在我的应用中，我在MainActivity设置闹钟，我想从其他活动（FakeRinger）取消闹钟。这是我的代码。
MainActivity
public class MainActivity extends AppCompatActivity {
public static final String LOG_TAG = "MainActivity";
ImageView imageView;
EditText number, name;
Button setTimeButton;
ImageButton imageButton;
TimePickerDialog timePicker;
long selectedTimeInMillis;
String enteredName, enteredNumber;
private static final int SELECT_IMAGE = 100;
public static final int REQUEST_CODE_PI = 1001;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
PreferenceManager.setDefaultValues(this, R.xml.settings, false);
imageView = findViewById(R.id.image_view);
setTimeButton = findViewById(R.id.set_time);
imageButton = findViewById(R.id.place_call_button);
number = findViewById(R.id.number);
name = findViewById(R.id.name);
imageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent galleryIntent = new Intent(Intent.ACTION_PICK);
galleryIntent.setType("image/*");
startActivityForResult(galleryIntent, SELECT_IMAGE);
}
});
setTimeButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final Calendar calendar = Calendar.getInstance();
int hour = calendar.get(Calendar.HOUR_OF_DAY);
int minute = calendar.get(Calendar.MINUTE);
timePicker = new TimePickerDialog(MainActivity.this, new TimePickerDialog.OnTimeSetListener() {
@Override
public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
calendar.set(Calendar.HOUR_OF_DAY, hourOfDay);
calendar.set(Calendar.MINUTE, minute);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
selectedTimeInMillis = calendar.getTimeInMillis();
if (hourOfDay > 12) {
hourOfDay = hourOfDay - 12;
}
Toast.makeText(MainActivity.this, hourOfDay + ":" + minute, Toast.LENGTH_SHORT).show();
Log.v(LOG_TAG, "Selected time in millis:" + selectedTimeInMillis);
}
}, hour, minute, false);
timePicker.show();
}
});
imageButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
enteredName = name.getText().toString().trim();
enteredNumber = number.getText().toString().trim();
if (enteredNumber.isEmpty()){
Toast.makeText(MainActivity.this, "Please enter a number", Toast.LENGTH_LONG).show();
return;
}
Intent intent = new Intent(MainActivity.this, AlarmReciever.class);
intent.putExtra("FAKE_NAME", enteredName);
intent.putExtra("FAKE_NUMBER", enteredNumber);
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), REQUEST_CODE_PI, intent, 0);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
if (alarmManager != null) {
alarmManager.set(AlarmManager.RTC_WAKEUP, selectedTimeInMillis, pendingIntent);
Toast.makeText(MainActivity.this, "Your call has been placed", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "Error: something wrong", Toast.LENGTH_SHORT).show();
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.settings:
Intent intent = new Intent(MainActivity.this, SettingsActivity.class);
startActivity(intent);
return true;
case R.id.quick_call:
quickCall();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
try {
Uri imageUri = data.getData();
InputStream imageStream = null;
if (imageUri != null) {
imageStream = getContentResolver().openInputStream(imageUri);
}
Bitmap selectedImage = BitmapFactory.decodeStream(imageStream);
imageView.setImageBitmap(selectedImage);
} catch (FileNotFoundException e) {
e.printStackTrace();
Toast.makeText(this, "Something went wrong", Toast.LENGTH_SHORT).show();
}
} else {
Toast.makeText(this, "You haven't picked any Image", Toast.LENGTH_SHORT).show();
}
}
public void quickCall(){
Calendar calendar = Calendar.getInstance();
calendar.get(Calendar.HOUR_OF_DAY);
calendar.get(Calendar.MINUTE);
long millis = calendar.getTimeInMillis();
Intent quickCallIntent = new Intent(MainActivity.this, AlarmReciever.class);
