c# - 没有 null XMLArray 的 XML 序列化

Question

让我直截了本地说。如果它为空，是否可以不序列化 XMLArray 元素？正如在下面的 XML 中一样，使用了“详细信息”。如果它为空，是否可以不在 XML 中使用它。请检查我的代码，并感谢您对此的一些想法。

<agr:InvoiceNo>99999</agr:InvoiceNo>
    <agr:Header>
      <agr:LineNo>1</agr:LineNo>
      <agrlib:InvoiceDate>2013-02-13</agrlib:InvoiceDate>
      <agrlib:DueDate>2013-03-15</agrlib:DueDate>
      <agr:ArchiveRef>27624642</agr:ArchiveRef>
      <agr:ArchivePath>Images\20130315\10_00000030_00000</agr:ArchivePath>
      <agr:Currency>SEK</agr:Currency>
      <agr:Seller>
        <agrlib:CompRegNo>999999</agrlib:CompRegNo>
      </agr:Seller>
      <agr:Buyer>
        <agrlib:CompanyCode>10</agrlib:CompanyCode>
        <agr:Accountable />
      </agr:Buyer>
      <agr:PaymentInfo>
        <agr:AccountNumber>99999</agr:AccountNumber>
        <agrlib:BacsId />
      </agr:PaymentInfo>
      <agrlib:ReferenceCode>
        <agrlib:Code>AA</agrlib:Code>
        <agrlib:Value>AAAA</agrlib:Value>
        <agrlib:Description />
      </agrlib:ReferenceCode>
    </agr:Header>
    <Details />                    <!-- this one -->
    <agr:Summary>
      <agr:TotalTax>170.36</agr:TotalTax>
      <agr:TotalInclTax>1590.00</agr:TotalInclTax>
    </agr:Summary>
  </agr:Invoice>

---

[Serializable]
public class Invoice
{
    private Header _header = new Header();
    private Summary _summary = new Summary();
    private List<Detail> _details = new List<Detail>();

    [XmlElement("InvoiceNo")]
    public string InvoiceNo { get; set; }

    [XmlElement("Header")]
    public Header Header
    {
        get { return _header; }
        set { _header = value; }
    }

    [XmlArray("Details"), XmlArrayItem("Detail", typeof(Detail), IsNullable=false)]
    public List<Detail> Details
    {
        get { return _details; }
        set { _details = value; }
    }

    [XmlElement("Summary")]
    public Summary Summary
    {
        get { return _summary; }
        set { _summary = value; }
    }
}

[XmlType(TypeName = "Detail"), Serializable]
public class Detail
{
    private Product _product = new Product();
    static CultureInfo ci = CultureInfo.InvariantCulture;
    private float _lineTotExclTax = 0;

    [XmlElement("LineNo")]
    public int LineNo { get; set; }

    [XmlIgnore]
    public float LineTotExclTax
    {
        get { return _lineTotExclTax; }
        set { _lineTotExclTax = value; }
    }

    [XmlElement("LineTotExclTax")]
    public string CustomLineTotExclTax
    {
        get { return LineTotExclTax.ToString("#0.00", ci); } 
        set { float.TryParse(value, NumberStyles.Float, ci, out _lineTotExclTax); }
    }

    [XmlElement("Products")]
    public Product Product
    {
        get { return _product; }
        set { _product = value; }
    }
}

Answer 1

如果列表真的是null，它会被忽略。要获得您显示的输出，它必须是一个空的非 null 列表，可能是由于字段初始化程序:

private List<Detail> _details = new List<Detail>();

如果你不能让它null，那么考虑ShouldSerialize*:

[Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
public bool ShouldSerializeDetails()
{
    return _details != null && _details.Count != 0;
}

这定义了属性 Details 应该/不应该序列化的自定义规则。