自定义适配器listview中存在问题 你能添加你得到的错误消息+堆栈跟踪吗？E/AndroidRuntime:致命异常：主进程：org.alljoyn.bus.sample.chat，PID:27015 java.util.ConcurrentModif

自定义适配器listview中存在问题

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你能添加你得到的错误消息+堆栈跟踪吗？E/AndroidRuntime:致命异常：主进程：org.alljoyn.bus.sample.chat，PID:27015 java.util.ConcurrentModificationException请将其添加到问题中。我不能确切地说出错误现在在哪里，但当您在遍历集合时修改集合时会引发该错误。当我在自定义适配器中动态获取值时，它会显示空指针异常

import org.alljoyn.bus.sample.chat.ChatApplication;
import org.alljoyn.bus.sample.chat.Observable;
import org.alljoyn.bus.sample.chat.Observer;
import org.alljoyn.bus.sample.chat.DialogBuilder;

import java.lang.reflect.Array;
// ... more imports

public class UseActivity extends Activity implements Observer {
    private static final String TAG = "chat.UseActivity";

    public void onCreate(Bundle savedInstanceState) {
        Log.i(TAG, "onCreate()");
        super.onCreate(savedInstanceState);
        setContentView(R.layout.use);

        ListView hlv = (ListView) findViewById(R.id.useHistoryList);
        hlv.setAdapter(mHistoryList);

        EditText messageBox = (EditText)findViewById(R.id.useMessage);
        messageBox.setSingleLine();
        messageBox.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            public boolean onEditorAction(TextView view, int actionId, KeyEvent event) {
                if (actionId == EditorInfo.IME_ACTION_DONE) {
                    message = view.getText().toString();
                    Log.i(TAG, "useMessage.onEditorAction(): got message " + message + ")");
                    mHistoryList.add(message);

                    mChatApplication.newLocalUserMessage(message);
                    view.setText("");
                }
                return true;
            }
        });

        Button mAlertButton = (Button)findViewById(R.id.alert);
        mAlertButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                message = "www.google.com" ;
                mHistoryList.add(message);
                mChatApplication.newLocalUserMessage(message);
            }
        });

        mJoinButton = (Button)findViewById(R.id.useJoin);
        mJoinButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                showDialog(DIALOG_JOIN_ID);
            }
        });

        mLeaveButton = (Button)findViewById(R.id.useLeave);
        mLeaveButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                showDialog(DIALOG_LEAVE_ID);
            }
        });

        mChannelName = (TextView)findViewById(R.id.useChannelName);
        mChannelStatus = (TextView)findViewById(R.id.useChannelStatus);

        /*
         * Keep a pointer to the Android Application class around.  We use this
         * as the Model for our MVC-based application.    Whenever we are started
         * we need to "check in" with the application so it can ensure that our
         * required services are running.
         */
        mChatApplication = (ChatApplication)getApplication();
        mChatApplication.checkin();

        /*
         * Call down into the model to get its current state.  Since the model
         * outlives its Activities, this may actually be a lot of state and not
         * just empty.
         */
        updateChannelState();
        updateHistory();

        /*
         * Now that we're all ready to go, we are ready to accept notifications
         * from other components.
         */
        mChatApplication.addObserver(this);
    }

    public void onDestroy() {
        Log.i(TAG, "onDestroy()");
        mChatApplication = (ChatApplication)getApplication();
        mChatApplication.deleteObserver(this);
        super.onDestroy();
    }

    public static final int DIALOG_JOIN_ID = 0;
    public static final int DIALOG_LEAVE_ID = 1;
    public static final int DIALOG_ALLJOYN_ERROR_ID = 2;

    protected Dialog onCreateDialog(int id) {
        Log.i(TAG, "onCreateDialog()");
        Dialog result = null;
        switch(id) {
        case DIALOG_JOIN_ID:
            {
                DialogBuilder builder = new DialogBuilder();
                result = builder.createUseJoinDialog(this, mChatApplication);
            }
            break;
        case DIALOG_LEAVE_ID:
            {
                DialogBuilder builder = new DialogBuilder();
                result = builder.createUseLeaveDialog(this, mChatApplication);
            }
            break;
        case DIALOG_ALLJOYN_ERROR_ID:
            {
                DialogBuilder builder = new DialogBuilder();
                result = builder.createAllJoynErrorDialog(this, mChatApplication);
            }
            break;
        }
        return result;
    }

    public synchronized void update(Observable o, Object arg) {
        Log.i(TAG, "update(" + arg + ")");
        String qualifier = (String)arg;

