flutter版本号对比

// 版本号对比
Future<bool> compareVersion(curV, reqV) async{
  if (curV != null && reqV != null) {
    //将两个版本号拆成数字
    var arr1 = curV.split('.'),
        arr2 = reqV.split('.');
    int arr1_len = arr1.length;
    int arr2_len = arr2.length;
    int minLength = math.min(arr1_len, arr2_len),
        position = 0,
        diff = 0;
    // 依次比较版本号每一位大小，当对比得出结果后跳出循环（后文有简单介绍）
    while (position < minLength && ((diff = int.parse(arr1[position]) - int.parse(arr2[position])) == 0)) {
      position++;
    }
    diff = (diff != 0) ? diff : (arr1.length - arr2.length);
    //若curV大于reqV，则返回true
    return diff > 0;
  } else {
    //输入为空
    print("版本号不能为空");
    return false;
  }
}