Question

是否可以使用lambda（C＃）

编写以下内容

private static void GetRecordList(List<CustomerInfo> lstCustinfo)
{
    for (int i = 1; i <= 5; i++)
    {
        if (i % 2 == 0)

            lstCustinfo.Add(new CustomerInfo { CountryCode = "USA", CustomerAddress = "US Address" + i.ToString(), CustomerName = "US Customer Name" + i.ToString(), ForeignAmount = i * 50 });

        else
           lstCustinfo.Add(new CustomerInfo { CountryCode = "UK", CustomerAddress = "UK Address" + i.ToString(), CustomerName = "UK Customer Name" + i.ToString(), ForeignAmount = i * 80 });

    }
}

Answer 1

List<CustomerInfo> lstCustinfo = 
    Enumerable.Range(1, 5).Select(i => (i % 2 == 0)
        ? new CustomerInfo { CountryCode = "USA", CustomerAddress = "US Address" + i.ToString(), CustomerName = "US Customer Name" + i.ToString(), ForeignAmount = i * 50 }
        : new CustomerInfo { CountryCode = "UK", CustomerAddress = "UK Address" + i.ToString(), CustomerName = "UK Customer Name" + i.ToString(), ForeignAmount = i * 80 })
    .ToList();

Answer 2

您必须先定义选择，然后将其添加到传入列表：

var range = Enumerable.Range(1, 5);
var customers = from i in range
                select (i % 2 == 0) ?
                      new CustomerInfo 
                      { 
                                    CountryCode = "USA", 
                                    CustomerAddress = "US Address" + i, 
                                    CustomerName = "US Customer Name" + i, 
                                    ForeignAmount = i * 50 
                      }
                      :
                      new CustomerInfo 
                      { 
                                    CountryCode = "UK", 
                                    CustomerAddress = "UK Address" + i,
                                    CustomerName = "UK Customer Name" + i,
                                    ForeignAmount = i * 80 
                      };

lstCustinfo.AddRange(customers);

或许甚至更明确：

var range = Enumerable.Range(1, 5);
var usCustomers = from i in range
                  where i % 2 == 0 
                select new CustomerInfo 
                      { 
                                    CountryCode = "USA", 
                                    CustomerAddress = "US Address" + i, 
                                    CustomerName = "US Customer Name" + i, 
                                    ForeignAmount = i * 50 
                      };

var ukCustomers = from i in range
                where i % 2 != 0
                select new CustomerInfo 
                      { 
                                    CountryCode = "UK", 
                                    CustomerAddress = "UK Address" + i,
                                    CustomerName = "UK Customer Name" + i,
                                    ForeignAmount = i * 80 
                      };

lstCustinfo.AddRange(usCustomers.Union(ukCustomers));

使用LINQ重写语句（C＃）

2 个答案: