Visual C＃存储和读取自定义选项到Appdata中的自定义XML

Question

我有一个应用程序，我从VB转换为C＃在Visual Studio 2013和.NET不再支持PrivateProfileString，但希望我使用XML代替。

我需要一个非常简单的代码的帮助，它可以存储和读取XML中的两个字符串setting1和setting2并从中读取它。

我想知道什么是最有效的方法去做这件事。是否使用XMLDocument或XMLWriter？

如果有人能给我一个简单的脚本，我会非常感激。谢谢！

Answer 1

让我们假设你有一个包含settings.xml文件的地方：

<?xml version="1.0" encoding="utf-8" ?> 
<Settings> 
    <Section1> 
     <Key1>Value1</Key1> 
     <Key2>Value2</Key2> 
    </Section1> 
    <Section2> 
     <Key1>Value3</Key1> 
     <Key2>Value4</Key2> 
     <KeyX>Value5</KeyX> 
    </Section2> 
</Settings> 

然后你就可以有一个SettingsProvider类是这样的：

using System.Xml.Linq; 

public static class SettingsProvider 
{ 
    private const string settingsFileName = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "settings.xml"); 

    private static XDocument settings; 

    static SettingsProvider() 
    { 
     try 
     { 
      settings = XDocument.Load(settingsFileName); 
     } 
     catch 
     { 
      settings = XDocument.Parse("<Settings/>"); 
     } 
    } 

    public static string GetValue(string section, string key, string defaultValue) 
    { 
     XElement settingElement = GetSettingElement(section, key); 

     return settingElement == null ? defaultValue : settingElement.Value; 
    } 

    public static void SetValue(string section, string key, string value) 
    { 
     XElement settingElement = GetSettingElement(section, key, true); 

     settingElement.Value = value; 
     settings.Save(settingsFileName); 
    } 

    private static XElement GetSettingElement(string section, string key, bool createIfNotExist = false) 
    { 
     XElement sectionElement = 
      settings 
       .Root 
       .Elements(section) 
       .FirstOrDefault(); 

     if (sectionElement == null) 
     { 
      if (createIfNotExist) 
      { 
       sectionElement = new XElement(section); 
       settings.Root.Add(sectionElement); 
      } 
      else 
      { 
       return null; 
      } 
     } 

     XElement settingElement = 
      sectionElement 
       .Elements(key) 
       .FirstOrDefault(); 

     if (settingElement == null) 
     { 
      if (createIfNotExist) 
      { 
       settingElement = new XElement(key); 
       sectionElement.Add(settingElement); 
      } 
     } 

     return settingElement; 
    } 

    public static void RemoveSetting(string section, string key) 
    { 
     XElement settingElement = GetSettingElement(section, key); 

     if (settingElement == null) 
     { 
      return; 
     } 

     XElement sectionElement = settingElement.Parent; 

     settingElement.Remove(); 

     if (sectionElement.IsEmpty) 
     { 
      sectionElement.Remove(); 
     } 

     settings.Save(settingsFileName); 
    } 
} 

您可以使用它像这样：

string section1Key1 = SettingsProvider.GetValue("Section1", "Key1", "default"); 
SettingsProvider.SetValue("Section1", "Key1", "OtherValue"); 
SettingsProvider.SetValue("Section1", "Key2", "Value2"); 
SettingsProvider.SetValue("Section2", "Key1", "Value3"); 
SettingsProvider.RemoveSetting("Section2", "Key1"); 
SettingsProvider.RemoveSetting("Section1", "Key2");