a亚洲精品_精品国产91乱码一区二区三区_亚洲精品在线免费观看视频_欧美日韩亚洲国产综合_久久久久久久久久久成人_在线区

首頁 > 系統 > Android > 正文

android中ListView數據刷新時的同步方法

2020-04-11 11:32:12
字體:
來源:轉載
供稿:網友

本文實例講述了android中ListView數據刷新時的同步方法。分享給大家供大家參考。具體實現方法如下:

public class Main extends BaseActivity {  private static final String TAG = "tag";  private static final int STATUS_CHANGE = 0;  ExpandableListView mElv;  ArrayList<GroupInfo> mGroupArray;  @Override  public void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.main);   mElv = (ExpandableListView) findViewById(R.id.contact_list);   mStatus = (TextView) findViewById(R.id.setStatus);   mGroupArray = getIntent().getParcelableArrayListExtra("groupArray");// => 取數據   mExpandableAdapter = new ExpandableAdapter(this, Main.this);   mElv.setAdapter(mExpandableAdapter);     // 異步對比服務器分組和本地分組   HandlerThread handlerThread = new HandlerThread("handler_thread");   handlerThread.start();   UpdateGroupHandler myHandler = new UpdateGroupHandler(     handlerThread.getLooper());   Message message = myHandler.obtainMessage();   message.sendToTarget();   mHandler = new Handler() {    public void handleMessage(Message msg) {     switch (msg.what) {     case STATUS_CHANGE:      // 處理UI更新等操作      updateUI();      break;     }    };   };   }  /**   * 發送消息更新UI   */  private void sendMessageToUpdateUI() {   Message msg = new Message();   msg.what = STATUS_CHANGE;   mHandler.sendMessage(msg);  // 向Handler發送消息,更新UI  }  private void updateUI() {   // 詳細的更新   mExpandableAdapter.notifyDataSetChanged();  // 更新ExpandableListView  }  /**   * 異步刷新分組的handler   *   * @author administrator   *   */  class UpdateGroupHandler extends Handler {   public UpdateGroupHandler() {   }   public UpdateGroupHandler(Looper looper) {    super(looper);   }   @Override   public void handleMessage(Message msg) {    ContactsManagerDbAdapter dbAdapter = new ContactsManagerDbAdapter(      Main.this);    dbAdapter.open();    // =>doSomeThing...    mGroupArray = groupList;    System.out.println("========數據更新后,刷新listview=========");    sendMessageToUpdateUI();   }  }  private class ExpandableAdapter extends BaseExpandableListAdapter {   Activity activity;   LayoutInflater layoutInflater;   public ExpandableAdapter(Activity a, Context context) {    activity = a;    layoutInflater = (LayoutInflater) context      .getSystemService(Context.LAYOUT_INFLATER_SERVICE);   }   public Object getChild(int groupPosition, int childPosition) {    return mGroupArray.get(groupPosition).getChildList()      .get(childPosition);   }   public long getChildId(int groupPosition, int childPosition) {    return childPosition;   }   public int getChildrenCount(int groupPosition) {    return mGroupArray.get(groupPosition).getChildList().size();   }   public View getChildView(int groupPosition, int childPosition,     boolean isLastChild, View convertView, ViewGroup parent) {    // .....    return vi;   }   public Object getGroup(int groupPosition) {    return mGroupArray.get(groupPosition);   }   public int getGroupCount() {    return mGroupArray.size();   }   public long getGroupId(int groupPosition) {    return groupPosition;   }   public View getGroupView(int groupPosition, boolean isExpanded,     View convertView, ViewGroup parent) {    GroupInfo groupInfo = mGroupArray.get(groupPosition);    String string = groupInfo.getName();    convertView = (View) layoutInflater.inflate(R.layout.group_layout,      null);    final TextView textView = (TextView) convertView      .findViewById(R.id.groupName);    if (textView != null) {     textView.setText(string);    }    return convertView;   }   public boolean hasStableIds() {    return true;   }   public boolean isChildSelectable(int groupPosition, int childPosition) {    return true;   }  } }

代碼只是提取的部分,應該沒多大影響.

