知道如何解决。我已经查看了 stackoverflow 的其他答案，但我不知道我需要如何实现它。谁能帮我解决这个错误？
这是我的控制台：
V/MediaPlayer(18403): resetDrmState: mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
V/MediaPlayer(18403): cleanDrmObj: mDrmObj=null mDrmSessionId=null
V/MediaHTTPService(18403): MediaHTTPService(android.media.MediaHTTPService@7866d26): Cookies: null
V/MediaHTTPService(18403): makeHTTPConnection: CookieHandler (java.net.CookieManager@cb6c9fd) exists.
V/MediaHTTPService(18403): makeHTTPConnection(android.media.MediaHTTPService@7866d26): cookieHandler: java.net.CookieManager@cb6c9fd Cookies: null
I/flutter (18403): [{station: {id: 1, name: LeagueFM, shortcode: leaguefm, description: We make the music play!, frontend: icecast, backend: liquidsoap, listen_url: https://radiopaneel.something-something.nl/listen/something/stream, url: https://something-something.nl/, public_player_url: https://radiopaneel.something-something.nl/public/something, playlist_pls_url: https://radiopaneel.something-something.nl/public/something/playlist.pls, playlist_m3u_url: https://radiopaneel.something-something.nl/public/something/playlist.m3u, is_public: true, mounts: [{id: 1, name: 320kbps MP3, url: https://radiopaneel.something-something.nl/listen/something/stream, bitrate: 320, format: mp3, listeners: {total: 14, unique: 5, current: 14}, path: /stream, is_default: true}], remotes: [], hls_enabled: false, hls_url: null, hls_listeners: 0}, listeners: {total: 14, unique: 5, current: 14}, live: {is_live: true, streamer_name: name, broadcast_start: 1678204893, art: null}, now_playing: {sh_id: id, played_at: 1678207342, duration: 0, playlist: , streamer: name, is_request: false, song: {id: 3866ae5415bf7
E/flutter (18403): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: type 'String' is not a subtype of type 'int' of 'index'
E/flutter (18403): #0 _MyHomePageState.getTrack (package:something/main.dart:96:38)
E/flutter (18403): <asynchronous suspension>
E/flutter (18403):
这是从 AzuraCast 接收数据并使用接收到的数据设置字符串的代码：
Future<void> getTrack(Set<dynamic> set) async {
final response = await http.get(
Uri.parse('https://radiopaneel.something-something.nl/api/nowplaying'),
headers: {
'X-API-Key':
'something',
},
);
if (response.statusCode == 200) {
final data = jsonDecode(response.body);
print(data);
final song = Song.fromJson(data['station']['now_playing']['song']);
print(data);
final id = song.id;
final songTitle = song.title;
final songArtist = song.artist;
final streamer = song.streamer_name;
print(id);
print(streamer);
setState(() {
titleString = songTitle;
streamerr = streamer;
});
} else {
throw Exception('Failed to retrieve current track.');
}
}
class Song {
final String id;
final String title;
final String artist;
final String streamer_name;
Song({required this.id, required this.title, required this.artist, required this.streamer_name});
factory Song.fromJson(Map<String, dynamic> json) {
return Song(
id: json['id'].toString(),
title: json['title'].toString(),
artist: json['artist'].toString(),
streamer_name: json['streamer_name'].toString()
);
}
}
字符串因此总是返回空。
全身反应：
[
{
"station": {
"id": 1,
"name": "something",
"shortcode": "something",
"description": "We make the music play!",
"frontend": "icecast",
"backend": "liquidsoap",
"listen_url":
"is_public": true,
"mounts": [
{
"id": 1,
"name": "320kbps MP3",
"url": "https://radiopaneel.something-something.nl/listen/something/stream",
