Android 添加更多保存结果到记事本示例

Question

我试图通过操作 Google 已经通过示例编写的代码来学习 Android 平台。我一直在编辑记事本示例，并向注释本身添加了一些新项目，现在正在尝试允许其保存。直到它尝试将值输入数据库进行保存之前，它似乎没有问题，但作为新手，我很难确定位置。下面我决定从 NoteEditor.java 文件复制我的代码：

public class NoteEditor extends Activity {
private static final String TAG = "NoteEditor";

/**
 * Standard projection for the interesting columns of a normal note.
 */
private static final String[] PROJECTION = new String[] {
    NoteColumns._ID, // 0
    NoteColumns.NOTE, // 1
    NoteColumns.TITLE, // 2
    //NoteColumns.DATE, //3
    //NoteColumns.TIME, //4
    //NoteColumns.CHOICE, //5
};
/** The index of the note column */
private static final int COLUMN_INDEX_NOTE = 1;
/** The index of the title column */
private static final int COLUMN_INDEX_TITLE = 2;

// This is our state data that is stored when freezing.
private static final String ORIGINAL_CONTENT = "origContent";

// The different distinct states the activity can be run in.
private static final int STATE_EDIT = 0;
private static final int STATE_INSERT = 1;

private int mState;
private Uri mUri;
private Cursor mCursor;
private DatePicker mPicker;
private TimePicker mTime;
private Spinner mChoice;
private EditText mText;
private String mOriginalContent;

/**
 * A custom EditText that draws lines between each line of text that is displayed.
 */
public static class LinedEditText extends EditText {
    private Rect mRect;
    private Paint mPaint;

    // we need this constructor for LayoutInflater
    public LinedEditText(Context context, AttributeSet attrs) {
        super(context, attrs);

        mRect = new Rect();
        mPaint = new Paint();
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setColor(0x800000FF);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int count = getLineCount();
        Rect r = mRect;
        Paint paint = mPaint;

        for (int i = 0; i < count; i++) {
            int baseline = getLineBounds(i, r);

            canvas.drawLine(r.left, baseline + 1, r.right, baseline + 1, paint);
        }

        super.onDraw(canvas);
    }
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    final Intent intent = getIntent();




    // Do some setup based on the action being performed.
    final String action = intent.getAction();
    if (Intent.ACTION_EDIT.equals(action)) {
        // Requested to edit: set that state, and the data being edited.
        mState = STATE_EDIT;
        mUri = intent.getData();
    } else if (Intent.ACTION_INSERT.equals(action)) {
        // Requested to insert: set that state, and create a new entry
        // in the container.
        mState = STATE_INSERT;
        mUri = getContentResolver().insert(intent.getData(), null);

        // If we were unable to create a new note, then just finish
        // this activity.  A RESULT_CANCELED will be sent back to the
        // original activity if they requested a result.
        if (mUri == null) {
            Log.e(TAG, "Failed to insert new project into " + getIntent().getData());
            finish();
            return;
        }

        // The new entry was created, so assume all will end well and
        // set the result to be returned.
        setResult(RESULT_OK, (new Intent()).setAction(mUri.toString()));

    } else {
        // Whoops, unknown action!  Bail.
        Log.e(TAG, "Unknown action, exiting");
        finish();
        return;
    }

    // Set the layout for this activity.  You can find it in res/layout/note_editor.xml
    setContentView(R.layout.note_editor);

    Spinner spinner = (Spinner) findViewById(R.id.spinner1);
    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.spinnerss, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);

    // The text view for our note, identified by its ID in the XML file.
    mText = (EditText) findViewById(R.id.note);
    mTime = (TimePicker) findViewById(R.id.timePicker1);
    mPicker = (DatePicker) findViewById(R.id.datePicker1);
    mChoice = (Spinner) findViewById(R.id.spinner1);

    // Get the note!
    mCursor = managedQuery(mUri, PROJECTION, null, null, null);

    // If an instance of this activity had previously stopped, we can
    // get the original text it started with.
    if (savedInstanceState != null) {
        mOriginalContent = savedInstanceState.getString(ORIGINAL_CONTENT);
    }
}

@Override
protected void onResume() {
    super.onResume();
    // If we didn't have any trouble retrieving the data, it is now
    // time to get at the stuff.
    if (mCursor != null) {
        // Requery in case something changed while paused (such as the title)
        mCursor.requery();
        // Make sure we are at the one and only row in the cursor.
        mCursor.moveToFirst();

