formatEditUpdate method

  1. @override
TextEditingValue formatEditUpdate(
  1. TextEditingValue oldValue,
  2. TextEditingValue newValue
)
override

Called when text is being typed or cut/copy/pasted in the EditableText.

You can override the resulting text based on the previous text value and the incoming new text value.

When formatters are chained, oldValue reflects the initial value of TextEditingValue at the beginning of the chain.

Implementation

@override
TextEditingValue formatEditUpdate(
  TextEditingValue oldValue,
  TextEditingValue newValue,
) {
  final newNumber = num.tryParse(newValue.text);
  // 如果输入的不是数字, 则返回空的字符
  if (newNumber == null) return const TextEditingValue();

  if (newNumber < min) return TextEditingValue(text: min.toString());
  if (newNumber > max) return TextEditingValue(text: max.toString());

  return oldValue;
}