使用ViewModel中的单打截击

我有一个由Android Studio 3.2.1创建的ViewModel的新片段。

目标是使用Google提出的截击Singleton请求 here .

问题是Google单例模式对于截击单例依赖于一个ViewModel中不直接存在的上下文。

如何从ViewModel获取应用程序上下文,然后将由Volley Singleton使用?

网球场单杆截击

package com.developer.pochttp.sampledata

import android.content.Context
import android.graphics.Bitmap
import android.support.v4.util.LruCache
import com.android.volley.Request
import com.android.volley.RequestQueue
import com.android.volley.toolbox.ImageLoader
import com.android.volley.toolbox.Volley

class WebsiteRestApi constructor(context: Context) {
    companion object {
        @Volatile
        private var INSTANCE: WebsiteRestApi? = null
        fun getInstance(context: Context) =
            INSTANCE ?: synchronized(this) {
                INSTANCE ?: WebsiteRestApi(context).also {
                    INSTANCE = it
                }
            }
    }
    val imageLoader: ImageLoader by lazy {

        ImageLoader(requestQueue,
            object : ImageLoader.ImageCache {
                private val cache = LruCache<String, Bitmap>(20)
                override fun getBitmap(url: String): Bitmap? {
                    return cache.get(url)
                }
                override fun putBitmap(url: String, bitmap: Bitmap) {
                    cache.put(url, bitmap)
                }
            })
    }
    val requestQueue: RequestQueue by lazy {
        // applicationContext is key, it keeps you from leaking the
        // Activity or BroadcastReceiver if someone passes one in.
        Volley.newRequestQueue(context.applicationContext)
    }
    fun <T> addToRequestQueue(req: Request<T>) {
        requestQueue.add(req)
    }
}

视图模型

package com.developer.pochttp.ui.main

import android.arch.lifecycle.ViewModel

class MainViewModel : ViewModel() {


}