如何以最短的方式创建自定义事件？

发布于 2025-02-13 22:15:30 字数 926 浏览 0 评论 0原文

有customWebViewClient带有Override函数OnPageFined。关于触发该函数的通知mainViewModel的最短方法是什么？我的意思是一些活动。

我想可以使用stateflow，类似的内容：

class MainViewModel : ViewModel() { 
    init {
        val client = CustomWebViewClient()
        viewModelScope.launch {
            client.onPageFinished.collect {
                // ...
            }
        }
    }
}

class CustomWebViewClient() : WebViewClient() {

    private val _onPageFinished = MutableStateFlow("")
    val onPageFinished = _onPageFinished.asStateFlow()

    override fun onPageFinished(view: WebView, url: String) {
        _onPageFinished.update { "" }
    }
}

但是在这种情况下，需要传输不必要的空字符串，并将在OnPageFineded之前首先呼叫，因为mutableStateflow < /代码>具有值。因此，出现需要添加一些枚举或类，以便在关键字时使用进行过滤。

也许有更多最短的方法可以做到这一点？

原文

There is CustomWebViewClient with override function onPageFinished. What is the shortest way to notify MainViewModel about the function triggered? I mean some event.

I suppose that can use StateFlow, something like this:

class MainViewModel : ViewModel() { 
    init {
        val client = CustomWebViewClient()
        viewModelScope.launch {
            client.onPageFinished.collect {
                // ...
            }
        }
    }
}

class CustomWebViewClient() : WebViewClient() {

    private val _onPageFinished = MutableStateFlow("")
    val onPageFinished = _onPageFinished.asStateFlow()

    override fun onPageFinished(view: WebView, url: String) {
        _onPageFinished.update { "" }
    }
}

But in this case need to transfer unnecessary empty string and will be occurs first call before onPageFinished called because MutableStateFlow has value. So appear required add some enum or class in order to do filter with when keyword.

Maybe is there more shortest way to do that?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

送你一个梦 2025-02-20 22:15:36

如果您想使用mutablStateFlow方法，另一个选项也是覆盖onPagestarted ，并做类似的事情，

class CustomWebViewClient(): WebViewClient() {
    private val _onPageFinished = MutableStateFlow(false)
    val onPageFinished = _onPageFinished.asStateFlow()
    override fun onPageStarted(
        view: WebView?,
        url: String?,
        favicon: Bitmap?,
    ) {
        _onPageFinished.update { false }
    }

    override fun onPageFinished(view: WebView?, url: String?) {
        _onPageFinished.update { true }
    }
}

class MainViewModel : ViewModel() {
    init {
        val client = CustomWebViewClient()
        viewModelScope.launch {
            client.onPageFinished.collect {
                if (it) {
                    // Do stuff when page is loaded
                } else {
                    // Do stuff when page starts loading
                }
            }
        }
    }
}

尽管最终使用FOLLOWS为此是有点过分的夸张，并且使用lambda方法Mieszko Koinma建议的可能更为直接。

If you want to use the MutablStateFlow approach, another option is to also override onPageStarted as well and do something like

class CustomWebViewClient(): WebViewClient() {
    private val _onPageFinished = MutableStateFlow(false)
    val onPageFinished = _onPageFinished.asStateFlow()
    override fun onPageStarted(
        view: WebView?,
        url: String?,
        favicon: Bitmap?,
    ) {
        _onPageFinished.update { false }
    }

    override fun onPageFinished(view: WebView?, url: String?) {
        _onPageFinished.update { true }
    }
}

class MainViewModel : ViewModel() {
    init {
        val client = CustomWebViewClient()
        viewModelScope.launch {
            client.onPageFinished.collect {
                if (it) {
                    // Do stuff when page is loaded
                } else {
                    // Do stuff when page starts loading
                }
            }
        }
    }
}

Though ultimately using flows for this is kinda overkill and using the lambda approach suggested by Mieszko Koźma is probably more straight forward.

回复收藏 0 原文

极度宠爱 2025-02-20 22:15:34

您可以将lambda参数添加到CustomWebViewClient构造函数中，该构造器一旦完成后就会被调用。

class MainViewModel : ViewModel() { 
    init {
        val client = CustomWebViewClient({handle the event})
    }
}

class CustomWebViewClient(onPageFinished: () -> Unit) : WebViewClient() {
    override fun onPageFinished(view: WebView, url: String) {
        onPageFinished()
    }
}

请注意，引用Android中的任何内容。* ViewModel中的软件包通常是一个很大的无行为。

You can add lambda parameter into CustomWebViewClient constructor that will get called once page is finished.

class MainViewModel : ViewModel() { 
    init {
        val client = CustomWebViewClient({handle the event})
    }
}

class CustomWebViewClient(onPageFinished: () -> Unit) : WebViewClient() {
    override fun onPageFinished(view: WebView, url: String) {
        onPageFinished()
    }
}

Please note that referencing anything from android.* package in a ViewModel is most often a big no-go.

回复收藏 0 原文

~没有更多了~