how to know the calling activity in android

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余生分开走
余生分开走 2020-11-29 11:59

I have an activity which is called by few other activities. For example: I have Activity1,Activity2,Activity3. Activity1 calls Activity2 and pass parameter. Activity3 also c

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  • 2020-11-29 12:24

    Pass anything(String/ int etc.) to putExtra and base on that do the your work like

    Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
         intent.putExtra("PARENT_ACTIVITY_REF", "ParentActivityIsA");
         startActivity(intent);
    

    And then receive in child like

    String parentActivityRef = intent.getStringExtra("PARENT_ACTIVITY_REF");
    

    then

    if (parentActivityRef.equals("ParentActivityIsA"){
                  // do your work here
    }else if ...{
                 // ...
    }else{
         //...
    }
    
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  • 2020-11-29 12:26

    A. If you can use startActivityForResult

    As per Zain Ali's answer below: If you can start Activity with startActivityForResult() then you can get name of calling Activity class by this.getCallingActivity().getClassName();

    B. If you can not use startActivityForResult

    If you can not use startActivityForResult(), then you can use following method: You can pass additional parameter in intent, check the value in activity and act accordingly.

    1) Define an interface or constants class to define integer constants to indicate calling activity

    public interface ActivityConstants {
                public static final int ACTIVITY_1 = 1001;
                public static final int ACTIVITY_2 = 1002;
                public static final int ACTIVITY_3 = 1003;
    }
    

    2) Add extra parameter in intent while calling Activity2.

            Intent act2 = new Intent(context, Activity2.class);
                    act2.putExtra("calling-activity", ActivityConstants.ACTIVITY_1);
        // or ActivityConstants.ACTIVITY_3 if called form Activity3
    startActivity(act2);
    

    3) Check the value of this extra parameter in Activity2 and act accordingly..

    int callingActivity = getIntent().getIntExtra("calling-activity", 0);
    
            switch (callingActivity) {
            case ActivityConstants.ACTIVITY_1:
                // Activity2 is started from Activity1
                break;
            case ActivityConstants.ACTIVITY_3:
                // Activity2 is started from Activity3
                break;
            }
    
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  • 2020-11-29 12:27

    You could pass an additional parameter that specifies the calling Activity.

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  • 2020-11-29 12:32

    I successfully use: (Activity).getLocalClassName()

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  • 2020-11-29 12:33

    In your calling activity (FirstActivity):

    Intent i = new Intent(FirstActivity.this, SecondActivity.class);
    i.putExtra("classFrom", FirstActivity.class.toString());
    startActivity(i);
    

    And add the following code in the onCreate of the called activity (SecondActivity):

    Bundle bundle = getIntent().getExtras();
    
    if (bundle.getString("classFrom").equals(FirstActivity.class.toString())) {
         //Do some task
    }
    

    Notice that you should be carefully because the bundle object can't be null when you perform "b.getString("classFrom")".

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  • 2020-11-29 12:36

    If you start the activity with startActivityForResult(Intent, int), then you can get calling activity by getCallingActivity().getClassName().

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