颤振 '值 >= 最小值 &&值 <= 最大值'：不为 真

Question

我正在构建一个简单的音乐播放器类型的应用程序。我面临一个问题，当我的音频完成的时间，它显示

'package:flutter/src/material/slider.dart': Failed assertion: line 166 pos 15: 'value >= min && value <= max': is not true.

我的代码

Expanded(
child: Slider(
activeColor: Color(0xffe7ad29),
inactiveColor: Color(0xFF707070),
value: model.playerBarValue,
onChanged: (val) {
model.seekFromBar(val);
},
),
),
class PlayerProvider extends ChangeNotifier {
final player = AssetsAudioPlayer();
String link;
Duration playerTimeNow = Duration(seconds: 0);
Duration playerLength;
double playerBarValue = 0.0;
Episode episode;
Item podcastInfo;
String episodeName, episodeThumbnail;
bool isPlaying = false;
PlayerProvider() {
updateState();
}
play() async {
print("Started Playing");
// Stop previous playing
player.stop();
playerTimeNow = Duration(seconds: 0);
isPlaying = false;
// link = updateLinkToHttps(link);
print(link);
final audio = Audio.network(
link,
metas: Metas(
title: podcastInfo.collectionName,
artist: podcastInfo.artistName,
album: podcastInfo.trackName,
image: MetasImage.network(podcastInfo.artworkUrl600),
//can be MetasImage.network
),
);
var duration = await player.open(
audio,
showNotification: true,
notificationSettings: NotificationSettings(
//seekBarEnabled: false,
//stopEnabled: true,
//customStopAction: (player){
//  player.stop();
//}
//prevEnabled: false,
customNextAction: (player) {
print("next1");
forward();
}, customPrevAction: (player) {
print("next2");
backword();
}
//customStopIcon: AndroidResDrawable(name: "ic_stop_custom"),
//customPauseIcon: AndroidResDrawable(name:"ic_pause_custom"),
//customPlayIcon: AndroidResDrawable(name:"ic_play_custom"),
),
);
isPlaying = true;
// player.play(); // Usually you don't want to wait for playback to finish.
print("started");
setState();
}
pause() async {
await player.pause();
isPlaying = false;
print("paused");
setState();
}
resume() async {
//TODO: Setup resume
await player.seek(playerTimeNow);
player.play();
isPlaying = true;
}
speed(double val) async {
print(val);
//TODO: Setup resume
await player.setPlaySpeed(val);
isPlaying = true;
}
updateState() {
player.currentPosition.listen((event) {
playerTimeNow = event;
updatePlayerBar();
});
}
updatePlayerBar() {
int totalLengthInMilliSeconds = playerLength.inMilliseconds;
int totalPlayedInMilliSeconds = playerTimeNow.inMilliseconds;
double newPlayerBarValue =
totalPlayedInMilliSeconds / totalLengthInMilliSeconds;
playerBarValue = newPlayerBarValue;
// print(playerBarValue);
// print(playerTimeNow);
// print(playerLength);
// print(playerLength);
// if (playerLength == playerTimeNow) {
//   print('Finish');
//   player.stop();
// }
notifyListeners();
}
forward() async {
//TODO: Check if at-least 10 seconds are left;
if (playerTimeNow + Duration(seconds: 10) < playerLength)
await player.seek(playerTimeNow + Duration(seconds: 10));
else
await player.seek(playerLength);
print("Forwarded 10 seconds");
}
backword() async {
Duration back = playerTimeNow.inSeconds > 10
? playerTimeNow - Duration(seconds: 10)
: Duration(seconds: 0);
await player.seek(back);
print("Backwarded 10 seconds");
}
seekFromBar(double val) async {
double totalMillis = playerLength.inMilliseconds * val;
int newMillis = totalMillis.toInt();
Duration newSeekLocations = Duration(milliseconds: newMillis);
await player.seek(newSeekLocations);
print("Seek from Bar");
}
setState() {
notifyListeners();
}
}

当时间结束时，它会在红色屏幕上显示这个错误。我需要知道怎么解决这个问题?意思是当它完成的时候，时间是0或什么的。我想问题出在滑块上，因为如果我从红色屏幕返回，滑块就会归零。

Answer 1

查看model的值。playerBarValue既不是Nan也不是null，并为滑动条设置一个最大值。

Slider(
value: model.playerBarValue.isNaN==true || model.playerBarValue==null? 0 : model.playerBarValue,
min: 0.0,
max: duration.inSeconds.toDouble() + 1.0,
onChanged: (value) {
. . .
},
)