Swift 5：如何获取BehaviorRelay的值并绑定RxSwift和MVVM

Question

我正在尝试从视图模型中的服务获取金额值，然后在 ViewController 中将其绑定到 amountLabel。

这是我的视图模型：

class AmountViewModel {
    
    private let accountService: AccountManagerProtocol        
    
    let _amount = BehaviorRelay<Int>(value: 0)
    let amount: Observable<Int>
        
    private let disposeBag = DisposeBag()
   
    init(accountService: AccountManagerProtocol = AccountManager()) {

        self.accountService = accountService
    
        amount = _amount.asObservable()
        
        getAmount()   
    }

    func getAmount(){
        accountService.getAccount()
            .map{ [=11=].amount ?? 0 }
            .bind(to: _amount)
            .disposed(by: disposeBag)
    }
}

这是我的 ViewController, 我做了这样的事情，获取viewModel的金额，但我觉得这不是最好的方法，我想获取金额的值并能够以更简单的方式将其绑定到amountLabel。

private extension AmountViewController {
    private func bindViewModel() {
        amountView.titleLabel.text = viewModel.title
               
        //Get Amount
        viewModel.amount
            .observe(on: MainScheduler.instance)
            .withUnretained(self)
            .subscribe(onNext: { owner, amount in
                if let amountString = amount.currencyToString() {
                owner.inputAmountView.amountLabel.text = "BALANCE: \(amountString)"
                }
            })
            .disposed(by: disposeBag)
 }

Answer 1

这是最明显的简化：

class AmountViewModel {
    let amount: Observable<Int>
    
    init(accountService: AccountManagerProtocol = AccountManager()) {
        amount = accountService.getAccount()
            .map { [=10=].amount ?? 0 }
    }
}

private extension AmountViewController {
    private func bindViewModel() {
        viewModel.amount
            .compactMap { [=10=].currencyToString().map { "BALANCE: \([=10=])"} }
            .observe(on: MainScheduler.instance)
            .bind(to: inputAmountView.amountLabel.rx.text)
            .disposed(by: disposeBag)
    }
}

但我想我会把 compactMap 闭包中的代码移到视图模型中...

Swift 5：如何获取BehaviorRelay的值并绑定RxSwift和MVVM

Swift 5: How to get the value of a BehaviorRelay and binding with RxSwift and MVVM

ios

swift

mvvm

rx-swift