android中ListView數據刷新時的同步

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("========數據更新後,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內容時不要在後臺線程中,必須在UI線程中處理

我將上面子線程UpdateGroupHandler裏的數據更新利用handler提取到了主線程賦值

Message.obj = groupList;

額,改好後測試多次,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("========數據更新後,刷新listview=========");
                        sendMessageToUpdateUI(groupList);
                }

        }