Problem in killing activity - android

I have developed a small android app with 3 activities. In first activity there has a button(Next_Button). If i click the button then the second activity will appear. In second activity there also a button which will forward to third activity after clicking it. In third activity there is a button (Home_Button). If i click this button(Home_Button) then first activity will appear. Now i want to kill second activity when i click the Home_Button in the third activity to make first activity visible. How can i do this?
Please help.
Best wishes
Md. Fazla Rabbi

In third activity, write the below code for your Home button click event:
btnHome.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
startActivity(new Intent(this, firstActivity.class)
.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
}
});
For example, for back key pressed, we can override onBackPressed function:
#Override
public void onBackPressed() {
startActivity(new Intent(this, first firstActivity.class)
.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
return;
}
Update:
For your reference, this one is the same as your requirement: Android Intent.FLAG_ACTIVITY_SINGLE_TOP AND Intent.FLAG_ACTIVITY_CLEAR_TOP,
And one more example:
Go home feature with FLAG_ACTIVITY_CLEAR_TOP

You don't need to "kill" your activity.
In your third activity, if you start the first one with startActivity, you first activity will be shown.
The system will decide if your second activity (or your third) should be paused or destroyed.

just call finish() method of the second activity on Home button click.

Related

Wrong activity resumed after pressed back button

here is the brief of my activities actions :
Activity A is a launcher that call activity B with intent flag Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK.
When Activity A launch activity B, ondestroy is called in activity A, as expected.
When I press back button in activity B, ondestroy is called in activity B and it bring me to the hope launcher.
There are no alive activity at this moment, but the application is still visible and the task manager. When I click on it, it brings me to the activity A (maybe because it is the action MAIN in the manifest).
The behaviour I try to get is that when i press back button in activity B, it brings me to the home screen and I can return to is, as if it is root activity.
Can anyone help me for this ?
Thanks you !
If you click on the Back button in activity B, you will be able to navigate to the Home screen and return to the root activity(A) from the following sources.
why you used Intent.FLAG_ACTIVITY_CLEAR_TASK?
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
((Button)findViewById(R.id.btn_send)).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//Case 1.
//startActivity(new Intent(A.this, B.class).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK));
//Case 2.
startActivity(new Intent(A.this, B.class).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP));
}
});
}
FLAG_ACTIVITY_CLEAR_TASK
added in API level 11
int FLAG_ACTIVITY_CLEAR_TASK
If set in an Intent passed to Context.startActivity(), this flag will cause any existing task that would be associated with the activity to be cleared before the activity is started. That is, the activity becomes the new root of an otherwise empty task, and any old activities are finished. This can only be used in conjunction with FLAG_ACTIVITY_NEW_TASK.
Constant Value: 32768 (0x00008000)
Google Developer
You have to remove the flag FLAG_ACTIVITY_CLEAR_TASK, because as the android developer site here, the behavior will destroy your Activity A,
You need to remove that flag and then your activity will remain in the stack, and you will be able to back to activity A

Check if a previous activity exists

I have an activity. After checking some stuff, I want to go back to previous activity if a previous exists, and if not I want to start a SpecificActivity. How do i do it?
Edited:
Seems like no one is understanding what I meant, so let me rephrase. Lets say I am in Activity A. I don't know if A is the only activity in the stack. If there are other activities, then I want to finish A and pop the activity right below A in the stack into the foreground. If A is the only activity in the stack, I want to start some activity Z. How do i do it?
You have to pass class name as intent extra from both Splash and DashboardActiviy.
In List Activity you have to get the class name using getIntent().
When the user click back button, you need to check the class name based on that you can take decision.
if(name.equalIgnorecase(DashboardActivit.class.getSimpleName()){
//Add your intent
}else{
//
}
This may give you definite solution to you.Give a try
you can simply override the onBackpress()
#Override
public void onBackPressed() {
super.onBackPressed();
startActivity(new Intent(this, Destination_Activity.class));
finish();
}
call the next activity like.
Intent intent = new Intent(this,Your_Next_Activity.class);
startActivity(intent);
then it will call your another activity and your current activity will be on background if you will use finish() after calling next activity it will finish your current activity so don't use finish() after calling your next activity in this scenario.
After that when you press back button it will automatically finish current activity.

