android - Flutter-dart http 库 ClientException

Question

我正在使用 HTTP dart 包 在 flutter 中执行这样的发布请求，但有时当网络出现故障时，IOClient 会抛出 ClientException类，但我在 catch block 和应用程序崩溃中没有得到任何东西。

http.post(url, headers: headers, body: body).then((response) {
  //response parsing
}).catchError((error) {
 //ClientException is never catched in this block.
});

Answer 1

如package:http/src/io_client.dart中所述:

Any internal HTTP errors should be wrapped as [ClientException]s.

如 docs 中所述这是一个明显的例子:

Potential problem: accidentally mixing synchronous and asynchronous errors

要解决此问题，您需要将代码包装在 Future.sync() 中。

Future.sync() makes your code resilient against uncaught exceptions. If your function has a lot of code packed into it, chances are that you could be doing something dangerous without realizing it:

return new Future.sync(() {
  http.post(url, headers: headers, body: body).then((response) {});
});

Future.sync() not only allows you to handle errors you know might occur, but also prevents errors from accidentally leaking out of your function.