How to display and set click event on Back Arrow on Toolbar?

问题

How can I set back arrow in Android toolbar and also apply click listener?

回答1:

First make one toolbar.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:local="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minHeight="?attr/actionBarSize"
    android:background="@color/colorPrimary"
    local:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    local:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

then include it in activity_main.xml like this way:

<LinearLayout
    android:id="@+id/container_toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <include
        android:id="@+id/toolbar"
        layout="@layout/toolbar" />

</LinearLayout>

then in your MainActivity.java file, put this code:

mToolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(mToolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setTitle("MyTitle");

To add listener on back press, use following method:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            // todo: goto back activity from here

            Intent intent = new Intent(CurrentActivity.this, MainActivity.class);
            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
            startActivity(intent);
            finish();
            return true;

        default:
            return super.onOptionsItemSelected(item);
    }
}

回答2:

Toolbar mToolbar= (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(mToolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);    
mToolbar.setNavigationOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        // perform whatever you want on back arrow click 
    }
});

// with lamda expression

toolbar.setNavigationOnClickListener(view -> onBackPressed());

回答3:

If you are using the default back button for android by using

getSupportActionBar().setDisplayHomeAsUpEnabled(true);

Then override the onOptionsItemSelected like

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            //do whatever
            return true;
        default:
           return super.onOptionsItemSelected(item);
    }
}

回答4:

If you want to know when home is clicked is an AppCompatActivity then you should try it like this: Use this code :

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);

Listen for click events on android.R.id.home like usual:

@Override
public boolean onOptionsItemSelected(MenuItem menuItem) {
    if (menuItem.getItemId() == android.R.id.home) {
         Intent intent = new Intent(CurrentActivity.this, MainActivity.class);
         startActivity(intent);
         finish();
    }
    return super.onOptionsItemSelected(menuItem);
}

回答5:

Complete example here http://www.freakyjolly.com/how-to-add-back-arrow-in-android-activity/

Use getSupportActionBar() Activity on which you want to show Back Icon

In OtherActivity.class

public class OtherActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.other_activity);


    ActionBar actionBar = getSupportActionBar();
    if (actionBar != null) {
        actionBar.setDisplayHomeAsUpEnabled(true);
    }
}

public boolean onOptionsItemSelected(MenuItem item){
    switch (item.getItemId()) {
        case android.R.id.home:
            finish();
            return true;
    }
    return super.onOptionsItemSelected(item);
}

public boolean onCreateOptionsMenu(Menu menu) {
    return true;
}

}

This will add a event listen

回答6:

Add this

 Toolbar toolbar = (Toolbar) findViewById(R.id.my_awesome_toolbar);
 setSupportActionBar(toolbar);
 getSupportActionBar().setDisplayHomeAsUpEnabled(true);
 getSupportActionBar().setDisplayShowHomeEnabled(true);

and in onOptionsItemSelected add this

 @Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            finish();
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

Check this

Display Back Arrow on Toolbar Android

http://developer.android.com/intl/es/training/implementing-navigation/ancestral.html

来源：https://stackoverflow.com/questions/35810229/how-to-display-and-set-click-event-on-back-arrow-on-toolbar