我有一个EditText 框，它必须允许用户输入最多 7 个数字和两个小数位。输入七位数字后，不应再添加一位数字，但我可以允许最多两位小数。我对 2 个小数位使用十进制过滤器，并在 XML 中使用此代码
android:maxLength="7"
android:imeOptions="actionDone"
android:inputType="numberDecimal"
但EditText 允许enter 8 位数字。怎么解决？
【问题讨论】：
标签： android android-layout android-edittext
在 onCreate 下试试这个
youreditText.setFilters(new InputFilter[] {new DecimalDigitsInputFilter(5,1)});
程序中的任何位置
public class DecimalDigitsInputFilter implements InputFilter {
Pattern mPattern;
public DecimalDigitsInputFilter(int digitsBeforeZero,int digitsAfterZero) {
mPattern=Pattern.compile("[0-9]{0," + (digitsBeforeZero-1) + "}+((\\.[0-9]{0," + (digitsAfterZero-1) + "})?)||(\\.)?");
}
@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
Matcher matcher=mPattern.matcher(dest);
if(!matcher.matches())
return "";
return null;
}
}
【讨论】：
您可以使用此输入过滤器来解决您的问题。 设置过滤器：
mEditText.setFilters(new InputFilter[]{new DigitsInputFilter(maxDigitsBeforeDot, maxDigitsAfterDot, maxValue)});
如果您不想限制点之前或之后的数字，只需输入Integer.MAX_VALUE，禁用最大值限制使用Double.POSITIVE_INFINITY。
您可以将此过滤器用于输入数字或数字和文本的文本字段。
public class DigitsInputFilter implements InputFilter {
private final String DOT = ".";
private int mMaxIntegerDigitsLength;
private int mMaxDigitsAfterLength;
private double mMax;
public DigitsInputFilter(int maxDigitsBeforeDot, int maxDigitsAfterDot, double maxValue) {
mMaxIntegerDigitsLength = maxDigitsBeforeDot;
mMaxDigitsAfterLength = maxDigitsAfterDot;
mMax = maxValue;
}
@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
String allText = getAllText(source, dest, dstart);
String onlyDigitsText = getOnlyDigitsPart(allText);
if (allText.isEmpty()) {
return null;
} else {
double enteredValue;
try {
enteredValue = Double.parseDouble(onlyDigitsText);
} catch (NumberFormatException e) {
return "";
}
return checkMaxValueRule(enteredValue, onlyDigitsText);
}
}
private CharSequence checkMaxValueRule(double enteredValue, String onlyDigitsText) {
if (enteredValue > mMax) {
return "";
} else {
return handleInputRules(onlyDigitsText);
}
}
private CharSequence handleInputRules(String onlyDigitsText) {
if (isDecimalDigit(onlyDigitsText)) {
return checkRuleForDecimalDigits(onlyDigitsText);
} else {
return checkRuleForIntegerDigits(onlyDigitsText.length());
}
}
private boolean isDecimalDigit(String onlyDigitsText) {
return onlyDigitsText.contains(DOT);
}
private CharSequence checkRuleForDecimalDigits(String onlyDigitsPart) {
String afterDotPart = onlyDigitsPart.substring(onlyDigitsPart.indexOf(DOT), onlyDigitsPart.length() - 1);
if (afterDotPart.length() > mMaxDigitsAfterLength) {
return "";
}
return null;
}
private CharSequence checkRuleForIntegerDigits(int allTextLength) {
if (allTextLength > mMaxIntegerDigitsLength) {
return "";
}
return null;
}
private String getOnlyDigitsPart(String text) {
return text.replaceAll("[^0-9?!\\.]", "");
}
private String getAllText(CharSequence source, Spanned dest, int dstart) {
String allText = "";
if (!dest.toString().isEmpty()) {
if (source.toString().isEmpty()) {
allText = deleteCharAtIndex(dest, dstart);
} else {
allText = new StringBuilder(dest).insert(dstart, source).toString();
}
}
return allText;
}
private String deleteCharAtIndex(Spanned dest, int dstart) {
StringBuilder builder = new StringBuilder(dest);
builder.deleteCharAt(dstart);
return builder.toString();
}
}
希望对你有帮助。
【讨论】：
edittext.setFilters(new InputFilter[] { new DigitsKeyListener(
Boolean.FALSE, Boolean.TRUE) {
int beforeDecimal = 7, afterDecimal = 2;
@Override
public CharSequence filter(CharSequence source, int start, int end,
Spanned dest, int dstart, int dend) {
String etText = edittext.getText().toString();
if (etText.isEmpty()){
return null;
}
String temp = edittext.getText() + source.toString();
if (temp.equals(".")) {
return "0.";
} else if (temp.toString().indexOf(".") == -1) {
// no decimal point placed yet
if (temp.length() > beforeDecimal) {
return "";
}
} else {
int dotPosition ;
int cursorPositon = edittext.getSelectionStart();
if (etText.indexOf(".") == -1) {
Log.i("First time Dot", etText.toString().indexOf(".")+" "+etText);
dotPosition = temp.indexOf(".");
Log.i("dot Positon", cursorPositon+"");
Log.i("dot Positon", etText+"");
Log.i("dot Positon", dotPosition+"");
}else{
dotPosition = etText.indexOf(".");
Log.i("dot Positon", cursorPositon+"");
Log.i("dot Positon", etText+"");
Log.i("dot Positon", dotPosition+"");
