Question

我正在尝试阅读一个简单的文本文件，该文件是一个单词和数字列表，并将其显示在Android应用程序的可滚动列表中。

我在代码中指定的任意字符串数组没有任何问题，例如字符串数组“myStringArray”或“alphabts”。但是，当我尝试读取文本文件并在其中一个列表中使用它时，我的应用程序崩溃了。

这可能是文本文件的格式错误，或者我应该将文件放在不同的位置并从那里引用它。

感谢您的帮助！

Java代码：

package com.coderzheaven.pack;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;



public class AlphabetListDemo extends Activity {
    //String of alphabets //
    String[] myStringArray = {"Calories","Protein","Carbs"};
    String[] alphabts = {"1","2","3"};
    ListView L1, L2;
    myAdapter myadp;
    myAdapter2 myadp2;
    String prod_arr[] = {};



    InputStream is = this.getResources().openRawResource(
            R.drawable.filetoread);

    DataInputStream myDIS = new DataInputStream(is);
    ArrayList<String> list = new ArrayList<String>();

    final String[] bob = list.toArray(new String[list.size()]);
    //final String[] bob = alphabts; Here if I comment out the four 
    //lines above and and use the alphabts string it works fine

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);




    L1 = (ListView)findViewById(R.id.list1);
    L2 = (ListView)findViewById(R.id.list2);

    myadp = new myAdapter(this,alphabts);
    L2.setAdapter(myadp);

    L2.setOnItemClickListener(new OnItemClickListener(){
        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, 
                long arg3) {
            setProducts(arg2);

        }  
    });

}

public void setProducts(int number){
    prod_arr = new String[25];
    // adding some dummy data //
    for(int i = 0; i < 25 ; i++){
        prod_arr[i] = bob[number];
    }
    //setting the adapter in listview //
     myadp2 = new myAdapter2(AlphabetListDemo.this,prod_arr);
     L1.setAdapter(myadp2);    
}

class myAdapter extends ArrayAdapter<String>
{
   TextView label;     
   ImageView image; 
   View row;
   public myAdapter(Context context,String[] arr)
   {
        super(context, android.R.layout.simple_list_item_1, arr); 
   }        

   public View getView(final int position, View convertView, ViewGroup parent)
    {
           try{
                LayoutInflater inflater=getLayoutInflater();
                row = inflater.inflate(R.layout.lv_rows, parent, false);
                label = (TextView)row.findViewById(R.id.item_title);
                label.setText(myStringArray[position]);
                label.setTextColor(Color.YELLOW);                   
           }catch(Exception e){

           }                    
        return row;
    }
}
// adapter for second list.....
class myAdapter2 extends ArrayAdapter<String>
{
   TextView label;     
   ImageView image; 
   View row;
   public myAdapter2(Context context,String[] arr)
   {
        super(context, android.R.layout.simple_list_item_1, arr); 
   }        

   public View getView(final int position, View convertView, ViewGroup parent)
    {
           try{
                LayoutInflater inflater=getLayoutInflater();
                row = inflater.inflate(R.layout.lv_rows, parent, false);
                label = (TextView)row.findViewById(R.id.item_title);
                label.setText(prod_arr[position]);
                label.setTextColor(Color.WHITE);                    
           }catch(Exception e){

           }                    
        return row;
    }
}
}

main.xml中：

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

<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" 
    android:layout_marginLeft="5dp"
    android:layout_marginRight="5dp"
    android:layout_marginTop="5dp"
    android:orientation="horizontal">

    <!--  this list contains products -->

     <ListView
         android:id="@+id/list1"
         android:layout_width="192dp"
         android:layout_height="wrap_content"
         android:layout_marginBottom="5dip"
         android:layout_marginLeft="5dip"
         android:layout_marginRight="5dip"
         android:layout_marginTop="5dip"
         android:cacheColorHint="#00000000"
         android:dividerHeight="1px"
         android:drawSelectorOnTop="false"
         android:fadingEdge="vertical"
         android:padding="0dip"
         android:scrollbars="none"
         android:smoothScrollbar="true"
         android:soundEffectsEnabled="true" />

      <ListView
        android:id="@+id/list2"
        android:layout_weight="4"
        android:cacheColorHint="#00000000"
        android:scrollbars="none"
        android:fadingEdge="vertical"   
        android:soundEffectsEnabled="true"
        android:dividerHeight="1px"
        android:padding="0dip"
        android:smoothScrollbar="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:drawSelectorOnTop="false"
        android:layout_marginTop="5dip"
        android:layout_marginLeft="5dip"
        android:layout_marginRight="5dip"
        android:layout_marginBottom="5dip" />

</LinearLayout>

lv_rows.xml与main.xml位于同一位置

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="7dp"
    >
        <TextView
            android:id="@+id/item_title"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:padding="2dp"
            android:text="Main Item"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:textSize="14dp"
            android:textStyle="normal" />

</RelativeLayout>

Answer 1

遇到问题你忘记了+号。

InputStream is = this.getResources().openRawResource(
            +R.drawable.filetoread);

点击Android openRawResource() not working for a drawable

Answer 2

为什么要从drawable文件夹中读取文本文件？正确的方法是将此文件放入项目的assets文件夹中。如果您使用Android Studio，请右键单击您的项目 - ＆gt;新 - ＆gt;文件夹 - ＆gt;资产文件夹。

然后将文件移入其中，只需使用AssetManager打开它：

AssetManager assetsManager = getApplicationContext().getAssets(); // or getBaseContext()
    try{
        InputStream inputStream = assetsManager.open("yourfile.txt");
        // read inputStream ...
        // and do not forget to close it here when your read is completed!!!
    }catch (IOException ex){
        ex.printStackTrace();
    }

适用于Android的Java - 在列表中读取文本文件和显示数据

2 个答案: