ContextMenu菜单创建 上下文菜单的基本认识q

public class MainActivity extends AppCompatActivity {

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

    }

    private void showlistView() {
        ListView listView = (ListView) findViewById(R.id.listview);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,getData());
        listView.setAdapter(adapter);
        this.registerForContextMenu(listView);//view注册到上下文菜单

    }

    private ArrayList<String> getData(){
        ArrayList<String> list = new ArrayList<String>();
        for(int i = 0; i < 5 ;i++){
            list.add("ITEM" + i);
        }
        return list;
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
        super.onCreateContextMenu(menu, v, menuInfo);
        //设置上下文菜单显示的内容
        menu.setHeaderTitle("文件的操作");
        menu.setHeaderIcon(R.mipmap.ic_launcher);
        //方法一、动态代码加载项目
//        menu.add(1, 1, 1, "复制");
//        menu.add(1,2,1,"粘贴");
//        menu.add(1,3,1,"剪切");
//        menu.add(1,4,1,"重命名");
        //方法二、静态加载项目
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu_main,menu);

    }

    //点击事件
    @Override
    public boolean onContextItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case 1:{
                Toast.makeText(this,"点击了复制",Toast.LENGTH_SHORT).show();
                break;
            }
            case 2:{
                Toast.makeText(this,"点击了粘贴",Toast.LENGTH_SHORT).show();
                break;
            }
            case 3:{
                Toast.makeText(this,"点击了剪切",Toast.LENGTH_SHORT).show();
                break;
            }
            case 4:{
                Toast.makeText(this,"点击了重命名",Toast.LENGTH_SHORT).show();
                break;
            }
        }
        return super.onContextItemSelected(item);
    }
}