Dart 颤振未来返回空值
我已经看过了: 遵循了解决方案,但在我的情况下不起作用 今天下午我会得到一些启发Dart 颤振未来返回空值,dart,flutter,Dart,Flutter,我已经看过了: 遵循了解决方案,但在我的情况下不起作用 今天下午我会得到一些启发 Future<String> loadInterest() async { print('Going to load interests'); final whenDone = new Completer(); SharedPreferences prefs = await SharedPreferences.getInstance(); final token
Future<String> loadInterest() async {
print('Going to load interests');
final whenDone = new Completer();
SharedPreferences prefs = await SharedPreferences.getInstance();
final token = await prefs.getString('token');
print('The token ${token}');
await this.api.interests(token).then((res) {
// print('The response: ${res['interests']}'); <-- this prints response alright. Data is coming.
whenDone.complete(res['interests']);
});
return whenDone.future;
}
其中兴趣芯片(…)
是:
InterestChips(items) {
print('Interest Chips ${items}');
List chipList;
for (Object item in items) {
chipList.add(Text('${item}'));
}
return chipList;
}
但是,我总是得到null
作为快照,这意味着未来的的loadInterest()
没有返回任何内容
如果我正确地理解了这个答案,那么我的回答是这样的:你不需要为这个使用补全符。因为您的方法已经是异步的
,所以您应该只对第一个代码块执行以下操作:
Future<String> loadInterest() async {
print('Going to load interests');
final whenDone = new Completer();
SharedPreferences prefs = await SharedPreferences.getInstance();
final token = await prefs.getString('token');
print('The token ${token}');
final res = await this.api.interests(token).then((res) {
// print('The response: ${res['interests']}'); <-- this prints response alright. Data is coming.
return res['interests']);
}
Future loadInterest()异步{
打印(“准备加载利息”);
最终whenDone=新的完成符();
SharedReferences prefs=等待SharedReferences.getInstance();
final token=wait prefs.getString('token');
打印('thetoken${token}');
final res=等待这个.api.interests(令牌)。然后((res){
//print('response:${res['interests']}');是否检查快照。hasError?发送发送HTTP请求的链接。
Future<String> loadInterest() async {
print('Going to load interests');
final whenDone = new Completer();
SharedPreferences prefs = await SharedPreferences.getInstance();
final token = await prefs.getString('token');
print('The token ${token}');
final res = await this.api.interests(token).then((res) {
// print('The response: ${res['interests']}'); <-- this prints response alright. Data is coming.
return res['interests']);
}