调用课程时遇到问题。我没有得到解决我的确切问题的方法。直到我的工作是：
Task.java：
public class Task extends AsyncTask<Void, Void, String>
{
Context context;
FragmentActivity currentActivity;
ProgressDialog dialog;
public Task(FragmentActivity activity)
{
currentActivity = activity;
context=Constant.getContext();
}
@Override
protected void onPreExecute()
{
dialog=ProgressDialog.show(currentActivity, "Please wait...", "Loading...");
}
@Override
protected String doInBackground(Void... params)
{
ActivityWeatherSetting hh = new ActivityWeatherSetting();
hh.initialize();
return "success";
}
@Override
protected void onPostExecute(String params)
{
//asyncclass.dismissProgressDialog();
dialog.dismiss();
}
}
AsyncClass.java：
public abstract class AsyncClass extends Activity
{
protected static final String TAG = AsyncClass.class.getSimpleName();
public ProgressDialog progressDialog;
private boolean destroyed = false;
Context context;
@Override
protected void onDestroy()
{
super.onDestroy();
destroyed = true;
}
public void showLoadingProgressDialog()
{
context=Constant.getContext();
this.showProgressDialog("Loading. Please wait...");
Log.d("this",this.toString());
}
public void showProgressDialog(CharSequence message)
{
if (progressDialog == null)
{
progressDialog = new ProgressDialog(this);
progressDialog.setIndeterminate(true);
}
progressDialog.setMessage(message);
progressDialog.show();
}
public void dismissProgressDialog()
{
if (progressDialog != null && !destroyed)
{
progressDialog.dismiss();
}
}
}
ActivityWeatherSetting.java：
public void initialize()
{
LayoutInflater layout = new LayoutInflater(Constant.getContext()) {
@Override
public LayoutInflater cloneInContext(Context newContext) {
return null;
}
};
view=(View)layout.inflate(R.layout.activity_grid_layout, null);
boolean bResult = initializeData();
if (bResult != false ){
bResult = initializeView();
}
if (bResult == false){
Log.e(TAG,"Init data failed");
return;
}
drawWeatherScreen();
}
private void updateDataOfCurrentLocation(){
requestUpdateWeather();
}
private void requestUpdateWeather(){
Message msgFetchData = new Message();
msgFetchData.what = REG_GET_WEATHER_START;
m_HandleRequest.sendMessage(msgFetchData);
}
private void initializeHandleRequest(){
m_Runnable = new Runnable(){
//@Override
public void run() {
requestUpdateWeather();
}
};
/* Setting up handler for ProgressBar */
m_HandleRequest = new Handler(){
@Override
public void handleMessage(Message message) {
int nRequest = message.what;
switch(nRequest){
case REG_GET_WEATHER_START:
String strWOEID = m_Preferneces.getLocation();
if (strWOEID == null){
Log.e(TAG,"Can not get WOEID");
//m_ProgressDialog.dismiss();
//displayNotifyCation(R.string.strFetchFailed);
return;
} else {
//Get weather information
m_WeatherInfo = m_DataModel.getWeatherData(strWOEID);
}
Message msgRegSearch = new Message();
msgRegSearch.what = REG_GET_WEATHER_FINISH;
sendMessage(msgRegSearch);
break;
case REG_GET_WEATHER_FINISH:
if (m_WeatherInfo != null){
updateWeatherInfo(m_WeatherInfo);
//notifyUpdateTime();
}
//m_ProgressDialog.dismiss();
m_HandleRequest.postDelayed(m_Runnable, (ONE_MINUTE*m_Preferneces.getTimeUpdate()));
break;
default:
Log.e(TAG,"Can not handle this message");
break;
}
}
};
}
private boolean initializeView(){
m_TextLocation = (TextView)view.findViewById(R.id.weatherset_location_txtview);
m_Temperature = (TextView)view.findViewById(R.id.weatherset_temp_txtview);
m_Humimidy = (TextView)view.findViewById(R.id.weatherset_humidity_txtview);
m_Visibility = (TextView)view.findViewById(R.id.weatherset_visibility_txtview);
m_WeatherIcon = (ImageView) view.findViewById(R.id.weather_icon);
m_Date = (TextView)view.findViewById(R.id.dateTime);
if ((m_TextLocation == null) || (m_Temperature == null) ||
(m_Humimidy == null) || (m_WeatherIcon == null) ||
(m_Visibility == null) || (m_Date == null)){
Log.e(TAG,"View init failed");
return false;
}
return true;
}
private boolean initializeData(){
/* Get application context */