How to close activity and go back to previous activity in android

I have a main activity, that when I click on a button, starts a new activity, i used the following code to do so:
Intent intent = new Intent(this, SettingsActivity.class);
startActivity(intent);
The above code was run from the main activity.
Now in my new activity which is called by the main activity, I have a back button.
When I click on this back button I want my new activity to close and it must go back to the original main activity.
I have tried calling super.finish() and just finish() (from the new activity) but this then closes my entire application (including my main activity).
How can I just close the activity that is currently in focus, and then return to the main activity?
EDITED
The fact that my phone's back button also closes my entire app, leads me to think that i have started up the second activity incorrectly?
OK I have been looking,
I created a Settings Activity that uses the same manifest code and the same code to Start the activity.
For the settings Activity when I push the back button, it returns to the Main activity.
With the activity mentioned above in the main question it simply exits my entire app.
So the problem doesn't seem to be with the code to finish the activity but the activity itself.
I think you are calling finish() method in MainActivity before starting SettingsActivity.
The scenario which you have described will occur in following two ways:
EITHER
You have set android:noHistory = "true" for MainActivity inside AndroidManifest.xml which causes MainActivity to finish automatically on pressing the back key.
OR
Before switching to your 'SettingsActivity', you have called finish() in your MainActivity, which kills it. When you press back button,since no other activity is preset in stack to pop, it goes back to main screen.
You can go back to the previous activity by just calling finish() in the activity you are on. Note any code after the finish() call will be run - you can just do a return after calling finish() to fix this.
If you want to return results to activity one then when starting activity two you need:
startActivityForResults(myIntent, MY_REQUEST_CODE);
Inside your called activity you can then get the Intent from the onCreate() parameter or used
getIntent();
To set return a result to activity one then in activity two do
setResult(Activity.RESULT_OK, MyIntentToReturn);
If you have no intent to return then just say
setResult(Activity.RESULT_OK);
If the the activity has bad results you can use Activity.RESULT_CANCELED (this is used by default). Then in activity one you do
onActivityResult(int requestCode, int resultCode, Intent data) {
// Handle the logic for the requestCode, resultCode and data returned...
}
To finish activity two use the same methods with finish() as described above with your results already set.
if you use fragment u should use
getActivity().onBackPressed();
if you use single activity u can use
finish();
When you click your button you can have it call:
super.onBackPressed();
Button edit = (Button) view.findViewById(R.id.yourButton);
edit.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(this, YourMainActivity.class);
startActivity(intent);
finish();
}
});
try this code instead of finish:
onBackPressed();
I believe your second activity is probably not linked to your main activity as a child activity. Check your AndroidManifest.xml file and see if the <activity> entry for your child activity includes a android:parentActivityName attribute. It should look something like this:
<?xml ...?>
...
<activity
android:name=".MainActivity"
...>
</activity>
<activity
android:name=".ChildActivity"
android:parentActivityName=".MainActivity"
...>
</activity>
...
This closes the entire application:
this.finish();
You are making this too hard. If I understand what you are trying to do correctly, the built-in 'back' button and Android itself will do all the work for you: http://developer.android.com/guide/components/tasks-and-back-stack.html
Also, implementing a custom "back" button violates Core App Quality Guideline UX-N1: http://developer.android.com/distribute/googleplay/quality/core.html
I don't know if this is even usefull or not but I was strugling with the same problem and I found a pretty easy way, with only a global boolean variable and onResume() action. In my case, my Activity C if clicked in a specific button it should trigger the finish() of Activity B!
