LINQ在自定義類型的列表中選擇？

Question

我在我的應用程序上使用SparkPost向我和客戶發送電子郵件。爲了做到這一點，我需要使用C＃序列化一個數組。我有下面的代碼似乎沒有工作，我不知道爲什麼。

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

toAddresses只是一個List<string>與電子郵件地址。

收件人類：

class Recipient { 
    public string address; 
} 

是LINQ選擇的輸出應該是這樣的：

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" 
    } 
} 

任何幫助將是巨大的，謝謝！

特定錯誤：

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

請求字符串：

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

好像你需要簡單的映射

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

不能使用IEnumerable作爲參數列表初始化

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

初始化邏輯將調用List.Add在每次你在{ }通過項目，所以預計情況Recepient用英文逗號分隔，但是當你通過IEnumerable時失敗。

List<T>具有過載構造函數接受IEnumerable<T>作爲參數，所以你可以使用這個

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

但在我自己的意見簡單的映射似乎更具可讀性。

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() 
}