isNull<T> static method

String? isNull<T>(
  1. T? val, {
  2. String? tipText,
})

为空判断

val 需要校验数据 tipText 校验提示文字

Implementation

static String? isNull<T>(T? val, {String? tipText}) {
  if (val is! T) {
    return tipText ?? '该项不能为空';
  }
  return null;
}