Android 如何从活动中的API调用的ViewModel中获取错误?
在Android中使用ViewModel时,我在ViewModel类中使用了两个可变的LiveData对象Android 如何从活动中的API调用的ViewModel中获取错误?,android,mvvm,rx-java2,rx-android,android-viewmodel,Android,Mvvm,Rx Java2,Rx Android,Android Viewmodel,在Android中使用ViewModel时,我在ViewModel类中使用了两个可变的LiveData对象 var imageList: MutableLiveData<List<HitsItem>> = MutableLiveData() var errorMessage: MutableLiveData<String> = MutableLiveData() var-imageList:MutableLiveData=MutableLiveData()
var imageList: MutableLiveData<List<HitsItem>> = MutableLiveData()
var errorMessage: MutableLiveData<String> = MutableLiveData()
var-imageList:MutableLiveData=MutableLiveData()
var errorMessage:MutableLiveData=MutableLiveData()
我想要的是,每当设置API调用errorMessage时发生错误,同样,当API调用成功时,设置imageList
如何检查API在活动中是否成功,当API调用未成功时,我希望在活动中显示Toast错误消息
ImageViewModel.kt
fun getImages(): LiveData<List<HitsItem>> {
imageList = MutableLiveData()
loadImages()
return imageList
}
fun loadImages() {
val api = PexelClient.getClient().create(ApiInterface::class.java)
val imageObservable = api.images
imageObservable.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.map({ result -> result })
.subscribe(
Consumer<ImageModel> { this.handleResults(it) },
Consumer<Throwable> { this.handleError(it) }
)
}
private fun handleResults(list: ImageModel) {
imageList.value = list.hits
errorMessage.value = null
}
private fun handleError(t: Throwable) {
imageList.value = null
errorMessage.value = t.message
}
fun getImages():LiveData{
imageList=MutableLiveData()
loadImages()
返回图像列表
}
趣味加载图像(){
val api=PexelClient.getClient().create(apinterface::class.java)
val imageObservable=api.images
imageObservable.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.map({result->result})
.订阅(
消费者{this.handleResults(it)},
消费者{this.handleError(it)}
)
}
私人娱乐手册结果(列表:ImageModel){
imageList.value=list.hits
errorMessage.value=null
}
私人娱乐手柄错误(t:可丢弃){
imageList.value=null
errorMessage.value=t.message
}
活动
lateinit var imagesViewModel:ImagesViewModel
lateinit var adapter:ImageAdapter
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_mvvm_rx_retrofit)
rv_images.setHasFixedSize(true)
rv_images.layoutManager = LinearLayoutManager(this)
imagesViewModel = ViewModelProviders.of(this).get(ImagesViewModel::class.java)
imagesViewModel.getImages().observe(this, object : Observer<List<HitsItem>> {
override fun onChanged(imageList: List<HitsItem>?) {
if(imageList != null){
adapter = ImageAdapter(this@MvvmRxRetrofit,imageList)
rv_images.adapter = adapter
}
}
})
}
lateinit var imagesViewModel:imagesViewModel
lateinit变量适配器:ImageAdapter
重写创建时的乐趣(savedInstanceState:Bundle?){
super.onCreate(savedInstanceState)
setContentView(R.layout.activity\U mvvm\U rx\U改装)
rv_图像。setHasFixedSize(真)
rv_images.layoutManager=LinearLayoutManager(此)
imagesViewModel=ViewModelProviders.of(this.get)(imagesViewModel::class.java)
imagesViewModel.getImages().observe(此,对象:Observer{
更改后覆盖乐趣(imageList:List?){
如果(imageList!=null){
适配器=图像适配器(this@MvvmRxRetrofit,图像列表)
rv_images.adapter=适配器
}
}
})
}
public ResponseStatus responseStatus ;
public Throwable error ;
public JsonElement data ;
AsyncResponse(ResponseStatus responseStatus, JsonElement data ,Throwable error){
this.responseStatus = responseStatus ;
this.data = data ;
this.error = error ;
}
public static AsyncResponse loading(){
return new AsyncResponse(ResponseStatus.LOADING,null,null);
}
public static AsyncResponse success(JsonElement data){
return new AsyncResponse(ResponseStatus.SUCCESS,data,null);
}
public static AsyncResponse error(Throwable error){
return new AsyncResponse(ResponseStatus.ERROR,null,error);
}
}
mChatDialogViewModel.getResponse().observe(this, new Observer<AsyncResponse>() {
@Override
public void onChanged(@Nullable AsyncResponse asyncResponse) {
if (asyncResponse != null)
consumeResponse(asyncResponse);
}
});
private void consumeResponse(AsyncResponse asyncResponse) {
switch (asyncResponse.responseStatus) {
case LOADING: {
break;
}
case SUCCESS: {
break;
}
case ERROR: {
break;
}
default:
break;
}
mChatDialogViewModel.getResponse().observe(这是新的观察者(){
@凌驾
已更改公共void(@Nullable AsyncResponse){
if(异步响应!=null)
用户响应(异步响应);
}
});
私有void消费响应(异步响应异步响应){
开关(asyncResponse.responseStatus){
箱子装载:{
打破
}
成功案例:{
打破
}
案例错误:{
打破
}
违约:
打破
}
make handleResults,handleError in methods in activity而不是viewmodelStill,如何在Activity1中同时获得结果、错误和列表。不要在getImages()中执行imageList=MutableLiveData()
function.2.将livedata设置为val而不是var.3.在活动中也观察errorMessage
,就像通过getImages()观察imageList
)
.4.当您有数据errorMessage.value=null
时,不要向错误发送null。当您有错误imageList.value=null
时,不要向数据发送null。请删除这些。谢谢,但您能用示例代码演示如何在活动中获取errorMessage吗