        if (qualifier.equals(ChatApplication.APPLICATION_QUIT_EVENT)) {
            Message message = mHandler.obtainMessage(HANDLE_APPLICATION_QUIT_EVENT);
            mHandler.sendMessage(message);
        }

        if (qualifier.equals(ChatApplication.HISTORY_CHANGED_EVENT)) {
            Message message = mHandler.obtainMessage(HANDLE_HISTORY_CHANGED_EVENT);
            mHandler.sendMessage(message);
        }

        if (qualifier.equals(ChatApplication.USE_CHANNEL_STATE_CHANGED_EVENT)) {
            Message message = mHandler.obtainMessage(HANDLE_CHANNEL_STATE_CHANGED_EVENT);
            mHandler.sendMessage(message);
        }

        if (qualifier.equals(ChatApplication.ALLJOYN_ERROR_EVENT)) {
            Message message = mHandler.obtainMessage(HANDLE_ALLJOYN_ERROR_EVENT);
            mHandler.sendMessage(message);
        }
    }

    private void updateHistory() {
        Log.i(TAG, "updateHistory()");
      List <String> messages = mChatApplication.getHistory();
        mHistoryList = new SimpleAdapter (this, messages);
        for (String message : messages) {
            mHistoryList.add(message);
        }
        mHistoryList.notifyDataSetChanged();
    }

    private void updateChannelState() {
        Log.i(TAG, "updateHistory()");
        AllJoynService.UseChannelState channelState = mChatApplication.useGetChannelState();
        String name = mChatApplication.useGetChannelName();
        if (name == null) {
            name = "Not set";
        }
        mChannelName.setText(name);

        switch (channelState) {
        case IDLE:
            mChannelStatus.setText("Idle");
            mJoinButton.setEnabled(true);
            mLeaveButton.setEnabled(false);
            break;
        case JOINED:
            mChannelStatus.setText("Joined");
            mJoinButton.setEnabled(false);
            mLeaveButton.setEnabled(true);
            break;
        }
    }

    /**
     * An AllJoyn error has happened.  Since this activity pops up first we
     * handle the general errors.  We also handle our own errors.
     */
    private void alljoynError() {
        if (mChatApplication.getErrorModule() == ChatApplication.Module.GENERAL ||
            mChatApplication.getErrorModule() == ChatApplication.Module.USE) {
            showDialog(DIALOG_ALLJOYN_ERROR_ID);
        }
    }

    private static final int HANDLE_APPLICATION_QUIT_EVENT = 0;
    private static final int HANDLE_HISTORY_CHANGED_EVENT = 1;
    private static final int HANDLE_CHANNEL_STATE_CHANGED_EVENT = 2;
    private static final int HANDLE_ALLJOYN_ERROR_EVENT = 3;

    private Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case HANDLE_APPLICATION_QUIT_EVENT:
                {
                    Log.i(TAG, "mHandler.handleMessage(): HANDLE_APPLICATION_QUIT_EVENT");
                    finish();
                }
                break;
            case HANDLE_HISTORY_CHANGED_EVENT:
                {
                    Log.i(TAG, "mHandler.handleMessage(): HANDLE_HISTORY_CHANGED_EVENT");
                    updateHistory();
                    break;
                }
            case HANDLE_CHANNEL_STATE_CHANGED_EVENT:
                {
                    Log.i(TAG, "mHandler.handleMessage(): HANDLE_CHANNEL_STATE_CHANGED_EVENT");
                    updateChannelState();
                    break;
                }
            case HANDLE_ALLJOYN_ERROR_EVENT:
                {
                    Log.i(TAG, "mHandler.handleMessage(): HANDLE_ALLJOYN_ERROR_EVENT");
                    alljoynError();
                    break;
                }
            default:
                break;
            }
        }
    };

    private ChatApplication mChatApplication = null;

    String message;

    private SimpleAdapter mHistoryList;

    private Button mJoinButton;
    private Button mLeaveButton;

    private TextView mChannelName;

    private TextView mChannelStatus;
}

import android.text.util.Linkify;
// ... more imports

public class SimpleAdapter extends ArrayAdapter<String> {
    private final Context context;
    private final List<String> values;

    public SimpleAdapter(Context context, List <String> values) {
        super(context, -1, values);
        this.context = context;
        this.values = values;
    }

    @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.view, parent, false);
        TextView textView = (TextView) rowView.findViewById(R.id.text);
        textView.setText(values.get(position));
        Linkify.addLinks(textView,Linkify.WEB_URLS);

        return rowView;
    }
}