在 EditText 中键入时执行操作

你需要TextWatcher。例如这样的事情：

editText.addTextChangedListener(new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        Log.d("TAG", "onTextChanged with text: " + charSequence);
    }

    @Override
    public void afterTextChanged(Editable editable) {

    }
});