PendingIntent quickCallPendingIntent = PendingIntent.getBroadcast(getApplicationContext(), REQUEST_CODE_PI, quickCallIntent, 0);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
if (alarmManager != null) {
alarmManager.set(AlarmManager.RTC_WAKEUP, millis + 10000, quickCallPendingIntent);
Toast.makeText(MainActivity.this, "Your call has been placed", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "Error: something wrong", Toast.LENGTH_SHORT).show();
}
}
}
这是AlarmReciever类。
public class AlarmReciever extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String getFakeName = intent.getStringExtra("FAKE_NAME");
String getFakeNumber = intent.getStringExtra("FAKE_NUMBER");
Intent fakeRinger = new Intent();
fakeRinger.setClassName("com.example.mani.fakecall", "com.example.mani.fakecall.FakeRinger");
fakeRinger.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
fakeRinger.putExtra("USER_FAKE_NAME", getFakeName);
fakeRinger.putExtra("USER_FAKE_NUMBER", getFakeNumber);
context.startActivity(fakeRinger);
if(getFakeName != null){
Log.v("Fake name is", getFakeName);
}
if(getFakeNumber != null){
Log.v("Fake number is", getFakeNumber);
}
}
}
这是我要取消闹钟的FakeRinger活动。
public class FakeRinger extends AppCompatActivity {
TextView displayName, displayNumber, displayCarrier;
ImageButton alarmOffButton;
String carrierName;
ImageView displayImage;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fake_ringer);
displayName = findViewById(R.id.display_name);
displayNumber = findViewById(R.id.display_number);
displayCarrier = findViewById(R.id.network_operator);
displayImage = findViewById(R.id.display_image);
TelephonyManager telephonyManager = (TelephonyManager) getSystemService(TELEPHONY_SERVICE);
if (telephonyManager != null) {
carrierName = telephonyManager.getNetworkOperatorName();
}
if (carrierName != null) {
displayCarrier.setText(getResources().getString(R.string.incoming_call, carrierName));
} else {
displayCarrier.setText(getResources().getString(R.string.incoming_call));
}
Intent intent = getIntent();
String userFakeNumber = intent.getExtras().getString("USER_FAKE_NUMBER");
displayNumber.setText(userFakeNumber);
displayName.setText(getFakeName());
alarmOffButton = findViewById(R.id.hang_up_call);
alarmOffButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(getApplicationContext(), AlarmReciever.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1001, intent, 0);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
if (alarmManager != null) {
alarmManager.cancel(pendingIntent);
}
}
});
}
private String getFakeName(){
String contacName = null;
Intent intent = getIntent();
contacName = intent.getExtras().getString("USER_FAKE_NAME");
if (contacName.isEmpty()){
contacName = "Unknown";
}
return contacName;
}
}
我在FakeRinger活动中使用的代码无效。我不知道为什么。
答案 0 :(得分：0)
快速而肮脏的方式是使用静态调用：
class MainActivity extends AppCompatActivity{
static MainActivity instance;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
instance = this;
}
public static MainActivity getInstance() {
return instance;
}
....
public void cancelAlarm(){
if (alarmManager != null) {
alarmManager.cancel(pendingIntent);
}
}
并在课堂上FakeAlarm：
class FakeAlarm extends AppCompatActivity{
public void clearData(){
MainActivity a = MainActivity.getInstance();
a.clear();
}
}
漫长道路：
为什么不将MainActivity从AppCompatActivity更改为FragmentActivity并创建FakeRinger
作为Fragment。这样，您可以更轻松地在父FragmentActivity和子Fragments之间共享组件和方法。有两个独立的父母＆＃34; （活动）在尝试共享方法/数据时会产生更多问题/障碍。
例如，您可以在MainActivity（FragmentActivity）中使用此功能一次：
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
然后有一个方法取消MainActivity中的警报：
public void cancelAlarm(){
if (alarmManager != null) {
alarmManager.cancel(pendingIntent);
}
}
如果您愿意，请在另一个片段（FakeAlarm）中调用该方法：
((MainActivity)getActivity()).cancelAlarm();
Pass object data between fragments and activity in android