导航栏中的“返回首页”按钮在我的Android应用中不起作用

Question

After activating Navigation Up Button in Action Bar, Home Back button in Navigation bar doesn't work in my app. Where am I doing wrong? when I click on the navigation app up button, it works. But, Navigation back button as you can see on the pivture doesn't work...

Back Button

enter image description here

public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    super.onOptionsItemSelected(item);
    switch (item.getItemId()) {
        case R.id.action_email:
            emailMenuItem();
            break;
        case R.id.action_settings:
            settingsMenuItem();
            break;
    }
    return true;
}

Answer 1

First understand following things:

@Override
public void onBackPressed() {
    super.onBackPressed();
    // executed this when hardware back button is pressed
}

is called when you press back button .

AND

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    switch(id) {
        case android.R.id.home:
            // executed this when back button on Actionbar is pressed
            return true;
        default:
            break;
    }
    return super.onOptionsItemSelected(item);
}

is called when you press back button on Actionbar .

Comment below if you have any queries.