使用未分配的变量? [英] Use of unassigned variable?

问题描述

在声明paymentstatus是否为空或在"if"语句中具有值时，我得到未分配变量"ps"的错误使用.我以为我已经声明了ps，但显然我做错了什么.为什么编译器会对此抱怨?

I'm getting the error use of unassigned variable "ps" when declaring if paymentstatus is null or has value in the "if" statement. I'm thinking that i allready declared ps but obviously im doing something wrong. Why does the compiler complain about this?

这是上下文中的错误:

public IList<BestsellersReportLine> DailyBestsellersReport()
        {


            OrderStatus os; 
            PaymentStatus? ps; 
            ShippingStatus ss;
            int billingCountryId = 0;
            int recordsToReturn = 999; 
            int orderBy = 1;
            int groupBy = 1;



            int? paymentStatusId = null;
            if (ps.HasValue)
                paymentStatusId = (int)ps.Value;



            // Specifies the time range for sold products/day
            var range = new
            {
                startTimeUtc = DateTime.Today.AddDays(-1),
                endTimeUtc = DateTime.Today.AddSeconds(-1),



                CreatedOnUtc = DateTime.Today.AddDays(-1),

            };




            var query1 = from opv in _opvRepository.Table
                         join o in _orderRepository.Table on opv.OrderId equals o.Id
                         join pv in _productVariantRepository.Table on opv.ProductVariantId equals pv.Id
                         join p in _productRepository.Table on pv.ProductId equals p.Id
                         where (o.CreatedOnUtc >= range.startTimeUtc && o.CreatedOnUtc <= range.endTimeUtc) &&
                         (!paymentStatusId.HasValue || paymentStatusId == o.PaymentStatusId)
                         select opv;
}

谢谢！

推荐答案

您已经声明了局部变量，但尚未分配值.因此，编译器可以帮助您防止该错误.

You have declared the local variable but you have not assigned a value. Therefore the compiler helps you to prevent this bug.

PaymentStatus? ps;  
// ...
if (ps.HasValue)

因此分配一个值:

PaymentStatus? ps = null;  
// ...
if (ps.HasValue)

但是，thix修复了编译器错误，但仍然毫无意义，因为它永远不会有值.也许您想改用方法参数:

However, thix fixes the compiler error but is still pointless since it will never have a value. Maybe you want to use a method parameter instead:

public IList<BestsellersReportLine> DailyBestsellersReport(PaymentStatus? ps)
{

这篇关于使用未分配的变量?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！