Question

我在LongClick上设置ListActivity，调用AlertDialogue并选择delete或cancel，然后选择另一个AlertDialogue确认删除。

但是，我需要刷新列表以显示更改，但无法看到如何执行此操作（注意列表使用ResourceCursorAdapter填充）：

public class InspectionActivity extends ListActivity {
private Button newInspection;
private static final int ACTIVITY_CREATE=0;

private RMDbAdapter rmDbHelper;
//private AlertDialog longClickOptionsDialog;
private AlertDialog clickOptionsDialog;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_inspection);
    setUpViews();
    setLongClick();

    rmDbHelper = new RMDbAdapter(this);
    rmDbHelper.open();

    // Get a Cursor for the list items
    Cursor listCursor = rmDbHelper.fetchAllInspections();
    startManagingCursor(listCursor);           

    // set the custom list adapter     
    setListAdapter(new MyListAdapter(this, listCursor));


}



private void setUpViews() {
    newInspection = (Button)findViewById(R.id.new_inspection);
    newInspection.setOnClickListener(new View.OnClickListener() {                       
        public void onClick(View v) {
            createInspection();
        }
    }); 

}

private void setLongClick() {
    ListView lv = getListView(); 
    lv.setOnItemLongClickListener(new OnItemLongClickListener() { 
        public boolean onItemLongClick(AdapterView<?> arg0, View arg1,int row, final long id) {
            Cursor cursor = (Cursor) rmDbHelper.fetchInspection(id);

            String inspectionRef = RMUtilities.notEmpty(cursor.getString(cursor.getColumnIndex( 
                    RMDbAdapter.INSPECTION_REF)), "Reference unknown"); 
            String companyName = RMUtilities.notEmpty(cursor.getString(cursor.getColumnIndex( 
                    RMDbAdapter.INSPECTION_COMPANY)), "company unknown"); 
            final String inspectionDialogueText = "(" + inspectionRef + ", " + companyName + ")"; 

            clickOptionsDialog = new AlertDialog.Builder(InspectionActivity.this)
            .setTitle(inspectionDialogueText)
            .setMessage(R.string.general_text_select_option)
            .setPositiveButton(R.string.general_button_delete, new AlertDialog.OnClickListener(){
                private AlertDialog confirmDeleteDialog;
                public void onClick(DialogInterface dialog, int which){
                    confirmDeleteDialog = new AlertDialog.Builder(InspectionActivity.this)
                    .setTitle(R.string.general_text_confirmation)
                    .setMessage(R.string.general_text_confirm_delete)
                    .setPositiveButton(R.string.general_button_yes, new AlertDialog.OnClickListener(){
                        public void onClick(DialogInterface dialog, int which){
                            rmDbHelper.deleteInspection(id);

**//REFRESH STATEMENT NEEDED HERE..**
                            }
                        })
                    .setNegativeButton(R.string.general_button_cancel, new AlertDialog.OnClickListener(){
                        public void onClick(DialogInterface dialog, int which){
                            confirmDeleteDialog.cancel();
                            }
                        })
                    .create();
                    confirmDeleteDialog.show();
                    }
                })                  
            .setNegativeButton(android.R.string.cancel, new AlertDialog.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    clickOptionsDialog.cancel();
                    }
                })
            .create();
            clickOptionsDialog.show();
            return true;
        } 
    });
}

// In your ListActivity class, create a new inner class that extends ResourceCursorAdapter. 
//This inner class is the custom CursorAdapter we will use to manage how data is bound to a list item:

private class MyListAdapter extends ResourceCursorAdapter { 

    public MyListAdapter(Context context, Cursor cursor) { 
        super(context, R.layout.inspection_row, cursor);
    } 

    @Override
    public void bindView(View view, Context context, Cursor cursor) { 
        TextView title = (TextView) view.findViewById(R.id.inspection_row_item_main_title);
        title.setText(cursor.getString(                            
                cursor.getColumnIndex(RMDbAdapter.INSPECTION_REF)));

        TextView description = (TextView) view.findViewById(R.id.inspection_row_item_description);        

        String companyName = RMUtilities.notEmpty(cursor.getString(cursor.getColumnIndex(
                        RMDbAdapter.INSPECTION_COMPANY)), "Company unknown");
        String inspectionDate = RMUtilities.notEmpty(cursor.getString(cursor.getColumnIndex(
                        RMDbAdapter.INSPECTION_DATE)), "date unknown");
        description.setText("(" + companyName + ", " + inspectionDate + ")");
    }
}


private void createInspection() {
    Intent i = new Intent(this, InspectionEdit.class);
    startActivityForResult(i, ACTIVITY_CREATE);
}


protected void onListItemClick(ListView l, View v, final int pos, final long id){


    Cursor cursor = (Cursor) rmDbHelper.fetchInspection(id);

    String inspectionRef = RMUtilities.notEmpty(cursor.getString(cursor.getColumnIndex( 
            RMDbAdapter.INSPECTION_REF)), "Reference unknown"); 
    String companyName = RMUtilities.notEmpty(cursor.getString(cursor.getColumnIndex( 
            RMDbAdapter.INSPECTION_COMPANY)), "company unknown"); 
    final String inspectionDialogueText = "(" + inspectionRef + ", " + companyName + ")"; 

    super.onListItemClick(l, v, pos, id);
    clickOptionsDialog = new AlertDialog.Builder(InspectionActivity.this)
    .setTitle(inspectionDialogueText)
    .setMessage(R.string.general_text_select_option)
    .setPositiveButton(R.string.general_button_open, new AlertDialog.OnClickListener(){
        public void onClick(DialogInterface dialog, int which) {
            Intent i = new Intent(InspectionActivity.this, AreaActivity.class);
            i.putExtra("intentID", id);
            startActivityForResult(i, ACTIVITY_CREATE);
            }
        })
    .setNeutralButton(R.string.general_button_edit, new AlertDialog.OnClickListener(){
        public void onClick(DialogInterface dialog, int which){
            Intent i = new Intent(InspectionActivity.this, InspectionEdit.class);
            i.putExtra("intentID", id);
            startActivityForResult(i, ACTIVITY_CREATE);
            }
        })

    .setNegativeButton(android.R.string.cancel, new AlertDialog.OnClickListener(){
        public void onClick(DialogInterface dialog, int which){
            clickOptionsDialog.cancel();
            }
        })
    .create();
    clickOptionsDialog.show();

}

感谢您的帮助。

亲切的问候，

戴夫

Answer 1

尝试使用适配器的notifyDataSetChanged（）。

youradapter.notifyDataSetChanged()

Answer 2

您需要重新拉动光标。您正在更改数据库，因此您需要更新光标，这将导致您的列表更新。

根据您展示的代码，listCursor.requery()应该为您提供帮助。

请注意，对于较新的API，您应该使用CursorLoaders将数据活动从UI线程移开。

数据库删除后无法刷新ListActivity

2 个答案: