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DBファイルに2列と3行を作成しました。次に、そのデータを 内に表示する必要がありますGridView。コードにエラーはありませんが、シミュレーターでエラーが発生します"Force close"。以下はコードです：

public class Grid_testActivity extends Activity {

    // We need some kind of Adapter to made the connection between ListView UI component and SQLite data set.
    //private ArrayAdapter<String> uGraduateListAdapter;    
 // We need this while we read the query using Cursor and pass data
    //private ArrayList<UndergraduateDetailsPojo> pojoArrayList;

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

     // Initialize UI components
       GridView grid = (GridView) findViewById(R.id.grid); 
       TextView txt= (TextView) findViewById(R.id.textView1);



 dbHelper db = new  dbHelper(this);

 Log.d("read data","reading");
 List<UndergraduateDetailsPojo> c=db.getAllContacts(); 

        grid.setAdapter((ListAdapter) txt);
    }}

DBHelper クラス:

public class dbHelper extends SQLiteOpenHelper {

    static String DB_PATH = "/data/data/com.apcog/databases/";

    //database name
    static String DB_NAME = "SAMPLE.sqlite";

    //define table name
    private static final String DB_TABLE="TEMP";



    //define table entries
    //private static final String ID="ID";
    //private static final String NAME="NAME";



    public dbHelper(Context context) 
    {
        super(context, DB_NAME, null, 1);
    }


public dbHelper(Context context, boolean copyDatabase) 
    {
this(context);
}

private boolean checkDataBaseExistence() 
        {

            // database to be verified
            SQLiteDatabase dbToBeVerified = null;

            try 
            {
                // get database path
                String dbPath = DB_PATH + DB_NAME;
                // try to open the database
                dbToBeVerified = SQLiteDatabase.openDatabase(dbPath, null,
                        SQLiteDatabase.OPEN_READONLY);

            } 
            catch (SQLiteException e) 
            {
                // do nothing since the database does not exist
            }

            // in case it exists, close it
            if (dbToBeVerified != null) 
            {
                // close DB
                dbToBeVerified.close();

            }

            // in case there is a DB entity, the DB exists
            return dbToBeVerified != null ? true : false;
        }


        public List<UndergraduateDetailsPojo> getAllContacts() {
            List<UndergraduateDetailsPojo> contactList = new ArrayList<UndergraduateDetailsPojo>();
            // Select All Query
            String selectQuery = "SELECT  * FROM " + DB_TABLE;

            SQLiteDatabase db = this.getWritableDatabase();
            Cursor cursor = db.rawQuery(selectQuery, null);

            // looping through all rows and adding to list
            if (cursor.moveToFirst()) {
                do {
                    UndergraduateDetailsPojo contact = new UndergraduateDetailsPojo();
                    contact.setID(cursor.getString(0));
                    contact.setName(cursor.getString(1));

                    // Adding contact to list
                    contactList.add(contact);
                } while (cursor.moveToNext());
            }

            // return contact list
            return contactList;
        }

        // Getting Count
        public int getCount() {
            String countQuery = "SELECT  * FROM " + DB_TABLE;
            SQLiteDatabase db = this.getReadableDatabase();
            Cursor cursor = db.rawQuery(countQuery, null);
            cursor.close();

            // return count
            return cursor.getCount();
        }


    }

別のクラス:

public class UndergraduateDetailsPojo {


    private String _ID;
    private String _NAME;

    public UndergraduateDetailsPojo()
    {

    }

    public UndergraduateDetailsPojo(String id,String name){

            this._ID=id;
            this._NAME = name;
    }

    //getting ID
    public String getID() {
        return this._ID;
    }

    //setting ID
    public void setID(String ID) {
        this._ID = ID;
    }

    //getting name 
    public String getName() {
        return this._NAME;  
    }

    //setting name
    public void setName(String NAME) {
        this._NAME = NAME;
    }


}

ログキャットは次のとおりです。

05-28 19:22:26.372: WARN/dalvikvm(3971): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971): FATAL EXCEPTION: main
05-28 19:22:26.382: ERROR/AndroidRuntime(3971): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.apcog/com.apcog.Grid_testActivity}: java.lang.ClassCastException: java.util.ArrayList
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at android.os.Looper.loop(Looper.java:123)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at android.app.ActivityThread.main(ActivityThread.java:4627)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at java.lang.reflect.Method.invokeNative(Native Method)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at java.lang.reflect.Method.invoke(Method.java:521)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at dalvik.system.NativeStart.main(Native Method)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971): Caused by: java.lang.ClassCastException: java.util.ArrayList
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at com.apcog.Grid_testActivity.onCreate(Grid_testActivity.java:44)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
05-28 19:22:26.382: ERROR/AndroidRuntime(3971):     ... 11 more
05-28 19:22:26.402: WARN/ActivityManager(70):   Force finishing activity com.apcog/.Grid_testActivity
05-28 19:22:26.432: INFO/UsageStats(70): Deleting usage file : usage-20120514
05-28 19:22:26.722: DEBUG/dalvikvm(210): GC_FOR_MALLOC freed 8714 objects / 471808 bytes in 2976ms
05-28 19:22:26.932: WARN/ActivityManager(70): Activity pause timeout for HistoryRecord{45076730 com.apcog/.Grid_testActivity}
05-28 19:22:28.172: INFO/Process(3971): Sending signal. PID: 3971 SIG: 9
05-28 19:22:28.202: WARN/InputManagerService(70): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@450aa150
05-28 19:22:28.222: INFO/ActivityManager(70): Process com.apcog (pid 3971) has died.
05-28 19:22:32.691: DEBUG/dalvikvm(195): GC_EXPLICIT freed 156 objects / 7480 bytes in 132ms
05-28 19:22:37.265: WARN/ActivityManager(70): Activity destroy timeout for HistoryRecord{45076730 com.apcog/.Grid_testActivity}

私はtry..catchを追加しました...テキストビューを取得していますが、データがありません...これはDBコンテンツを表示するための正しいアプローチですか...

試す {

   UndergraduateDetailsPojo(this,android.R.layout.simple_list_item_1,cursor,);

dbHelper db = 新しい dbHelper(this);

Log.d("読み取りデータ","読み取り"); リスト c=db.getAllContacts();

    grid.setAdapter((ListAdapter) txt);
}
   catch(Exception e)
   {


   }
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