在 C# 中使用 XmlReader 在 xml 段中查找值

Question

我正在使用 XML reader 来搜索我们使用的 xml 配置文件。我想找到某个键下的值，并能够更改它们或添加它们（如果它们不存在）。

XML样本

<DBSimulatorConfigurations>
  <Configurations>
    <DBSimulatorConfiguration>
      <Key>Test1</Key>
      <Submit>0</Submit>
      <Amend>0</Amend>
      <Update>0</Update>
      <Delete>1</Delete>
    <ResponseTimeInSeconds>100</ResponseTimeInSeconds>
    </DBSimulatorConfiguration>
    <DBSimulatorConfiguration>
      <Key>Test2</Key>
      <Submit>0</Submit>
      <AutoUpdate>0</AutoUpdate>
      <Amend>0</Amend>
      <Update>0</Update>
      <Delete>1</Delete>
    <ResponseTimeInSeconds>100</ResponseTimeInSeconds>
    </DBSimulatorConfiguration>
    <DBSimulatorConfiguration>
  </Configurations> 
</DBSimulatorConfigurations>

到目前为止的代码...注释掉的位未在 'Test1'

中找到值

XmlReader reader = XmlReader.Create("C:\<path>\DBConfigs.xml");
while(reader.Read())
{
    if (reader.ReadToDescendant("Key"))
    {
        reader.Read();
        if (reader.Value == "Test1")
        {
            Console.WriteLine("Found_1 {0}", reader.Value);
            // Doesn't work :( 
            // reader.Read();
            //if (reader.ReadToDescendant("Submit")) {
            //  Console.WriteLine("Value for Submit is {0}", reader.Value);
            //}
        }

        if (reader.Value == "Test2")
        {
            Console.WriteLine("Found_2 {0}", reader.Value);
        }

        reader.Read(); //this moves reader to next node which is text 
        if (reader.ReadToDescendant("Full.2")) {
            Console.WriteLine("Found {0}", reader.Value);
        }

    }

但我想做的是找到并更改 'Submit' 或 'Amend' 等的值，或者如果没有条目 'Submit' 那么我将添加一个。

但首先我希望能够找到并更改 Test1 的值。

Answer 1

这是一种方法，使用 XDocument:

 string xml = @"
<DBSimulatorConfigurations>
  <Configurations>
    <DBSimulatorConfiguration>
      <Key>Test1</Key>
      <Submit>0</Submit>
      <Amend>0</Amend>
      <Update>0</Update>
      <Delete>1</Delete>
    <ResponseTimeInSeconds>100</ResponseTimeInSeconds>
    </DBSimulatorConfiguration>
    <DBSimulatorConfiguration>
      <Key>Test2</Key>
      <Submit>0</Submit>
      <AutoUpdate>0</AutoUpdate>
      <Amend>0</Amend>
      <Update>0</Update>
      <Delete>1</Delete>
    <ResponseTimeInSeconds>100</ResponseTimeInSeconds>
    </DBSimulatorConfiguration>
    <DBSimulatorConfiguration>
    </DBSimulatorConfiguration>
  </Configurations> 
</DBSimulatorConfigurations>";

XDocument xdoc = XDocument.Parse(xml);
//search for  all nodes with <DBSimulatorConfiguration> element
var elements = xdoc.Root.Elements().Elements().Where(x => x.Name == "DBSimulatorConfiguration");
//iterate through all those eleemnt
foreach (var element in elements)
{
    //now find it's child named Submit
    var submitElement = element.Elements().FirstOrDefault(x => x.Name == "Submit");
    //if such element is found
    if (submitElement != null)
    {
        //here you can change Submit element, like this:
        // submitElement.Value = "abc";
        //or you can check for something
        if (submitElement.ElementsBeforeSelf().Any(x=> x.Name == "Key" && x.Value== "Test2"))
        {
            //this is submitElement which is after element named Key with value Test2
            submitElement.Value = "some specific value";
        }
    }
    else
        element.Add(new XElement("Submit", 999));
}

Answer 2

这似乎可以找到价值并更新它。我已经更新了它，所以我可以找到特定值的任何值。

//search for  all nodes with <DBSimulatorConfiguration> element
string xml = "<path>.DBConfig.xml";
XDocument xdoc = XDocument.Load(xml);
var elements = xdoc.Root.Elements().Elements().Where(x => x.Name == "DBSimulatorConfiguration");
//iterate through all those eleemnt

foreach (var element in elements)
{
    //Console.WriteLine("Empty {0}", element.Value);
    //now find it's child named Submit
    var configKey = element.Elements().FirstOrDefault(x => x.Name == "Key");
    var configSubmit = element.Elements().FirstOrDefault(x => x.Name == "Submit");
    var configAmend = element.Elements().FirstOrDefault(x => x.Name == "Amend");
    var configUpdate = element.Elements().FirstOrDefault(x => x.Name == "Update");
    var configDelete = element.Elements().FirstOrDefault(x => x.Name == "Delete");

    //if such element is found
    if (configSubmit != null)
    {
        if (configKey.ElementsBeforeSelf().Any(x => x.Name == "Key" && x.Value == "Test1"))
        {
            Console.WriteLine("Found Key for Test1 {0}", configKey.Value);
        }
        if (configSubmit.ElementsBeforeSelf().Any(x => x.Name == "Key" && x.Value == "Test1"))
        {
            configSubmit.Value = "1";
            Console.WriteLine("Submit value is updated to {0}", configSubmit.Value);        
        }
        if (configAmend.ElementsBeforeSelf().Any(x => x.Name == "Key" && x.Value == "Test1"))
        {
            Console.WriteLine("Amend value is: {0}", configAmend.Value);
        }
        if (configUpdate.ElementsBeforeSelf().Any(x => x.Name == "Key" && x.Value == "Test1"))
        {
            Console.WriteLine("Update value is: {0}", configUpdate.Value);
        }
    }
}
xdoc.Save("<path>.DBConfig.xml");

这是最有效的方法吗？

在 C# 中使用 XmlReader 在 xml 段中查找值

Finding a value within an xml segment using XmlReader in C#

c#

xml

xmlreader