        // Modify our overall title depending on the mode we are running in.
        if (mState == STATE_EDIT) {
            // Set the title of the Activity to include the note title
            String title = mCursor.getString(COLUMN_INDEX_TITLE);
            Resources res = getResources();
            String text = String.format(res.getString(R.string.title_edit), title);
            setTitle(text);
        } else if (mState == STATE_INSERT) {
            setTitle(getText(R.string.title_create));
        }

        // This is a little tricky: we may be resumed after previously being
        // paused/stopped.  We want to put the new text in the text view,
        // but leave the user where they were (retain the cursor position
        // etc).  This version of setText does that for us.
        String note = mCursor.getString(COLUMN_INDEX_NOTE);
        mText.setTextKeepState(note);

        // If we hadn't previously retrieved the original text, do so
        // now.  This allows the user to revert their changes.
        if (mOriginalContent == null) {
            mOriginalContent = note;
        }

    } else {
        setTitle(getText(R.string.error_title));
        mText.setText(getText(R.string.error_message));
    }
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    // Save away the original text, so we still have it if the activity
    // needs to be killed while paused.
    outState.putString(ORIGINAL_CONTENT, mOriginalContent);
}

@Override
protected void onPause() {
    super.onPause();
    // The user is going somewhere, so make sure changes are saved

    String text = mText.getText().toString();
    int length = text.length();

    // If this activity is finished, and there is no text, then we
    // simply delete the note entry.
    // Note that we do this both for editing and inserting...  it
    // would be reasonable to only do it when inserting.
    if (isFinishing() && (length == 0) && mCursor != null) {
        setResult(RESULT_CANCELED);
        deleteNote();
    } else {
        saveNote();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate menu from XML resource
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.editor_options_menu, menu);

    // Append to the
    // menu items for any other activities that can do stuff with it
    // as well.  This does a query on the system for any activities that
    // implement the ALTERNATIVE_ACTION for our data, adding a menu item
    // for each one that is found.
    Intent intent = new Intent(null, getIntent().getData());
    intent.addCategory(Intent.CATEGORY_ALTERNATIVE);
    menu.addIntentOptions(Menu.CATEGORY_ALTERNATIVE, 0, 0,
            new ComponentName(this, NoteEditor.class), null, intent, 0, null);

    return super.onCreateOptionsMenu(menu);
}



@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    if (mState == STATE_EDIT) {
        menu.setGroupVisible(R.id.menu_group_edit, true);
        menu.setGroupVisible(R.id.menu_group_insert, false);

        // Check if note has changed and enable/disable the revert option
        String savedNote = mCursor.getString(COLUMN_INDEX_NOTE);
        String currentNote = mText.getText().toString();
        if (savedNote.equals(currentNote)) {
            menu.findItem(R.id.menu_revert).setEnabled(false);
        } else {
            menu.findItem(R.id.menu_revert).setEnabled(true);
        }
    } else {
        menu.setGroupVisible(R.id.menu_group_edit, false);
        menu.setGroupVisible(R.id.menu_group_insert, true);
    }
    return super.onPrepareOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle all of the possible menu actions.
    switch (item.getItemId()) {
    case R.id.menu_save:
        saveNote();
        finish();
        break;
    case R.id.menu_delete:
        deleteNote();
        finish();
        break;
    case R.id.menu_revert:
    case R.id.menu_discard:
        cancelNote();
        break;
    }
    return super.onOptionsItemSelected(item);

}

private final void saveNote() {
    // Make sure their current
    // changes are safely saved away in the provider.  We don't need
    // to do this if only editing.
    if (mCursor != null) {
        // Get out updates into the provider.
        ContentValues values = new ContentValues();

        // Bump the modification time to now.
        values.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());

        String text = mText.getText().toString();
        //String date = mPicker.toString();
        //String time = mTime.toString();
        String choice = mChoice.toString();
        int length = text.length();
        // If we are creating a new note, then we want to also create
        // an initial title for it.
        if (mState == STATE_INSERT) {
            if (length == 0) {
                Toast.makeText(this, R.string.nothing_to_save, Toast.LENGTH_SHORT).show();
                return;
            }
            String title = text.substring(0, Math.min(30, length));
            if (length > 30) {
                int lastSpace = title.lastIndexOf(' ');
                if (lastSpace > 0) {
                    title = title.substring(0, lastSpace);
                }
            }
            values.put(NoteColumns.TITLE, title);
        }

