Question

我有一个名为theGarage的主类，其中包含我们的客户，供应商和工作类的实例。

我想将程序数据保存到XML文件中，我使用了下面的代码（只是一个片段，我有其他类的匹配代码）。我想知道是否有更简单的方法来执行此操作，例如将整个theGarage类写入XML文件并将其读入，而不必像下面那样编写所有这些代码。

   public void saveToFile()
    {
        using (XmlWriter writer = XmlWriter.Create("theGarage.xml"))
        {
            writer.WriteStartDocument();

            ///
            writer.WriteStartElement("theGarage");
            writer.WriteStartElement("Customers");

            foreach (Customer Customer in Program.theGarage.Customers)
            {
                writer.WriteStartElement("Customer");
                writer.WriteElementString("FirstName", Customer.FirstName);
                writer.WriteElementString("LastName", Customer.LastName);
                writer.WriteElementString("Address1", Customer.Address1);
                writer.WriteElementString("Address2", Customer.Address2);
                writer.WriteElementString("Town", Customer.Town);
                writer.WriteElementString("County", Customer.County);
                writer.WriteElementString("PostCode", Customer.Postcode);
                writer.WriteElementString("TelephoneHome", Customer.TelephoneHome);
                writer.WriteElementString("TelephoneMob", Customer.TelephoneMob);

                //begin vehicle list
                writer.WriteStartElement("Vehicles");

                foreach (Vehicle Vehicle in Customer.Cars)
                {
                    writer.WriteStartElement("Vehicle");
                    writer.WriteElementString("Make", Vehicle.Make);
                    writer.WriteElementString("Model", Vehicle.Model);
                    writer.WriteElementString("Colour", Vehicle.Colour);
                    writer.WriteElementString("EngineSize", Vehicle.EngineSize);
                    writer.WriteElementString("Registration", Vehicle.Registration);
                    writer.WriteElementString("Year", Vehicle.YearOfFirstReg);
                    writer.WriteEndElement();
                }
                writer.WriteEndElement();
                writer.WriteEndElement();
            }
        }
    }

Answer 1

有更简单的序列化对象的方法，请使用XmlSerializer。请参阅文档here。

将您的车库序列化为文件的代码段可能如下所示：

var garage = new theGarage();

// TODO init your garage..

XmlSerializer xs = new XmlSerializer(typeof(theGarage));
TextWriter tw = new StreamWriter(@"c:\temp\garage.xml");
xs.Serialize(tw, garage);

从文件加载车库的代码：

using(var sr = new StreamReader(@"c:\temp\garage.xml"))
{
   garage = (theGarage)xs.Deserialize(sr);
}

Answer 2

如果有几个漂亮的扩展方法，那么你可以轻松地从/向文件读/写这个。

public static class Extensions
{
    public static string ToXml(this object obj)
    {
        XmlSerializer s = new XmlSerializer(obj.GetType());
        using (StringWriter writer = new StringWriter())
        {
            s.Serialize(writer, obj);
            return writer.ToString();
        }
    }

    public static T FromXml<T>(this string data)
    {
        XmlSerializer s = new XmlSerializer(typeof(T));
        using (StringReader reader = new StringReader(data))
        {
            object obj = s.Deserialize(reader);
            return (T)obj;
        }
    }
}

例如

 var xmlData = myObject.ToXml();

 var anotherObject = xmlData.FromXml<ObjectType>();

Answer 3

我刚写了a blog post on saving an object's data to Binary, XML, or Json。以下是向/从XML写入和读取类实例的函数。有关详细信息，请参阅我的博文。

要求System.Xml程序集包含在项目中。

/// <summary>
/// Writes the given object instance to an XML file.
/// <para>Only Public properties and variables will be written to the file. These can be any type though, even other classes.</para>
/// <para>If there are public properties/variables that you do not want written to the file, decorate them with the [XmlIgnore] attribute.</para>
/// <para>Object type must have a parameterless constructor.</para>
/// </summary>
/// <typeparam name="T">The type of object being written to the file.</typeparam>
/// <param name="filePath">The file path to write the object instance to.</param>
/// <param name="objectToWrite">The object instance to write to the file.</param>
/// <param name="append">If false the file will be overwritten if it already exists. If true the contents will be appended to the file.</param>
public static void WriteToXmlFile<T>(string filePath, T objectToWrite, bool append = false) where T : new()
{
    TextWriter writer = null;
    try
    {
        var serializer = new XmlSerializer(typeof(T));
        writer = new StreamWriter(filePath, append);
        serializer.Serialize(writer, objectToWrite);
    }
    finally
    {
        if (writer != null)
            writer.Close();
    }
}

/// <summary>
/// Reads an object instance from an XML file.
/// <para>Object type must have a parameterless constructor.</para>
/// </summary>
/// <typeparam name="T">The type of object to read from the file.</typeparam>
/// <param name="filePath">The file path to read the object instance from.</param>
/// <returns>Returns a new instance of the object read from the XML file.</returns>
public static T ReadFromXmlFile<T>(string filePath) where T : new()
{
    TextReader reader = null;
    try
    {
        var serializer = new XmlSerializer(typeof(T));
        reader = new StreamReader(filePath);
        return (T)serializer.Deserialize(reader);
    }
    finally
    {
        if (reader != null)
            reader.Close();
    }
}

实施例

// Write the list of salesman objects to file.
WriteToXmlFile<Customer>("C:\TheGarage.txt", customer);

// Read the list of salesman objects from the file back into a variable.
Customer customer = ReadFromXmlFile<Customer>("C:\TheGarage.txt");

Answer 4

对于我的项目，我使用DataContractSerializer。我与XmlSerializer形成对比，它可以处理对同一对象的多个引用，使得数据不会在xml中重复并恢复为已保存。

轻松将整个类实例写入XML文件并重新读入

4 个答案:

实施例