我必须在根设置组中保存 2 组不同的设置。它应该看起来像这样:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>    
    <sectionGroup name="ROOT_GROUP">
       <sectionGroup name="GROUP_1">
         ........................
         some_settings
         ........................
       </sectionGroup>
       <sectionGroup name="GROUP_2">
         ........................
         some_other_settings
         ........................
       </sectionGroup>
     </sectionGroup>
  </configSections>
................................
other_system_tags
................................
</configuration>

细微差别是我必须在我的代码中的不同地方一个接一个地保存它。 (例如，GROUP_1 可以是连接字符串，GROUP_2 是一些环境设置，它们一起由用户在我的应用程序的不同部分填充)

我制作了这个简单的测试类以获得预期的结果

[TestFixture]
public class Tttt
{
    private string ROOT_GROUP = "ROOT_GROUP";
    private string GROUP_1 = "GROUP_1";
    private string GROUP_2 = "GROUP_2";

    [Test]
    public void SaveSettingsGroups()
    {
        SaveGroup1();
        SaveGroup2();
        Assert.True(true);
    }

    private Configuration GetConfig()
    {
        var configFilePath = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile;
        var map = new ExeConfigurationFileMap { ExeConfigFilename = configFilePath };
        var config = ConfigurationManager.OpenMappedExeConfiguration(map, ConfigurationUserLevel.None);
        return config;
    }

    private void SaveGroup1()
    {
        var config = GetConfig();

        var root = new UserSettingsGroup();

        config.SectionGroups.Add(ROOT_GROUP, root);

        config.Save(ConfigurationSaveMode.Modified);
        ConfigurationManager.RefreshSection(root.Name);

        var nested = new UserSettingsGroup();

        root.SectionGroups.Add(GROUP_1, nested);

        config.Save(ConfigurationSaveMode.Modified);
        ConfigurationManager.RefreshSection(nested.Name);             
    }

    private void SaveGroup2()
    {
        var config = GetConfig();

        var root = config.GetSectionGroup(ROOT_GROUP);

        var nested = new UserSettingsGroup();
        root.SectionGroups.Add(GROUP_2, nested);

        config.Save(ConfigurationSaveMode.Modified);
        ConfigurationManager.RefreshSection(nested.Name);
    }
}

但由于某些原因，这段代码的结果不同

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>    
    <sectionGroup name="ROOT_GROUP">
      <sectionGroup name="GROUP_1">
        ........................
        some_settings
        ........................
      </sectionGroup>
    </sectionGroup>
    <sectionGroup name="ROOT_GROUP">
      <sectionGroup name="GROUP_2">
      ........................
      some_other_settings
      ........................
      </sectionGroup>
    </sectionGroup>
  </configSections>
................................
other_system_tags
................................
</configuration>

ROOT_GROUP 节点是重复的，当然 visual studio 抛出一个 ROOT_GROUP 已经存在的异常。显然，当我将新的嵌套组添加到现有根组然后保存它时，我的问题隐藏在方法 SaveGroup2() 中 - 但为什么呢？

UPD 我刚刚添加了新方法

    private void SaveGroup3()
    {
        var config = GetConfig();

        var root = config.GetSectionGroup(ROOT_GROUP);
        var nested1 = root.SectionGroups.Get(0);

        var nested2 = new UserSettingsGroup();
        var nested3 = new UserSettingsGroup();

        nested1.SectionGroups.Add("GROUP_2", nested2);
        root.SectionGroups.Add("GROUP_3", nested3);
        config.Save(ConfigurationSaveMode.Modified);
        ConfigurationManager.RefreshSection(nested2.Name);
        ConfigurationManager.RefreshSection(nested3.Name);
    }

并在测试中替换它

[Test]
public void SaveSettingsGroups()
{
    SaveGroup1();
    SaveGroup3();
    Assert.True(true);
}

