如何处理 IOException？
How to handle IOException?
我正在尝试在我的应用程序中同步 google 任务。我创建了一个 class 来处理用于获取任务列表的方法和所有与任务相关的方法。
我想在UI中调用这些方法。
出于测试目的，我创建了一个 class，它扩展了 AsyncTask，在此我调用了 getTaskList 的方法。但它抛出异常，我认为我以错误的方式处理了它。
我想知道getTaskList方法提供的参数是listId。它应该 return 指定 id 列表中的所有任务。
现在我应该如何传递列表的 Id 来测试它是否完成 return 所有任务？
现在我得到的错误是：
FATAL EXCEPTION: AsyncTask #1
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: Process: com.example.siddhi.taskdemo, PID: 15993
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: java.lang.RuntimeException: An error occured while executing doInBackground()
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.AsyncTask.done(AsyncTask.java:304)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.FutureTask.run(FutureTask.java:242)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.lang.Thread.run(Thread.java:818)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.Handler.<init>(Handler.java:200)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.Handler.<init>(Handler.java:114)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.widget.Toast$TN.<init>(Toast.java:344)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.widget.Toast.<init>(Toast.java:100)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.widget.Toast.makeText(Toast.java:258)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at com.example.siddhi.taskdemo.TestAsyncTask.doInBackground(TestAsyncTask.java:54)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at com.example.siddhi.taskdemo.TestAsyncTask.doInBackground(TestAsyncTask.java:25)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.AsyncTask.call(AsyncTask.java:292)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.lang.Thread.run(Thread.java:818)
主要activity:
public class MainActivity extends AppCompatActivity {
GoogleAccountCredential mCredential;
public TextView mOutputText;
ProgressDialog mProgress;
static final int REQUEST_ACCOUNT_PICKER = 1000;
static final int REQUEST_AUTHORIZATION = 1001;
static final int REQUEST_GOOGLE_PLAY_SERVICES = 1002;
private static final String PREF_ACCOUNT_NAME = "accountName";
private static final String[] SCOPES = { TasksScopes.TASKS };
public com.google.api.services.tasks.Tasks mService = null;
/**
* Create the main activity.
* @param savedInstanceState previously saved instance data.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout activityLayout = new LinearLayout(this);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
activityLayout.setLayoutParams(lp);
activityLayout.setOrientation(LinearLayout.VERTICAL);
activityLayout.setPadding(16, 16, 16, 16);
ViewGroup.LayoutParams tlp = new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
mOutputText = new TextView(this);
mOutputText.setLayoutParams(tlp);
mOutputText.setPadding(16, 16, 16, 16);
mOutputText.setVerticalScrollBarEnabled(true);
mOutputText.setMovementMethod(new ScrollingMovementMethod());
activityLayout.addView(mOutputText);
mProgress = new ProgressDialog(this);
mProgress.setMessage("Calling Google Tasks API ...");
setContentView(activityLayout);
// Initialize credentials and service object.
SharedPreferences settings = getPreferences(Context.MODE_PRIVATE);
mCredential = GoogleAccountCredential.usingOAuth2(
getApplicationContext(), Arrays.asList(SCOPES))
.setBackOff(new ExponentialBackOff())
.setSelectedAccountName(settings.getString(PREF_ACCOUNT_NAME, null));
HttpTransport transport = AndroidHttp.newCompatibleTransport();
JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
mService = new com.google.api.services.tasks.Tasks.Builder(
transport, jsonFactory, mCredential)
.setApplicationName("Google Tasks API Android Quickstart")
.build();
}
/**
* Called whenever this activity is pushed to the foreground, such as after
* a call to onCreate().
*/
@Override
protected void onResume() {
super.onResume();
if (isGooglePlayServicesAvailable()) {
refreshResults();
} else {
mOutputText.setText("Google Play Services required: " +
"after installing, close and relaunch this app.");
}
}
/**
* Called when an activity launched here (specifically, AccountPicker
* and authorization) exits, giving you the requestCode you started it with,
* the resultCode it returned, and any additional data from it.
