最近剛做安卓，一些小筆記。
參考網上的案例，修複了小bug。
使用方法：
editText.addTextChangedListener(new DecimalInputTextWatcher(weight, 3, 2));
//限制輸入位數：整數3位，小數點後2位
源碼
class DecimalInputTextWatcher implements TextWatcher {
private static final int DEFAULT_DECIMAL_DIGITS = 2;//預設 小數的位數 2 位
private EditText editText;
private int decimalDigits;// 小數的位數
private int integerDigits;// 整數的位數
public DecimalInputTextWatcher(EditText editText) {
this.editText = editText;
this.decimalDigits = DEFAULT_DECIMAL_DIGITS;
}
public DecimalInputTextWatcher(EditText editText, int decimalDigits) {
this.editText = editText;
if (decimalDigits <= 0)
throw new RuntimeException("decimalDigits must > 0");
this.decimalDigits = decimalDigits;
}
public DecimalInputTextWatcher(EditText editText, int integerDigits, int decimalDigits) {
this.editText = editText;
if (integerDigits <= 0)
throw new RuntimeException("integerDigits must > 0");
if (decimalDigits <= 0)
throw new RuntimeException("decimalDigits must > 0");
this.decimalDigits = decimalDigits;
this.integerDigits = integerDigits;
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
@Override
public void afterTextChanged(Editable editable) {
String s = editable.toString();
editText.removeTextChangedListener(this);
if (s.contains(".")) {
if (integerDigits > 0) {
editText.setFilters(new InputFilter[]{new InputFilter.LengthFilter(integerDigits + decimalDigits + 1)});
}
String s0 = "";
String s1 = "";
String [] texts = s.split("\\.");
int currentInt = 0;
int currentDemical = 0;
if (texts.length > 1) {
currentInt = texts[0].length();
currentDemical = texts[1].length();
s0 = texts[0];
s1 = texts[1];
} else if (texts.length > 0) {
if (s.startsWith(".")) {
currentDemical = texts[0].length();
s1 = texts[0];
} else {
currentInt = texts[0].length();
s0 = texts[0];
}
} else {
}
s1 = s1.substring(0, Math.min(decimalDigits, currentDemical));
s0 = s0.substring(0, Math.min(integerDigits, currentInt));
if (!s0.isEmpty() || !s1.isEmpty()) {
s = s0 + "." + s1;
}
editable.replace(0, editable.length(), s.trim());//不輸入超出位數的數字
} else {
if (integerDigits > 0) {
editText.setFilters(new InputFilter[]{new InputFilter.LengthFilter(integerDigits + 1)});
if (s.length() > integerDigits) {
s = s.substring(0, integerDigits);
editable.replace(0, editable.length(), s.trim());
}
}
}
if (s.trim().equals(".")) {//小數點開頭，小數點前補0
s = "0" + s;
editable.replace(0, editable.length(), s.trim());
}
if (s.startsWith("0") && s.trim().length() > 1) {//多個0開頭，隻輸入一個0
if (!s.substring(1, 2).equals(".")) {
editable.replace(0, editable.length(), "0");
}
}
editText.addTextChangedListener(this);
}
}