text: package com.sensorsdata.analytics.android.demo.activity;
  
  import android.os.Bundle;
  import android.view.MenuItem;
  
  import androidx.annotation.Nullable;
  import androidx.appcompat.app.ActionBar;
  import androidx.appcompat.app.AppCompatActivity;
  
  import com.sensorsdata.analytics.android.demo.R;
  
  public class ActionBarAndToolBarTestActivity extends AppCompatActivity {
  
      @Override
      protected void onCreate(@Nullable Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_actionbar);
          ActionBar actionBar = getSupportActionBar();
          if (actionBar != null) {
              actionBar.setDisplayHomeAsUpEnabled(true);
              actionBar.setDisplayShowHomeEnabled(true);
              actionBar.setTitle("测试返回");
          }
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          switch (item.getItemId()) {
              //actionbar navigation up 按钮
              case android.R.id.home:
                  finish();
                  break;
              default:
                  break;
          }
          return true;
      }
  }
  