Context appContext = view.getContext();
/* Get preference instance */
m_Preferneces = WeatherPreferences.getInstance(appContext);
if (m_Preferneces == null){
Log.e(TAG, "Get preference instance failed, check please");
return false;
}
/* Get instance of data model */
m_DataModel = WeatherDataModel.getInstance();
if (m_DataModel == null){
Log.e(TAG,"Can not get data model");
return false;
}
initializeHandleRequest();
return true;
}
private void drawWeatherScreen(){
/
updateDataOfCurrentLocation();
}
private void updateWeatherInfo(WeatherInfo weatherInfo)
{
try
{
if (weatherInfo == null){
Log.e(TAG,"Weather is null");
return;
}
String strCode = weatherInfo.getCode();
int nCode = getImageByCode(strCode);
m_WeatherIcon.setImageResource(nCode);
boolean bIsC = m_Preferneces.getTempFmt();
String strFmt;
String strTemp = weatherInfo.getTemperature(WeatherInfo.TEMPERATURE_FMT_CELSIUS);
if (bIsC == true){
strFmt = view.getContext().getString(R.string.str_temperature_fmt);
} else {
strFmt = view.getContext().getString(R.string.str_temperature_fmt_f);
strTemp = WeatherDataModel.convertC2F(strTemp);
}
//String strTemperature = String.format(strFmt, strTemp);
strTemperature = String.format(strFmt, strTemp);
m_TextLocation.setText(weatherInfo.getCity());
m_Temperature.setText(strTemperature);
m_Date.setText(weatherInfo.getDate());
TextView humidity=(TextView)view.findViewById(R.id.humidityValue);
TextView visibility=(TextView)view.findViewById(R.id.visiValue);
strFmt = view.getContext().getString(R.string.str_humidity_fmt);
String strHumidity = String.format(strFmt, weatherInfo.getHumidity());
//m_Humimidy.setText(strHumidity);
humidity.setText(strHumidity);
strFmt = view.getContext().getString(R.string.str_visi_fmt);
String strVisi = String.format(strFmt, weatherInfo.getVisibility());
//m_Visibility.setText(strVisi);
visibility.setText(strVisi);
}
catch(Exception e)
{
//Toast.makeText(ActivityWeatherSetting.this, e.getMessage(), Toast.LENGTH_LONG).show();
}
private int getImageByCode(String strCode){
int nImageCode = R.drawable.a0;
if (strCode == null){
Log.e(TAG,"Code is null");
return nImageCode;
}
int nCode = Integer.parseInt(strCode);
int nNumber= YahooWeatherHelper.m_ImageArr.length;
for (int i=0; i < nNumber; i++){
if (nCode == YahooWeatherHelper.m_ImageArr[i][1]){
return YahooWeatherHelper.m_ImageArr[i][0];
}
}
return nImageCode;
}
LogCat中的例外：
11-18 13:38:20.510: E/AndroidRuntime(585): FATAL EXCEPTION: AsyncTask #1
11-18 13:38:20.510: E/AndroidRuntime(585): java.lang.RuntimeException: An error occured while executing doInBackground()
11-18 13:38:20.510: E/AndroidRuntime(585): at android.os.AsyncTask$3.done(AsyncTask.java:278)
11-18 13:38:20.510: E/AndroidRuntime(585): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
11-18 13:38:20.510: E/AndroidRuntime(585): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
11-18 13:38:20.510: E/AndroidRuntime(585): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
11-18 13:38:20.510: E/AndroidRuntime(585): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
11-18 13:38:20.510: E/AndroidRuntime(585): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
11-18 13:38:20.510: E/AndroidRuntime(585): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
11-18 13:38:20.510: E/AndroidRuntime(585): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
11-18 13:38:20.510: E/AndroidRuntime(585): at java.lang.Thread.run(Thread.java:856)
11-18 13:38:20.510: E/AndroidRuntime(585): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
11-18 13:38:20.510: E/AndroidRuntime(585): at android.os.Handler.<init>(Handler.java:121)
11-18 13:38:20.510: E/AndroidRuntime(585): at com.net.elderlyhealth.weather.ActivityWeatherSetting$3.<init>(ActivityWeatherSetting.java:384)
11-18 13:38:20.510: E/AndroidRuntime(585): at com.net.elderlyhealth.weather.ActivityWeatherSetting.initializeHandleRequest(ActivityWeatherSetting.java:384)
