项目未显示在 RecyclerView 中

问题描述 投票：0回答：0

我有一个

Activity
，在
RecyclerView
中有一个
layout
，我想用
layout
在这个
RecyclerView
中显示一些数据，问题是当我输入
Activity
数据时不可见并且为空。数据是在名为 
java class
的 
"recyclerViewModel"
的帮助下收集的，这里我设置了一个带有 6 
variables
的构造函数，然后我在 
activity
代码中创建了一个 
Arraylist
class
我用一个
objects
和
for
arrays
快速创建了总共3个
(setDataRecycler method).
，这3个
objects
每一个都有6个
variables
，每个对象都意味着“一个配置文件” 。 
objects
保存在 
ArrayList
中，目的是在 
RecyclerView

中显示它们，正如我所说的

活动java代码：

package com.example.calculoimcwithui;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;

import java.util.ArrayList;

public class Profiles extends AppCompatActivity {

    ArrayList<recyclerViewModel> data;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_profiles);
        RecyclerView recyclerView = findViewById(R.id.recyclerView);
        data = new ArrayList<recyclerViewModel>();
        setDataRecycler();
        recyclerViewAdapter adapter = new recyclerViewAdapter(this,data);
        recyclerView.setAdapter(adapter);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
    }

    private void setDataRecycler () {
        String [] nombres = {"Rober","Carlos","Laura"};
        String [] edades = {"16","16","21"};
        String [] alturas = {"178","180","162"};
        String [] pesos = {"72","68","54"};
        String [] afs = {"Bastante","Mucha","Bastante"};
        String [] generos = {"Hombre","Hombre","Mujer"};
        for (int i = 0; i<nombres.length;i++) {
            data.add(new recyclerViewModel(nombres[i],edades[i],alturas[i],pesos[i],afs[i],generos[i]));

        }
    }
}

活动 xml 代码：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Profiles">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="399dp"
        android:layout_height="627dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.495"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.452" />
</androidx.constraintlayout.widget.ConstraintLayout>

RecyclerView适配器：

package com.example.calculoimcwithui;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.example.calculoimcwithui.R;
import com.example.calculoimcwithui.recyclerViewModel;

import java.util.ArrayList;

public class recyclerViewAdapter  extends RecyclerView.Adapter<recyclerViewAdapter.ViewHolder> {

    Context context;
    ArrayList<recyclerViewModel> data;

    public recyclerViewAdapter (Context context, ArrayList<recyclerViewModel> data) {
        this.context = context;
        this.data = data;

    }
    @NonNull
    @Override

    public recyclerViewAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater inflater = LayoutInflater.from(context);
        View view = inflater.inflate(R.layout.recyclerviewmodel,parent,false);

        return  new recyclerViewAdapter.ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull recyclerViewAdapter.ViewHolder holder, int position) {
        holder.name.setText(data.get(position).getName());
        holder.age.setText(data.get(position).getAge());
        holder.height.setText(data.get(position).getAltura());
        holder.weight.setText(data.get(position).getPeso());
        holder.af.setText(data.get(position).getAf());
        holder.gender.setText(data.get(position).getGenero());

    }

    @Override
    public int getItemCount() {
        return data.size();
    }

    public static class ViewHolder extends  RecyclerView.ViewHolder {

        TextView name;
        TextView age;

        TextView height;
        TextView weight;
        TextView af;
        TextView gender;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);

            name = itemView.findViewById(R.id.name);
            age = itemView.findViewById(R.id.age);
            height = itemView.findViewById(R.id.height);
            weight = itemView.findViewById(R.id.weight);
            af = itemView.findViewById(R.id.af);
            gender = itemView.findViewById(R.id.gender);

        }
    }


}

recyclerViewModel java 代码

package com.example.calculoimcwithui;

public class recyclerViewModel {

    String name;
    String age;
    String altura;
    String peso;
    String af;
    String genero;

    public recyclerViewModel(String name, String age, String altura, String peso, String af, String genero) {
        this.name = name;
        this.age = age;
        this.altura = altura;
        this.peso = peso;
        this.af = af;
        this.genero = genero;
    }

    public String getName() {
        return name;
    }

    public String getAge () {
        return age;
    }
    public String getAltura () {
        return  altura;
    }
    public String getPeso () {
        return peso;
    }

    public String getAf () {
        return af;
    }
    public String getGenero () {
        return genero;
    }
}

RecyclerView 模型卡

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.cardview.widget.CardView
        android:layout_width="441dp"
        android:layout_height="117dp"
        android:layout_marginStart="1dp"
        android:layout_marginTop="245dp"
        android:layout_marginEnd="1dp"
        android:layout_marginBottom="486dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/recCard"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <TextView
                android:id="@+id/name"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="16dp"
                android:layout_marginBottom="31dp"
                android:text="Nombre"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintVertical_bias="0.373" />

            <TextView
                android:id="@+id/age"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="16dp"
                android:text="Edad"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintVertical_bias="0.673" />

            <TextView
                android:id="@+id/af"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginEnd="156dp"
                android:text="Af"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintVertical_bias="0.234" />

            <TextView
                android:id="@+id/weight"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="140dp"
                android:text="Peso"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintVertical_bias="0.673" />

            <TextView
                android:id="@+id/gender"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginEnd="136dp"
                android:text="Genero"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintVertical_bias="0.663" />

            <TextView
                android:id="@+id/height"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="140dp"
                android:text="Altura"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintVertical_bias="0.244" />
        </androidx.constraintlayout.widget.ConstraintLayout>
    </androidx.cardview.widget.CardView>
</androidx.constraintlayout.widget.ConstraintLayout>

我检查了适配器类中的 

getItemCount
方法实际上返回了正确的大小，还有 
width
的 
height
和 
RecyclerView
，并且我检查了它们不在 
wrap_content
中。还有项目的数量，我检查了 
xml
膨胀文件是否正确，我检查了 
setLayoutManager
方法，确保已写入，我不知道我还能做什么。 （该应用程序工作正常，它不会抛出任何错误，但问题是。）

java android android-recyclerview
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