        // Write our text back into the provider.
        values.put(NoteColumns.NOTE, text);
        //values.put(NoteColumns.DATE, date);
        //values.put(NoteColumns.TIME, time);
        //values.put(NoteColumns.CHOICE, choice);

        // Commit all of our changes to persistent storage. When the update completes
        // the content provider will notify the cursor of the change, which will
        // cause the UI to be updated.
        try {
            getContentResolver().update(mUri, values, null, null);
        } catch (NullPointerException e) {
            Log.e(TAG, e.getMessage());
        }

    }
}

/**
 * Take care of canceling work on a note.  Deletes the note if we
 * had created it, otherwise reverts to the original text.
 */
private final void cancelNote() {
    if (mCursor != null) {
        if (mState == STATE_EDIT) {
            // Put the original note text back into the database
            mCursor.close();
            mCursor = null;
            ContentValues values = new ContentValues();
            values.put(NoteColumns.NOTE, mOriginalContent);
            getContentResolver().update(mUri, values, null, null);
        } else if (mState == STATE_INSERT) {
            // We inserted an empty note, make sure to delete it
            deleteNote();
        }
    }
    setResult(RESULT_CANCELED);
    finish();
}

/**
 * Take care of deleting a note.  Simply deletes the entry.
 */
private final void deleteNote() {
    if (mCursor != null) {
        mCursor.close();
        mCursor = null;
        getContentResolver().delete(mUri, null, null);
        mText.setText("");
    }
}
}

希望我没有从文件中包含太多内容，我删除了顶部的导入和版权以节省更多空间，但不确定需要什么来正确分析问题并帮助我更好地解释它。

谢谢 迈克尔

DDMS：

07-18 10:27:49.757: ERROR/Database(25136): Error updating   choice=android.widget.Spinner@40551ea0 note=Blah burger
07-18 10:27:49.757: ERROR/Database(25136): T
07-18 10:27:49.757: ERROR/Database(25136):  modified=1311002869768 using UPDATE notes SET choice=?, note=?, modified=? WHERE _id=1
07-18 10:27:49.817: ERROR/AndroidRuntime(25136): FATAL EXCEPTION: main
07-18 10:27:49.817: ERROR/AndroidRuntime(25136): java.lang.RuntimeException: Unable to   pause activity {com.example.android.notepad/com.example.android.notepad.NoteEditor}:   android.database.sqlite.SQLiteException: no such column: choice: , while compiling: UPDATE   notes SET choice=?, note=?, modified=? WHERE _id=1
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.app.ActivityThread.performPauseActivity(ActivityThread.java:2731)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.app.ActivityThread.performPauseActivity(ActivityThread.java:2678)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.app.ActivityThread.handlePauseActivity(ActivityThread.java:2651)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.app.ActivityThread.access$1700(ActivityThread.java:132)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1049)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.os.Looper.loop(Looper.java:143)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.app.ActivityThread.main(ActivityThread.java:4263)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at java.lang.reflect.Method.invokeNative(Native Method)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at java.lang.reflect.Method.invoke(Method.java:507)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at dalvik.system.NativeStart.main(Native Method)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136): Caused by: android.database.sqlite.SQLiteException: no such column: choice: , while compiling: UPDATE notes SET choice=?, note=?, modified=? WHERE _id=1
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.database.sqlite.SQLiteCompiledSql.compile(SQLiteCompiledSql.java:92)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.database.sqlite.SQLiteCompiledSql.<init>(SQLiteCompiledSql.java:65)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:83)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:41)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.database.sqlite.SQLiteDatabase.compileStatement(SQLiteDatabase.java:1231)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.database.sqlite.SQLiteDatabase.updateWithOnConflict(SQLiteDatabase.java:1813)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.database.sqlite.SQLiteDatabase.update(SQLiteDatabase.java:1763)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at com.example.android.notepad.NotePadProvider.update(NotePadProvider.java:235)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.content.ContentProvider$Transport.update(ContentProvider.java:240)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.content.ContentResolver.update(ContentResolver.java:726)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at com.example.android.notepad.NoteEditor.saveNote(NoteEditor.java:357)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at com.example.android.notepad.NoteEditor.onPause(NoteEditor.java:247)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at android.app.Activity.performPause(Activity.java:3988)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at   android.app.Instrumentation.callActivityOnPause(Instrumentation.java:1313)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     at       android.app.ActivityThread.performPauseActivity(ActivityThread.java:2708)
07-18 10:27:49.817: ERROR/AndroidRuntime(25136):     ... 12 more

