关闭接收通道异常和数据绑定的问题

Question

我正在编写一段使用 Kotlin 的协程 pipilens 和 Androids Data Binding 的代码。

在工作时，我发现当我的couroutine由于"ClosedReceiveChannelException"而崩溃时，绑定视图模型(通过数据绑定(不会更新"数据绑定组件"。

fun onProcessStart(cachedImageId: String) = viewModelScope.launch {
    text = "Started for image: $cachedImageId"
    try {
        val extractedTextPipe = extractText(cachedImageId)
        val processedTextPipe = processText(extractedTextPipe)
        val processedText = processedTextPipe.receive()
        text = "Finished for image: $cachedImageId"
    } catch (t: Throwable) {
        Log.d("TEST", t.message+ " "+t)
        text = "Failed for image: $cachedImageId with code: ${t.message}"
    }
}

尽管会触发捕获并且日志中存在Log.d，但带有新消息的text永远不会更新。

如果以下方法不起作用，那也就不足为奇了：

 fun onProcessStart(cachedImageId: String) = viewModelScope.launch {
        text = "Started for image: $cachedImageId"
        try {
            throw IllegalStateException()
            text = "Finished for image: $cachedImageId"
        } catch (t: Throwable) {
            Log.d("TEST", t.message+ " "+t)
            text = "Failed for image: $cachedImageId with code: ${t.message}"
        }
    }

上面的代码有效 - catch中的文本已更新。

我的问题是 - 为什么一旦val processedText = processedTextPipe.receive()抛出ClosedReceiveChannelException text值就会停止更新。

--编辑也可以通过以下方式观察到此问题：

  text = "Started for image: $cachedImageId"
    try {
        delay(10000)
        throw IllegalStateException()
    } catch (t: Throwable) {
        Log.d("TEST", t.message + " " + t + " " + Thread.currentThread().id)
        text = "Failed for image: $cachedImageId with code: ${t.message}"
    }

Answer 1

好吧 - 经过一夜好眠，我发现我忘记在text字段中使用LiveData。