}
if(cursorPositon <= dotPosition){
Log.i("cursor position", "in left");
String beforeDot = etText.substring(0, dotPosition);
if(beforeDot.length()<beforeDecimal){
return source;
}else{
if(source.toString().equalsIgnoreCase(".")){
return source;
}else{
return "";
}
}
}else{
Log.i("cursor position", "in right");
temp = temp.substring(temp.indexOf(".") + 1);
if (temp.length() > afterDecimal) {
return "";
}
}
}
return super.filter(source, start, end, dest, dstart, dend);
}
} });
【讨论】：
DigitsKeyListener 已弃用
public class DecimalDigitsInputFilter implements InputFilter {
Pattern mPattern;
int digitsBeforeZero;
public DecimalDigitsInputFilter(int digitsBeforeZero, int digitsAfterZero) {
this.digitsBeforeZero = digitsBeforeZero;
mPattern = Pattern.compile("[0-9]{0," + (digitsBeforeZero - 1) + "}+((\\.[0-9]{0," + (digitsAfterZero - 1) + "})?)||(\\.)?");
}
@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
Matcher matcher = mPattern.matcher(dest);
if (!matcher.matches()) {
if (dest.toString().contains(".")) {
if (dest.toString().substring(dest.toString().indexOf(".")).length() > 2) {
return "";
}
return null;
} else if (!Pattern.compile("[0-9]{0," + (digitsBeforeZero - 1) + "}").matcher(dest).matches()) {
if (!dest.toString().contains(".")) {
if (source.toString().equalsIgnoreCase(".")) {
return null;
}
}
return "";
} else {
return null;
}
}
return null;
}
}
【讨论】：
您可以使用此输入过滤器来解决您的问题。设置过滤器： 对于 4 位数字和两个小数点
public class DecimalDigitsInputFilter implements InputFilter {
Pattern mPattern;
public DecimalDigitsInputFilter(int digitsBeforeZero, int digitsAfterZero) {
mPattern = Pattern.compile("[0-9]{0," + (digitsBeforeZero - 1) + "}+((\\.[0-9]{0," + (digitsAfterZero - 1) + "})?)||(\\.)?");
}
@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
String s = Html.toHtml(dest).replaceAll("\\<.*?>","").replaceAll("\n","");
Matcher matcher = mPattern.matcher(dest);
if (!matcher.matches())
return "";
try {
if(Double.parseDouble(s)<9999.99 && s.contains(".")) {
return null;
}else if ((Double.parseDouble(s)<1000 && !s.contains("."))||source.equals(".")) {
return null;
}else {
return "";
}
}catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
editText.setFilters(new InputFilter[]{new DecimalDigitsInputFilter(7, 2)});
【讨论】：
首先在 onCreate 中创建这个
DecimalFormat amountFormate = new DecimalFormat("#######.##");
amountFormate.setMinimumFractionDigits(2);
amountFormate.setMaximumFractionDigits(2);
editText.setText(amountFormate.format(yourValue));
示例：
double amount = 1234567.54;
editText.setText(amountFormate.format(amount));
输出-> 1234567.54
【讨论】：
虽然不是直接的解决方案，但您可以通过 TextWatcher 控制从 IME 到 EditText 的每个字符
关于如何使用TextWatcher 的SO Q&A 之一是here
更多关于TextWatcher的是here
您可能需要Regular expression to match floating point precision 和pattern matcher 的帮助来验证输入。
【讨论】：
您可以像这样使用 Android 数据绑定来增强它：
定义自定义绑定适配器：
@BindingAdapter({"digitsBeforeZero", "digitsAfterZero"})
public void bindAmountInputFilter(EditText view, int digitsBeforeZero, int digitsAfterZero) {
view.setFilters(new InputFilter[]{new DecimalDigitsInputFilter(digitsBeforeZero, digitsAfterZero)});
}
为 EditText 添加属性：
app:digitsBeforeZero="@{7}"
app:digitsAfterZero="@{2}"
它会自动为编辑文本设置输入过滤器
【讨论】：
editText.addTextChangedListener(new TextWatcher() {
String firstString;
String beforeInt = "";
String beforeDec = "";
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
txtAmt.setText("");
firstString = charSequence.toString();
String[] rupee = firstString.split("\\.");
if ( rupee.length > 0 )
beforeInt = rupee[0];
if ( rupee.length > 1 )
beforeDec = rupee[1];
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
try {
String amount = charSequence.toString().replaceAll(",","");
if ( txtAmt != null && !amount.isEmpty()){
String[] rupee = amount.split("\\.");
if ( rupee.length == 0 )
return;
String intPart = rupee[0];
int arrayLength = rupee.length;
if ( arrayLength == 2 ){
String decPart = rupee[1];
if ( decPart.length() == 1 )
decPart += "0";
if ( intPart.length() > 6 || decPart.length() > 2 ){
editText.removeTextChangedListener(this);
firstString = beforeInt;
if ( !beforeDec.isEmpty() )
firstString += "."+beforeDec;
editText.setText( firstString );
editText.setSelection( firstString.length());
editText.addTextChangedListener( this );
}
}
}
}catch (Exception e){
//Do nothing
}
}
@Override
public void afterTextChanged(Editable s) {
//Do nothing
}
});
【讨论】：