Android EditText輸入框中限制輸入小數點兩位

用到EditText的方法setFilters過濾輸入的內容用法是et.setFilters(new InputFilter[]{lengthFilter});

private InputFilter lengthFilter = new InputFilter() {
        @Override
        public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
            // source:當前輸入的字符
            // start:輸入字符的開始位置
            // end:輸入字符的結束位置
            // dest：當前已顯示的內容
            // dstart:當前光標開始位置
            // dent:當前光標結束位置
            //Log.e("", "source=" + source + ",start=" + start + ",end=" + end + ",dest=" + dest.toString() + ",dstart=" + dstart + ",dend=" + dend);
            if (dest.length() == 0 && source.equals(".")) {
                return "0.";
            }
            String dValue = dest.toString();
            String[] splitArray = dValue.split("\\.");
            if (splitArray.length > 1) {
                String dotValue = splitArray[1];
//                if (dotValue.length() == 2) {//輸入框小數的位數是2的狀況，整個輸入框都不容許輸入
//                    return "";
//                }
                if (dotValue.length() == 2 && dest.length() - dstart < 3){ //輸入框小數的位數是2的狀況時小數位不能夠輸入，整數位能夠正常輸入
                    return "";
                }
            }
            return null;
        }
    };