有什么方法可以让 Activity 在单击时对每个按钮做出不同的反应？

Question

Consider you have a Button A and button B both of them when clicked it start Activity1 which contains only one TextView. Now When I click on Button A it should start Activity1 and setTextView to "The click was from A" and when clicked on B it should set the text to "The click was from B".

So I figure out that by making a global Boolean variable but I wanted to know is there any other way that is more efficient than making a global Boolean variable(the code become really messy with Boolean)

And this all is just an example in reality I want to add a lot of code instead of just setting the text.

And pls if anyone one of you is leaving a Downvote kindly also say the reason way, this will help me frame a better question next time. Thank you

Answer 1

TL;DR

Pass arguments with your Intent object that launches Activity2 . Use putExtra methods. That is the default way of passing small pieces of data.

Explained

"making a global Boolean variable" is a bad solution (nothing personal, it just does not fit the given problem) in this situation as anyone has access to that variable and the value can be changed at any point in time making it unreliable.

When you launch activity with Intent you can use putExtra methods on it ( example of such method in docs ). For example, there is a putExtra that accepts boolean as a value: link . Using that method you can remove the global variable, but the code still could be messy.

If this boolean variable is simply deciding which label to show you can pass the label itself using these putExtra methods. It would look like this:

// From Activity1 when you click Button A
buttonA.setOnClickListener {
    Intent intent = new Intent(Activity1.this, Activity2.class);
    intent.putExtra(Activity2.SOME_KEY, "This label is from buttonA.");
    startActivity(intent);
}

// From Activity1 when you click Button B
buttonB.setOnClickListener {
    Intent intent = new Intent(Activity1.this, Activity2.class);
    intent.putExtra(Activity2.SOME_KEY, "This label is from buttonB. A slightly different one.");
    startActivity(intent);
}

Activity2.SOME_KEY is some public static variable that you should declare to be sure that you use the same key for setting and getting back the value. You can name it differently. It must be of String type. There is no need to declare it in Activity2 class but since it is the key for passing arguments for Activity2 only I think that is the most fitting place.

And now in you can get that value back in Activity2 :

class Activity2 extends Activity {
    public static String SOME_KEY = "some string value";

    private String labelValue = "";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        labelValue = getIntent().getStringExtra(SOME_KEY);
        
        // ... other stuff here like setContentView
        // use `labelValue` to set text into some TextView.
    }
}