我已经尝试了几种从 SQLite 数据库加载微调器的不同方法，这种方法似乎是最简单和最简单的。唯一的事情是因为我添加了几个我自己的变量（另外三个）。当我运行编辑后的版本以适应我的测试需要时，除了微调器没有填充数据库中的数据外，一切都运行正常
SpinnerLoad 类
public class SpinnerLoad extends Activity implements OnClickListener {
private Db thisTestDBAdapter;
Button save;
EditText one, two, three;
Spinner spinner;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.spinnerform);
save = (Button) findViewById(R.id.spinLoad_save);
save.setOnClickListener(this);
one = (EditText) findViewById(R.id.spinLoad_serial);
two = (EditText) findViewById(R.id.spinLoad_name);
three = (EditText) findViewById(R.id.spinLoad_place);
fillData();
spinner = (Spinner) findViewById(R.id.spinLoad_spinner);
try {
spinner.setOnItemSelectedListener(new Person());
} catch (Exception e) {
e.printStackTrace();
}
}
public static class Person implements OnItemSelectedListener {
static String personReturn;
static boolean personTest = false;
@Override
public void onItemSelected(AdapterView<?> x, View y, int z, long w) {
personReturn = (x.getItemAtPosition(z)).toString();
personTest = true;
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
personTest = false;
}
}
private void fillData() {
try {
Cursor coloursCursor;
spinner = (Spinner) findViewById(R.id.spinLoad_spinner);
coloursCursor = thisTestDBAdapter.fetchAllColours();
startManagingCursor(coloursCursor);
String[] from = new String[] { thisTestDBAdapter.KEY_TWO };
int[] to = new int[] { R.id.tvDBViewRow };
SimpleCursorAdapter colourAdapter = new SimpleCursorAdapter(this,
R.layout.db_view_row, coloursCursor, from, to);
spinner.setAdapter(colourAdapter);
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.spinLoad_save:
String bx = two.getText().toString();
/**/
String ax = one.getText().toString();
String cx = three.getText().toString();
String returned = Person.personReturn;
Db entry = new Db(this);
entry.open();
entry.createEntry(ax, bx, cx, returned);
entry.close();
fillData();
/**/
break;
}
}
}
数据库 SQL 帮助程序类
public class Db {
private static final String TAG = "SpinnerDBHelper";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private static final int DATABASE_VERSION = 2;
private final Context mCtx;
/**/
private static final String KEY_DB = "DataBaseName";
private static final String KEY_TABLE = "DbTable";
public static final String KEY_ROWID = "_rowid"; // 0
public static final String KEY_ONE = "serial";
public static final String KEY_TWO = "name";
public static final String KEY_THREE = "place";
public static final String KEY_FOUR = "returned";
/**/
private static final String DATABASE_CREATE = "CREATE TABLE DbTable (_rowid INTEGER PRIMARY KEY AUTOINCREMENT, "
+ "serial TEXT NOT NULL, "+ "name TEXT NOT NULL, " + "place TEXT NOT NULL, " + "returned TEXT NOT NULL);";
public Db(Context ctx) {
this.mCtx = ctx;
}
public Db open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
public long createEntry(String ax, String bx, String cx, String returned) {
if (mDb == null) {
this.open();
}
ContentValues cv = new ContentValues();
cv.put(KEY_ONE, ax);
cv.put(KEY_TWO, bx);
cv.put(KEY_THREE, cx);
cv.put(KEY_FOUR, returned);
return mDb.insert(KEY_TABLE, null, cv);
}
public boolean deleteEntry(long rowId) {
return mDb.delete(KEY_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
public boolean deleteAll() {
if (mDb == null) {
this.open();
}
return mDb.delete(KEY_TABLE, null, null) > 0;
}
public Cursor fetchAllColours() {
if (mDb == null) {
this.open();
}
return mDb.query(KEY_TABLE, new String[] { KEY_ROWID, KEY_TWO},
null, null, null, null, null);
}
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, KEY_DB, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE);
}
@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 " + KEY_TABLE);
onCreate(db);
}
}
}
LOGCAT
