android无法清除清单前的数据刷新前

Question

我有一个应用程序，显示交易列表。当我点击一个按钮来获得第二天的交易时，该列表视图仍然有前一天的交易附加到它。如何在getView重新填充之前清除数组或适配器？

我试过clear（）和adapter.notifyDataSetChanged（），但它仍然不起作用。

@Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.getrotalayout); 

     setCurrentDateOnView(); 


     Log.e(TAG, "title = " + getTitle()); 
     Log.e(TAG, "super.title = " + super.getTitle()); 
     nfcscannerapplication = (NfcScannerApplication) getApplication(); 
     date = nfcscannerapplication.getDate(); 
     listView = (ListView) findViewById(R.id.rotalist); 
     intent = this.getIntent(); 
     Bundle bundle = intent.getBundleExtra("rotaArrayBundle"); 
     if(array != null){ 
      array.clear(); 
     } 
     array = (ArrayList<?>) bundle.get("rotaArray"); 

     arrayAdapter = new MySimpleArrayAdapter(this, array); 
     arrayAdapter.notifyDataSetChanged(); 

     listView.setAdapter(arrayAdapter); 
     listView.setOnItemClickListener(this); 

。[更新]

@Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.getrotalayout); 

     setCurrentDateOnView(); 


     Log.e(TAG, "title = " + getTitle()); 
     Log.e(TAG, "super.title = " + super.getTitle()); 
     nfcscannerapplication = (NfcScannerApplication) getApplication(); 
     date = nfcscannerapplication.getDate(); 
     listView = (ListView) findViewById(R.id.rotalist); 
     intent = this.getIntent(); 
     Bundle bundle = intent.getBundleExtra("rotaArrayBundle"); 

     array = (ArrayList<?>) bundle.get("rotaArray"); 

     if (arrayAdapter == null){ 

     arrayAdapter = new MySimpleArrayAdapter(this, array); 
     }else{ 

      ((MySimpleArrayAdapter)getListAdapter()).clear(); 

     } 

     for(YourListItem item : yourNewDataArray){ 
      ((MySimpleArrayAdapter)getListAdapter()).add(item); 
     } 



     listView.setAdapter(arrayAdapter); 
     listView.setOnItemClickListener(this); 


    }// end of onCreate 

    private MySimpleArrayAdapter getListAdapter() { 
     // TODO Auto-generated method stub 
     return arrayAdapter; 
    } 

。 [update2]

public class GetRota extends NfcBaseActivity implements OnItemClickListener { 

    private static final String TAG = GetRota.class.getSimpleName(); 
    ListView listView; 
    Intent intent; 
    String callID; 
    DateTime date; 
    NfcScannerApplication nfcscannerapplication; 
    ArrayList<?> array; 
    String needName = ""; 
    MySimpleArrayAdapter arrayAdapter; 
    private DatePicker dpResult; 
    private int year; 
    private int month; 
    private int day; 

    static final int DATE_DIALOG_ID = 999; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.getrotalayout); 

     setCurrentDateOnView(); 


     Log.e(TAG, "title = " + getTitle()); 
     Log.e(TAG, "super.title = " + super.getTitle()); 
     nfcscannerapplication = (NfcScannerApplication) getApplication(); 
     date = nfcscannerapplication.getDate(); 
     listView = (ListView) findViewById(R.id.rotalist); 
     intent = this.getIntent(); 
     Bundle bundle = intent.getBundleExtra("rotaArrayBundle"); 

     array = (ArrayList<?>) bundle.get("rotaArray"); 

     if (arrayAdapter == null){ 

     arrayAdapter = new MySimpleArrayAdapter(this, array); 
     }else{ 

      ((MySimpleArrayAdapter)getListAdapter()).clear(); 

     } 

//  for(YourListItem item : yourNewDataArray){ 
//   ((MySimpleArrayAdapter)getListAdapter()).add(item); 
//  } 



     listView.setAdapter(arrayAdapter); 
     listView.setOnItemClickListener(this); 


