RecyclerView之更新UI數據的高級用法

最後是重要的MainActivity類，其中涉及到了對Toolbar的使用，不熟悉的朋友也可以順便復習下，Toolbar上面4個菜單分別對應了新增列表，刪除列表，新增批量列表，列表項移動的操作，具體可以參考下面代碼注釋，MainActivity.java

/**
 * Created by LeeJizhou on 2016/4/18.
 * Blog:www.lijizhou.com
 * QQ:3107777777
 */
public class MainActivity extends AppCompatActivity {
    private RecyclerView mRecyclerView;
    //item 顯示所需
    private String[] title = {"JAVA","C","C++","C#","PYTHON","PHP"
            ,".NET","JAVASCRIPT","RUBY","PERL","VB","OC","SWIFT"
    };
    private ArrayList mTitle=new ArrayList<>();
    private RecyclerViewAdapter mRecyclerViewAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //Toolbar
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        //去除Toolbar標題
        getSupportActionBar().setDisplayShowTitleEnabled(false);
        //設置菜單點擊監聽
        toolbar.setOnMenuItemClickListener(onMenuItemClick);

        mRecyclerView = (RecyclerView) findViewById(R.id.rv_list);
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        mRecyclerView.setLayoutManager(layoutManager);
        Collections.addAll(mTitle,title);
        //為RecyclerView添加默認動畫效果，測試不寫也可以
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());
        mRecyclerView.setAdapter(mRecyclerViewAdapter=new RecyclerViewAdapter(this, mTitle));

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return super.onCreateOptionsMenu(menu);
    }

    private Toolbar.OnMenuItemClickListener onMenuItemClick = new Toolbar.OnMenuItemClickListener() {
        @Override
        public boolean onMenuItemClick(MenuItem menuItem) {

            switch (menuItem.getItemId()) {
                case R.id.menu_add:
                    //添加模擬數據到第一項
                    mTitle.add(0, "www.lijizhou.com");
                    //RecyclerView列表進行UI數據更新
                    mRecyclerViewAdapter.notifyItemInserted(0);
                    //如果在第一項添加模擬數據需要調用 scrollToPosition（0）把列表移動到頂端（可選）
                    mRecyclerView.scrollToPosition(0);

                    break;

                case R.id.menu_del:
                    //刪除模擬數據第一項
                    mTitle.remove(0);
                    //RecyclerView 列表進行UI數據更新
                    mRecyclerViewAdapter.notifyItemRemoved(0);
                    break;

                case R.id.menu_move:
                    //列表中第二項移到第三項 進行UI數據更新
                    mRecyclerViewAdapter.notifyItemMoved(1,2);
                    break;

                case R.id.menu_addmore:
                    //模擬數據批量添加4條數據
                    mTitle.add(0,"test");
                    mTitle.add(0,"test1");
                    mTitle.add(0,"test2");
                    mTitle.add(0,"test3");
                    //RecyclerView列表進行批量UI數據更新
                    mRecyclerViewAdapter.notifyItemRangeInserted(0,4);
                   // scrollToPosition（0）作用是把列表移動到頂端
                    mRecyclerView.scrollToPosition(0);
                    break;

            }

            return true;
        }
    };

}