上面集合mGroupArray存在數據共享,測試多次發現報錯有兩種:

=>1.java.lang.IndexOutOfBoundsException: Invalid location 3, size is 3
=>2.The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread.

第一個問題,數據同步問題,我弄了下沒解決.
第二個問題,改變適配器Adapter內容時不要在后臺線程中,必須在UI線程中處理
我將上面子線程UpdateGroupHandler里的數據更新利用handler提取到了主線程賦值

Message.obj = groupList;

額,改好后測試多次,發現這兩問題都解決了,發現還是對handler理解的不夠.

發下更改的代碼段:

@Override public void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.main);  mElv = (ExpandableListView) findViewById(R.id.contact_list);  mStatus = (TextView) findViewById(R.id.setStatus);  mGroupArray = getIntent().getParcelableArrayListExtra("groupArray"); // => 取數據  mExpandableAdapter = new ExpandableAdapter(this, Main.this);  mElv.setAdapter(mExpandableAdapter);    // 異步對比服務器分組和本地分組  HandlerThread handlerThread = new HandlerThread("handler_thread");  handlerThread.start();  UpdateGroupHandler myHandler = new UpdateGroupHandler(    handlerThread.getLooper());  Message message = myHandler.obtainMessage();  message.sendToTarget();  mHandler = new Handler() {   public void handleMessage(Message msg) {    switch (msg.what) {    case STATUS_CHANGE:     // 處理UI更新等操作     updateUI(msg.obj);     break;    }   };  };  } /** * 發送消息更新UI */ private void sendMessageToUpdateUI(ArrayList<GroupInfo> groupList) {  Message msg = new Message();  msg.what = STATUS_CHANGE;  msg.obj = groupList;  mHandler.sendMessage(msg); // 向Handler發送消息,更新UI }  @SuppressWarnings("unchecked") private void updateUI(Object obj) {  // 詳細的更新  mGroupArray = (ArrayList<GroupInfo>) obj;  mExpandableAdapter.notifyDataSetChanged(); // 更新ExpandableListView } /**  * 異步刷新分組的handler  *  * @author administrator  *  */ class UpdateGroupHandler extends Handler {  public UpdateGroupHandler() {  }  public UpdateGroupHandler(Looper looper) {   super(looper);  }  @Override  public void handleMessage(Message msg) {   ContactsManagerDbAdapter dbAdapter = new ContactsManagerDbAdapter(     Main.this);   dbAdapter.open();   // =>doSomeThing...   System.out.println("========數據更新后,刷新listview=========");   sendMessageToUpdateUI(groupList);  } }

希望本文所述對大家的Android程序設計有所幫助。

發表評論 共有條評論
用戶名: 密碼:
驗證碼: 匿名發表
主站蜘蛛池模板: 亚洲精品亚洲人成人网 | 久久久www成人免费无遮挡大片 | 国产精品69久久久久水密桃 | 亚洲色欧美 | 久久久国产一区二区三区 | 午夜在线影院 | 亚洲综合首页 | 国产乱a视频在线 | 亚洲免费小视频 | 免费av一区二区三区 | a视频在线观看免费 | 国产又黄又粗又爽的视频 | 国产精品成人品 | 欧美精品一区二区久久 | 成人一区视频 | 久久久久久久国产 | 色精品视频 | 97超碰超碰| 国产性×xxx盗摄xxxx | 一级片免费在线视频 | 久久成人在线视频 | 精产国产伦理一二三区 | 免费小视频 | 天天干com| 操人网| 夜夜操操操 | 久在线观看 | www.五月天婷婷 | 久久久精品一区 | 久久国产电影 | 在线看黄色av | 一区二区三区在线 | 久久密 | 一级免费毛片 | aaa级片| 久草久草 | 91蜜桃视频 | 一区二区三区在线观看视频 | 午夜精品在线观看 | 日韩精品 | 国产小视频在线播放 |