异步造成的参数传不进去

这是困扰我很久的一个问题。现在做一下总结。
出于性能优化角度考虑，Android UI操作并不是线程安全的，意味着如果有多个线程并发操作UI组件可能导致线程安全问题。因而，只允许UI线程修改Activity里的UI组件。当程序第一次启动时，Android会同时启动一条Main Thread（主线程），Main Thread主要负责处理与UI相关的事件，比如按键触屏及屏幕绘图，并将相关事件分发到对应的组件进行处理。因此Main Thread称为UI线程。
Android 的消息传递机制是另一种形式的“事件处理”，这种传递机制主要为了解决Android 应用多线程的问题——新启动的线程无法动态改变界面组件的属性值。实际开发中，需让新启动的线程周期性改变界面组件的属性值，需要借助Handle消息传递机制来实现。
————————————————————————————

Handle，作用有二：在新启动的线程里发送消息；在主线程中获取处理消息。为了使主线程能适时处理新线程所发动的消息，显然只能通过回调的方式——重写Handle类中处理消息的办法，当启动新线程发送消息时，消息会发生到与之关联的MessageQuene，Handle会不断从MessageQueue获取并处理消息——这将导致Handle类中处理消息方法回调。

Message：Handle接受处理的消息；
Looper：每个线程只有一个。它的loop方法负责读取 MessageQueue中的消息，读到后将消息给Handle处理；
MessageQueue：消息队列，采用先进先出得方式管理Message。程序创建Looper对象时会在其构造器中创建MessageQueue对象。

在线程中调用Handle步骤：调用Looper的prepare（），为当前线程创建Looper对象，构造器与此同时创建配套MessageQueue；创建Handle子类实例，重写handleMessage();调用Looper的loop方法启动。

