一旦用户从数字十进制键盘 android Edittext 输入 2 位数字，自动设置小数点 (.)

Question

一旦用户在 android Edit-text

中从数字十进制键盘输入 2 位数字，自动设置小数点 (.)

Answer 1

创建 class:-

public class DecimalDigitsInputFilter implements InputFilter
{
    Pattern pattern;

    public DecimalDigitsInputFilter(int digitsBeforeDecimal, int digitsAfterDecimal)
    {
        pattern = Pattern.compile("(([1-9]{1}[0-9]{0," + (digitsBeforeDecimal - 1) + "})?||[0]{1})((\.[0-9]{0," + digitsAfterDecimal + "})?)||(\.)?");
    }

    @Override public CharSequence filter(CharSequence source, int sourceStart, int sourceEnd, Spanned destination, int destinationStart, int destinationEnd)
    {
        // Remove the string out of a destination that is to be replaced.
        String newString = destination.toString().substring(0, destinationStart) + destination.toString().substring(destinationEnd, destination.toString().length());

        // Add the new string in.
        newString = newString.substring(0, destinationStart) + source.toString() + newString.substring(destinationStart, newString.length());

        // Now check if the new string is valid.
        Matcher matcher = pattern.matcher(newString);

        if(matcher.matches())
        {
            // Returning null indicates that the input is valid.
            return null;
        }

        // Returning the empty string indicates the input is invalid.
        return "";
    }
}

现在像这样设置你的编辑文本：

edittext.setFilters(new InputFilter[]{new DecimalDigitsInputFilter(2, 2)});

Answer 2

使用TextWatcher:

editText.addTextChangedListener(new TextWatcher() {
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {

    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) 
    {

    }

    @Override
    public void afterTextChanged(Editable s) {
        if (s.toString().length() == 2)
            editText.append('.');
    }
});

Answer 3

您可以使用 TextWatcher 来监听用户输入的文本，然后验证长度，然后设置输入文本的 edittext 文本 +"。"

一旦用户从数字十进制键盘 android Edittext 输入 2 位数字，自动设置小数点 (.)

Automatically set decimal point (.) once user enters 2 digits from number decimal keyboard android Edittext

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decimal-point