如何將 xml 元素值反序列化為 C# 類屬性

Question

這是我第一次在 StackOverflow 上發帖，所以請原諒任何錯誤。 鑒於此 xml：

<document name="doc1.pdf">
  <propertyValues>      
    <propertyValue><name>InvoiceID</name><value>123</value></propertyValue>
    <propertyValue><name>CompanyName</name><value>Company1</value></propertyValue>
    <propertyValue><name>VendorName</name><value>Vendor1</value></propertyValue>    
    <propertyValue><name>GrossAmt</name><value>176.33</value></propertyValue>
    <propertyValue><name>InvoiceDate</name><value>26-03-2019</value></propertyValue>
  </propertyValues>
</document>
<document name="doc2.pdf">
  <propertyValues>      
    <propertyValue><name>InvoiceID</name><value>223</value></propertyValue>
    <propertyValue><name>CompanyName</name><value>Company2</value></propertyValue>
    <propertyValue><name>VendorName</name><value>Vendor2</value></propertyValue>    
    <propertyValue><name>GrossAmt</name><value>5300.88</value></propertyValue>
    <propertyValue><name>InvoiceDate</name><value>31-03-2019</value></propertyValue>
  </propertyValues>
</document>

有沒有更簡單的方法將它反序列化為 C# 類，例如。

    public class Invoice
    {
        public string InvoiceId { get; set; }
        public string CompanyName { get; set; }
        public string VendorName { get; set; }
        public decimal GrossAmt { get; set; }
        public DateTime InvoiceDate { get; set; }
    }

當 xml 元素名稱映射到屬性名稱時，反序列化很簡單，但在這種情況下它是一個值。 試圖避免遍歷 xml 並手動提取值。

Answer 1

至少使用標准的 .Net XMLSerializer 沒有辦法用屬性來裝飾你的類來讓序列化按照你的意願工作。 但是你可以使用這樣的類結構來解決這個問題：

public class InvoiceList {
    [XmlElement("document")]
    public Invoice[] Invoices { get; set; }
}

public class Invoice {
    [XmlIgnore]
    public string InvoiceId => this.PropertyValues.First(p => p.Name == "InvoiceID").Value;
    [XmlIgnore]
    public string CompanyName => this.PropertyValues.First(p => p.Name == "CompanyName").Value;
    [XmlIgnore]
    public string VendorName => this.PropertyValues.First(p => p.Name == "VendorName").Value;
    [XmlIgnore]
    public decimal GrossAmt => decimal.Parse(this.PropertyValues.First(p => p.Name == "GrossAmt").Value);
    [XmlIgnore]
    public DateTime InvoiceDate => DateTime.Parse(this.PropertyValues.First(p => p.Name == "InvoiceDate").Value);
    [XmlArray("propertyValues")]
    [XmlArrayItem("propertyValue")]
    public PropertyValue[] PropertyValues { get; set; }
}

public class PropertyValue {
    [XmlElement("name")]
    public string Name { get; set; }
    [XmlElement("value")]
    public string Value { get; set; }
}

Invoice 類看起來仍然相同（至少對於閱讀而言，寫作需要更多的工作，但我希望你能明白）。 當然，需要一些更有意義的錯誤處理。

xml 字符串需要包含在<InvoiceList>...</InvoiceList>標記中才能工作：

<?xml version="1.0" encoding="UTF-8"?>
<InvoiceList>
  <document name="doc1.pdf">
    <propertyValues>
      <propertyValue><name>InvoiceID</name><value>123</value></propertyValue>
      <propertyValue><name>CompanyName</name><value>Company1</value></propertyValue>
      <propertyValue><name>VendorName</name><value>Vendor1</value></propertyValue>
      <propertyValue><name>GrossAmt</name><value>176.33</value></propertyValue>
      <propertyValue><name>InvoiceDate</name><value>26-03-2019</value></propertyValue>
    </propertyValues>
  </document>
  <document name="doc2.pdf">
    <propertyValues>
      <propertyValue><name>InvoiceID</name><value>223</value></propertyValue>
      <propertyValue><name>CompanyName</name><value>Company2</value></propertyValue>
      <propertyValue><name>VendorName</name><value>Vendor2</value></propertyValue>
      <propertyValue><name>GrossAmt</name><value>5300.88</value></propertyValue>
      <propertyValue><name>InvoiceDate</name><value>31-03-2019</value></propertyValue>
    </propertyValues>
  </document>
</InvoiceList>

反序列化本身：

var xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><InvoiceList><document name=\"doc1.pdf\"><propertyValues><propertyValue><name>InvoiceID</name><value>123</value></propertyValue><propertyValue><name>CompanyName</name><value>Company1</value></propertyValue><propertyValue><name>VendorName</name><value>Vendor1</value></propertyValue><propertyValue><name>GrossAmt</name><value>176.33</value></propertyValue><propertyValue><name>InvoiceDate</name><value>26-03-2019</value></propertyValue></propertyValues></document><document name=\"doc2.pdf\"><propertyValues><propertyValue><name>InvoiceID</name><value>223</value></propertyValue><propertyValue><name>CompanyName</name><value>Company2</value></propertyValue><propertyValue><name>VendorName</name><value>Vendor2</value></propertyValue><propertyValue><name>GrossAmt</name><value>5300.88</value></propertyValue><propertyValue><name>InvoiceDate</name><value>31-03-2019</value></propertyValue></propertyValues></document></InvoiceList>";
using var stream = new MemoryStream();
using var writer = new StreamWriter(stream);
writer.Write(xml);
writer.Flush();
stream.Position = 0;

using var serializer = new XmlSerializer(typeof(InvoiceList));
var list = (InvoiceList)serializer.Deserialize(stream);

foreach (var i in list.Invoices) {
    Console.WriteLine($"{i.InvoiceId}, {i.CompanyName}");
}