LINQ在自定义类型的列表中选择？

Question

我在我的应用程序上使用SparkPost向我和客户发送电子邮件。为了做到这一点，我需要使用C＃序列化一个数组。我有下面的代码似乎没有工作，我不知道为什么。

recipients = new List<Recipient>() { 
    toAddresses.Select(addr => new Recipient() { 
     address = addr.ToString() 
    }) 
} 

toAddresses只是一个List<string>与电子邮件地址。

收件人类：

class Recipient { 
    public string address; 
} 

是LINQ选择的输出应该是这样的：

recipients = new List<Recipient>(){ 
    new Recipient() { 
     address ="joe_scotto@1.net" 
    }, 
    new Recipient() { 
     address ="joe_scotto@2.net" 
    }, 
    new Recipient() { 
     address ="joe_scotto@1.net" 
    }, 
    new Recipient() { 
     address ="jscotto@2.com" 
    } 
} 

任何帮助将是巨大的，谢谢！

特定错误：

Error CS1503 Argument 1: cannot convert from 'System.Collections.Generic.IEnumerable' to 'app.Recipient'

Error CS1950 The best overloaded Add method 'List.Add(Recipient)' for the collection initializer has some invalid arguments

请求字符串：

wc.UploadString("https://api.sparkpost.com/api/v1/transmissions", JsonConvert.SerializeObject(
new { 
    options = new { 
     ip_pool = "sa_shared" 
    }, 
    content = new { 
     from = new { 
      name = "a Sports", 
      email = "no-reply@colorizer.a.com" 
     }, 
     subject = subject, 
     html = emailBody 
    }, 
    recipients = new List<Recipient>() { 
     toAddresses.Select(addr => new Recipient() { 
      address => addr 
     }) 
    } 
} 

））;

Answer 1

好像你需要简单的映射

var recipients = toAddresses.Select(addr => new Recipient { address = addr }).ToList(); 

不能使用IEnumerable作为参数列表初始化

var recipients = new List<Recipient>() { toAddresses.Select... } 

初始化逻辑将调用List.Add在每次你在{ }通过项目，所以预计情况Recepient用英文逗号分隔，但是当你通过IEnumerable时失败。

List<T>具有过载构造函数接受IEnumerable<T>作为参数，所以你可以使用这个

var recepients = new List<Recepient>(toAddresses.Select(addr => new Recipient {address = addr})); 

但在我自己的意见简单的映射似乎更具可读性。

var message = new 
{ 
    options = new 
    { 
     ip_pool = "sa_shared" 
    }, 
    content = new 
    { 
     from = new 
     { 
      name = "a Sports", 
      email = "no-reply@colorizer.a.com" 
     }, 
     subject = subject, 
     html = emailBody 
    }, 
    recipients = toAddresses.Select(addr => new Recipient() { address = addr}).ToList() 
}