"bitrate": 320,
"format": "mp3",
"listeners": {
"total": 9,
"unique": 4,
"current": 9
},
"path": "/stream",
"is_default": true
}
],
"remotes": [],
"hls_enabled": false,
"hls_url": null,
"hls_listeners": 0
},
"listeners": {
"total": 9,
"unique": 4,
"current": 9
},
"live": {
"is_live": true,
"streamer_name": "something",
"broadcast_start": 1678204893,
"art": null
},
"now_playing": {
"sh_id": 87956,
"played_at": 1678206744,
"duration": 0,
"playlist": "",
"streamer": "something",
"is_request": false,
"song": {
"id": "id",
"text": "Guus Meeuwis - Het Is Een Nacht",
"artist": "Guus Meeuwis",
"title": "Het Is Een Nacht",
"album": "",
"genre": "",
"isrc": "",
"lyrics": "",
"art": "art",
"custom_fields": []
},
"elapsed": 51,
"remaining": 0
},
"playing_next": {
"cued_at": 1678204813,
"played_at": 1678206782,
"duration": 203,
"playlist": "Non-Stop",
"is_request": false,
"song": {
"id": "id",
"text": "Demi Lovato - Sorry Not Sorry",
"artist": "Demi Lovato",
"title": "Sorry Not Sorry",
"album": "Tell Me You Love Me (Deluxe)",
"genre": "Pop",
"isrc": "",
"lyrics": "",
"art": "id",
"custom_fields": []
}
},
"song_history": [
{
"sh_id": id,
"played_at": 1678206515,
"duration": 229,
"playlist": "",
"streamer": "something",
"is_request": false,
"song": {
"id": "id",
"text": "Glass Animals - Heat Waves",
"artist": "Glass Animals",
"title": "Heat Waves",
"album": "",
"genre": "",
"isrc": "",
"lyrics": "",
"art": "art",
"custom_fields": []
}
},
{
"sh_id": id,
"played_at": 1678206356,
"duration": 159,
"playlist": "",
"streamer": "something",
"is_request": false,
"song": {
"id": "id",
"text": "text",
"artist": "artist",
"title": "title",
"album": "",
"genre": "",
"isrc": "",
"lyrics": "",
"art": "art",
"custom_fields": []
}
},
{
"sh_id": id,
"played_at": 1678206092,
"duration": 264,
"playlist": "",
"streamer": "Jules",
"is_request": false,
"song": {
"id": "id",
"text": "something",
"artist": "something",
"title": "Good Time",
"album": "",
"genre": "",
"isrc": "",
"lyrics": "",
"art": "art",
"custom_fields": []
}
},
{
"sh_id": id,
"played_at": 1678205913,
"duration": 179,
"playlist": "",
"streamer": "something",
"is_request": false,
"song": {
"id": "id",
"text": "text",
"artist": "artist",
"title": "title",
"album": "",
"genre": "",
"isrc": "",
"lyrics": "",
"art": "something",
"custom_fields": []
}
},
{
"sh_id": id,
"played_at": 1678205742,
"duration": 171,
"playlist": "",
"streamer": "something",
"is_request": false,
"song": {
"id": "dc383b8d72296caa9cb5d3851ee5910a",
"text": "S10 - De Diepte",
"artist": "S10",
"title": "De Diepte",
"album": "",
"genre": "",
"isrc": "",
"lyrics": "",
"art": "something",
"custom_fields": []
}
}
],
"is_online": true,
"cache": null
}
]
你可以看到响应顶部有一个列表，所以如果你想提取数据，你必须首先使用这样的索引进入列表：
final song = Song.fromJson(data[0]['station']['now_playing']['song']);
响应是一个数组（开始的“[”）。 所以首先你需要找到你想要的电台，第一个是
data[0]如果您从响应中删除一些您不使用的字段，您可以看到：
[
{
"station": {
"id": 1,
"name": "something",
...
},
"listeners": {
"total": 9,
...
},
"live": {
"is_live": true,
...
},
"now_playing": {
"sh_id": 87956,
"played_at": 1678206744,
"duration": 0,
...
"song": {
"id": "id",
"text": "Guus Meeuwis - Het Is Een Nacht",
"artist": "Guus Meeuwis",
"title": "Het Is Een Nacht",
...
},
},
"is_online": true,
"cache": null
}
]
这表明返回数组中的每个对象都具有“station”和“now_playing”属性 - 因此要从您想要的第一个正在播放的对象中获取歌曲
data[0]["now_playing"]["song"]