//onCreate方法中ActionBar actionBar = this.getSupportActionBar();actionBar.setTitle("搜索功能");actionBar.setDisplayHomeAsUpEnabled(true);//activity類中的方法@Override  public boolean onOptionsItemSelected(MenuItem item) {    if(item.getItemId() == android/196353.html">android/251502.html">android.R.id.home)    {      finish();      return true;    }    return super.onOptionsItemSelected(item);  }

//onCreate函數中Toolbar mToolbarTb = (Toolbar) findViewById(R.id.toolbar);setSupportActionBar(mToolbarTb);getSupportActionBar().setDisplayHomeAsUpEnabled(true);//activity類中的方法//添加點擊返回箭頭事件@Overridepublic boolean onOptionsItemSelected(MenuItem item) {  if(item.getItemId() == android.R.id.home)  {    finish();    return true;  }  return super.onOptionsItemSelected(item);}