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我想弄清楚如何「刷新」列表視圖當用戶在我的列表視圖中的項目被刪除時。我已經嘗試notifyDataSetChanged（）但無濟於事，這是令我費解的，因爲這在我添加項目時起作用。ListView不「刷新」後，從項目中刪除
P.S.我知道該項目正在被刪除，因爲如果我按下後退按鈕並再次進入我的活動，該項目將從視圖中從列表視圖中刪除。
public void deleteButtonClicked(View view){
dbHandler.deleteExerciseFromDatabase(exerciseClickedbyUser, workoutClicked);
exerciseListView.setAdapter(edsAdapter);
edsAdapter.notifyDataSetChanged();
Toast.makeText(getBaseContext(),"Exercise Deleted", Toast.LENGTH_SHORT).show();
}
當我在模擬器中運行這個時，Toast會出現。
公共類CustomExerciseAdapter擴展ArrayAdapter {
public CustomExerciseAdapter(Context context, ArrayList<String> workouts) {
super(context, R.layout.exercise_custom_row, workouts);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = LayoutInflater.from(getContext());
View customView = inflater.inflate(R.layout.exercise_custom_row, parent, false);
String singleExerciseItem = getItem(position);
TextView exerciseTV = (TextView) customView.findViewById(R.id.exerciseTV);
exerciseTV.setText(singleExerciseItem);
return customView;
}
這裏是我的類，它包含deleteButtonClicked
public class ExercisesSection extends ActionBarActivity {
private EditText userWorkoutInput;
private Button addNewWorkoutButton;
private CustomExerciseAdapter edsAdapter;
private ArrayList<String> itemHold;
private MyDBHandler dbHandler;
private String workoutClicked;
private String exerciseClickedbyUser;
private ListView exerciseListView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().hide();
setContentView(R.layout.activity_exercises_section);
initViews();
handleIntentData();
inputTextHandler();
loadDataFromDatabase();
}
//This method initializes all the views
public void initViews(){
userWorkoutInput = (EditText) findViewById(R.id.userWorkoutInput);
addNewWorkoutButton = (Button) findViewById(R.id.addNewWorkoutButton);
exerciseListView = (ListView) findViewById(R.id.exerciseListView);
itemHold = new ArrayList<String>();
dbHandler = new MyDBHandler(this,null,null,1);
}
//This method makes the "Add new workout Button" clickable or not depending on user input
public void inputTextHandler(){
userWorkoutInput.addTextChangedListener(
new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
boolean isEmpty = false;
if ((userWorkoutInput.getText().toString().trim()).equals("")) {
isEmpty = true;
}
addNewWorkoutButton.setEnabled(!isEmpty);
}
@Override
public void afterTextChanged(Editable s) {
}
}
);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
THIS IS THE BUTTON LISTENER FOR @id+/addNewWorkoutButton
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
public void addWorkoutButtonClicked(View view){
String input = (userWorkoutInput.getText().toString().trim());
if (!input.equals("")){
addItemToList(input);
userWorkoutInput.setText(""); //Empties the edit text section
saveDataToDatabase(input);
}
}
public void saveDataToDatabase(String input){
//GIVE THE EXERCISES OBJ VALUES!
Exercises exercises = new Exercises(input, workoutClicked);
dbHandler.addExerciseToDatabase(exercises);
}
public void loadDataFromDatabase(){
String exerName = dbHandler.getExercisesForBodyParts(workoutClicked);
//IF STATEMENT WEEDS OUT EMPTY DATA
if(!(exerName.trim().equals(""))) {
String delim = ",";
String[] tokens = exerName.split(delim);
for (int i = 0; i < tokens.length; i++) {
addItemToList(tokens[i]);
}
}
}
public void addItemToList(String input){
itemHold.add(input);
edsAdapter = new CustomExerciseAdapter(this, itemHold);
exerciseListView.setAdapter(edsAdapter);
edsAdapter.notifyDataSetChanged();
exerciseListView.setOnItemClickListener(
new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
exerciseClickedbyUser = String.valueOf(parent.getItemAtPosition(position));
textClicked(view, exerciseClickedbyUser); //starts intent and sends to Exercise Clicked Activity
}
}
);
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This method is an onClick Method from exercise_custom_row.xml
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
public void deleteButtonClicked(View view){
dbHandler.deleteExerciseFromDatabase(exerciseClickedbyUser, workoutClicked);
itemHold.remove(exerciseClickedbyUser);
edsAdapter.notifyDataSetChanged();
Toast.makeText(getBaseContext(),"Exercise Deleted", Toast.LENGTH_SHORT).show();
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This method gets the data (name of section clicked) from MainActivity
and changes the textView in exercise_section accordingly
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
public void handleIntentData(){
Bundle workoutData = getIntent().getExtras();
if (workoutData == null){
return;
}
workoutClicked = workoutData.getString("exerciseChosen");
TextView exerciseChosenText = (TextView) findViewById(R.id.exerciseChosenText);
exerciseChosenText.setText(workoutClicked);
exerciseChosenText.setTypeface(null, Typeface.BOLD);
}
public void textClicked(View view, String exercise){
Intent i = new Intent(this, ExerciseClicked.class);
i.putExtra("exerciseClicked", exercise);
startActivity(i);
}
爲什麼在OnClick中設置Adapter（使用setAdapter方法）？ – GVillani82
張貼您的適配器。它是直接從數據庫中獲取數據嗎？ – FWeigl
在重新加載適配器之後調用'notifyDataSetChanged（）'是沒有意義的...您是否正在重新加載它？ –