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- class Validators {
- Validators._();
- static String? required(String? value) {
- if (value == null || value.trim().isEmpty) return '此项为必填';
- return null;
- }
- static String? amount(String? value) {
- if (value == null || value.trim().isEmpty) return '请输入金额';
- final amount = double.tryParse(value);
- if (amount == null) return '请输入有效金额';
- if (amount <= 0) return '金额必须大于0';
- return null;
- }
- static String? maxLength(String? value, int max) {
- if (value != null && value.length > max) return '最多输入$max个字符';
- return null;
- }
- }
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