Question

我是android编程的新手，我编写了一个程序，没有错误地构建它，但是当我运行它时，它会给我错误消息，不幸的是我的应用程序已停止工作。这是我的计划。

listview_main.xml

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

<EditText
    android:id="@+id/search"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:inputType="text"
    android:hint="@string/hint_message"/>

<ListView
    android:id="@+id/listview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_below="@+id/search"/>

</RelativeLayout>

listview_item.xml

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

<TextView
    android:id="@+id/universitylabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/universitylabel" />

<TextView
    android:id="@+id/university"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_toRightOf="@+id/universitylabel" />

<TextView
    android:id="@+id/Statelabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/universitylabel"
    android:text="@string/Statelabel" />

<TextView
    android:id="@+id/State"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/university"
    android:layout_toRightOf="@+id/Statelabel" />

<TextView
    android:id="@+id/vicechancellorlabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/Statelabel"
    android:text="@string/vicechancellorlabel" />

<TextView
    android:id="@+id/vicechancellor"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/State"
    android:layout_toRightOf="@+id/vicechancellorlabel" />

<TextView
    android:id="@+id/websitelabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/vicechancellorlabel"
    android:text="@string/websitelabel"/>

<TextView
    android:id="@+id/website"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/vicechancellor"
    android:layout_toRightOf="@+id/websitelabel" />


</RelativeLayout>

singleitemview.xml

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

<TextView
    android:id="@+id/universitylabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/universitylabel" />

<TextView
    android:id="@+id/university"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_toRightOf="@+id/universitylabel" />

<TextView
    android:id="@+id/Statelabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/universitylabel"
    android:text="@string/Statelabel" />

<TextView
    android:id="@+id/State"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/university"
    android:layout_toRightOf="@+id/Statelabel" />

<TextView
    android:id="@+id/vicechancellorlabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/Statelabel"
    android:text="@string/vicechancellorlabel" />

<TextView
    android:id="@+id/vicechancellor"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/State"
    android:layout_toRightOf="@+id/vicechancellorlabel" />

<TextView
    android:id="@+id/websitelabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/vicechancellorlabel"
    android:text="@string/websitelabel" />

<TextView
    android:id="@+id/website"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/vicechancellor"
    android:layout_toRightOf="@+id/websitelabel" />


</RelativeLayout>

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.spookyapp.findme"
android:versionCode="1"
android:versionName="1.0">

<uses-sdk
    android:minSdkVersion="14"
    android:targetSdkVersion="21" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity
        android:name="com.spookyapp.findme.MainActivity"
        android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name="com.spookyapp.findme.SingleItemView"
        android:label="@string/app_name">
    </activity>
</application>

</manifest>

MainActivity.java

   package com.spookyapp.findme;

   import android.app.Activity;
   import android.os.Bundle;
   import android.text.Editable;
   import android.text.TextWatcher;
   import android.view.Menu;
   import android.view.MenuItem;
   import android.widget.EditText;
   import android.widget.ListView;

   import java.util.ArrayList;
   import java.util.Locale;

 public class MainActivity extends Activity {

// Declare Variables
private ListView list;
private ListViewAdapter adapter;
private EditText editsearch;
private String[] university;
private String[] State;
private String[] vicechancellor;
private String[] website;

private final ArrayList<UniversityDetails> arraylist = new ArrayList<>();

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

    // Generate sample data
    university = new String[]{"Abubakar Tafawa Balewa University","Adeyemi University Education","Ahmadu Bello University","Alvan Ikoku University of Education","Bayero University","Federal University Gashua","Federal University of Education kano","Federal University of Education Zaria","Federal University of Health Science Otukpo","Federal University of Petroleum Resources Effurun","Federal University of Technology Akure","Federal University of Technology Minna","Federal University of Technology Owerri","Federal University Dutse","Federal University Dutsin-Ma","Federal University Kashere","Federal University Lafia","Federal University, Lokoja","Federal University, Ndufu-Alike","Federal University, Otuoke","Federal University, Oyo-Ekiti","Federal University, Wukari","Federal University,Birnin Kebbi","Federal University,Gusau","Michael Okpara Uni. of Agric., Umudike","Modibbo Adama University of Technology","National Open University of Nigeria","Nigeria Maritime University, Okerenkoko","Nigeria Police Academy Wudil","Nigerian Defence Academy","Nnamdi Azikiwe University, Awka","Obafemi Awolowo University,Ile-Ife","University of Abuja, Gwagwalada","University of Agriculture, Abeokuta","University of Agriculture, Makurdi","University of Benin","University of Calabar","University of Ibadan","University of Ilorin","University of Jos","University of Lagos","University of Maiduguri","University of Nigeria, Nsukka","University of Port-Harcourt","University of Uyo","Usumanu Danfodiyo University"
    };

