使用Glide

Question

我有一个使用recyclerview的帖子列表。列表很棒，但是当我尝试在recyclerview上添加图像时会出现问题。我正在使用Glide添加图像。我已经成功地使用导航抽屉滑动添加图像，但是当我尝试使用Recyclerview时，它显示的不是我采购的默认图像。

这是我的kotlin ，

class InformationListActivity : MainActivity() {
private val glide: RequestManager? = null

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_information_list)

    val toolbar = findViewById<View>(R.id.toolbar) as Toolbar
    setSupportActionBar(toolbar)
    supportActionBar!!.setDisplayHomeAsUpEnabled(true)
    supportActionBar!!.setDisplayShowHomeEnabled(true)

    val user = FirebaseAuth.getInstance().currentUser
    val uName = user?.displayName
    val uEmail = user?.email
    val uPhotoUrl = user?.photoUrl
    user?.uid

    val navigationView = findViewById<View>(R.id.nav_view) as NavigationView
    navigationView.setNavigationItemSelectedListener(this)
    val headerView = navigationView.getHeaderView(0)

    val navName = headerView.findViewById<TextView>(R.id.navName)
    navName.text = uName
    val navEmail = headerView.findViewById<TextView>(R.id.navEmail)
    navEmail.text = uEmail
    val navImage = headerView.findViewById<ImageView>(R.id.navImage)
    Glide.with(this).load(uPhotoUrl).into(navImage)

    window.clearFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS)

    val signOut = findViewById<View>(R.id.btnSignOut) as LinearLayout
    signOut.setOnClickListener {
        FirebaseAuth.getInstance().signOut()
        val goToLogin = Intent(this@InformationListActivity, LoginActivity::class.java)
        startActivity(goToLogin)
    }


    val recyclerView = findViewById<View>(R.id.recycler_view) as RecyclerView
    recyclerView.setHasFixedSize(true)
    recyclerView.layoutManager = LinearLayoutManager(this)
    val myref = FirebaseDatabase.getInstance().reference.child("/posts")
    val recyclerAdapter = object : FirebaseRecyclerAdapter<Post, InformationListActivity.PostViewHolder>(
            Post::class.java,
            R.layout.information_model,
            InformationListActivity.PostViewHolder::class.java,
            myref
    ) {
        override fun populateViewHolder(viewHolder: InformationListActivity.PostViewHolder, model: Post, position: Int) {
            val data_empty = findViewById<View>(R.id.data_empty) as TextView
            data_empty.visibility = View.GONE
            viewHolder.run {
                glide?.let { setmPostImageUrl(it,model.getmPostImageUrl()) }
                setmPostTitle(model.getmPostTitle())
                setmPostDescription(model.getmPostDescription())
                viewHolder.setItemClickListener(object : ItemClickListener {
                    override fun onItemClick(pos: Int) {
                        //OPEN DETAIL ACTIVITY
                        openInformationDetail(model.getmPostImageUrl(), model.getmPostTitle(), model.getmPostDescription())
                    }
                })
            }
        }
    }
    recyclerView.adapter = recyclerAdapter
}

private fun openInformationDetail(vararg details: String) {
    val i = Intent(this, InformationDetailActivity::class.java)
    i.putExtra("POSTIMAGEURL_KEY", details[0])
    i.putExtra("POSTTITLE_KEY", details[1])
    i.putExtra("POSTDESCRIPTION_KEY", details[2])
    startActivity(i)
}

class PostViewHolder(mView: View) : RecyclerView.ViewHolder(mView), View.OnClickListener {
    private var modelImgPost: ImageView = mView.findViewById(R.id.imgPost)
    private var modelPostTitle: TextView = mView.findViewById(R.id.modelPostTitle)
    private var modelPostDescription: TextView = mView.findViewById(R.id.modelPostDescription)
    private var btnMore: Button = mView.findViewById(R.id.btnMore)
    private lateinit var itemClickListener: ItemClickListener

    init {
        btnMore.setOnClickListener(this)
    }

    fun setItemClickListener(itemClickListener: ItemClickListener) {
        this.itemClickListener = itemClickListener
    }

    override fun onClick(view: View) {
        this.itemClickListener.onItemClick(this.layoutPosition)
    }

    fun setmPostImageUrl(glide: RequestManager, mPostImageUrl: String) {
        glide.load(Uri.parse(mPostImageUrl)).into(modelImgPost)
    }

    fun setmPostTitle(mPostTitle: String) {
        modelPostTitle.text = mPostTitle
    }

    fun setmPostDescription(mPostDescription: String) {
        modelPostDescription.text = mPostDescription
    }
}

Answer 1

if (glide != null) {
    setmPostImageUrl(glide, model.getmPostImageUrl())
}

Glide null 因为您从不分配/实例化它。

替换此行：

private val glide: RequestManager? = null

with：

private var glide: RequestManager? = null

并在onCreate()中执行：

glide = Glide.with(this)