XML 反序列化返回空值

本文关键字：空值 返回 反序列化 XML | 更新日期: 2023-09-27 18:31:59

我有以下类，其中包含我想要的类的对象 反序列化 xml。 我使用以下技术显示空。实际上，我想在问题的最后一部分反序列化xml定义。为此，我使用以下技术可能是我走错了路，请纠正我

[Serializable]
public class Param 
{
    public Professor Professor { get; set; }
    public Course Course { get; set; }
}
public class Professor
{
    public int id;
    public String name;
    public Professor() { }
}
public class Course
{
    public int id;
    public String name;
    public Course() { }
}

下面是用于反序列化的 C# 代码，从文件计划中读取 xml.xml下面定义了 xml 的示例

 string path = "//schedule.xml";
    XmlRootAttribute xRoot = new XmlRootAttribute();
    xRoot.ElementName = "param";
    xRoot.IsNullable = true;
    XmlSerializer serializer = new XmlSerializer(typeof(Param),xRoot);
    using (StreamReader reader = new StreamReader(path))
    {
    param = (Param)serializer.Deserialize(reader);
    }

这是在计划.xml文件中定义的xml示例

 <param>
      <professor id='1' name='Novak J.'></professor>
      <Professor id='2' name='Stanek A.'>  </Professor>
      <course id='1' name='Mathematics' biolab='false'> </course>
      <course id='2' name='Biology' biolab='true'>  </course>
 </param>

XML 反序列化返回空值

像这样更改您的类，然后重试。这是 VS 为 xml 生成的代码。我使用您的 xml 结构对此进行了测试，它可以工作。但是您可能需要为完整的 xml 再次重新生成代码。

/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
[System.Xml.Serialization.XmlRootAttribute(Namespace = "", IsNullable = false)]
public partial class param
{
    private paramProfessor professorField;
    private paramProfessor1 professorField1;
    private paramCourse[] courseField;
    /// <remarks/>
    public paramProfessor professor
    {
        get
        {
            return this.professorField;
        }
        set
        {
            this.professorField = value;
        }
    }
    /// <remarks/>
    public paramProfessor1 Professor
    {
        get
        {
            return this.professorField1;
        }
        set
        {
            this.professorField1 = value;
        }
    }
    /// <remarks/>
    [System.Xml.Serialization.XmlElementAttribute("course")]
    public paramCourse[] course
    {
        get
        {
            return this.courseField;
        }
        set
        {
            this.courseField = value;
        }
    }
}
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class paramProfessor
{
    private byte idField;
    private string nameField;
    /// <remarks/>
    [System.Xml.Serialization.XmlAttributeAttribute()]
    public byte id
    {
        get
        {
            return this.idField;
        }
        set
        {
            this.idField = value;
        }
    }
    /// <remarks/>
    [System.Xml.Serialization.XmlAttributeAttribute()]
    public string name
    {
        get
        {
            return this.nameField;
        }
        set
        {
            this.nameField = value;
        }
    }
}
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class paramProfessor1
{
    private byte idField;
    private string nameField;
    /// <remarks/>
    [System.Xml.Serialization.XmlAttributeAttribute()]
    public byte id
    {
        get
        {
            return this.idField;
        }
        set
        {
            this.idField = value;
        }
    }
    /// <remarks/>
    [System.Xml.Serialization.XmlAttributeAttribute()]
    public string name
    {
        get
        {
            return this.nameField;
        }
        set
        {
            this.nameField = value;
        }
    }
}
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class paramCourse
{
    private byte idField;
    private string nameField;
    private bool biolabField;
    /// <remarks/>
    [System.Xml.Serialization.XmlAttributeAttribute()]
    public byte id
    {
        get
        {
            return this.idField;
        }
        set
        {
            this.idField = value;
        }
    }
    /// <remarks/>
    [System.Xml.Serialization.XmlAttributeAttribute()]
    public string name
    {
        get
        {
            return this.nameField;
        }
        set
        {
            this.nameField = value;
        }
    }
    /// <remarks/>
    [System.Xml.Serialization.XmlAttributeAttribute()]
    public bool biolab
    {
        get
        {
            return this.biolabField;
        }
        set
        {
            this.biolabField = value;
        }
    }
}
您必须在

类中将 id 和名称标记为 XML 属性，以便在 desrialzation 期间选取值。我还重组了您的 XML。看看下面 

static void Main(string[] args)
    {
        string xml = File.ReadAllText(path of the file);
        Param p = DeserializeFromXml<Param>(xml);
    }
    public static T DeserializeFromXml<T>(string xml)
    {
        try
        {
            T result;
            XmlSerializer ser = new XmlSerializer(typeof(T));
            using (TextReader tr = new StringReader(xml))
            {
                result = (T)ser.Deserialize(tr);
            }
            return result;
        }
        catch { throw; }
    }
}
[Serializable]
[XmlRoot(Namespace = "", ElementName = "param")]
public class Param
{
    [XmlArray("professors")]
    public List<professor> Professor { get; set; }
    [XmlArray("courses")]
    public List<course> Course { get; set; }
}
public class professor
{
   [XmlAttribute("id")]
    public int id { get; set; }
   [XmlAttribute("name")]
    public string name { get; set; }

    public professor() { }
}
public class course
{
     [XmlAttribute("id")]
    public int id { get; set; }
       [XmlAttribute("name")]
    public string name { get; set; }
    public course() { }
}

新的 XML

<param>
<professors>
      <professor id='1' name='Novak J.'></professor>
      <professor id='2' name='Stanek A.'>  </professor>
</professors>
<courses>
      <course id='1' name='Mathematics' biolab='false'> </course>
      <course id='2' name='Biology' biolab='true'>  </course>
</courses>
</param>

您的示例 XML：

 <param>
      <professor id='1' name='Novak J.'></professor>
      <professor id='2' name='Stanek A.'>  </professor>
      <course id='1' name='Mathematics' biolab='false'> </course>
      <course id='2' name='Biology' biolab='true'>  </course>
 </param>

可序列化类：

[XmlRoot(Namespace = "", ElementName = "param")]
public class Param
{
    [XmlElement("professor")]
    public List<professor> Professor { get; set; }
    [XmlElement("course")]
    public List<course> Course { get; set; }
}
public class professor
{
    [XmlAttribute("id")]
    public int professorid;
    [XmlAttribute("name")]
    public string professorname;
    public professor() { }
}
public class course
{
    [XmlAttribute("id")]
    public int courseid;
    [XmlAttribute("name")]
    public string coursename;
    public course() { }
}

调用反序列化代码： 

DeserializeFromXml<Param>(XMLinStringVariable);

用于反序列化的 C# 代码：

public static T DeserializeFromXml<T>(string xml)
{
    try
    {
        T result;
        XmlSerializer ser = new XmlSerializer(typeof(T));
        using (TextReader tr = new StringReader(xml))
        {
            result = (T)ser.Deserialize(tr);
        }
        return result;
    }
    catch { throw; }
}

编辑：错误在于<professor>和<course>标签使用相同的属性名称。因此，我在序列化类中添加了XmlElement和XmlAttribute标记以将它们分开。

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