得到了这个奇怪的行为

  <sectionGroup name="ROOT_GROUP">
    <sectionGroup name="GROUP_1">
      <sectionGroup name="GROUP_2">
      </sectionGroup>
    </sectionGroup>
    <sectionGroup name="GROUP_3">
    </sectionGroup>
  </sectionGroup>

如您所见，奇怪之处在于结果完全在意料之中。 ROOT_GROUP 不是重复的，因为我需要它，但为什么它在 SaveGroup2() 中呢？我是否遗漏了 SaveGroup2() 中的某些内容？

UPD2 - 破解

只是尝试了一个简单的想法 - 如果我在向其添加新的嵌套元素之前清除 root_group 会怎样？

    private void SaveGroup2()
    {
        var config = GetConfig();

        var root = config.GetSectionGroup(ROOT_GROUP);

        var nested = new ConfigurationSectionGroup();

        //Copy exiting nested groups to array
        var gr = new ConfigurationSectionGroup[5];       
        root.SectionGroups.CopyTo(gr,0);
        gr[1] = nested;
        //<!----

        root.SectionGroups.Clear();

        config.Save(ConfigurationSaveMode.Modified);
        ConfigurationManager.RefreshSection(root.Name);

        root.SectionGroups.Add(gr[0].Name, gr[0]);
        root.SectionGroups.Add(GROUP_2, gr[1]);

        config.Save(ConfigurationSaveMode.Modified);
        ConfigurationManager.RefreshSection(root.Name);
    }

你怎么猜 - 它有效!

<sectionGroup name="ROOT_GROUP">
  <sectionGroup name="GROUP_1" type="System.Configuration.UserSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
  </sectionGroup>
  <sectionGroup name="GROUP_2" type="System.Configuration.ConfigurationSectionGroup, System.Configuration, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" >
  </sectionGroup>
</sectionGroup>

我认为它看起来像是一个错误，或者我遗漏了一些隐藏的东西。有人可以解释我做错了什么吗？

最佳答案

我花了一段时间才弄清楚发生了什么事，tl;dr 对我来说，框架代码本身似乎存在问题，特别是 method WriteUnwrittenConfigDeclarationsRecursive(SectionUpdates declarationUpdates, XmlUtilWriter utilWriter, int linePosition, int indent, bool skipFirstIndent) 类 MgmtConfigurationRecord 内。我不想写很长的故事，但如果您愿意，可以调试 .Net 框架代码并亲眼看看。

您可以通过以下方式修复您的代码:

<强>1。将所有组一起保存

private void SaveGroups()
{
    var config = GetConfig();
    var root = new ConfigurationSectionGroup();
    config.SectionGroups.Add(ROOT_GROUP, root);
    config.Save(ConfigurationSaveMode.Modified);
    ConfigurationManager.RefreshSection(root.Name);

    var nested = new UserSettingsGroup();
    root.SectionGroups.Add(GROUP_1, nested);

    nested = new UserSettingsGroup(); 
    root.SectionGroups.Add(GROUP_2, nested);

    config.Save(ConfigurationSaveMode.Modified);
    ConfigurationManager.RefreshSection(root.Name);
}

<强>2。在添加新项目之前删除现有的组项目

private void SaveGroup2()
{
    var config = GetConfig();
    var root = config.SectionGroups[ROOT_GROUP];
    var existingGroups = new Dictionary<string, ConfigurationSectionGroup>();
    while (root.SectionGroups.Count > 0)
    {
        existingGroups.Add(root.SectionGroups.Keys[0], root.SectionGroups[0]);
        root.SectionGroups.RemoveAt(0);
    }

    config.Save(ConfigurationSaveMode.Modified);

    existingGroups.Add(GROUP_2, new UserSettingsGroup());
    foreach (var key in existingGroups.Keys)
    {
        existingGroups[key].ForceDeclaration(true);
        root.SectionGroups.Add(key, existingGroups[key]);
    }

    config.Save(ConfigurationSaveMode.Modified);
    ConfigurationManager.RefreshSection(root.Name);
}

关于c# - App.config 将嵌套组添加到现有节点，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52344542/