10.基本控件 ToolBar

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

<!--    titleMarginStart title距左边的距离-->
    <androidx.appcompat.widget.Toolbar
        android:id="@+id/TB"
        android:background="#ff00ff"
        android:layout_width="match_parent"
        android:layout_height="?actionBarSize"
        app:navigationIcon="@drawable/ic_arrow_back_black_24dp"
        app:title="标题"
        app:titleTextColor="#FFFFFF"
        app:titleMarginStart="120dp"
        app:subtitle="小标题"
        app:subtitleTextColor="#FFFF00"/>

</LinearLayout>

package com.example.senventoolbar;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

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

        Toolbar toolbar = findViewById(R.id.TB);
        //点自己设置的navigationIcon会有事件出来
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(MainActivity.this,"点击了ToolBar",Toast.LENGTH_SHORT).show();
            }
        });
    }
}