Flutter - 如何格式化电话号码文本框

Question

我希望使用TextFormField将输入数字格式化为正确的电话号码格式。

我已经尝试使用以下TextInputFormatter：

class NumberTextInputFormatter extends TextInputFormatter {
  @override
  TextEditingValue formatEditUpdate(
      TextEditingValue oldValue, TextEditingValue newValue) {
    final int newTextLength = newValue.text.length;
    int selectionIndex = newValue.selection.end;
    int usedSubstringIndex = 0;
    final StringBuffer newText = new StringBuffer();
    if (newTextLength >= 1) {
      newText.write('+');
      if (newValue.selection.end >= 1) selectionIndex++;
    }
    if (newTextLength >= 3) {
      newText.write(newValue.text.substring(0, usedSubstringIndex = 1) + ' ');
      if (newValue.selection.end >= 2) selectionIndex += 1;
    }
    if (newTextLength >= 3) {
      newText.write( ' ');
      if (newValue.selection.end >= 6) selectionIndex += 1;
    }
    if (newTextLength >= usedSubstringIndex)
      newText.write(newValue.text.substring(usedSubstringIndex));
    return new TextEditingValue(
      text: newText.toString(),
      selection: new TextSelection.collapsed(offset: selectionIndex),
    );
  }
}

但我没有得到预期的输出

我的预期号码格式为"[phone]"

如果需要更多信息，请告诉我。谢谢您的努力，将不胜感激。

- Goku

---

我相信一定有两个字段 - 一个是国家前缀，另一个是家庭号码。 - user10539074

Answer 1

最终我决定从两个单独的中获取电话号码和国家代码

CountryCodeTextInputFormatter 用于输出+12

class CountryCodeTextInputFormatter extends TextInputFormatter {
  @override
  TextEditingValue formatEditUpdate(
      TextEditingValue oldValue, TextEditingValue newValue) {
    final int newTextLength = newValue.text.length;
    int selectionIndex = newValue.selection.end;
    int usedSubstringIndex = 0;
    final StringBuffer newText = new StringBuffer();
    if (newTextLength >= 1) {
      newText.write('+');
      if (newValue.selection.end >= 1) selectionIndex++;
    }
    if (newTextLength >= usedSubstringIndex)
      newText.write(newValue.text.substring(usedSubstringIndex));
    return new TextEditingValue(
      text: newText.toString(),
      selection: new TextSelection.collapsed(offset: selectionIndex),
    );
  }
}

PhoneNumberTextInputFormatter 用于输出如下格式：132-456-7890

class PhoneNumberTextInputFormatter extends TextInputFormatter {
  @override
  TextEditingValue formatEditUpdate(
      TextEditingValue oldValue, TextEditingValue newValue) {
    final int newTextLength = newValue.text.length;
    int selectionIndex = newValue.selection.end;
    int usedSubstringIndex = 0;
    final StringBuffer newText = new StringBuffer();
    if (newTextLength >= 4) {
      newText.write(newValue.text.substring(0, usedSubstringIndex = 3) + '-');
      if (newValue.selection.end >= 3)
        selectionIndex += 2;
    }
    if (newTextLength >= 7) {
      newText.write(newValue.text.substring(3, usedSubstringIndex = 6) + '-');
      if (newValue.selection.end >= 6)
        selectionIndex++;
    }
    if (newTextLength >= 11) {
      newText.write(newValue.text.substring(6, usedSubstringIndex = 10) );
      if (newValue.selection.end >= 10)
        selectionIndex++;
    }
    if (newTextLength >= usedSubstringIndex)
      newText.write(newValue.text.substring(usedSubstringIndex));
    return new TextEditingValue(
      text: newText.toString(),
      selection: new TextSelection.collapsed(offset: newText.length),
    );
  }
}

- Goku