Android remove Activity from back stack

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最佳答案

FLAG_ACTIVITY_CLEAR_TOP clears your Activity stack , you can use the code below:

Intent intent = new Intent(this, Activity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

Remember that this flag clears just Intermediate Activities , for example if you have A,B,C in your Back Stack then going from C Activity to D with this flag this does not clear Back Stack and the Stack would be A,B,C,D but if you go from Activity D to Activity A with this flag , B,C,D Activities will pop up from the stack and you will have just A in the Back Stack .

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It seems, that you will get the desired behavior if you do not specify any flags at all. The back button would just do the right thing. To get an activity closed from within your code use the finish() method it has the same effect as the user pressing the back button. So you will automatically arrive at DegreePlan when you finish the EditDegreePlan, no need to call any Intents either.

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Here is your flow:

MainActivity --> DegreePlanActivty --> EditDegreePlan--> DegreePlan --> MainActivty

Override these method inside your "DegreePlan"

public void onBackPressed() {
super.onBackPressed();
Intent goToMainActivity = new Intent(getApplicationContext(), MainActivity.class);
goToMainActivity.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); // Will clear out your activity history stack till now
startActivity(goToMainActivity);
}

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I would suggest that you use startActivityForResult(), instead of simply startActivity(), when you launch the EditDegreePlan-Activity, as described in the Android tutorials.

In the EditDegreePlan-Activity you then call

setResult(RESULT_OK);
finish();

If you don't expect any data from the EditDegreePlan-Activity, then you don't necessarily have to implement the onActivityResult.

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simple solution for API >= 15 to API 23 user activity name in intent.

 Intent nextScreen = new Intent(currentActivity.this, MainActivity.class);
nextScreen.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | IntentCompat.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(nextScreen);
ActivityCompat.finishAffinity(currentActivity.this);

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use this to clear the stack :

 menuIntent.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_CLEAR_TOP);

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You can call finish before you start your new activity. This will remove the current activity from the stack, so when you press back button from the next activity, the first activity will not be called from the stack history.

Intent i = new Intent(MainActivity.this, NextActivity.class);
finish();
startActivity(i);

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You can add flags as follows and start Activity, try below code

Intent i = new Intent(activity, Payment.class);
i.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_CLEAR_TOP);
activity.startActivity(i);

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To remove activity from back stack inside manifest add android:noHistory="true" to your activity inside the manifest file.

See sample below.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.activity"
android:versionCode="1"
android:versionName="1.0">
<application android:name="MyApp" android:label="My Application">
<activity android:name=".LoginActivity"
android:noHistory="true"> //add this line to your activity inside manifest
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
</manifest>

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Intent intent = new Intent(getContext(), MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);


startActivity(intent);

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This code should help you out: It is in Kotlin
private fun verifyIfUserIsLoggedIn(){
val uid = FirebaseAuth.getInstance().uid
if(uid== null){
val intent = Intent(this, MainActivity::class.java)
intent.flags = Intent.FLAG_ACTIVITY_CLEAR_TASK.or(Intent.FLAG_ACTIVITY_NEW_TASK)
startActivity(intent)
}
}