这是我的数据库帮助：
public class PersonDatabaseHelper {
private static final String TAG = PersonDatabaseHelper.class.getSimpleName();
// database configuration
// if you want the onUpgrade to run then change the database_version
private static final int DATABASE_VERSION = 7;
private static final String DATABASE_NAME = "database.db";
// table configuration
static final String TABLE_NAME = "person_table"; // Table name
static final String PERSON_TABLE_COLUMN_ID = "_id"; // a column named "_id" is required for cursor
static final String PERSON_TABLE_COLUMN_NAME = "person_name";
static final String PERSON_TABLE_COLUMN_SURNAME = "person_surname";
static final String PERSON_TABLE_COLUMN_ENTERDATE = "person_enterdate";
static final String PERSON_TABLE_COLUMN_ENTERTIME = "person_entertime";
static final String PERSON_TABLE_COLUMN_EXITDATE = "person_exitdate";
static final String PERSON_TABLE_COLUMN_EXITTIME = "person_exittime";
private DatabaseOpenHelper openHelper;
private SQLiteDatabase database;
// this is a wrapper class. that means, from outside world, anyone will communicate with PersonDatabaseHelper,
// but under the hood actually DatabaseOpenHelper class will perform database CRUD operations
public PersonDatabaseHelper(Context aContext) {
openHelper = new DatabaseOpenHelper(aContext);
database = openHelper.getWritableDatabase();
}
public void insertData (String aPersonName, String aPersonSurName, String aPersonEnterDate,String aPersonEnterTime, String aPersonExitDate,String aPersonExitTime) {
// we are using ContentValues to avoid sql format errors
ContentValues contentValues = new ContentValues();
contentValues.put(PERSON_TABLE_COLUMN_NAME, aPersonName);
contentValues.put(PERSON_TABLE_COLUMN_SURNAME, aPersonSurName);
contentValues.put(PERSON_TABLE_COLUMN_ENTERDATE, aPersonEnterDate);
contentValues.put(PERSON_TABLE_COLUMN_ENTERTIME, aPersonEnterTime);
contentValues.put(PERSON_TABLE_COLUMN_EXITDATE, aPersonExitDate);
contentValues.put(PERSON_TABLE_COLUMN_EXITTIME, aPersonExitTime);
database.insert(TABLE_NAME, null, contentValues);
}
public void update_byID(int id, String name, String surname, String enterDate, String enterTime,String exitDate,String exitTime){
ContentValues values = new ContentValues();
values.put(PERSON_TABLE_COLUMN_NAME, name);
values.put(PERSON_TABLE_COLUMN_SURNAME, surname);
values.put(PERSON_TABLE_COLUMN_ENTERDATE, enterDate);
values.put(PERSON_TABLE_COLUMN_ENTERTIME, enterTime);
values.put(PERSON_TABLE_COLUMN_EXITDATE, exitDate);
values.put(PERSON_TABLE_COLUMN_EXITTIME, exitTime);
database.update(TABLE_NAME, values, PERSON_TABLE_COLUMN_ID+"="+id, null);
}
public Cursor getAllData () {
String buildSQL = "SELECT * FROM " + TABLE_NAME;
Log.d(TAG, "getAllData SQL: " + buildSQL);
return database.rawQuery(buildSQL, null);
}
// this DatabaseOpenHelper class will actually be used to perform database related operation
private class DatabaseOpenHelper extends SQLiteOpenHelper {
public DatabaseOpenHelper(Context aContext) {
super(aContext, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
// Create your tables here
String buildSQL = "CREATE TABLE " + TABLE_NAME + "( " + PERSON_TABLE_COLUMN_ID + " INTEGER PRIMARY KEY, " +
PERSON_TABLE_COLUMN_NAME + " TEXT, " + PERSON_TABLE_COLUMN_SURNAME + " TEXT, " + PERSON_TABLE_COLUMN_ENTERDATE + " TEXT," + PERSON_TABLE_COLUMN_ENTERTIME + " TEXT," + PERSON_TABLE_COLUMN_EXITDATE + " TEXT," + PERSON_TABLE_COLUMN_EXITTIME + " TEXT )";
Log.d(TAG, "onCreate SQL: " + buildSQL);
sqLiteDatabase.execSQL(buildSQL);
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int oldVersion, int newVersion) {
// Database schema upgrade code goes here
String buildSQL = "DROP TABLE IF EXISTS " + TABLE_NAME;
Log.d(TAG, "onUpgrade SQL: " + buildSQL);
sqLiteDatabase.execSQL(buildSQL); // drop previous table
onCreate(sqLiteDatabase); // create the table from the beginning
}
}
我的列表类：
public class List extends ActionBarActivity{
private CustomCursorAdapter customAdapter;
private PersonDatabaseHelper databaseHelper;
private static final int ENTER_DATA_REQUEST_CODE = 1;
private ListView listView;
private static final String TAG = List.class.getSimpleName();
/**
* Called when the activity is first created.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listview);
databaseHelper = new PersonDatabaseHelper(this);
listView = (ListView) findViewById(R.id.list_data);
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Log.d(TAG, "clicked on item: " + position);
Intent intent = new Intent(List.this, Edit.class);
Person p = new Person();
Cursor cursor = (Cursor) customAdapter.getItem(position);
p.name = cursor.getString(cursor.getColumnIndex("person_name"));
p.surname = cursor.getString(cursor.getColumnIndex("person_surname"));
p.enterDate = cursor.getString(cursor.getColumnIndex("person_enterdate"));
p.enterTime = cursor.getString(cursor.getColumnIndex("person_entertime"));
p.exitDate = cursor.getString(cursor.getColumnIndex("person_exitdate"));
p.exitTime = cursor.getString(cursor.getColumnIndex("person_exittime"));
intent.putExtra("update_id", position);
intent.putExtra("name",p.name);
intent.putExtra("surname",p.surname );
intent.putExtra("enterdate",p.enterDate );
intent.putExtra("entertime",p.enterTime);
intent.putExtra("exitdate", p.exitDate);
intent.putExtra("exittime", p.exitTime);
startActivity(intent);
}
});
listView.setOnLongClickListener(new OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
return false;
// TODO Auto-generated method stub
}
});
// Database query can be a time consuming task ..
