Android 如何在数据插入SQLite后立即更新listview
我有一个名为Custom的类，它扩展了片段。在CreateView中，它将通过在视图v中传递来调用同一类中的populateListView方法。单击fab按钮后，它将打开一个名为CustomForm的新活动，这是一个允许用户填写的表单，从而将数据插入SQLite数据库Android 如何在数据插入SQLite后立即更新listview,android,Android,我有一个名为Custom的类，它扩展了片段。在CreateView中，它将通过在视图v中传递来调用同一类中的populateListView方法。单击fab按钮后，它将打开一个名为CustomForm的新活动，这是一个允许用户填写的表单，从而将数据插入SQLite数据库 @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle s
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_custom, container, false);
openDB();
ListView myList = (ListView) v.findViewById(R.id.customlistview);
populateListView(v);
View fabbutton = v.findViewById(R.id.fab);
fabbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent myIntent = new Intent(getActivity(), CustomForm.class);
startActivity(myIntent);
}
});
return v;
}
public void populateListView(View v) {
Cursor cursor = dbAdapter.getAllRows();
String[] fromFieldNames = new String[]{DBAdapter.KEY_DRUG_NAME, DBAdapter.KEY_DRUG_OTHER_NAME, DBAdapter.KEY_DRUG_DOSE_1};
int[] toViewIDs = new int[]{R.id.lineone, R.id.linetwo, R.id.dose1};
SimpleCursorAdapter myCursorAdapter;
myCursorAdapter = new SimpleCursorAdapter(getContext(), R.layout.custom_row, cursor, fromFieldNames, toViewIDs, 0);
ListView myList = (ListView) v.findViewById(R.id.customlistview);
myList.setAdapter(myCursorAdapter);
}
public class CustomForm extends AppCompatActivity {
View create = findViewById(R.id.create);
create.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Drug Item Created", Toast.LENGTH_SHORT).show();
if (!TextUtils.isEmpty(custom_drug_name_main.getText())) {
dbAdapter.insertRow(custom_drug_name_main.getText().toString(), custom_drug_name_other.getText().toString(), dose1.getText().toString());
} else {
}
finish();
}
});
}
public class DBAdapter {
private static final String TAG = "DBAdapter"; //used for logging database version changes
// Field Names:
public static final String KEY_ROWID = "_id";
public static final String KEY_DRUG_NAME = "drugName";
public static final String KEY_DRUG_OTHER_NAME = "drugOtherName";
public static final String KEY_DRUG_DOSE_1 = "dose1";
public static final String[] ALL_KEYS = new String[]{KEY_ROWID, KEY_DRUG_NAME, KEY_DRUG_OTHER_NAME,KEY_DRUG_DOSE_1};
// DataBase info:
public static final String DATABASE_NAME = "custom_drug";
public static final String DATABASE_TABLE = "custom_drug_table";
public static final int DATABASE_VERSION = 3; // The version number must be incremented each time a change to DB structure occurs.
//SQL statement to create database
private static final String DATABASE_CREATE_SQL =
"CREATE TABLE " + DATABASE_TABLE
+ " (" + KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_DRUG_NAME + " TEXT NOT NULL, "
+ KEY_DRUG_OTHER_NAME + " TEXT,"
+ KEY_DRUG_DOSE_1 + " TEXT NOT NULL"
+ ");";
private final Context context;
private DatabaseHelper myDBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx) {
this.context = ctx;
myDBHelper = new DatabaseHelper(context);
}
// Open the database connection.
public DBAdapter open() {
db = myDBHelper.getWritableDatabase();
return this;
}
// Close the database connection.
public void close() {
myDBHelper.close();
}
// Add a new set of values to be inserted into the database.
public long insertRow(String drugName, String drugOtherName, String dose1) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_DRUG_NAME, drugName);
initialValues.put(KEY_DRUG_OTHER_NAME, drugOtherName);
initialValues.put(KEY_DRUG_DOSE_1, dose1);
// Insert the data into the database.
return db.insert(DATABASE_TABLE, null, initialValues);
}
// Delete a row from the database, by rowId (primary key)
public boolean deleteRow(long rowId) {
String where = KEY_ROWID + "=" + rowId;
return db.delete(DATABASE_TABLE, where, null) != 0;
}
public void deleteAll() {
Cursor c = getAllRows();
long rowId = c.getColumnIndexOrThrow(KEY_ROWID);
if (c.moveToFirst()) {
do {
deleteRow(c.getLong((int) rowId));
} while (c.moveToNext());
}
c.close();
}
// Return all data in the database.
public Cursor getAllRows() {
String where = null;
Cursor c = db.query(true, DATABASE_TABLE, ALL_KEYS, where, null, null, null, null, null);
if (c != null) {
c.moveToFirst();
}
return c;
}
// Get a specific row (by rowId)
public Cursor getRow(long rowId) {
String where = KEY_ROWID + "=" + rowId;
Cursor c = db.query(true, DATABASE_TABLE, ALL_KEYS,
where, null, null, null, null, null);
if (c != null) {
c.moveToFirst();
}
return c;
}
// Change an existing row to be equal to new data.
public boolean updateRow(long rowId, String drugName, String drugOtherName) {
String where = KEY_ROWID + "=" + rowId;
ContentValues newValues = new ContentValues();
newValues.put(KEY_DRUG_NAME, drugName);
newValues.put(KEY_DRUG_OTHER_NAME, drugOtherName);
// Insert it into the database.