    State = new String[]{" Bauchi"," Ondo"," Zaria","Imo","Kano","Yobe","Kano","Zaria","Benue","Delta","Ondo","Niger","Imo","Jigawa","Kastina","Gombe","Nasarawa","Kogi","Ebonyi","Bayelsa","Ekiti","Taraba","Kebbi","Zamfara","Abia","Adamawa","Lagos","Delta","Kano","Kaduna","Anambra","Oyo","Abuja","Ogun","Benue","Edo","Cross,Rivers","Oyo","Kwara","Plateau","Lagos","Borno","Enugu","Rivers" ,"Akwa,Ibom" ,"Sokoto"};

    vicechancellor=new String[]{"Prof. Saminu Ibrahim","Prof. Richard King","Prof.Ibrahim Garba","Prof.Sadiq Abubakar" ,"Prof.Abubakar Adamu Rasheed mni","Prof.Shehu Abdulrahman","Prof.Victor Awonusi" ,"Prof.Ibrahim Kolo","Prof. Martins Aghaji","Prof. Akaehomen O.A Ibhadode","Prof. Adebiyi Gregory Daramola","Prof. Musibau Adewunmi Akanji","Prof. Chigozie C. Asiabaka","Prof. Jibril Dahiru Amin","Prof. James O. I. Ayatse","Prof. Mohammed Kabiru Farouk","Prof. Ekanem Ikpi Braide","Prof. Abdulmumini Rafindadi","Prof. Oye Ibidapo-Obe","Prof. Mobolaji E. Aluko","Prof. Isaac Asuzu","Prof. Geoffrey Okogbaa","Prof.Lawal Suleiman Bilbis","Prof. Ben Chuks Okeke","Prof. Hillary Odo Edoga","Prof. B. H. Usman","Prof. Vincent A. Tenebe","Prof. Ongoebi Maureen O. Etebu","Prof. Munzali Jibril","Prof. S.O Okeniyi","Prof. Joseph E. Ehaneku","Prof. Bamitale Omole","Prof. Michael Umale Adikwu","Prof. O. B. Oyewole","Prof. Emmanuel I. Kucha","Prof. Faraday Orumwense","Prof. James Epoke","Prof. Isaac Folorunso Adewole","Prof. Abdulganiyu Ambali","Prof. Hayward B. Mafuyai","Prof. Rahman A. Bello","Prof. Ibrahim A. Njodi","Prof. Benjamin C. Ozumba","Prof. Joseph Ajienka" ,"Prof. Comfort M. Ekpo","Prof. Riskuwa A. Shehu "};

    website=new String[]{"http://www.atbu.edu.ng","","http://www.abu.edu.ng","","http://www.buk.edu.ng","www.fugashua.edu.ng","","","http://www.fupre.edu.ng","http://www.futa.edu.ng","http://www.futminna.edu.ng","http://www.futo.edu.ng","http://www.fud.edu.ng","http://www.fudutsinma.edu.ng","www.fukashere.edu.ng","http://www.fulafia.edu.ng","http://www.fulokoja.edu.ng","http://www.funai.edu.ng","http://www.fuotuoke.edu.ng","http://www.fuoye.edu.ng","http://www.fuwukari.edu.ng","www.fubk.edu.ng","www.fugus.edu.ng","http://www.moua.org","http://www.futy.edu.ng","http://www.nou.edu.ng","","www.npf.gov.ng","www.nda.edu.ng","http://www.unizik.edu.ng","http://www.oauife.edu.ng","http://www.uniabuja.edu.ng","http://www.unaab.edu.ng","http://www.uam.edu.ng","http://www.uniben.edu.ng","http://www.unical.edu.ng","http://www.ui.edu.ng","http://www.unilorin.edu.ng","http://www.unijos.edu.ng","http://www.unilag.edu.ng","http://www.unimaid.edu.ng","http://www.unn.edu.ng","http://www.uniport.edu.ng","http://www.uniuyo.edu.ng","http://www.udusok.edu.ng"};