* @param requestCode code indicating which activity result is incoming.
* @param resultCode code indicating the result of the incoming
* activity result.
* @param data Intent (containing result data) returned by incoming
* activity result.
*/
@Override
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch(requestCode) {
case REQUEST_GOOGLE_PLAY_SERVICES:
if (resultCode != RESULT_OK) {
isGooglePlayServicesAvailable();
}
break;
case REQUEST_ACCOUNT_PICKER:
if (resultCode == RESULT_OK && data != null &&
data.getExtras() != null) {
String accountName =
data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
if (accountName != null) {
mCredential.setSelectedAccountName(accountName);
SharedPreferences settings =
getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putString(PREF_ACCOUNT_NAME, accountName);
editor.apply();
}
} else if (resultCode == RESULT_CANCELED) {
mOutputText.setText("Account unspecified.");
}
break;
case REQUEST_AUTHORIZATION:
if (resultCode != RESULT_OK) {
chooseAccount();
}
break;
}
super.onActivityResult(requestCode, resultCode, data);
}
/**
* Attempt to get a set of data from the Google Tasks API to display. If the
* email address isn't known yet, then call chooseAccount() method so the
* user can pick an account.
*/
private void refreshResults() {
if (mCredential.getSelectedAccountName() == null) {
chooseAccount();
} else {
if (isDeviceOnline()) {
new TestAsyncTask(mCredential, MainActivity.this).execute();
} else {
mOutputText.setText("No network connection available.");
}
}
}
/**
* Starts an activity in Google Play Services so the user can pick an
* account.
*/
private void chooseAccount() {
startActivityForResult(
mCredential.newChooseAccountIntent(), REQUEST_ACCOUNT_PICKER);
}
/**
* Checks whether the device currently has a network connection.
* @return true if the device has a network connection, false otherwise.
*/
private boolean isDeviceOnline() {
ConnectivityManager connMgr =
(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
return (networkInfo != null && networkInfo.isConnected());
}
/**
* Check that Google Play services APK is installed and up to date. Will
* launch an error dialog for the user to update Google Play Services if
* possible.
* @return true if Google Play Services is available and up to
* date on this device; false otherwise.
*/
private boolean isGooglePlayServicesAvailable() {
final int connectionStatusCode =
GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (GooglePlayServicesUtil.isUserRecoverableError(connectionStatusCode)) {
showGooglePlayServicesAvailabilityErrorDialog(connectionStatusCode);
return false;
} else if (connectionStatusCode != ConnectionResult.SUCCESS ) {
return false;
}
return true;
}
/**
* Display an error dialog showing that Google Play Services is missing
* or out of date.
* @param connectionStatusCode code describing the presence (or lack of)
* Google Play Services on this device.
