RxSwift 系列(八) -- Error Handing Operators
前言
本篇文章我们将学习RxSwift
中的错误处理,包括:
catchErrorJustReturn
遇到error
事件的时候,返回一个值,并且结束。更多详情
let disposeBag = DisposeBag()
let sequenceFail = PublishSubject<String>()
sequenceFail.catchErrorJustReturn("😁").subscribe(onNext: {print($0)}).disposed(by: disposeBag)
sequenceFail.onNext("😝")
sequenceFail.onNext("😓")
sequenceFail.onError(TestError.test)
运行结果:
😝
😓
😁
catchError
捕获error
进行处理,可以返回另一个sequence
进行订阅。更多详情
let disposeBag = DisposeBag()
let sequenceThatFails = PublishSubject<String>()
let recoverySequence = PublishSubject<String>()
sequenceThatFails.catchError {
print("Error:", $0)
return recoverySequence
}.subscribe { print($0) }.disposed(by: disposeBag)
sequenceThatFails.onNext("😬")
sequenceThatFails.onNext("😨")
sequenceThatFails.onNext("😡")
sequenceThatFails.onError(TestError.test)
recoverySequence.onNext("😊")
运行结果:
next(😬)
next(😨)
next(😡)
Error: test
next(😊)
retry
遇见error事件可以进行重试,比如网络请求失败,可以进行重新连接。更多详情
let disposeBag = DisposeBag()
var count = 1
let retrySequence = Observable<String>.create { (observer) -> Disposable in
observer.onNext("🍎")
observer.onNext("🍐")
if count == 1 {
observer.onError(TestError.test)
print("Error encountered")
count += 1
}
observer.onNext("🐶")
observer.onNext("🐱")
return Disposables.create()
}
retrySequence.retry().subscribe(onNext: {print($0)}).disposed(by: disposeBag)
运行结果:
🍎
🍐
Error encountered
🍎
🍐
🐶
🐱
retry(_😃
与retry
相同,只是指定了重试次数。
let disposeBag = DisposeBag()
var count = 1
let sequenceThatErrors = Observable<String>.create { observer in
observer.onNext("🍎")
observer.onNext("🍐")
observer.onNext("🍊")
if count < 5 {
observer.onError(TestError.test)
print("Error encountered")
count += 1
}
observer.onNext("🐶")
observer.onNext("🐱")
observer.onCompleted()
return Disposables.create()
}
sequenceThatErrors.retry(3).subscribe(onNext: { print($0) }).disposed(by: disposeBag)
运行结果:
🍎
🍐
🍊
Error encountered
🍎
🍐
🍊
Error encountered
🍎
🍐
🍊
Error encountered
Received unhandled error: Playground.xcplaygroundpage:41:__lldb_expr_18 -> test
致谢
如果发现有错误的地方,欢迎评论,感谢!