使用LINQ到转换列表＆LT; U＆GT;列出＆LT; T＆GT; [英] Using LINQ to convert List<U> to List<T>

问题描述

我有2类，它们有一些相同的属性。 我进的股票从1级列表的属性，而在那之后，我想采取一些必要的属性，并把它们纳入到第二类类型的列表。 我已经通过C＃铸铁序列和运行正常，但我必须这样做使用LINQ。我试图做一些事情，但没有很好的效果。帮我请与建议。

第一类：

 公共类ServiceInfo {
    专用长_id;
    众长ID {
        {返回this._id; }
        集合{_id = value的; }
    }

    私人字符串_name;
    公共字符串名称{
        {返回this._name; }
        集合{_name =价值; }
    }

    专用长_qty;
    众长量{
        {返回this._qty; }
        集合{_qty =价值; }
    }

    私人双人_amount;
    公共双倍金额{
        {返回this._amount; }
        集合{_amount =价值; }
    }

    私人字符串_currency;
    公共字符串货币{
        {返回this._currency; }
        集合{_currency =价值; }
    }

    私营的DateTime？ _日期;
    公开日期时间？日期 {
        {返回this._date; }
        集合{_date =价值; }
    }
}
 

第二类：

 类InvoiceWithEntryInfo {
    私人字符串currencyField;

    专用长IdField;
    众长IdIWEI {
        {返回this.IdField; }
        集合{IdIWEI =价值; }
    }

    私人字符串为nameField;
    公共字符串NameIWEI {
        {返回this.nameField; }
        集合{NameIWEI =价值; }
    }

    专用长qtyField;
    众长QuantityIWEI {
        {返回this.qtyField; }
        集合{QuantityIWEI =价值; }
    }

    私人双人amountField;
    公共双AmountIWEI {
        {返回this.amountField; }
        集合{AmountIWEI =价值; }
    }

    私营的DateTime的DateField;
    公开日期时间？ DateIWEI {
        {返回this.dateField; }
        集合{DateIWEI =价值; }
    }

    公共字符串OwnerIWEI {
        得到;组;
    }
}
 

C＃示例它运行正常： ......

  VAR SIL =新的名单，其中，ServiceInfo＆GT;（）;
VAR iweil =新的名单，其中，InvoiceWithEntryInfo＆GT;（）;
 

...

 如果（SIL！= NULL）
    {
        的foreach（在SIL ServiceInfo项）
        {
            iweil.Add（新InvoiceWithEntryInfo
                {
                    IdIWEI = item.ID，
                    AmountIWEI = item.Amount，
                    DateIWEI = item.Date
                }）;
        }
 

LINQ样品至极犯规运行正常：

  iweilCOPY = sil.ConvertAll＆LT; InvoiceWithEntryInfo＆GT;（A =＆GT;（InvoiceWithEntryInfo）一）;

            iweilCOPY = sil.FindAll（一个=＆GT;（SIL是InvoiceWithEntryInfo））ConvertAll＆所述; InvoiceWithEntryInfo＆GT;（一个=＆GT;（InvoiceWithEntryInfo）一个）;
 

解决方案

  VAR iweilCopy = sil.Select（项目=＆gt;新建InvoiceWithEntryInfo（）
{
  IdWEI = item.Id，
  NameWEI = item.Name，
  ....
}）了ToList（）。
 

I have 2 classes which have some identical properties. I stock into a list properties from 1st class, and after that, i want to take some needed properties and put them into a list of 2nd class type. I've made cast sequence through C# and that runs OK, but i must do with LINQ. I tried to do something but without good results. Help me please with suggestions.

1st Class:

   public class ServiceInfo {
    private long _id;
    public long ID {
        get { return this._id; }
        set { _id = value; }
    }

    private string _name;
    public string Name {
        get { return this._name; }
        set { _name = value; }
    }

    private long _qty;
    public long Quantity {
        get { return this._qty; }
        set { _qty = value; }
    }

    private double _amount;
    public double Amount {
        get { return this._amount; }
        set { _amount = value; }
    }

    private string _currency;
    public string Currency {
        get { return this._currency; }
        set { _currency = value; }
    }

    private DateTime? _date;
    public DateTime? Date {
        get { return this._date; }
        set { _date = value; }
    }
}

2nd Class:

class InvoiceWithEntryInfo {
    private string currencyField;

    private long IdField;
    public long IdIWEI {
        get { return this.IdField; }
        set { IdIWEI = value; }
    }

    private string nameField;
    public string NameIWEI {
        get { return this.nameField; }
        set { NameIWEI = value; }
    }

    private long qtyField;
    public long QuantityIWEI {
        get { return this.qtyField; }
        set { QuantityIWEI = value; }
    }

    private double amountField;
    public double AmountIWEI {
        get { return this.amountField; }
        set { AmountIWEI = value; }
    }

    private DateTime dateField;
    public DateTime? DateIWEI {
        get { return this.dateField; }
        set { DateIWEI = value; }
    }

    public string OwnerIWEI {
        get; set;
    }
}

C# sample which runs OK: ...

var sil = new List<ServiceInfo>();
var iweil = new List<InvoiceWithEntryInfo>();

...

if (sil != null)
    {
        foreach (ServiceInfo item in sil)
        {
            iweil.Add(new InvoiceWithEntryInfo
                {
                    IdIWEI = item.ID,
                    AmountIWEI = item.Amount,
                    DateIWEI = item.Date
                });
        }

LINQ sample wich doesnt run OK:

            iweilCOPY = sil.ConvertAll<InvoiceWithEntryInfo>(a => (InvoiceWithEntryInfo)a);

            iweilCOPY = sil.FindAll(a => (sil is InvoiceWithEntryInfo)).ConvertAll<InvoiceWithEntryInfo>(a => (InvoiceWithEntryInfo)a);

解决方案

var iweilCopy = sil.Select(item => new InvoiceWithEntryInfo()
{
  IdWEI = item.Id,
  NameWEI = item.Name,
  ....
}).ToList();

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