如何在用户输入时避免EditText上的多个触发器？

Question

当用户在EditText中键入时,我使用以下代码执行搜索:

EditText queryView = (EditText) findViewById(R.id.querybox);
queryView.addTextChangedListener(new TextWatcher() {
  @Override
  public void afterTextChanged(Editable s) {
    triggerSearch(s.toString()); 
  }
  @Override
  public void beforeTextChanged(CharSequence s, int start, int count, int after) {
  }
  @Override
  public void onTextChanged(CharSequence s, int start, int before, int count) {
  }
});

但是,当用户键入单词时,这会多次触发.也就是说,如果用户输入"hello",则此代码将触发5次值("h","he","hel","hell","hello").通常情况下,这样会很好但是触发搜索很昂贵,而且我不想在没有太大用处的中间搜索上浪费资源.我想要的是在用户开始输入后仅触发某个阈值的侦听器,或者在调用之前在侦听器中等待的某种框架,triggerSearch如果在该等待之前触发了另一个事件,则取消自身.

Answer 1

由于找不到合适的事件接口,尝试触发延迟搜索.代码实际上非常简单和强大.

private final int TRIGGER_SERACH = 1;
// Where did 1000 come from? It's arbitrary, since I can't find average android typing speed.
private final long SEARCH_TRIGGER_DELAY_IN_MS = 1000;

  private Handler handler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
      if (msg.what == TRIGGER_SERACH) {
        triggerSearch();
      }
    }
  };

 queryView.addTextChangedListener(new TextWatcher() {

   @Override
   public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {

   }

   @Override
   public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {

   }

   @Override
   public void afterTextChanged(Editable s) {
    handler.removeMessages(TRIGGER_SERACH);
    handler.sendEmptyMessageDelayed(TRIGGER_SERACH, SEARCH_TRIGGER_DELAY_IN_MS);
   });