package ustb.sk.iotintelligence.activity;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.util.Log;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Button;import android.widget.ListView;import android.widget.SimpleAdapter;import com.android.volley.Request;import com.android.volley.RequestQueue;import com.android.volley.Response;import com.android.volley.VolleyError;import com.android.volley.toolbox.JsonObjectRequest;import com.android.volley.toolbox.Volley;import com.iflytek.cloud.RecognizerResult;import com.iflytek.cloud.SpeechConstant;import com.iflytek.cloud.SpeechError;import com.iflytek.cloud.SpeechUtility;import com.iflytek.cloud.ui.RecognizerDialog;import com.iflytek.cloud.ui.RecognizerDialogListener;import org.json.JSONException;import org.json.JSONObject;import java.net.URLEncoder;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Date;import java.util.HashMap;import java.util.LinkedHashMap;import java.util.List;import java.util.Map;import ustb.sk.iotintelligence.R;import ustb.sk.iotintelligence.speech.util.JsonParser;public class ChatTogether extends Activity {//回答没有显示在listview中    private Button btChat;    private ListView lvChat;    String TAG = ChatTogether.class.getSimpleName();    private RequestQueue mRequestQueue;    private String baseUrl="http://apis.baidu.com/turing/turing/turing";    private HashMap<String,String> mIatResults = new LinkedHashMap<String, String>();// 用HashMap存储说话人听写结果    List<Map<String,String>> lists = new ArrayList<Map<String, String>>();//创建一个List集合，集合元素是Map    Map<String,String> list = new HashMap<String, String>();//list由time与detail组成    final SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy年mm月dd日HH:mm:ss");    Date date = new Date(System.currentTimeMillis());//时间    final Handler handler=new Handler()    {        @Override        public void handleMessage(Message msg) {            switch (msg.what)            {                case 0x123:                    Log.v("vvvvv", "0123");                    String input  = msg.obj.toString();//将说话内容放入参数中                    Log.v("vvvvv","45");                    String requestUrl = baseUrl + "?key=879a6cb3afb84dbf4fc84a1df2ab7319&info=" + URLEncoder.encode(input) + "&userid=eb2edb736";      //              Log.v("test", "request url is" + requestUrl);                   //     String requestUrl="key=879a6cb3afb84dbf4fc84a1df2ab7319&info=%E6%9F%A5%E5%A4%A9%E6%B0%94%E2%80%9C%E5%8C%97%E4%BA%AC%E4%BB%8A%E5%A4%A9%E5%A4%A9%E6%B0%94%E2%80%9D&userid=eb2edb736";                    JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, requestUrl, null, new Response.Listener<JSONObject>() {                        @Override                        public void onResponse(JSONObject jsonObject) {                            try {                                Log.v("test", "get response success");                                Log.v("test", "response is" + jsonObject.get("text").toString());                                list.put("time", simpleDateFormat.format(date));                                list.put("detail", jsonObject.get("text").toString());                                lists.add(list);                                Log.v("timewhat2",list.get("time"));                                Log.v("detailwhat2", list.get("detail"));                            } catch (Exception exception) {                                Log.v("test", "json exception" + exception.toString());                            }                        }                    }, new Response.ErrorListener() {                        @Override                        public void onErrorResponse(VolleyError volleyError) {                            Log.v("test", "get response fail");                        }                    }) {                        @Override                        public Map<String, String> getHeaders() {                            HashMap<String, String> headers = new HashMap<String, String>();                            headers.put("apikey", "37d6b6cc3972f5392e35cf9e391b8b5e");//37d6b6cc3972f5392e35cf9e391b8b5e                            return headers;                        }                    };                    mRequestQueue.add(jsonObjectRequest);                    SimpleAdapter simpleAdapter = new SimpleAdapter(ChatTogether.this,lists,R.layout.notelist_item,new String[] { "time" , "detail" },new int[] {R.id.time, R.id.detail} );                    ListView listView = (ListView)findViewById(R.id.lvChat);                    listView.setAdapter(simpleAdapter);                    break;            }        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        SpeechUtility.createUtility(getApplicationContext(), SpeechConstant.APPID + "=55b20041");        setContentView(R.layout.activity_chat_together);        mRequestQueue = Volley.newRequestQueue(getApplication());        btChat = (Button) findViewById(R.id.btChat);        btChat.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {//点击说话                RecognizerDialog recognizerDialog = new RecognizerDialog(ChatTogether.this, null);//创建对象，本地听写的话第二个参数传InitListener                recognizerDialog.setParameter(SpeechConstant.DOMAIN, "iat");//设置听写参数,详见《科大讯飞MSC API手册(Android)》SpeechConstant类                recognizerDialog.setParameter(SpeechConstant.LANGUAGE, "zh_cn");                recognizerDialog.setParameter(SpeechConstant.ACCENT, "mandarin ");                recognizerDialog.setListener(recognizerDialogListener);//开始听写                recognizerDialog.show();//asset下的动画                Log.v("test", "click button");            }        });    }    public RecognizerDialogListener recognizerDialogListener = new RecognizerDialogListener() {//听写监听器        @Override        public void onResult(RecognizerResult recognizerResult, boolean isLast) {       /* 听写结果回调接口(返回Json格式结果,用户可参见附录12.1);         一般情况下会通过onResults接口多次返回结果,完整的识别内容是多次结果的累加;         关于解析Json的代码可参见MscDemo中JsonParser类;        isLast等于true时会话结束。*/            Log.v("jsonresult", recognizerResult.getResultString());            Log.v("this is dialog result", JsonParser.parseIatResult(recognizerResult.getResultString()));            Message  msg=new Message();            msg.what=0x123;            msg.obj=jsonChange(recognizerResult);            handler.sendMessage(msg);            list.put("time", simpleDateFormat.format(date));            list.put("detail", msg.obj.toString());            Log.v("timewhat1", list.get("time"));            Log.v("detailwhat1", list.get("detail"));        }        @Override        public void onError(SpeechError speechError) {            Log.v(TAG,"this is error");            Log.v(TAG, speechError.toString());        }    };    public  String jsonChange(RecognizerResult results) {//将json转换为汉字－－我还不太懂        String text = JsonParser.parseIatResult(results.getResultString());        String sn = null;        // 读取json结果中的sn字段        try {            JSONObject resultJson = new JSONObject(results.getResultString());            sn = resultJson.optString("sn");        } catch (JSONException e) {            e.printStackTrace();        }        mIatResults.put(sn, text);        StringBuffer resultBuffer = new StringBuffer();        for (String key : mIatResults.keySet()) {            resultBuffer.append(mIatResults.get(key));        }        Log.v("finalresult", resultBuffer.toString());        return resultBuffer.toString();    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.menu_chat_together, menu);        return true;    }    @Override    public boolean onOptionsItemSelected(MenuItem item) {        // Handle action bar item clicks here. The action bar will        // automatically handle clicks on the Home/Up button, so long        // as you specify a parent activity in AndroidManifest.xml.        int id = item.getItemId();        //noinspection SimplifiableIfStatement        if (id == R.id.action_settings) {            return true;        }        return super.onOptionsItemSelected(item);    }}