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我想弄清楚如何“刷新”列表视图当用户在我的列表视图中的项目被删除时。我已经尝试notifyDataSetChanged（）但无济于事，这是令我费解的，因为这在我添加项目时起作用。ListView不“刷新”后，从项目中删除
P.S.我知道该项目正在被删除，因为如果我按下后退按钮并再次进入我的活动，该项目将从视图中从列表视图中删除。
public void deleteButtonClicked(View view){
dbHandler.deleteExerciseFromDatabase(exerciseClickedbyUser, workoutClicked);
exerciseListView.setAdapter(edsAdapter);
edsAdapter.notifyDataSetChanged();
Toast.makeText(getBaseContext(),"Exercise Deleted", Toast.LENGTH_SHORT).show();
}
当我在模拟器中运行这个时，Toast会出现。
公共类CustomExerciseAdapter扩展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;
}
这里是我的类，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);
}
为什么在OnClick中设置Adapter（使用setAdapter方法）？ – GVillani82
张贴您的适配器。它是直接从数据库中获取数据吗？ – FWeigl
在重新加载适配器之后调用'notifyDataSetChanged（）'是没有意义的...您是否正在重新加载它？ –