@ click时，自动完成文本视图应显示列表

Question

我的应用程序中有一个要求。我正在使用自动完整文本视图。但是我想在用户输入“@”时显示我的项目，一旦用户输入“@”，则应显示整个列表，如果输入“@Y”，则过滤器应该开始工作。我怎么做到这一点。

AutoCompleteTextView txtSearch;  
     List<People> mList;
    PeopleAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mList = retrievePeople();
        txtSearch = (AutoCompleteTextView) findViewById(R.id.txt_search);
        txtSearch.setThreshold(1);
        adapter = new PeopleAdapter(this, R.layout.activity_main, R.id.lbl_name, mList);


          // txtSearch.setAdapter(adapter);

        txtSearch.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                int occurrences = 0;
               if (txtSearch.getText().toString().endsWith("@")){
                   txtSearch.setAdapter(adapter);
               }
            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });


    }

    private List<People> retrievePeople() {
        List<People> list = new ArrayList<People>();
        list.add(new People("James", "Bond", 1));
        list.add(new People("Jason", "Bourne", 2));
        list.add(new People("Ethan", "Hunt", 3));
        list.add(new People("Sherlock", "Holmes", 4));
        list.add(new People("David", "Beckham", 5));
        list.add(new People("Bryan", "Adams", 6));
        list.add(new People("Arjen", "Robben", 7));
        list.add(new People("Van", "Persie", 8));
        list.add(new People("Zinedine", "Zidane", 9));
        list.add(new People("Luis", "Figo", 10));
        list.add(new People("John", "Watson", 11));
        return list;

    }

这是我的代码。如果我使用的是文本chnage listner，那就什么都没发生。如果我删除该列表，如果它包含相关字符，则始终显示。我希望实现与应用程序组标记完全相同的内容   请帮我解决这个问题。

提前致谢。