*/
void showGooglePlayServicesAvailabilityErrorDialog(
final int connectionStatusCode) {
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(
connectionStatusCode,
MainActivity.this,
REQUEST_GOOGLE_PLAY_SERVICES);
dialog.show();
}
}
TestAsyncTask
public class TestAsyncTask extends AsyncTask<Void, Void, List<Task>>{
private com.google.api.services.tasks.Tasks mService = null;
private Exception mLastError = null;
private MainActivity activity;
private com.google.api.services.tasks.Tasks client = null;
public TestAsyncTask(GoogleAccountCredential credential, MainActivity activity) {
HttpTransport transport = AndroidHttp.newCompatibleTransport();
JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
mService = new com.google.api.services.tasks.Tasks.Builder(
transport, jsonFactory, credential)
.setApplicationName("Google Tasks API Android Quickstart")
.build();
this.activity = activity;
}
protected List<Task> doInBackground(Void... params) {
GTaskSyncer gTaskSyncer = new GTaskSyncer(activity);
List<Task> result = new ArrayList<>();
try {
result = gTaskSyncer.getTaskList("Bdjxxuj");
} catch (IOException e) {
Toast.makeText(activity,"IO Exception",Toast.LENGTH_SHORT).show();
}
return result;
}
@Override
protected void onPostExecute(List<Task> output) {
activity.mProgress.hide();
if (output == null || output.size() == 0) {
activity.mOutputText.setText("No results returned.");
} else {
activity.mOutputText.setText(TextUtils.join("\n", output));
}
}
}
GTaskSyncer
public class GTaskSyncer
{
final MainActivity activity;
final com.google.api.services.tasks.Tasks mService;
private Exception mLastError = null;
GTaskSyncer(MainActivity activity) {
this.activity = activity;
mService = activity.mService;
}
public List<TaskList> getAllTaskList() throws IOException
{
List<TaskList> result = new ArrayList<TaskList>();
TaskLists taskLists = mService.tasklists().list().execute();
for (TaskList taskList : taskLists.getItems()) {
result.add(taskList);
}
return result;
}
public TaskList createList() throws IOException
{
TaskList taskList = new TaskList();
taskList = activity.mService.tasklists().insert(taskList).execute();
return taskList;
}
public Task createTask(String listId) throws IOException
{
Task task = new Task();
task = activity.mService.tasks().insert(listId, task).execute();
return task;
}
public Task getTask(String listId,String taskId) throws IOException
{
Task task = activity.mService.tasks().get(listId, taskId).execute();
return task;
}
public List<Task> getTaskList(String listId) throws IOException {
List<Task> result = new ArrayList<Task>();
List<Task> tasks = mService.tasks().list(listId).execute().getItems();
if (tasks != null) {
for (Task task : tasks) {
result.add(task);
}
} else {
Toast.makeText(activity, "No tasks.", Toast.LENGTH_SHORT).show();
}
return result;
}
}
请帮忙..
您不能在后台线程中显示 toast。
使用这个：
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(activity, "No tasks.", Toast.LENGTH_SHORT).show();
}
});
我正在尝试在我的应用程序中同步 google 任务。我创建了一个 class 来处理用于获取任务列表的方法和所有与任务相关的方法。
我想在UI中调用这些方法。
出于测试目的，我创建了一个 class，它扩展了 AsyncTask，在此我调用了 getTaskList 的方法。但它抛出异常，我认为我以错误的方式处理了它。
我想知道getTaskList方法提供的参数是listId。它应该 return 指定 id 列表中的所有任务。
现在我应该如何传递列表的 Id 来测试它是否完成 return 所有任务？
现在我得到的错误是：
FATAL EXCEPTION: AsyncTask #1
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: Process: com.example.siddhi.taskdemo, PID: 15993
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: java.lang.RuntimeException: An error occured while executing doInBackground()
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.AsyncTask.done(AsyncTask.java:304)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.FutureTask.run(FutureTask.java:242)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.lang.Thread.run(Thread.java:818)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.Handler.<init>(Handler.java:200)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.Handler.<init>(Handler.java:114)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.widget.Toast$TN.<init>(Toast.java:344)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.widget.Toast.<init>(Toast.java:100)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.widget.Toast.makeText(Toast.java:258)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at com.example.siddhi.taskdemo.TestAsyncTask.doInBackground(TestAsyncTask.java:54)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at com.example.siddhi.taskdemo.TestAsyncTask.doInBackground(TestAsyncTask.java:25)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.AsyncTask.call(AsyncTask.java:292)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
03-30 21:21:10.593 15993-16025/com.example.siddhi.taskdemo E/AndroidRuntime: at java.lang.Thread.run(Thread.java:818)
主要activity:
public class MainActivity extends AppCompatActivity {
GoogleAccountCredential mCredential;
public TextView mOutputText;
ProgressDialog mProgress;
static final int REQUEST_ACCOUNT_PICKER = 1000;
static final int REQUEST_AUTHORIZATION = 1001;
static final int REQUEST_GOOGLE_PLAY_SERVICES = 1002;
private static final String PREF_ACCOUNT_NAME = "accountName";
private static final String[] SCOPES = { TasksScopes.TASKS };
public com.google.api.services.tasks.Tasks mService = null;
/**
* Create the main activity.
