訪問列表時獲取ArrayIndexOutOfBoundsException

Question

我正在嘗試調用一個調用列表的類。 從我的原始列表項中選擇時。 列表中的列表差不多如此，而且我從跳出錯誤中得到了一個數組。 Logcat顯示的錯誤是ArrayIndexOutOfBoundsException。

我最初只是希望我的列表值可以從另一個列表中調用更多的值。 我知道可能有一種更簡單的方法來執行此操作，但是我還沒有偶然發現它。 這個類的BarBars是我正在嘗試的27個類中的1個。

package com.cerealBarApps;

import android.app.ListActivity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class HelloListViewActivity extends ListActivity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle cerealBarApps) {
        super.onCreate(cerealBarApps);

        final String[] DepartmentNames = { "a",
                "b", "c",
                "d", "e",
                "f",
                "g", "h",
                "i", "j",
                "k", "l", "m", "n",
                "o",
                "o",
                "q", "r",
                "s" };

        String[] departments = getResources().getStringArray(
                R.array.departments_array);
        setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item,
                departments));
        ListView lv = getListView();
        lv.setTextFilterEnabled(true);

        lv.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                String openDepartment = DepartmentNames[position];

                try {
                    Class selected = Class.forName("com.cerealBarApps"
                            + openDepartment);
                    Intent selectedIntent = new Intent(/*this, selected*/);
                    startActivity(selectedIntent);
                } catch (ClassNotFoundException e) {
                    e.printStackTrace();
                }
            }
        });
    };
};

我要調用的類是AboutCerealBarApps

package com.cerealBarApps;

import android.app.Activity;
import android.app.ListActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.TextView;
import android.widget.Toast;

public class AboutCerealBarApps extends ListActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.list_item);

        String[] cerealBarApps = getResources().getStringArray(
                R.array.cerealBarApps_array);

        setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item,
                cerealBarApps));
        ListView lv = getListView();
        lv.setTextFilterEnabled(true);



        lv.setOnItemClickListener(new OnItemClickListener(){

    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {
        Toast.makeText(getApplicationContext(), ((TextView) view).getText(),
                Toast.LENGTH_SHORT).show();
    }
    });

};
};

我的String.xml是我存儲數組值的地方。

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="hello">Hello World, HelloListViewActivity!</string>
    <string name="app_name">HelloListView</string>

    <string-array name="departments_array">
        <item>B</item>
        <item>A(AFROTC)</item>
        <item>O</item>
        <item>H</item>
        <item>C</item>
        <item>E</item>
        <item>M</item>
        <item>P</item>
        <item>E</item>
        <item>M</item>
        <item>T</item>
        <item>P</item>
        <item>B</item>
        <item>H</item>
        <item>E</item>
        <item>R</item>
        <item>A</item>
        <item>M</item>
        <item>A</item>
        <item>C</item>
        <item>I</item>
        <item>I</item>
        <item>M</item>
        <item>About Cereal Bar Apps</item>
    </string-array>


    <string-array name="cerealBarApps_array">
        <item>Ex</item>
        <item>xi</item>
        <item>An App Within an App</item>
        <item>BADUMM!!!!!</item>
        <item>In Your Soup</item>
        <item>GGWP</item>
         <item>Ebenezer Ackon</item>
        <item>Ernest Grzybowski</item>
        <item>An App Within an App</item>
        <item>BADUMM!!!!!</item>
        <item>In Your Soup</item>
        <item>GGWP</item>
         <item>Ex</item>
        <item>xki</item>
        <item>An App Within an App</item>
        <item>BADUMM!!!!!</item>
        <item>In Your Soup</item>
        <item>GGWP</item>
         <item>Exn</item>
        <item>Exi</item>
        <item>An App Within an App</item>
        <item>BADUMM!!!!!</item>
        <item>In Your Soup</item>
        <item>GGWP</item>
            </string-array>

</resources>

我的Logcat

12-17 12:48:26.072: E/AndroidRuntime(229): Uncaught handler: thread main exiting due to uncaught exception
12-17 12:48:26.082: E/AndroidRuntime(229): java.lang.ArrayIndexOutOfBoundsException
12-17 12:48:26.082: E/AndroidRuntime(229):  at com.cerealBarApps.HelloListViewActivity$1.onItemClick(HelloListViewActivity.java:43)
12-17 12:48:26.082: E/AndroidRuntime(229):  at android.widget.AdapterView.performItemClick(AdapterView.java:284)
12-17 12:48:26.082: E/AndroidRuntime(229):  at android.widget.ListView.performItemClick(ListView.java:3285)
12-17 12:48:26.082: E/AndroidRuntime(229):  at android.widget.AbsListView$PerformClick.run(AbsListView.java:1640)
12-17 12:48:26.082: E/AndroidRuntime(229):  at android.os.Handler.handleCallback(Handler.java:587)
12-17 12:48:26.082: E/AndroidRuntime(229):  at android.os.Handler.dispatchMessage(Handler.java:92)
12-17 12:48:26.082: E/AndroidRuntime(229):  at android.os.Looper.loop(Looper.java:123)
12-17 12:48:26.082: E/AndroidRuntime(229):  at android.app.ActivityThread.main(ActivityThread.java:4363)
12-17 12:48:26.082: E/AndroidRuntime(229):  at java.lang.reflect.Method.invokeNative(Native Method)
12-17 12:48:26.082: E/AndroidRuntime(229):  at java.lang.reflect.Method.invoke(Method.java:521)
12-17 12:48:26.082: E/AndroidRuntime(229):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
12-17 12:48:26.082: E/AndroidRuntime(229):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
12-17 12:48:26.082: E/AndroidRuntime(229):  at dalvik.system.NativeStart.main(Native Method)
12-17 12:48:26.094: I/dalvikvm(229): threadid=7: reacting to signal 3
12-17 12:48:26.094: E/dalvikvm(229): Unable to open stack trace file '/data/anr/traces.txt': Permission denied

這是第43-46行上的代碼lv.setOnItemClickListener（new OnItemClickListener（）{public void onItemClick（AdapterView parent，View view，int position，long id）{String openDepartment = DepartmentNames [position];

Answer 1

當您將索引傳遞給不存在的數組時，將發生ArrayIndexOutOfBounds異常。

如果我有一個數組{“ One”，“ Two”，“ 3”}，則有效索引將為0、1和2。

如果我有一個循環或方法函數試圖像這樣訪問數組：

String string = myArray[-1] //ArrayIndexOutOfBoundsException
String string = myArray[0] //string="One"
String string = myArray[1] //string="two"
String string = myArray[2] //string="three"
String string = myArray[3] //ArrayIndexOutOfBoundsException

任何無效的索引都將通過此異常。