EditText添加字数限制

private void addLengthFilter(EditText editText) {
    editText.setFilters(new InputFilter[]{new InputFilter.LengthFilter(20) {
        @Override
        public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
            CharSequence sequence = super.filter(source, start, end, dest, dstart, dend);
            if (sequence == null) return null;
            if (!TextUtils.equals(sequence, source)) {
                ToastUtil.showMessage("备注长度最多支持20字");
            }
            return sequence;
        }
    }});
}