android:logo

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.pingyijinren.helloworld">
 
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:logo="@mipmap/twitter"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
 
</manifest>

package com.pingyijinren.helloworld;
 
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
 
public class MainActivity extends AppCompatActivity {
    private Button button;
    private ActionBar actionBar;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        actionBar = getSupportActionBar();
        actionBar.setDisplayShowHomeEnabled(true);
        actionBar.setLogo(R.mipmap.twitter);
        actionBar.setDisplayUseLogoEnabled(true);
 
        button=(Button)findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(actionBar.isShowing()){
                    actionBar.hide();
                }
                else{
                    actionBar.show();
                }
            }
        });
    }
}