Question

我正在尝试使用android studio制作我的第一个应用程序。在主要活动中，我尝试使用RecyclerView以网格样式创建菜单。我希望每个菜单选项都有标题，描述和图像。

目前我在测试时菜单上只有3个选项。当我调试我的应用程序它有点工作但不像我预期的那样。在它加载时，它显示我的arrayList中的3个选项的标题，但不显示描述或图像。我已检查说明和图像字段是否正确填充在我的arrayList中。我不确定为什么它只显示标题？以下是我的代码。

代码 - XML

activity_main

(function($){

  $('#xmlFile').unbind('change')
    .bind('change', function(e){
    if(this.files.length > 0){
      var file = this.files[0];
      if(file.type == 'text/xml'){
          setTimeout(function(){
              console.log('Reader');
             var reader = new FileReader();
            reader.addEventListener('load', function(){
              console.log(reader.result);
              parser = new DOMParser();
              xmlDoc = parser.parseFromString(reader.result, file.type);
              console.log(xmlDoc);
            });
            reader.readAsDataURL(file);
          }, 100);
         }
       // $('#txtFileInfo').text('Type: '+ file.type);
     }
  });


 })($);

menu_layout

    <?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="com.example.mark.spanishapp.MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/esp_menu"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</android.support.constraint.ConstraintLayout>

代码 - Java

MainActivity

  <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:background="#FFFFFF"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/title"
        android:textStyle="bold"
        android:layout_gravity="center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/description"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <ImageView
        android:id="@+id/menuImg"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

MenuEsp

  package com.example.mark.spanishapp;

    import android.database.sqlite.SQLiteException;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.support.v7.widget.GridLayoutManager;
    import android.support.v7.widget.LinearLayoutManager;
    import android.support.v7.widget.RecyclerView;
    import android.util.Log;

    import java.io.IOException;
    import java.sql.SQLException;
    import java.util.ArrayList;

    public class MainActivity extends AppCompatActivity {

        private final static String TAG = "MainActivity";
        DBHandler dbHandler = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        dbHandler = new DBHandler(this);
        try {
            dbHandler.createDataBase();

        }catch (IOException ioe){
            throw new Error("unable to create database");
        }

        try{
            dbHandler.openDataBase();
        }catch (SQLException sqle)
        {
            Log.e(TAG, sqle.getMessage());
        }

        RecyclerView recyclerView = (RecyclerView)findViewById(R.id.esp_menu);
        recyclerView.setHasFixedSize(true);

        RecyclerView.LayoutManager layoutManager = new GridLayoutManager(getApplicationContext(), 2);
        recyclerView.setLayoutManager(layoutManager);
        ArrayList<MenuEsp> menuList = dbHandler.Get_MenuList();

        MyAdapter adapter = new MyAdapter(getApplicationContext(), menuList);
        recyclerView.setAdapter(adapter);

    }
}

MyAdapter

  package com.example.mark.spanishapp;

    public class MenuEsp {

    public String getMenu() {
        return menu;
    }

    public void setMenu(String menu) {
        this.menu = menu;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getImageName() {
        return imageName;
    }

    public void setImageName(String imageName) {
        this.imageName = imageName;
    }

    private String menu;
    private String description;
    private String imageName;
}

Answer 1

对onBindViewHolder()课程中的Adapter方法进行更改

int id = this.context.getResources().getIdentifier(menuList.get(position).getImageName(), "drawable", this.context.getPackageName());
    holder.img.setImageResource(id);
holder.descirption.setText(menuList.get(position).getDescription());

Answer 2

在onBindViewholder中设置描述值即

holder.descirption.setText(menuList.get(position).getDescription());

下，从

更改代码

int id = this.context.getResources().getIdentifier(menuList.get(position).getImageName(), "drawable", this.context.getPackageName());
holder.img.setImageResource(id);

要

holder.img.setImageResource(Integer.parseInt(menuList.get(position).getImageName()));

RecyclerView不显示arraylist的所有属性

2 个答案: