Android new activity with back button

To create a new activity with a back button in Android, you can follow these steps:

Step 1: Create a new activity

In your Android project, create a new Java class that extends the Activity class. For example, let's call it MyNewActivity.java.

Step 2: Define the activity in the AndroidManifest.xml file

In the AndroidManifest.xml file, add a new <activity> element to define the new activity:

<activity
    android:name=".MyNewActivity"
    android:label="@string/title_new_activity">
</activity>

Step 3: Create the activity layout

Create a new layout file for the new activity, for example activity_my_new_activity.xml. This file will define the UI elements for the activity.

Step 4: Set the activity layout in the activity class

In the MyNewActivity.java file, set the layout for the activity using the setContentView() method:

public class MyNewActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my_new_activity);
    }
}

Step 5: Add a back button

To add a back button to the activity, you can use the ActionBar or a custom button. Here, we'll use the ActionBar:

public class MyNewActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my_new_activity);

        // Set the action bar
        ActionBar actionBar = getSupportActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
    }
}

Step 6: Handle the back button click

To handle the back button click, you need to override the onOptionsItemSelected() method:

public class MyNewActivity extends AppCompatActivity {
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == android.R.id.home) {
            // Handle the back button click
            finish();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

In this example, when the back button is clicked, the finish() method is called to close the activity.

Step 7: Start the new activity

To start the new activity, you can use the Intent class:

Intent intent = new Intent(this, MyNewActivity.class);
startActivity(intent);

That's it! You should now have a new activity with a back button that closes the activity when clicked.

Here's the complete code:

public class MyNewActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my_new_activity);

        // Set the action bar
        ActionBar actionBar = getSupportActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == android.R.id.home) {
            // Handle the back button click
            finish();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

And the AndroidManifest.xml file:

<activity
    android:name=".MyNewActivity"
    android:label="@string/title_new_activity">
</activity>

Note: Make sure to replace @string/title_new_activity with the actual string resource for the title of your new activity.