Activity_A -> Activity_B -> Activity_C
Activity_A (opens normally Activity_B)
Activity_B (on some button click opens Activity_C):
// Global:
boolean its_detail = false;
// -------
SharedPreferences prefs = getApplicationContext().getSharedPreferences("sharedpreferences", 0);
boolean v = prefs.getBoolean("select_client", false);
its_detail = v;
startActivity(C);
#Override
public void onResume(){
super.onResume();
if(its_detail == true){
finish();
}
}
So, whenever I click the button on Activity C it would do the "onResume()" function of Activity B and go back to Activity A.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if ( id == android.R.id.home ) {
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
Try this it works both on toolbar back button as hardware back button.
Finish closes the whole application, this is is something i hate in Android development not finish that is fine but that they do not keep up wit ok syntax they have
startActivity(intent)
Why not
closeActivity(intent)
?
We encountered a very similar situation.
Activity 1 (Opening) -> Activity 2 (Preview) -> Activity 3 (Detail)
Incorrect "on back press" Response
Device back press on Activity 3 will also close Activity 2.
I have checked all answers posted above and none of them worked. Java syntax for transition between Activity 2 and Activity 3 was reviewed to be correct.
Fresh from coding on calling out a 3rd party app. by an Activity. We decided to investigate the configuration angle - eventually enabling us to identify the root cause of the problem.
Scope: Configuration of Activity 2 (caller).
Root Cause:
android:launchMode="singleInstance"
Solution:
android:launchMode="singleTask"
Apparently on this "on back press" issue singleInstance considers invoked Activities in one instance with the calling Activity, whereas singleTask will allow for invoked Activities having their own identity enough for the intended on back press to function to work as it should to.
on onCreate method of your activity
write the following code.
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
Then override the onOptionsItem selected method of your activity as follows
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case android.R.id.home:
finish();
}
return super.onOptionsItemSelected(item);
}
And you are good to go.
Just don't call finish() on your MainActivity then this eliminates the need to Override your onBackPressed() in your SecondActivity unless you are doing other things in that function. If you feel the "need" for this back button then you can simply call finish() on the SecondActivity and that will take you to your MainActivity as long as you haven't called finish() on it
it may be possible you are calling finish(); in the click button event so the main activity is closed just after you clicking the button and when you are coming back from next activity the application is exit because main activity is already closed and there is no active activity.
You have to use this in your MainActivity
Intent intent = new Intent(context , yourActivity);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |Intent.FLAG_ACTIVITY_MULTIPLE_TASK);
context.startActivity(intent);
The flag will start multiple tasks that will keep your MainActivity, when you call finish it will kill the other activity and get you back to the MainActivity
In case none of the above answers helped, I think this might help someone.
I was also having the same problem while pressing the built-in back button or my custom back button, the app closes without returning to the previous activity.
I was calling the second activity from the first activity's toolbar.
But in the starter activity I was calling this:
case android.R.id.home:
if (isActionMode) {
clearSelectingToolbar();
adapter.notifyDataSetChanged();
} else {
onBackPressed(); // This was making the activity to finish
}
break;
And this code to start the activity
case R.id.settings:
context.startActivity(new Intent(ShowAllDirectoriesActivity.this, SettingsActivity.class));
After removing 'case android.R.id.home' part, my activity was able to perform in a normal flow i.e getting back to the previous activity.
So check it if you are also using the same thing!
{ getApplicationContext.finish(); }
Try this method..

