I pulled my hair against this left complement / edge, just did not leave, the problem became bald ... A solution to this would be very appreciated! I tried these answers from SO, it really moved some add-ons, but not all of them. Basically, all the answers they say set the contentInsetStart and contentInsetLeft to 0dp. This removes part of the gasket on the left, but I still see the registration, it’s just less than before I set contentInsetStart and contentInsetLeft to 0dp. . This solution works on Samsung phones, but not on any tablets. Such as Nexus 7, Nexus 9, Dell Venus 8, etc.

I believe that many people have encountered this problem, and these are the answers that I tried, but still leave a residence permit / margin on the left above.
Android: remove the left margin from the custom layout .
Android Lollipop, AppCompat ActionBar App Does Not Take Full Screen Width
Android API 21 Toolbar Tab
Padding / margin to the left of my activity / action bar - I don’t know where it came from, cannot delete it
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How to remove border between application icon and screen edge in ActionBar?
Style
<resources>
<style name="AppTheme" parent="Theme.AppCompat.Light">
<item name="actionBarStyle">@style/AppThemeActionBar</item>
<item name="logo">@android:color/transparent</item>
</style>
<style name="AppThemeActionBar" parent="@style/Widget.AppCompat.ActionBar">
<item name="displayOptions">showCustom</item>
<item name="background">@color/blue</item>
<item name="actionBarSize">50dp</item>
<item name="height">50dp</item>
<item name="contentInsetLeft">0dp</item>
<item name="contentInsetStart">0dp</item>
<item name="contentInsetEnd">0dp</item>
<item name="android:layout_marginLeft">0dp</item>
</style>
</resources>
The action layout, activity_main.xml, it is pretty empty, just the layout for the main activity class, the custom view of the action bar is in another layout file.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
</LinearLayout>
Now, this is a custom action bar layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="50dp" >
<Button
android:id="@+id/btn_home"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:background="#ea6464"
android:text="Home"/>
<TextView
android:id="@+id/title_text"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginLeft="10dp"
android:layout_toRightOf="@+id/btn_home"
android:gravity="center"
android:textColor="#fff"
android:textStyle="bold"
android:text="Hello"/>
<ImageButton
android:id="@+id/imageButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:src="@android:drawable/ic_menu_edit"
android:background="@null"/>
</RelativeLayout>
MainActivity.java, mActionBar.setCustomView(mCustomView);
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ActionBar mActionBar = getSupportActionBar();
mActionBar.setDisplayShowHomeEnabled(false);
mActionBar.setDisplayShowTitleEnabled(false);
LayoutInflater mInflater = LayoutInflater.from(this);
View mCustomView = mInflater.inflate(R.layout.custom_actionbar, null);
mActionBar.setCustomView(mCustomView);
mActionBar.setDisplayShowCustomEnabled(true);
Button btnHome = (Button) findViewById(R.id.btn_home);
btnHome.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Home Button Clicked!", Toast.LENGTH_SHORT).show();
}
});
}
}