* @param savedInstanceState previously saved instance data.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout activityLayout = new LinearLayout(this);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
activityLayout.setLayoutParams(lp);
activityLayout.setOrientation(LinearLayout.VERTICAL);
activityLayout.setPadding(16, 16, 16, 16);
ViewGroup.LayoutParams tlp = new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
mOutputText = new TextView(this);
mOutputText.setLayoutParams(tlp);
mOutputText.setPadding(16, 16, 16, 16);
mOutputText.setVerticalScrollBarEnabled(true);
mOutputText.setMovementMethod(new ScrollingMovementMethod());
activityLayout.addView(mOutputText);
mProgress = new ProgressDialog(this);
mProgress.setMessage("Calling Google Tasks API ...");
setContentView(activityLayout);
// Initialize credentials and service object.
SharedPreferences settings = getPreferences(Context.MODE_PRIVATE);
mCredential = GoogleAccountCredential.usingOAuth2(
getApplicationContext(), Arrays.asList(SCOPES))
.setBackOff(new ExponentialBackOff())
.setSelectedAccountName(settings.getString(PREF_ACCOUNT_NAME, null));
HttpTransport transport = AndroidHttp.newCompatibleTransport();
JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
mService = new com.google.api.services.tasks.Tasks.Builder(
transport, jsonFactory, mCredential)
.setApplicationName("Google Tasks API Android Quickstart")
.build();
}
/**
* Called whenever this activity is pushed to the foreground, such as after
* a call to onCreate().
*/
@Override
protected void onResume() {
super.onResume();
if (isGooglePlayServicesAvailable()) {
refreshResults();
} else {
mOutputText.setText("Google Play Services required: " +
"after installing, close and relaunch this app.");
}
}
/**
* Called when an activity launched here (specifically, AccountPicker
* and authorization) exits, giving you the requestCode you started it with,
* the resultCode it returned, and any additional data from it.
* @param requestCode code indicating which activity result is incoming.
* @param resultCode code indicating the result of the incoming
* activity result.
* @param data Intent (containing result data) returned by incoming
* activity result.
*/
@Override
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch(requestCode) {
case REQUEST_GOOGLE_PLAY_SERVICES:
if (resultCode != RESULT_OK) {
isGooglePlayServicesAvailable();
}
break;
case REQUEST_ACCOUNT_PICKER:
if (resultCode == RESULT_OK && data != null &&
data.getExtras() != null) {
String accountName =
data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
if (accountName != null) {
mCredential.setSelectedAccountName(accountName);
SharedPreferences settings =
getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putString(PREF_ACCOUNT_NAME, accountName);
editor.apply();
}
} else if (resultCode == RESULT_CANCELED) {
mOutputText.setText("Account unspecified.");
}
break;
case REQUEST_AUTHORIZATION:
if (resultCode != RESULT_OK) {
chooseAccount();
}
break;
}
super.onActivityResult(requestCode, resultCode, data);
}
/**
* Attempt to get a set of data from the Google Tasks API to display. If the
* email address isn't known yet, then call chooseAccount() method so the
* user can pick an account.
*/
private void refreshResults() {
if (mCredential.getSelectedAccountName() == null) {
chooseAccount();
} else {
if (isDeviceOnline()) {
new TestAsyncTask(mCredential, MainActivity.this).execute();
} else {
mOutputText.setText("No network connection available.");
}
}
}
/**
* Starts an activity in Google Play Services so the user can pick an
* account.
*/
private void chooseAccount() {
startActivityForResult(
mCredential.newChooseAccountIntent(), REQUEST_ACCOUNT_PICKER);
}
/**
* Checks whether the device currently has a network connection.
* @return true if the device has a network connection, false otherwise.