    // Locate the ListView in listview_main.xml
    list = (ListView) findViewById(R.id.listview);

    for (int i = 0; i < university.length; i++)
    {
        UniversityDetails ud = new UniversityDetails(university[i], State[i],
                vicechancellor[i],website[i]);

        // Binds all strings into an array
        arraylist.add(ud);
    }

    // Pass results to ListViewAdapter Class
    adapter = new ListViewAdapter(this, arraylist);

    // Binds the Adapter to the ListView
    list.setAdapter(adapter);

    // Locate the EditText in listview_main.xml
    editsearch = (EditText) findViewById(R.id.search);

    // Capture Text in EditText
    editsearch.addTextChangedListener(new TextWatcher(){

        @Override
        public void afterTextChanged(Editable arg0) {
            // TODO Auto-generated method stub
            String text = editsearch.getText().toString().toLowerCase(Locale.getDefault());
            adapter.filter(text);
    }

        @Override
        public void beforeTextChanged(CharSequence arg0, int arg1,
                                      int arg2, int arg3) {
            // TODO Auto-generated method stub
        }

        @Override
        public void onTextChanged(CharSequence arg0, int arg1, int arg2,
                                  int arg3) {
            // TODO Auto-generated method stub
        }
    });

  }

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
  }
 }

ListViewAdapter.java

package com.spookyapp.findme;

import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import android.view.View.OnClickListener;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

/**
* Created by ${hudds} on ${21/02/2016}.
*/
class ListViewAdapter extends BaseAdapter {

// Declare Variables
private final Context mContext;
private final LayoutInflater inflater;
private List<UniversityDetails> universityDetailsList = null;
private final ArrayList<UniversityDetails> arraylist;

public ListViewAdapter(Context context, List<UniversityDetails> universityDetailsList) {
    mContext = context;
    this.universityDetailsList = universityDetailsList;
    inflater = LayoutInflater.from(mContext);
    this.arraylist = new ArrayList<>();
    this.arraylist.addAll(universityDetailsList);

}

public class ViewHolder {
    TextView university;
    TextView State;
    TextView vicechancellor;
    TextView website;
}

@Override
public int getCount(){
    return universityDetailsList.size();
}

@Override
public UniversityDetails getItem(int position){
    return universityDetailsList.get(position);
}

@Override
public long getItemId(int position){
    return position;
}

public View getView(final int position, View view, ViewGroup parent){
    final ViewHolder holder;
    if (view == null){

        holder = new ViewHolder();
        view = inflater.inflate(R.layout.listview_item, null);

        // Locate the TextViews in listview_item.xml
        holder.university = (TextView) view.findViewById(R.id.university);
        holder.State = (TextView) view.findViewById(R.id.State);
        holder.vicechancellor = (TextView) view.findViewById(R.id.vicechancellor);
        holder.website = (TextView) view.findViewById(R.id.website);
        view.setTag(holder);
    }else {
        holder = (ViewHolder) view.getTag();
    }

    // Set the results into TextViews
    holder.university.setText(universityDetailsList.get(position).getUniversity());
    holder.State.setText(universityDetailsList.get(position).getState());
    holder.vicechancellor.setText(universityDetailsList.get(position).getVicechancellor());
    holder.website.setText(universityDetailsList.get(position).getWebsite());

    // Listen for ListView Item Click
    view.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0){
            // Send single item click data to SingleItemView Class
            Intent intent = new Intent(mContext, SingleItemView.class);
            // Pass all data university
            intent.putExtra("university",(universityDetailsList.get(position).getUniversity()));
            // Pass all data State
            intent.putExtra("State",(universityDetailsList.get(position).getState()));
            // Pass all data vicechancellor
            intent.putExtra("vicechancellor",(universityDetailsList.get(position).getVicechancellor()));
            // Pass all data website
            intent.putExtra ("website",(universityDetailsList.get(position).getWebsite()));
            // Pass all data flag
            // Start SingleItemView Class
            mContext.startActivity(intent);
        }


    });

    return view;
}

// Filter Class
public void filter(String charText) {
    charText = charText.toLowerCase(Locale.getDefault());
    universityDetailsList.clear();
    if (charText.length() == 0) {
        universityDetailsList.addAll(arraylist);
    } else {

        for (UniversityDetails ud : arraylist) {
            if (ud.getState().toLowerCase(Locale.getDefault()).contains(charText)) {
                universityDetailsList.add(ud);
            }
        }
    }
    notifyDataSetChanged();

