@Override 
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) { 
String sourceText = source.toString(); 
String destText = dest.toString(); 
//驗證刪除等按鍵 
if (TextUtils.isEmpty(sourceText)) { 
if(dstart==0&&destText.indexOf(POINTER)==1){//保證小數(shù)點不在第一個位置 
return "0"; 
} 
return ""; 
} 
Matcher matcher = mPattern.matcher(source); 
//已經(jīng)輸入小數(shù)點的情況下，只能輸入數(shù)字 
if(destText.contains(POINTER)) { 
if (!matcher.matches()) { 
return ""; 
} else { 
if (POINTER.equals(source)) { //只能輸入一個小數(shù)點 
return ""; 
} 
} 
//驗證小數(shù)點精度，保證小數(shù)點后只能輸入兩位 
int index = destText.indexOf(POINTER); 
int length = destText.trim().length() - index; 
if (length > POINTER_LENGTH&&dstart>index) { 
return ""; 
} 
} else { 
//沒有輸入小數(shù)點的情況下，只能輸入小數(shù)點和數(shù)字，但首位不能輸入小數(shù)點和0 
if (!matcher.matches()) { 
return ""; 
} else { 
if ((POINTER.equals(source)) && dstart==0) {//第一個位置輸入小數(shù)點的情況 
return "0."; 
} 
} 
} 
//驗證輸入金額的大小 
double sumText = Double.parseDouble(destText + sourceText); 
if (sumText > MAX_VALUE) { 
return dest.subSequence(dstart, dend); 
} 
return dest.subSequence(dstart, dend) + sourceText; 
}

<EditText 
android:id="@+id/et" 
android:layout_width="match_parent" 
android:layout_height="wrap_content" 
android:textSize="20sp" 
android:maxLength="10" 
android:inputType="numberDecimal" 
/>

EditText ed = (EditText) findViewById(R.id.et);
InputFilter[] is = {new CashierInputFilter()};
ed.setFilters(is);