How to make a clickable menu of buttons using switch?

Question

Android

Hello, I am making a menu of several buttons using two different methods.
One of them provides a transition to another activity at the click of a button, and the second method does not, that is, nothing happens when you click it.
Working method:

public class main extends AppCompatActivity {

    Button b1,b2,b3;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LinearLayout l1 = new LinearLayout(this);
        l1.setOrientation(LinearLayout.VERTICAL);
        LinearLayout.LayoutParams l2 = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        setContentView(l1,l2);


        b1 = (Button) findViewById(R.id.b1);
        b2 = (Button) findViewById(R.id.b2);
        b3 = (Button) findViewById(R.id.b3);


        LinearLayout.LayoutParams l3 = new LinearLayout.LayoutParams(200, ViewGroup.LayoutParams.WRAP_CONTENT);
        

        b1 = new Button(this);
        b1.setText("Button 1");
        l1.addView(b1,l3);

        b2= new Button(this);
        b2.setText("Button 2");
        l1.addView(b2,l3);

        b3 = new Button(this);
        b3.setText("Button 3");
        l1.addView(b3,l3);


        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(main.this,m2.class);
                startActivity(intent);
            }
        });

        b2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(main.this,m3.class);
                startActivity(intent);
            }
        });
        b3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(main.this,m4.class);
                startActivity(intent);
            }
        });
    }

and not working:

public class main extends AppCompatActivity {

    Button b1,b2,b3;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LinearLayout l1 = new LinearLayout(this);
        l1.setOrientation(LinearLayout.VERTICAL);
        LinearLayout.LayoutParams l2 = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        setContentView(l1,l2);


        b1 = (Button) findViewById(R.id.b1);
        b2 = (Button) findViewById(R.id.b2);
        b3 = (Button) findViewById(R.id.b3);


        LinearLayout.LayoutParams l3 = new LinearLayout.LayoutParams(200, ViewGroup.LayoutParams.WRAP_CONTENT);
        

        b1 = new Button(this);
        b1.setText("Button 1");
        l1.addView(b1,l3);

        b2= new Button(this);
        b2.setText("Button 2");
        l1.addView(b2,l3);

        b3 = new Button(this);
        b3.setText("Button 3");
        l1.addView(b3,l3);


       View.OnClickListener onClickListener = (new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                switch(v.getID()) {
                    case R.id.b1:
                            Intent intent = new Intent(main.this,m2.class);
                            startActivity(intent);
                            break;
                    case R.id.b2:
                            Intent intent1 = new Intent(main.this,m3.class);
                            startActivity(intent1);
                            break;
                    case R.id.b3:
                            Intent intent2 = new Intent(main.this,m4.class);
                            startActivity(intent2);
                            break;
                }
            }
        });
    
        b1.setOnClickListener(onClickListener);
        b2.setOnClickListener(onClickListener);
        b3.setOnClickListener(onClickListener);

}

What could be the problem? Thank you

Answer 1

First you assign to the variables b1, b2, b3 the Button objects created by the findViewById method

b1 = (Button) findViewById(R.id.b1);
        b2 = (Button) findViewById(R.id.b2);
        b3 = (Button) findViewById(R.id.b3);

Then assign new Button objects to the same variables

b1 = new Button(this);
....

Accordingly, these variables refer to completely different buttons, the id of which is automatically generated.
Therefore, in the switch, the condition does not work.