// so its safe to call database query in another thread
// Handler, will handle this stuff for you <img src="http://s0.wp.com/wp-includes/images/smilies/icon_smile.gif?m=1129645325g" alt=":)" class="wp-smiley">
new Handler().post(new Runnable() {
@Override
public void run() {
customAdapter = new CustomCursorAdapter(List.this, databaseHelper.getAllData());
listView.setAdapter(customAdapter);
}
});
}
public void onClickEnterData(View btnAdd) {
startActivityForResult(new Intent(this, Permission.class), ENTER_DATA_REQUEST_CODE);
}
public void onClickLogOut(View btnLogOut){
Intent intent = new Intent(List.this,
MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
databaseHelper.insertData(data.getExtras().getString("tag_person_name"), data.getExtras().getString("tag_person_surname"),data.getExtras().getString("tag_person_enterdate"),data.getExtras().getString("tag_person_entertime"),data.getExtras().getString("tag_person_exitdate"),data.getExtras().getString("tag_person_exittime"));
customAdapter.changeCursor(databaseHelper.getAllData());
}
if(resultCode == RESULT_FIRST_USER){
databaseHelper.update_byID(data.getExtras().getInt("update_id"),data.getExtras().getString("update_person_name"), data.getExtras().getString("update_person_surname"),data.getExtras().getString("update_person_enterdate"),data.getExtras().getString("update_person_entertime"),data.getExtras().getString("update_person_exitdate"),data.getExtras().getString("update_person_exittime"));
customAdapter.changeCursor(databaseHelper.getAllData());
}
}
我的Edit类，其中句柄更新按钮由onClickSave定义：
public class Edit extends ActionBarActivity {
EditText name;
EditText surName;
EditText date;
EditText time;
EditText eDate;
EditText eTime;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_edit);
Intent intent = getIntent();
String data_name = intent.getStringExtra("name");
String data_surname = intent.getStringExtra("surname");
String data_enterdate= intent.getStringExtra("enterdate");
String data_entertime = intent.getStringExtra("entertime");
String data_exitdate = intent.getStringExtra("exitdate");
String data_exittime = intent.getStringExtra("exittime"); //typo here
name = (EditText) findViewById(R.id.username); //corrected
surName = (EditText) findViewById(R.id.usersurname); //corrected
date = (EditText) findViewById(R.id.date2);
time = (EditText) findViewById(R.id.time2);
eDate = (EditText) findViewById(R.id.date3);
eTime = (EditText) findViewById(R.id.time3);
name.setText(data_name);
surName.setText(data_surname);
date.setText(data_enterdate);
time.setText(data_entertime);
eDate.setText(data_exitdate);
eTime.setText(data_exittime);
}
public void onCancel(View btnCancel){
finish();
}
public void onClickSave(View btnSave){
String personName = name.getText().toString();
String personSurName = surName.getText().toString();
String personEnterDate = date.getText().toString();
String personEnterTime = time.getText().toString();
String personExitDate = eDate.getText().toString();
String personExitTime = eTime.getText().toString();
if ( personName.length() != 0 && personSurName.length() != 0&& personEnterDate.length() != 0&& personEnterTime.length() != 0&& personExitDate.length() != 0&& personExitTime.length() != 0 ) {
Intent newIntent = getIntent();
newIntent.putExtra("update_person_name", personName);
newIntent.putExtra("update_person_surname", personSurName);
newIntent.putExtra("update_person_enterdate", personEnterDate);
newIntent.putExtra("update_person_entertime", personEnterTime);
newIntent.putExtra("update_person_exitdate", personExitDate);
newIntent.putExtra("updateperson_exittime", personExitTime);
this.setResult(RESULT_FIRST_USER, newIntent);
finish();
}else {
AlertDialog alertDialog = new AlertDialog.Builder(Edit.this).create();
alertDialog.setTitle("Alert");
alertDialog.setMessage("Fill all columns");
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
alertDialog.show();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.edit, 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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
所以问题是我试图通过调用编辑类来更新列表中的所选项目，我编辑信息，然后通过单击onClickSave更新数据库，我已经写了所有方法，但我不明白它是什么错，因为它不更新，什么也不做。即使logcat没有出现任何错误迹象。 :(请别人帮帮我:(
到目前为止我尝试做的是使用代码RESULT_FIRST_USER向列表活动发送字符串，并在受保护的void onActivityResult（int requestCode，int resultCode，Intent data）上的List活动中，从数据库调用update方法。
也是我的Person类：
public class Person {
int id;
String name;
String surname;
String enterDate;
String enterTime;
String exitDate;
String exitTime;
}
答案 0 :(得分：1)
在您的List活动中，当用户点击列表项并将商品数据发送到您的Edit活动而不是startActivity()时，您必须致电startActivityForResult() }。然后，当您存储已编辑的数据并在setResult()活动的onClickSave()中调用Edit时，数据将传递到onActivityResult()的{{1}}方法活动..