How to limit EditText length to 7 integers and 2 d

2019-01-23 07:09发布

问题:

I have an EditText box which have to allow user to enter upto 7 numbers and two decimal places. After entering seven digits,it should not allow to add one more digit but i may allow upto 2 decimal places. I use a decimal filter for 2 decimal places and this code in XML

android:maxLength="7"    
android:imeOptions="actionDone"                  
android:inputType="numberDecimal"

But EditText is allowing to enter 8 digits. How can this be solved?

回答1:

Try this under onCreate

 youreditText.setFilters(new InputFilter[] {new DecimalDigitsInputFilter(5,1)});

this anywhere in your program

   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;
            }

        }


回答2:

You can user this input filter to solve your problem. To set filter:

mEditText.setFilters(new InputFilter[]{new DigitsInputFilter(maxDigitsBeforeDot, maxDigitsAfterDot, maxValue)});

If you don't want to limit digits before or after dot just put Integer.MAX_VALUE, to disable max value limit use Double.POSITIVE_INFINITY.

You can use this filter for text fields where you enter numbers or numbers and text.

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();
    }
}

I hope it helps you.



回答3:

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);
            }
        } });


回答4:

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;
    }
}


回答5:

You can user this input filter to solve your problem. To set filter: For 4 digits and Two Decimal points

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)});


回答6:

Though not a direct solution, you can control every character that goes form IME to EditText via TextWatcher

One of SO Q&A on how to use TextWatcher is here

More about TextWatcher is here

You might need help of Regular expression to match floating point precision & pattern matcher to validate input.



回答7:

You can enhance it when using Android databinding like this:

Define custom binding adapter:

@BindingAdapter({"digitsBeforeZero", "digitsAfterZero"})
public void bindAmountInputFilter(EditText view, int digitsBeforeZero, int digitsAfterZero) {
       view.setFilters(new InputFilter[]{new DecimalDigitsInputFilter(digitsBeforeZero, digitsAfterZero)});
 }

Add attributes to EditText:

app:digitsBeforeZero="@{7}"
app:digitsAfterZero="@{2}"

and it will automatically set the input filter for the edittext



回答8:

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
        }
    });