11-18 13:38:20.510: E/AndroidRuntime(585): at com.net.elderlyhealth.weather.ActivityWeatherSetting.initializeData(ActivityWeatherSetting.java:561)
11-18 13:38:20.510: E/AndroidRuntime(585): at com.net.elderlyhealth.weather.ActivityWeatherSetting.initialize(ActivityWeatherSetting.java:137)
11-18 13:38:20.510: E/AndroidRuntime(585): at com.net.elderlyhealth.weather.Task.doInBackground(Task.java:44)
11-18 13:38:20.510: E/AndroidRuntime(585): at com.net.elderlyhealth.weather.Task.doInBackground(Task.java:1)
11-18 13:38:20.510: E/AndroidRuntime(585): at android.os.AsyncTask$2.call(AsyncTask.java:264)
11-18 13:38:20.510: E/AndroidRuntime(585): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
11-18 13:38:20.510: E/AndroidRuntime(585): ... 5 more
11-18 13:38:23.420: I/dalvikvm(585): threadid=3: reacting to signal 3
11-18 13:38:23.561: I/dalvikvm(585): Wrote stack traces to '/data/anr/traces.txt'
11-18 13:38:23.920: I/dalvikvm(585): threadid=3: reacting to signal 3
11-18 13:38:24.032: I/dalvikvm(585): Wrote stack traces to '/data/anr/traces.txt'
11-18 13:38:24.940: E/WindowManager(585): Activity com.net.elderlyhealth.view.ViewPagerFragmentActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4149f628 that was originally added here
11-18 13:38:24.940: E/WindowManager(585): android.view.WindowLeaked: Activity com.net.elderlyhealth.view.ViewPagerFragmentActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4149f628 that was originally added here
11-18 13:38:24.940: E/WindowManager(585): at android.view.ViewRootImpl.<init>(ViewRootImpl.java:344)
11-18 13:38:24.940: E/WindowManager(585): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:267)
11-18 13:38:24.940: E/WindowManager(585): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:215)
11-18 13:38:24.940: E/WindowManager(585): at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:140)
11-18 13:38:24.940: E/WindowManager(585): at android.view.Window$LocalWindowManager.addView(Window.java:537)
11-18 13:38:24.940: E/WindowManager(585): at android.app.Dialog.show(Dialog.java:278)
11-18 13:38:24.940: E/WindowManager(585): at android.app.ProgressDialog.show(ProgressDialog.java:116)
11-18 13:38:24.940: E/WindowManager(585): at android.app.ProgressDialog.show(ProgressDialog.java:99)
11-18 13:38:24.940: E/WindowManager(585): at android.app.ProgressDialog.show(ProgressDialog.java:94)
11-18 13:38:24.940: E/WindowManager(585): at com.net.elderlyhealth.view.SampleGridTwoFragment$1.onItemClick(SampleGridTwoFragment.java:119)
11-18 13:38:24.940: E/WindowManager(585): at android.widget.AdapterView.performItemClick(AdapterView.java:292)
11-18 13:38:24.940: E/WindowManager(585): at android.widget.AbsListView.performItemClick(AbsListView.java:1058)
11-18 13:38:24.940: E/WindowManager(585): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2514)
11-18 13:38:24.940: E/WindowManager(585): at android.widget.AbsListView$1.run(AbsListView.java:3168)
11-18 13:38:24.940: E/WindowManager(585): at android.os.Handler.handleCallback(Handler.java:605)
11-18 13:38:24.940: E/WindowManager(585): at android.os.Handler.dispatchMessage(Handler.java:92)
11-18 13:38:24.940: E/WindowManager(585): at android.os.Looper.loop(Looper.java:137)
11-18 13:38:24.940: E/WindowManager(585): at android.app.ActivityThread.main(ActivityThread.java:4424)
11-18 13:38:24.940: E/WindowManager(585): at java.lang.reflect.Method.invokeNative(Native Method)
11-18 13:38:24.940: E/WindowManager(585): at java.lang.reflect.Method.invoke(Method.java:511)
11-18 13:38:24.940: E/WindowManager(585): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
11-18 13:38:24.940: E/WindowManager(585): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
11-18 13:38:24.940: E/WindowManager(585): at dalvik.system.NativeStart.main(Native Method)
我在SO中看到了AsyncTask问题中的很多问题，但这些都没有帮助我。我需要帮助...
答案 0 :(得分：0)
问题在于，当您致电hh.initialize()时，您已经在后台线程中，创建Handler为时已晚。实际上，您的代码正在尝试从后台线程中执行大量UI工作。您应该将UI线程外部实际需要完成的内容分离到一个单独的方法中，并且只从AsyncTask的doInBackground调用该方法。