return db.update(DATABASE_TABLE, newValues, where, null) != 0;
}
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase _db) {
_db.execSQL(DATABASE_CREATE_SQL);
}
@Override
public void onUpgrade(SQLiteDatabase _db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading application's database from version " + oldVersion
+ " to " + newVersion + ", which will destroy all old data!");
// Destroy old database:
_db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
// Recreate new database:
onCreate(_db);
}
}
}
我的问题是：如何从自定义类调用populateListView方法，以便在插入数据后立即更新listview。我是编程新手，我希望我能把问题说清楚。谢谢。如果您想在将项目插入数据库后立即更新Listview。只用
dbAdapter.insertRow(custom_drug_name_main.getText().toString(), custom_drug_name_other.getText().toString(), dose1.getText().toString());
dbAdapter.notifyDataSetChanged();
若要在将项插入数据库后立即更新Listview。只用
dbAdapter.insertRow(custom_drug_name_main.getText().toString(), custom_drug_name_other.getText().toString(), dose1.getText().toString());
dbAdapter.notifyDataSetChanged();
下面是我说过的一个例子： DBAdapter 如您所见，getRow被getItem替换 list_item.xml
以下是我说过的一个例子：
DBAdapter
如您所见，getRow被getItem替换
list_item.xml
更好的做法是创建游标适配器，然后只需调用swapCursor（）：
但在您的情况下，您有一个SimpleCorsorAdapter，您希望从其他活动访问它，因此您可以尝试以下方法：
public class CustomForm extends AppCompatActivity {
View create = findViewById(R.id.create);
create.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Drug Item Created", Toast.LENGTH_SHORT).show();
if (!TextUtils.isEmpty(custom_drug_name_main.getText())) {
dbAdapter.insertRow(custom_drug_name_main.getText().toString(), custom_drug_name_other.getText().toString(), dose1.getText().toString());
} else {
}
Intent myIntent = new Intent(getActivity(), yourLastActivity.class);
startActivity(myIntent);
}
});
}
这样做可以调用populateListView（v）；在onCreateView（）中，当您返回到上一个活动时：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_custom, container, false);
openDB();
ListView myList = (ListView) v.findViewById(R.id.customlistview);
populateListView(v); // we are trying to call this after the dbAdapter.insertRow
希望这能有所帮助。更好的做法是创建游标适配器，然后只需调用swapCursor（）：
但在您的情况下，您有一个SimpleCorsorAdapter，您希望从其他活动访问它，因此您可以尝试以下方法：
public class CustomForm extends AppCompatActivity {
View create = findViewById(R.id.create);
create.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Drug Item Created", Toast.LENGTH_SHORT).show();
if (!TextUtils.isEmpty(custom_drug_name_main.getText())) {
dbAdapter.insertRow(custom_drug_name_main.getText().toString(), custom_drug_name_other.getText().toString(), dose1.getText().toString());
} else {
}
Intent myIntent = new Intent(getActivity(), yourLastActivity.class);
startActivity(myIntent);
}
});
}
这样做可以调用populateListView（v）；在onCreateView（）中，当您返回到上一个活动时：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_custom, container, false);
openDB();
ListView myList = (ListView) v.findViewById(R.id.customlistview);
populateListView(v); // we are trying to call this after the dbAdapter.insertRow
希望这有帮助首先，您应该将光标变量移出populateListView方法。并在自定义片段中声明它
public Cursor cursor;
然后创建下一段代码
public void updateList() {
cursor = dbAdapter.getAllRows();
myCursorAdapter.notifyDataSetChanged();
}
最后，将这个updateList（）方法放入onClick（）方法中。首先，应该将游标变量移出populateListView方法。并在自定义片段中声明它
public Cursor cursor;
然后创建下一段代码
public void updateList() {
cursor = dbAdapter.getAllRows();
myCursorAdapter.notifyDataSetChanged();
}
最后，将这个updateList（）方法放入onClick（）方法中显示适配器请在更新数据后调用myCursorAdapter.notifyDataSetChanged（）显示适配器更新数据后，请调用myCursorAdapter.notifyDataSetChanged（）
在我的CustomForm类中，我应该扩展其他类吗？因为我看不到notifyDataSetChanged（）；method@SimonHomyCursorAdapter.notifyDataSetChanged（）；不适合您？请尝试将扩展BaseAdapter
添加到您的dbAdapter。您不能调用dbAdapter.notifyDataSetChanged（）；dbAdapter不是适配器不能放线，因为myCursorAdapter来自自定义类，但不在CustomForm类中在我的CustomForm类中，我应该扩展其他类吗？因为我看不到notifyDataSetChanged（）；method@SimonHomyCursorAdapter.notifyDataSetChanged（）；不适合您？请尝试将扩展BaseAdapter
添加到您的dbAdapter。您不能调用dbAdapter.notifyDataSetChanged（）；dbAdapter不是适配器不能放线，因为myCursorAdapter来自自定义类，但不在CustomForm classI中。我发现我的问题是“finish（）；”我替换finish（）；为了重新打开mainactivity类解决我的问题，我发现我的问题是“finish（）；”我替换finish（）；为了重新打开mainactivity类，解决了我的问题