    }// end of onCreate 

    private MySimpleArrayAdapter getListAdapter() { 

     return arrayAdapter; 
    } 

    public void setCurrentDateOnView() { 

     dpResult = (DatePicker) findViewById(R.id.datepicker1); 

     final Calendar c = Calendar.getInstance(); 
     year = c.get(Calendar.YEAR); 
     month = c.get(Calendar.MONTH); 
     day = c.get(Calendar.DAY_OF_MONTH); 


    } 

    public boolean onCreateOptionsMenu(Menu menu) { 
     MenuInflater inflater = getMenuInflater(); 
     inflater.inflate(R.menu.menurotadetails, menu); 
     return true; 
    } 

    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
     case R.id.previous: 
      DateTime now2 = nfcscannerapplication.getDate(); 
      Log.e(TAG, "now2 = " + now2); 
      DateTime dateTimePlusOne2 = now2.minusDays(1); 
      Log.e(TAG, "now2 after -1 = " + dateTimePlusOne2); 
      nfcscannerapplication.setDate(dateTimePlusOne2); 
      DateTimeFormatter fmt2 = DateTimeFormat.forPattern("d-MMM-Y"); 
      String nextDay2 = fmt2.print(dateTimePlusOne2); 

      Intent i2 = new Intent(this, NfcscannerActivity.class); 
      i2.putExtra("nextRota", nextDay2); 
      i2.setAction("NEXT_ROTA"); 
      startActivity(i2); 
      return true; 

     case R.id.next: 

      DateTime now = nfcscannerapplication.getDate(); 
      Log.e(TAG, "now = " + now); 
      DateTime dateTimePlusOne = now.plusDays(1); 
      Log.e(TAG, "now after +1 = " + dateTimePlusOne); 
      nfcscannerapplication.setDate(dateTimePlusOne); 
      DateTimeFormatter fmt = DateTimeFormat.forPattern("d-MMM-Y"); 
      String nextDay = fmt.print(dateTimePlusOne); 

      Intent i = new Intent(this, NfcscannerActivity.class); 
      i.putExtra("nextRota", nextDay); 
      i.setAction("NEXT_ROTA"); 
      startActivity(i); 
      return true; 

     case R.id.today: 
      setCurrentDateOnView(); 
      showDialog(DATE_DIALOG_ID); 
      return true; 

     default: 

      return super.onOptionsItemSelected(item); 
     } 
    } 






    @Override 
    protected Dialog onCreateDialog(int id) { 
     switch (id) { 
     case DATE_DIALOG_ID: 
      // set date picker as current date 
      return new DatePickerDialog(this, datePickerListener, year, month, 
        day); 
     } 
     return null; 
    } 

    private DatePickerDialog.OnDateSetListener datePickerListener = new DatePickerDialog.OnDateSetListener() { 

     // when dialog box is closed, below method will be called. 
     public void onDateSet(DatePicker view, int selectedYear, 
       int selectedMonth, int selectedDay) { 
      year = selectedYear; 
      month = selectedMonth; 
      day = selectedDay; 



      DateTime spinnyTime = new DateTime(year, month+1, day, 1, 1); 
      Log.e(TAG, "spinnyTime = " + spinnyTime); 
      DateTimeFormatter fmt = DateTimeFormat.forPattern("d-MMM-Y"); 
      String formattedSpinnyTime = fmt.print(spinnyTime); 
      Log.e(TAG, "spinnyTime = " + formattedSpinnyTime); 
      Log.e(TAG, "year = " + year); 
      Log.e(TAG, "month = " + month); 
      Log.e(TAG, "day = " + day); 


      Intent i = new Intent(GetRota.this, NfcscannerActivity.class); 
      i.putExtra("nextRota", formattedSpinnyTime); 
      i.setAction("NEXT_ROTA"); 
      startActivity(i); 

