切换活动失去功能

Question

I have an app that consists of 3 Activities

• MainActivity
• CalculatorActivity
• InformationActivity

My MainActivity has a confirm button that onClick starts the CalculatorActivity and everything is done correct and working as intended.

CalculatorActivity has 2 buttons, one calculateButton that checks something and shows a message and a learnMorebutton that starts the InformationActivity .

When I am on the CalculatorActivity for the first time everything is fine and working.Pressing the learnMoreButton navigates me to the InformationActivity .That activity looks like this :

InformationActivity :

 goBackButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            switchActivity();
        }
    });
}
public void switchActivity(){
    final Intent intentObj = new Intent(this,CalculatorActivity.class);
    startActivity(intentObj);
}

A goBack button that gets me back to CalculatorActivity .Going back seems to break the functionality.Although the layout is there and everything looks as it should be, pressing the buttons (calculateButton,learnMoreButton) does nothing.

CalculatorActivity :

protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_calculator); final Button calculateButton = (Button) findViewById(R.id.calculateId); final Button learnMoreButton = (Button) findViewById(R.id.learnMoreButtonId);

there are some more TextView and EditText that dont show up here but you get the point.Some more methods that do the calculations ,getters and setters.

This method public void switchActivity(){ final Intent intentObj = new Intent(this,Information_activity.class); startActivity(intentObj); } public void switchActivity(){ final Intent intentObj = new Intent(this,Information_activity.class); startActivity(intentObj); }

But I am not using onResume() , onPause() or any methods from the lifecycle apart from onCreate() .

From some search that I have done I found out that I am doing something wrong with how I manage the activity lifecycle but I still can't find the solution.The dev documents didn't help me that much and a post with kinda the same problem as mine is old.

My question is, how the navigation from InformationActivity to CalculatorActivity should be done, so the functionality doesn't break when CalculatorActivity comes back to interact with the user.Which method should be called onResume() ? , onRestart() ? and how should it look like?

Thanks anyone who is willing to help.

PS: As I mentioned , I have read the documents for the lifecycle of an Activity but I haven't found the solution.

Answer 1

instead of starting new activity everytime, finish the informationactivity.

goBackButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        finish();
    }
});

}

Answer 2

You are creating too much activities moving going back and forth this way. You can use either destroy the activity with finish(); or you can also go back to previous activity using onBackPressed();

goBackButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        onBackPressed();
    }
});

Answer 3

Try this out

goBackButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        InformationActivity.this.finish();
    }
 });
}

Instead of saying where to go back, you can just finish the activity and it will automatically switch you to the previous one.

Answer 4

I think your activities are hierarchical thus you should be able to do the following from your main calculator activity:

Intent i = new Intent(this, InformationActivity.class);
startActivityForResult(i);

Your back button add this code:

goBackButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        setResult(Result.OK);
        finish();
    }
});

Answer 5

You are all suggesting the same thing.Adding

Information_Activity.this.finish()

fixed the broken functionality , though you are all correct I can pick only one answer.

Thanks