Android：外部ListView更改的適配器問題

Question

我正在嘗試使用Geocoder API構建地址搜索器，其中用戶鍵入位置名稱，並且所有相關地址都顯示在列表視圖中。

我在運行搜索時，出現此錯誤：

java.lang.IllegalStateException：適配器的內容 改變，但ListView控件沒有收到通知。確保您的適配器的 內容不是從後臺線程修改的，而是僅從修改的UI線程。

確保您的適配器在其內容更改時調用 notifyDataSetChanged（）。

這是我實現：

SimpleStringAdapter adapter; 
ArrayList<String> items = new ArrayList<>(); 
ListView addressList; 

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

    addressList = (ListView) findViewById(R.id.addressList); 
    addressBox = (EditText) findViewById(R.id.addressBox); 

    //Search for locations when the user types in 
    addressBox.addTextChangedListener(new TextWatcher() { 
      @Override 
      public void onTextChanged(final CharSequence s, int start, int before, int count) { 
       //Search the typed location 
       SearchAddresses(searchText); 
      } 

      @Override 
      public void beforeTextChanged(CharSequence s, int start, int count, 
              int after) { 

      } 

      @Override 
      public void afterTextChanged(Editable s) { 

      } 
    }); 
} 

private void SearchAddresses(String searchText) { 
    Geocoder geoCoder = new Geocoder(this, Locale.getDefault()); 
    try { 
     List<Address> addresses = geoCoder.getFromLocationName(searchText, 5); 
     addressList.setAdapter(null); 

     if (addresses.size() != 0) { 
      //Add the Address line to the list 
      items.add(addresses.get(0).getAddressLine(0)); 
      //Populate the listview 
      adapter = new SimpleStringAdapter(this, items); 
      addressList.setAdapter(adapter); 
     } 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
} 

而且ListView控件適配器只是簡單地設置文本到一個TextView。如果您需要查看，請告訴我。

我在做什麼錯？

Answer 1

不要onTextChanged（）方法來初始化適配器每次。使用notifyDataSetChanged（）。這裏是你的代碼的例子。

只需用您的代碼替換即可。而已。

SimpleStringAdapter adapter; 
ArrayList<String> items = new ArrayList<>(); 
ListView addressList; 

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

    addressList = (ListView) findViewById(R.id.addressList); 
    addressBox = (EditText) findViewById(R.id.addressBox); 

    adapter = new SimpleStringAdapter(this, items); 
    addressList.setAdapter(adapter); 

    //Search for locations when the user types in 
    addressBox.addTextChangedListener(new TextWatcher() { 
      @Override 
      public void onTextChanged(final CharSequence s, int start, int before, int count) { 
       //Search the typed location 
       SearchAddresses(searchText); 
      } 

      @Override 
      public void beforeTextChanged(CharSequence s, int start, int count, 
             int after) { 

      } 

      @Override 
      public void afterTextChanged(Editable s) { 

      } 
    }); 
} 

private void SearchAddresses(String searchText) { 
    Geocoder geoCoder = new Geocoder(this, Locale.getDefault()); 
    try { 
     List<Address> addresses =  geoCoder.getFromLocationName(searchText, 5); 
     addressList.setAdapter(null); 

     if (addresses.size() != 0) { 
      //Add the Address line to the list 
      items.add(addresses.get(0).getAddressLine(0)); 
      //Populate the listview 
      adapter.notifyDataSetChanged(); 

     } 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
} 

Answer 2

試試這個添加notifyDataSetChanged到適配器： -

private void SearchAddresses(String searchText) { 
    Geocoder geoCoder = new Geocoder(this, Locale.getDefault()); 
    try { 
     List<Address> addresses = geoCoder.getFromLocationName(searchText, 5); 
     addressList.setAdapter(null); 

     if (addresses.size() != 0) { 
      //Add the Address line to the list 
      items.add(addresses.get(0).getAddressLine(0)); 
      //Populate the listview 
      adapter = new SimpleStringAdapter(this, items); 
      addressList.setAdapter(adapter); 
      adapter.notifyDataSetChanged(); 
     } 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
}