     } 
    }; 








    private class MySimpleArrayAdapter extends ArrayAdapter<String> { 
     private final Context context; 
     private final ArrayList<?> list; 

     public MySimpleArrayAdapter(Context context, ArrayList<?> list) { 

      super(context, R.layout.rotarowlayout); 
      Log.e(TAG, "inside adapter constructor"); 
      this.context = context; 
      this.list = list; 

      if(list.get(6).toString().equalsIgnoreCase("Out of range")){ 

       AlertDialog alertDialog = new AlertDialog.Builder(GetRota.this).create(); 
       alertDialog.setTitle("No Rota Available Error"); 
       alertDialog.setMessage("Unable To View Rota For That Day"); 
       alertDialog.setButton("OK", new DialogInterface.OnClickListener() { 
         public void onClick(DialogInterface dialog, int which) { 



        } }); 

       alertDialog.show(); 
      } 
     } 

     @Override 
     public View getView(int position, View convertView, ViewGroup parent) { 


      LayoutInflater inflater = (LayoutInflater) context 
        .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

      View rowView = inflater.inflate(R.layout.rotarowlayout, parent, 
        false); 

      TextView startTime = (TextView) rowView 
        .findViewById(R.id.rowstarttime); 
      TextView duration = (TextView) rowView 
        .findViewById(R.id.rowduration); 
      TextView status = (TextView) rowView.findViewById(R.id.rowstatus); 
      TextView name = (TextView) rowView.findViewById(R.id.rowclientname); 

      String record = list.get(position).toString(); 
      String[] itemsInRecord = record.split(","); 
      Log.e(TAG, "itemin record = " + itemsInRecord.length); 
      String[] recordItem = new String[itemsInRecord.length]; 

      for (int x = 0; x < itemsInRecord.length; x++) { 

       recordItem[x] = itemsInRecord[x]; 
       Log.e(TAG, "x = " + x); 
      } 

      startTime.setText("Start Time: " + recordItem[0]); 
      duration.setText("Duration:" + recordItem[1]); 
      status.setText("Status:" + recordItem[2]); 
      name.setText("Client:" + recordItem[3] + recordItem[4]); 
      callID = recordItem[5]; 
      needName = recordItem[6]; 

      return rowView; 

     } 

     @Override 
     public int getCount() { 
      return this.list.size(); 
     } 

    }// end of adapter class 

    @Override 
    public void onItemClick(AdapterView<?> parent, View view, int position, 
      long id) { 

     Log.e(TAG, "inside onItemClick"); 

     Intent intent = new Intent(GetRota.this, GetRotaDetails.class); 
     intent.putExtra("callIDExtra", callID); 

     startActivity(intent); 

    } 

}// end of GetRota 

。

[UPDATE3]

@Override 
    protected void onNewIntent(Intent intent) { 
     setIntent(intent); 
     super.onNewIntent(intent); 

     // Get your ArrayList from getIntent.getExtras() here, and use my code from above 
     Bundle bundle = intent.getBundleExtra("rotaArrayBundle"); 
     array = (ArrayList<?>) bundle.get("rotaArray"); 
    } 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.getrotalayout); 

     setCurrentDateOnView(); 


     Log.e(TAG, "title = " + getTitle()); 
     Log.e(TAG, "super.title = " + super.getTitle()); 
     nfcscannerapplication = (NfcScannerApplication) getApplication(); 
     date = nfcscannerapplication.getDate(); 
     listView = (ListView) findViewById(R.id.rotalist); 
     onNewIntent(intent); 
     //intent = this.getIntent(); 
     //Bundle bundle = intent.getBundleExtra("rotaArrayBundle"); 

     //array = (ArrayList<?>) bundle.get("rotaArray"); 

     if (arrayAdapter == null){ 

     arrayAdapter = new MySimpleArrayAdapter(this, array); 
     }else{ 

      ((MySimpleArrayAdapter)getListAdapter()).clear(); 