NotepadProvider.java：

public class NotePadProvider extends ContentProvider {

private static final String TAG = "NotePadProvider";

private static final String DATABASE_NAME = "notepad.db";
private static final int DATABASE_VERSION = 2;
private static final String NOTES_TABLE_NAME = "notes";

private static HashMap<String, String> sNotesProjectionMap;
private static HashMap<String, String> sLiveFolderProjectionMap;

private static final int NOTES = 1;
private static final int NOTE_ID = 2;
private static final int LIVE_FOLDER_NOTES = 3;

private static final UriMatcher sUriMatcher;

/**
 * This class helps open, create, and upgrade the database file.
 */
private static class DatabaseHelper extends SQLiteOpenHelper {

    DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("CREATE TABLE " + NOTES_TABLE_NAME + " ("
                + NoteColumns._ID + " INTEGER PRIMARY KEY,"
                + NoteColumns.TITLE + " TEXT,"
                + NoteColumns.NOTE + " TEXT,"
                + NoteColumns.TIME + " TEXT,"
                + NoteColumns.DATE + " TEXT,"
                + NoteColumns.CHOICE + " TEXT,"
                + NoteColumns.CREATED_DATE + " INTEGER,"
                + NoteColumns.MODIFIED_DATE + " INTEGER"
                + ");");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                + newVersion + ", which will destroy all old data");
        db.execSQL("DROP TABLE IF EXISTS notes");
        onCreate(db);
    }
}

private DatabaseHelper mOpenHelper;

@Override
public boolean onCreate() {
    mOpenHelper = new DatabaseHelper(getContext());
    return true;
}

@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
        String sortOrder) {
    SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
    qb.setTables(NOTES_TABLE_NAME);

    switch (sUriMatcher.match(uri)) {
    case NOTES:
        qb.setProjectionMap(sNotesProjectionMap);
        break;

    case NOTE_ID:
        qb.setProjectionMap(sNotesProjectionMap);
        qb.appendWhere(NoteColumns._ID + "=" + uri.getPathSegments().get(1));
        break;

    case LIVE_FOLDER_NOTES:
        qb.setProjectionMap(sLiveFolderProjectionMap);
        break;

    default:
        throw new IllegalArgumentException("Unknown URI " + uri);
    }

    // If no sort order is specified use the default
    String orderBy;
    if (TextUtils.isEmpty(sortOrder)) {
        orderBy = NoteColumns.DEFAULT_SORT_ORDER;
    } else {
        orderBy = sortOrder;
    }

    // Get the database and run the query
    SQLiteDatabase db = mOpenHelper.getReadableDatabase();
    Cursor c = qb.query(db, projection, selection, selectionArgs, null, null, orderBy);

    // Tell the cursor what uri to watch, so it knows when its source data changes
    c.setNotificationUri(getContext().getContentResolver(), uri);
    return c;
}

@Override
public String getType(Uri uri) {
    switch (sUriMatcher.match(uri)) {
    case NOTES:
    case LIVE_FOLDER_NOTES:
        return NoteColumns.CONTENT_TYPE;

    case NOTE_ID:
        return NoteColumns.CONTENT_ITEM_TYPE;

    default:
        throw new IllegalArgumentException("Unknown URI " + uri);
    }
}

@Override
public Uri insert(Uri uri, ContentValues initialValues) {
    // Validate the requested uri
    if (sUriMatcher.match(uri) != NOTES) {
        throw new IllegalArgumentException("Unknown URI " + uri);
    }

    ContentValues values;
    if (initialValues != null) {
        values = new ContentValues(initialValues);
    } else {
        values = new ContentValues();
    }

    Long now = Long.valueOf(System.currentTimeMillis());

    // Make sure that the fields are all set
    if (values.containsKey(NoteColumns.CREATED_DATE) == false) {
        values.put(NoteColumns.CREATED_DATE, now);
    }

    if (values.containsKey(NoteColumns.MODIFIED_DATE) == false) {
        values.put(NoteColumns.MODIFIED_DATE, now);
    }

    if (values.containsKey(NoteColumns.TITLE) == false) {
        Resources r = Resources.getSystem();
        values.put(NoteColumns.TITLE, r.getString(android.R.string.untitled));
    }

    if (values.containsKey(NoteColumns.NOTE) == false) {
        values.put(NoteColumns.NOTE, "");
    }