12-26 23:39:33.409: W/System.err(30879): java.lang.NullPointerException 12-26 23:39:33.409: W/System.err(30879): at com.my.examples.SpinnerLoad.fillData(SpinnerLoad.java:59) 12-26 23:39:33.409: W/System.err(30879): at com.my.examples.SpinnerLoad.onCreate(SpinnerLoad.java:30) 12-26 23:39:33.418: W/System.err(30879): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 12-26 23:39:33.418: W/System.err(30879): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 12-26 23:39:33.418: W/System.err(30879): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 12-26 23:39:33.418: W/System.err(30879): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 12-26 23:39:33.418: W/System.err(30879): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 12-26 23:39:33.418: W/System.err(30879): at android.os.Handler.dispatchMessage(Handler.java:99) 12-26 23:39:33.418: W/System.err(30879): at android.os.Looper.loop(Looper.java:123) 12-26 23:39:33.418: W/System.err(30879): at android.app.ActivityThread.main(ActivityThread.java:4627) 12-26 23:39:33.428: W/System.err(30879): at java.lang.reflect.Method.invokeNative(Native Method) 12-26 23:39:33.428: W/System.err(30879): at java.lang.reflect.Method.invoke(Method.java:521) 12-26 23:39:33.428: W/System.err(30879): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 12-26 23:39:33.428: W/System.err(30879): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 12-26 23:39:33.428: W/System.err(30879): at dalvik.system.NativeStart.main(Native Method) 12-26 23:40:00.628: E/Database(30879): Error inserting place=zyxwvutsr returned=null serial=123456789 name=abcdefghij 12-26 23:40:00.628: E/Database(30879): android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed 12-26 23:40:00.628: E/Database(30879): at android.database.sqlite.SQLiteStatement.native_execute(Native Method) 12-26 23:40:00.628: E/Database(30879): at android.database.sqlite.SQLiteStatement.execute(SQLiteStatement.java:55) 12-26 23:40:00.628: E/Database(30879): at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1549) 12-26 23:40:00.628: E/Database(30879): at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1410) 12-26 23:40:00.628: E/Database(30879): at com.my.examples.Db.createEntry(Db.java:56) 12-26 23:40:00.628: E/Database(30879): at com.my.examples.SpinnerLoad.onClick(SpinnerLoad.java:86) 12-26 23:40:00.628: E/Database(30879): at android.view.View.performClick(View.java:2408) 12-26 23:40:00.628: E/Database(30879): at android.view.View$PerformClick.run(View.java:8816) 12-26 23:40:00.628: E/Database(30879): at android.os.Handler.handleCallback(Handler.java:587) 12-26 23:40:00.628: E/Database(30879): at android.os.Handler.dispatchMessage(Handler.java:92) 12-26 23:40:00.628: E/Database(30879): at android.os.Looper.loop(Looper.java:123) 12-26 23:40:00.628: E/Database(30879): at android.app.ActivityThread.main(ActivityThread.java:4627) 12-26 23:40:00.628: E/Database(30879): at java.lang.reflect.Method.invokeNative(Native Method) 12-26 23:40:00.628: E/Database(30879): at java.lang.reflect.Method.invoke(Method.java:521) 12-26 23:40:00.628: E/Database(30879): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 12-26 23:40:00.628: E/Database(30879): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 12-26 23:40:00.628: E/Database(30879): at dalvik.system.NativeStart.main(Native Method) 12-26 23:40:00.628: W/System.err(30879): java.lang.NullPointerException 12-26 23:40:00.639: W/System.err(30879): at com.my.examples.SpinnerLoad.fillData(SpinnerLoad.java:59) 12-26 23:40:00.639: W/System.err(30879): at com.my.examples.SpinnerLoad.onClick(SpinnerLoad.java:89) 12-26 23:40:00.639: W/System.err(30879): at android.view.View.performClick(View.java:2408) 12-26 23:40:00.639: W/System.err(30879): at android.view.View$PerformClick.run(View.java:8816) 12-26 23:40:00.639: W/System.err(30879): at android.os.Handler.handleCallback(Handler.java:587) 12-26 23:40:00.639: W/System.err(30879): at android.os.Handler.dispatchMessage(Handler.java:92) 12-26 23:40:00.639: W/System.err(30879): at android.os.Looper.loop(Looper.java:123) 12-26 23:40:00.639: W/System.err(30879): at android.app.ActivityThread.main(ActivityThread.java:4627) 12-26 23:40:00.639: W/System.err(30879): at java.lang.reflect.Method.invokeNative(Native Method) 12-26 23:40:00.649: W/System.err(30879): at java.lang.reflect.Method.invoke(Method.java:521) 12-26 23:40:00.649: W/System.err(30879): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 12-26 23:40:00.649: W/System.err(30879): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 12-26 23:40:00.649: W/System.err(30879): at dalvik.system.NativeStart.main(Native Method)
使用原木猫，我可以做关于初学者新手的东西哈哈..但我已经看了几次，并与原版并排看，不知道我可能搞砸了什么。希望有人能为我提供一点启示，如果需要更多信息，请告诉我。谢谢