     } 

//  for(YourListItem item : yourNewDataArray){ 
//   ((MySimpleArrayAdapter)getListAdapter()).add(item); 
//  } 



     listView.setAdapter(arrayAdapter); 
     listView.setOnItemClickListener(this); 


    }// end of onCreate 

Answer 1

你应该保持旧的适配器，每当你想更新列表，你可以做到以下几点：

((MySimpleArrayAdapter)getListAdapter()).clear(); 
for(String[] item : array){ 
    ((MySimpleArrayAdapter)getListAdapter()).add(item); 
} 

你不必调用notifyDataSetChange()因为clear()和add()是为你做的。

编辑：套装android:launchMode="singleTop"在你的活动清单XML，然后重写onNewIntent()方法是这样的：

@Override 
protected void onNewIntent(Intent intent) { 
    setIntent(intent); 
    super.onNewIntent(intent); 
} 

EDIT2：

@Override 
protected void onNewIntent(Intent intent) { 
    setIntent(intent); 
    super.onNewIntent(intent); 
} 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.getrotalayout); 

    setCurrentDateOnView(); 


    Log.e(TAG, "title = " + getTitle()); 
    Log.e(TAG, "super.title = " + super.getTitle()); 
    nfcscannerapplication = (NfcScannerApplication) getApplication(); 
    date = nfcscannerapplication.getDate(); 
    listView = (ListView) findViewById(R.id.rotalist); 


    listView.setAdapter(arrayAdapter); 
    listView.setOnItemClickListener(this); 


} 

@Override 
protected void onResume(){ 
    super.onResume(); 
    ArrayList<String[]> array = (ArrayList<String[]>)getIntent().getBundleExtra("rotaArrayBundle").get("rotaArray"); 
    MySimpleArrayAdapter arrayAdapter = new MySimpleArrayAdapter(this, array); 
    listView.setAdapter(arrayAdapter) 
} 

。

[更新4]

for(int i = 0; i < count; i++){ 

       String s = new Integer(i).toString(); 

       JSONObject jsonobject2 = (JSONObject) jsonObject1.get(s); 
       String startdate = jsonobject2.getString("StartDate"); 
       String duration = jsonobject2.getString("Duration"); 
       String callStatusName = jsonobject2.getString("CallStatusName"); 
       String clientForeName = jsonobject2.getString("ClientForename"); 
       String clientSurName = jsonobject2.getString("ClientSurname"); 
       String clientCallId = jsonobject2.getString("CallID"); 
       String needName = jsonobject2.getString("NeedName"); 

       ArrayList<String> arr = new ArrayList<String>(); 
       arr.add(startdate); 
       arr.add(duration); 
       arr.add(callStatusName); 
       arr.add(clientForeName); 
       arr.add(clientSurName); 
       arr.add(clientCallId); 
       arr.add(needName); 

       Log.e(TAG, "arr size = "+arr.size()); 
       arrayList.add(i, arr); 

       } 

      } catch (Exception e) { 

       e.printStackTrace(); 
      } 
      return arrayList; 


class TwoDimentionalArrayList<T> extends ArrayList<ArrayList<T>> { 

     private static final long serialVersionUID = 1L; 

     public void addToInnerArray(int index, T element) { 
      while (index >= this.size()) { 
       this.add(new ArrayList<T>()); 
      } 
      this.get(index).add(element); 
     } 

     public void addToInnerArray(int index, int index2, T element) { 
      while (index >= this.size()) { 
       this.add(new ArrayList<T>()); 
      } 

      ArrayList<T> inner = this.get(index); 
      while (index2 >= inner.size()) { 
       inner.add(null); 
      } 

      inner.set(index2, element); 
     } 
    } 

Answer 2

能否请您通过更改顺序尝试。

listView.setAdapter(arrayAdapter); 
arrayAdapter.notifyDataSetChanged();