Question

我正在使用Kotlin开发新闻应用程序，但它显示空白屏幕，并且logcat上没有错误或异常

在我的SportNewsAdapter.kt下面

class SportNewsAdapter(val context: Context) : RecyclerView.Adapter<SportNewsAdapter.MyViewHolder>() {

    var articleList : List<Article> = listOf()

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {

        val view = LayoutInflater.from(parent.context).inflate(R.layout.news_list,parent,false)
        return MyViewHolder(view)
    }

    override fun getItemCount(): Int {
        return articleList.size
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {

        holder.tvMovieName.text = articleList.get(position).title
        Glide.with(context).load(articleList.get(position).urlToImage)
            .apply(RequestOptions().centerCrop())
            .into(holder.image)
    }

    fun setMovieListItems(movieList: List<Article>){
        this.articleList = articleList;
        notifyDataSetChanged()
    }

    class MyViewHolder(itemView: View?) : RecyclerView.ViewHolder(itemView!!) {

        val tvMovieName: TextView = itemView!!.findViewById(R.id.title)
        val image: ImageView = itemView!!.findViewById(R.id.image)

    }
}

低于news_item.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="150dp"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <ImageView
        android:id="@+id/image"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>

    <TextView
        android:id="@+id/title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="@android:color/white"
        android:textStyle="bold"
        android:textSize="20sp"
        app:layout_constraintBottom_toBottomOf="parent"/>

</android.support.constraint.ConstraintLayout>

MainActivity.kt以下

class MainActivity : AppCompatActivity() {

    lateinit var recyclerView: RecyclerView
    lateinit var sportNewsAdapter: SportNewsAdapter


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        recyclerView = findViewById(R.id.recyclerView)
        sportNewsAdapter = SportNewsAdapter(this)
        recyclerView.layoutManager = LinearLayoutManager(this)
        recyclerView.adapter = sportNewsAdapter


        val apiInterface = SportNewsInterface.create().getNews()


        apiInterface.enqueue( object : Callback<List<Article>> {
            override fun onResponse(call: Call<List<Article>>?, response: Response<List<Article>>?) {

                if(response?.body() != null)
                    sportNewsAdapter.setMovieListItems(response.body()!!)
            }

            override fun onFailure(call: Call<List<Article>>?, t: Throwable?) {

            }
        })
    }
    }

activity_main.xml下面

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

SportNewsInterface.kt以下

界面SportNewsInterface {

@GET("v2/top-headlines?country=us&apiKey=da331087e3f3462bb534b3b0917cbee9")
fun getNews() : Call <List<Article>>

companion object {

    var BASE_URL = "https://newsapi.org/"

    fun create() : SportNewsInterface {

        val retrofit = Retrofit.Builder()
            .addConverterFactory(GsonConverterFactory.create())
            .baseUrl(BASE_URL)
            .build()
        return retrofit.create(SportNewsInterface::class.java)

    }
} }

在SportNewsResponse.kt下面，其中进行了改造

data class SportNewsResponse(
    val articles: List<Article>,
    val status: String,
    val totalResults: Int
)

Answer 1

更改回收站的视图高度以包装内容并再次运行

recyclerview显示空白屏幕？

1 个答案: