我在iterator()类上创建了一个扩展函数JSONArray，在使用for for循环时，我收到了以下错误：
Type inferece failed: Not enough information to infer parameter T in
operator fun <T> JSONArray.iterator () L Iterator<T>
我的代码是：
class GetFlickrJsonData(private val mCallBack: OnDataAvailable, private var mBaseUrl: String, private var mLanguage: String, private var mMatchAll: Boolean) : GetRawData.OnDownLoadComplete {
init {
Log.d(TAG,"GetFlickrJsonData Called")
}
companion object {
private val TAG = "GetFlickrJsonData"
}
private var mPhotosList: List<Photo>? = null
interface OnDataAvailable {
fun onDataAvailable(data: List<Photo>,status: ClientInfoStatus)
}
fun executeOnSameThread(searchCriteria: String){
Log.d(TAG,"executeOnSameThread starts...")
val destinationUri: String = createUri(searchCriteria,mLanguage,mMatchAll)
val getRawData = GetRawData(this)
getRawData.execute(destinationUri)
Log.d(TAG,"executeOnSameThread ends...")
}
fun createUri(searchCriteria: String,mLanguage: String,mMatchAll: Boolean): String{
Log.d(TAG,"createUri starts...")
return Uri.parse(mBaseUrl).buildUpon()
.appendQueryParameter("tags",searchCriteria)
.appendQueryParameter("tagmode",if(mMatchAll) "ALL" else "ANY")
.appendQueryParameter("lang",mLanguage)
.appendQueryParameter("format","json")
.appendQueryParameter("nojsoncallback","1")
.build().toString()
}
override fun onDownloadComplete(data: String?, status: DownloadStatus) {
Log.d(TAG,"onDownLoadComplete : $status")
if (status == DownloadStatus.OK) mPhotosList = ArrayList()
try {
val jsonData = JSONObject(data)
val jsonArray: JSONArray = jsonData.getJSONArray("items")
for (item: JSONObject in jsonArray){
}
}
}
}
扩展功能是：
operator fun <T>JSONArray.iterator(): Iterator<T> = (0 until length()).asSequence().map { get(it) as T }.iterator()
我如何明确地推断它？