How to prevent going back to the previous activity?

When the BACK button is pressed on the phone, I want to prevent a specific activity from returning to its previous one.
Specifically, I have login and sign up screens, both start a new activity called HomeScreen when successful login/signup occurs. Once HomeScreen is started, I want to prevent the users from being able to return to the login or sign up screens by pressing the BACK key.
I tried using Intent.FLAG_ACTIVITY_NO_HISTORY, but since the application has Facebook integration, when the 'Login with Facebook' is used, Facebook should return to the initial login screen, therefore I should keep a history of these activities.
I thought of overriding the behaviour of the BACK button on HomeScreen to directly finish an application when the button is pressed and I used
#Override
public void onBackPressed() {
finish();
}
but that also does not work.
My suggestion would be to finish the activity that you don't want the users to go back to. For instance, in your sign in activity, right after you call startActivity, call finish(). When the users hit the back button, they will not be able to go to the sign in activity because it has been killed off the stack.
Following solution can be pretty useful in the usual login / main activity scenario or implementing a blocking screen.
To minimize the app rather than going back to previous activity, you can override onBackPressed() like this:
#Override
public void onBackPressed() {
moveTaskToBack(true);
}
moveTaskToBack(boolean nonRoot) leaves your back stack as it is, just puts your task (all activities) in background. Same as if user pressed Home button.
Parameter boolean nonRoot - If false then this only works if the activity is the root of a task; if true it will work for any activity in a task.
I'm not sure exactly what you want, but it sounds like it should be possible, and it also sounds like you're already on the right track.
Here are a few links that might help:
Disable back button in android
MyActivity.java =>
#Override
public void onBackPressed() {
return;
}
How can I disable 'go back' to some activity?
AndroidManifest.xml =>
<activity android:name=".SplashActivity" android:noHistory="true"/>
There are two solutions for your case, activity A starts activity B, but you do not want to back to activity A in activity B.
1. Removed previous activity A from back stack.
Intent intent = new Intent(activityA.this, activityB.class);
startActivity(intent);
finish(); // Destroy activity A and not exist in Back stack
2. Disabled go back button action in activity B.
There are two ways to prevent go back event as below,
1) Recommend approach
#Override
public void onBackPressed() {
}
2)Override onKeyDown method
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode==KeyEvent.KEYCODE_BACK) {
return false;
}
return super.onKeyDown(keyCode, event);
}
Hope that it is useful, but still depends on your situations.
Since there are already many great solutions suggested, ill try to give a more dipictive explanation.
How to skip going back to the previous activity?
Remove the previous Activity from Backstack. Simple
How to remove the previous Activity from Backstack?
Call finish() method
The Normal Flow:
All the activities are stored in a Stack known as Backstack.
When you start a new Activity(startActivity(...)) then the new Activity is pushed to top of the stack and when you press back button the Activity is popped from the stack.
One key point to note is that when the back button is pressed then finish(); method is called internally. This is the default behavior of onBackPressed() method.
So if you want to skip Activity B?
ie A<--- C
Just add finish(); method after your startActvity(...) in the Activity B
Intent i = new Intent(this, C.class);
startActivity(i);
finish();
finish() gives you method to close current Activity not whole application. And you better don't try to look for methods to kill application. Little advice.
Have you tried conjunction of Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS | Intent.FLAG_ACTIVITY_NO_HISTORY? Remember to use this flags in Intent starting activity!
Put finish() just after
Intent i = new Intent(Summary1.this,MainActivity.class);
startActivity(i);
finish();
If you don't want to go back to all the activities on your application, you can use
android:launchMode="singleTask"
Learn more here: http://developer.android.com/guide/topics/manifest/activity-element.html
paulsm4's answer is the correct one. If in onBackPressed() you just return, it will disable the back button. However, I think a better approach given your use case is to flip the activity logic, i.e. make your home activity the main one, check if the user is signed in there, if not, start the sign in activity. The reason is that if you override the back button in your main activity, most users will be confused when they press back and your app does nothing.
This method is working fine
Intent intent = new Intent(Profile.this, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
#Override
public void onBackPressed() {
}
When you create onBackPressed() just remove super.onBackPressed();and that should work
Just override the onKeyDown method and check if the back button was pressed.
#Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if (keyCode == KeyEvent.KEYCODE_BACK)
{
//Back buttons was pressed, do whatever logic you want
}
return false;
}
Put
finish();
immediately after
ActivityStart
to stop the activity preventing any way of going back to it.
Then add
onCreate(){
getActionBar().setDisplayHomeAsUpEnabled(false);
...
}
to the activity you are starting.
AndroidManifest.xml
<activity
android:name=".welcome.SplashActivity"
android:noHistory="true" // just add this line
android:exported="true">
</activity>

How can I resume the previous activity with code?

I am using two activities first activity contain some edit texts and the second layout is displayed when the submit button is clicked.
So that the first activity is in pause state and when I press the back button from the second layout the first layout is resumed (That is the previous state is recovered).
Now I need the back button action in my own back button in the screen.
I tried with onFinish() in the button click but the previous state is not resumed.
I tried with startActivityForResult too.
Any other solution for this?
Please share your ideas.
Thanks in advance.
Call the finish() method of your Activity. That will close your second Activity and resume your previous Activity.
You have to make sure that the first activity saves it's state in onPause somehow (e.g. using bundles, database, statics, application class, ...) and then that it sets up the state again from that persisted state in onResume.
Hey try to save the state in
#Override
protected void onSaveInstanceState(Bundle outState) {
// TODO Auto-generated method stub
super.onSaveInstanceState(outState);
}
I don't think calling finish(); from arnab answer is the right thing to do. You should put:
intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
instead of finish(); but above startActivity();
backButton.setOnClickListener(v -> { Intent intent = new Intent(CurrentActivity.this, PreviousActivity.class); intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT); startActivity(intent); }); worked for me finish(); didn't resume the previous activity but started it.

Categories

Resources