   }

  }

SingleViewItem.java

package com.spookyapp.findme;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

/**
* Created by hudds on 21/02/2016.
*/
 public class SingleItemView extends Activity {

// Declare Variables
private TextView txtuniversity;
private TextView txtState;
private TextView txtvicechancellor;
private TextView txtwebsite;
private String university;
private String State;
private String vicechancellor;
private String website;

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

    // Retrieve data from MainActivity on item click event
    Intent i = getIntent();
    // Get the results of university
    university = i.getStringExtra("university");
    // Get the results of State
    State = i.getStringExtra("State");
    // Get the results of vice chancellor
    vicechancellor = i.getStringExtra("vicechancellor");
    // Get the results of website
    website = i.getStringExtra("website");

    // Locate the TextViews in singleitemview.xml
    txtuniversity = (TextView) findViewById(R.id.university);
    txtState = (TextView) findViewById(R.id.State);
    txtvicechancellor = (TextView) findViewById(R.id.vicechancellor);
    txtwebsite = (TextView) findViewById(R.id.website);

    // Load the results into the TextViews
    txtuniversity.setText(university);
    txtState.setText(State);
    txtvicechancellor.setText(vicechancellor);
    txtwebsite.setText(website);

  }
 }

UniversityDetail.java

package com.spookyapp.findme;

/**
* Created by hudds on 21/02/2016.
*/
public class UniversityDetails {

private final String university;
private final String State;
private final String vicechancellor;
private final String website;

public UniversityDetails(String university, String State, String vicechancellor, String website) {
    this.university = university;
    this.State = State;
    this.vicechancellor = vicechancellor;
    this.website = website;
}
public String getUniversity() {
    return this.university;
}
public String getState(){
    return this.State;
}

public String getVicechancellor(){
    return this.vicechancellor;
}

public String getWebsite(){
    return this.website;
  }
 }

log cat

 2-22 09:24:21.254 3618-3618/? I/art: Not late-enabling -Xcheck:jni (already on)
02-22 09:24:25.861 3618-3618/com.spookyapp.findme D/AndroidRuntime: Shutting down VM
02-22 09:24:25.954 3618-3618/com.spookyapp.findme E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.spookyapp.findme, PID: 3618
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.spookyapp.findme/com.spookyapp.findme.MainActivity}: java.lang.ArrayIndexOutOfBoundsException: length=45; index=45
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.ArrayIndexOutOfBoundsException: length=45; index=45
at com.spookyapp.findme.MainActivity.onCreate(MainActivity.java:48)
at android.app.Activity.performCreate(Activity.java:5937)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
at android.app.ActivityThread.access$800(ActivityThread.java:144) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5221) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 
02-22 09:24:31.691 3618-3618/com.spookyapp.findme I/Process: Sending signal. PID: 3618 SIG: 9

Answer 1

堆栈跟踪表示错误位于MainActivity第45行。我怀疑它会指向：

for (int i = 0; i < university.length; i++)
{
    UniversityDetails ud = new UniversityDetails(university[i], State[i],
            vicechancellor[i],website[i]);

    // Binds all strings into an array
    arraylist.add(ud);
}

university，State，vicechancellor和website数组可能不包含相同数量的项目。导致你的阵列超出范围。

Answer 2

你的logcat说你有一个arry，它只有一个元素，所以它在第45行出现了ArrayIndexOutOfBoundsException。

所以，在日志中打印所有数组长度，它将显示您在哪个数组中元素较少。

Answer 3

由于java.lang.ArrayIndexOutOfBoundsException而发生这种情况。

如果您仔细注意，变量＆＃34;网站＆＃34;有45个元素，而其他变量（＆＃34;大学＆＃34;，＆＃34;州＆＃34;和＃34;副校长＆＃34;）有46个元素。所以在你的for循环中＆＃34; MainActivity＆＃34; class，当您使用以下代码创建对象时，它会给出此异常。

UniversityDetails ud = new UniversityDetails(university[i], State[i],
            vicechancellor[i],website[i]);

要解决此问题，只需在您的＆＃34;网站中添加一个元素＆＃34;变量

不幸的是发现我的应用已停止工作

3 个答案: