复杂数组排序

SFBankListItemModel为数组中的对象，以该对象中的某个属性进行排序

//对数据按次数排序 降序
  NSArray *sortArrays = [userCards sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
        SFBankListItemModel *model1 = (SFBankListItemModel *)obj1;
        SFBankListItemModel *model2 = (SFBankListItemModel *)obj2;
        NSNumber *num1 = [NSNumber numberWithUnsignedLongLong:[model1.cardInfo.createTime longLongValue]];
        NSNumber *num2 = [NSNumber numberWithUnsignedLongLong:[model2.cardInfo.createTime longLongValue]];
       return [num2 compare:num1];
                        
   }];

[num2 compare:num1]降序，
[num2 compare:num1]升序