    SQLiteDatabase db = mOpenHelper.getWritableDatabase();
    long rowId = db.insert(NOTES_TABLE_NAME, NoteColumns.NOTE, values);
    if (rowId > 0) {
        Uri noteUri = ContentUris.withAppendedId(NoteColumns.CONTENT_URI, rowId);
        getContext().getContentResolver().notifyChange(noteUri, null);
        return noteUri;
    }

    throw new SQLException("Failed to insert row into " + uri);
}

@Override
public int delete(Uri uri, String where, String[] whereArgs) {
    SQLiteDatabase db = mOpenHelper.getWritableDatabase();
    int count;
    switch (sUriMatcher.match(uri)) {
    case NOTES:
        count = db.delete(NOTES_TABLE_NAME, where, whereArgs);
        break;

    case NOTE_ID:
        String noteId = uri.getPathSegments().get(1);
        count = db.delete(NOTES_TABLE_NAME, NoteColumns._ID + "=" + noteId
                + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs);
        break;

    default:
        throw new IllegalArgumentException("Unknown URI " + uri);
    }

    getContext().getContentResolver().notifyChange(uri, null);
    return count;
}

@Override
public int update(Uri uri, ContentValues values, String where, String[] whereArgs) {
    SQLiteDatabase db = mOpenHelper.getWritableDatabase();
    int count;
    switch (sUriMatcher.match(uri)) {
    case NOTES:
        count = db.update(NOTES_TABLE_NAME, values, where, whereArgs);
        break;

    case NOTE_ID:
        String noteId = uri.getPathSegments().get(1);
        count = db.update(NOTES_TABLE_NAME, values, NoteColumns._ID + "=" + noteId
                + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs);
        break;

    default:
        throw new IllegalArgumentException("Unknown URI " + uri);
    }

    getContext().getContentResolver().notifyChange(uri, null);
    return count;
}

static {
    sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
    sUriMatcher.addURI(NotePad.AUTHORITY, "notes", NOTES);
    sUriMatcher.addURI(NotePad.AUTHORITY, "choice", NOTES);
    sUriMatcher.addURI(NotePad.AUTHORITY, "date", NOTES);
    sUriMatcher.addURI(NotePad.AUTHORITY, "time", NOTES);
    sUriMatcher.addURI(NotePad.AUTHORITY, "notes/#", NOTE_ID);
    sUriMatcher.addURI(NotePad.AUTHORITY, "live_folders/notes", LIVE_FOLDER_NOTES);

    sNotesProjectionMap = new HashMap<String, String>();
    sNotesProjectionMap.put(NoteColumns._ID, NoteColumns._ID);
    sNotesProjectionMap.put(NoteColumns.TITLE, NoteColumns.TITLE);
    sNotesProjectionMap.put(NoteColumns.NOTE, NoteColumns.NOTE);
    sNotesProjectionMap.put(NoteColumns.CHOICE, NoteColumns.CHOICE);
    sNotesProjectionMap.put(NoteColumns.TIME, NoteColumns.TIME);
    sNotesProjectionMap.put(NoteColumns.DATE, NoteColumns.DATE);
    sNotesProjectionMap.put(NoteColumns.CREATED_DATE, NoteColumns.CREATED_DATE);
    sNotesProjectionMap.put(NoteColumns.MODIFIED_DATE, NoteColumns.MODIFIED_DATE);

    // Support for Live Folders.
    sLiveFolderProjectionMap = new HashMap<String, String>();
    sLiveFolderProjectionMap.put(LiveFolders._ID, NoteColumns._ID + " AS " +
            LiveFolders._ID);
    sLiveFolderProjectionMap.put(LiveFolders.NAME, NoteColumns.TITLE + " AS " +
            LiveFolders.NAME);
    // Add more columns here for more robust Live Folders.
}
}

Answer 1

DDMS 输出显示在尝试保存时出现错误：

07-18 10:27:49.817: ERROR/AndroidRuntime(25136): Caused by: android.database.sqlite.SQLiteException: no such column: choice: , while compiling: UPDATE notes SET choice=?, note=?, modified=? WHERE _id=1

显然您的数据库中没有 CHOICE 列，或者您有一个但已将其删除。

此错误位于 com.example.android.notepad.NotePadProvider 类的 update 方法中。您没有发布该类的源代码，但应该很容易发现问题。

Answer 2

好的，谢谢您发布该信息。粗略地（双关语）一瞥告诉我数据库没有名为“CHOICE”的列。乍一看，您的数据库创建代码看起来不错。

也许您的系统上挂着旧版本的数据库。擦除您的用户数据以清除所有旧数据库。