主螢幕的Intent程式碼：

public class MainActivity extends AppCompatActivity {
    private Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button=findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(MainActivity.this,sed.class);
                intent.putExtra("test","hello");
                startActivity(intent);
            }
        });
    }
}
 

副螢幕程式碼：

public class sed extends Activity{
    private TextView textView;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.sed);
        textView=findViewById(R.id.textView);
        Intent intent=getIntent();
        String data=intent.getStringExtra("test");
        textView.setText(data);

    }
}