*/
private boolean isDeviceOnline() {
ConnectivityManager connMgr =
(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
return (networkInfo != null && networkInfo.isConnected());
}
/**
* Check that Google Play services APK is installed and up to date. Will
* launch an error dialog for the user to update Google Play Services if
* possible.
* @return true if Google Play Services is available and up to
* date on this device; false otherwise.
*/
private boolean isGooglePlayServicesAvailable() {
final int connectionStatusCode =
GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (GooglePlayServicesUtil.isUserRecoverableError(connectionStatusCode)) {
showGooglePlayServicesAvailabilityErrorDialog(connectionStatusCode);
return false;
} else if (connectionStatusCode != ConnectionResult.SUCCESS ) {
return false;
}
return true;
}
/**
* Display an error dialog showing that Google Play Services is missing
* or out of date.
* @param connectionStatusCode code describing the presence (or lack of)
* Google Play Services on this device.
*/
void showGooglePlayServicesAvailabilityErrorDialog(
final int connectionStatusCode) {
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(
connectionStatusCode,
MainActivity.this,
REQUEST_GOOGLE_PLAY_SERVICES);
dialog.show();
}
}
TestAsyncTask
public class TestAsyncTask extends AsyncTask<Void, Void, List<Task>>{
private com.google.api.services.tasks.Tasks mService = null;
private Exception mLastError = null;
private MainActivity activity;
private com.google.api.services.tasks.Tasks client = null;
public TestAsyncTask(GoogleAccountCredential credential, MainActivity activity) {
HttpTransport transport = AndroidHttp.newCompatibleTransport();
JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
mService = new com.google.api.services.tasks.Tasks.Builder(
transport, jsonFactory, credential)
.setApplicationName("Google Tasks API Android Quickstart")
.build();
this.activity = activity;
}
protected List<Task> doInBackground(Void... params) {
GTaskSyncer gTaskSyncer = new GTaskSyncer(activity);
List<Task> result = new ArrayList<>();
try {
result = gTaskSyncer.getTaskList("Bdjxxuj");
} catch (IOException e) {
Toast.makeText(activity,"IO Exception",Toast.LENGTH_SHORT).show();
}
return result;
}
@Override
protected void onPostExecute(List<Task> output) {
activity.mProgress.hide();
if (output == null || output.size() == 0) {
activity.mOutputText.setText("No results returned.");
} else {
activity.mOutputText.setText(TextUtils.join("\n", output));
}
}
}
GTaskSyncer
public class GTaskSyncer
{
final MainActivity activity;
final com.google.api.services.tasks.Tasks mService;
private Exception mLastError = null;
GTaskSyncer(MainActivity activity) {
this.activity = activity;
mService = activity.mService;
}
public List<TaskList> getAllTaskList() throws IOException
{
List<TaskList> result = new ArrayList<TaskList>();
TaskLists taskLists = mService.tasklists().list().execute();
for (TaskList taskList : taskLists.getItems()) {
result.add(taskList);
}
return result;
}
public TaskList createList() throws IOException
{
TaskList taskList = new TaskList();
taskList = activity.mService.tasklists().insert(taskList).execute();
return taskList;
}
public Task createTask(String listId) throws IOException
{
Task task = new Task();
task = activity.mService.tasks().insert(listId, task).execute();
return task;
}
public Task getTask(String listId,String taskId) throws IOException
{
Task task = activity.mService.tasks().get(listId, taskId).execute();
return task;
}
public List<Task> getTaskList(String listId) throws IOException {
List<Task> result = new ArrayList<Task>();
List<Task> tasks = mService.tasks().list(listId).execute().getItems();
if (tasks != null) {
for (Task task : tasks) {
result.add(task);
}
} else {
Toast.makeText(activity, "No tasks.", Toast.LENGTH_SHORT).show();
}
return result;
}
}
请帮忙..
您不能在后台线程中显示 toast。
使用这个：
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(activity, "No tasks.", Toast.LENGTH_SHORT).show();
}
});