将对象名称空间和名称转换为对象

Question

我需要调用SetSettings()，并使用splitSettings中的3个元素，将EncodeAudio设置为False。我该怎么做呢?将对象的属性转换为字符串中包含的人的名字。我意识到我可以使用所有设置的switch语句，但是必须有一个更动态的方法来做到这一点。

namespace SettingsLib
{
  public class Settings
  {
    public Boolean EncodeAudio { get; set; }
  }
}
namespace Service
{
   void SetSettings()
   {
     string[] splitSettings = { "SettingsLib.Settings", "EncodeAudio", "False" };
     // Need to set EncodeAudio to False in SettingsLib.Settings
   }
}

是的，我有一个Settings

实例

说:

Settings settingManager = new Settings();

我想做的是动态设置EncodeAudo为False通过使用splitSettings

的元素

settingManager.EncodeAudio = False;

感谢TBohnen.jnr的帮助我得到了这个答案:

public void setProperty(object containingObject, string propertyName, object newValue)
{
    foreach (PropertyInfo p in containingObject.GetType().GetProperties())
    {
        if (p.Name == propertyName)
        {
            p.SetValue(containingObject, Convert.ChangeType(newValue, p.PropertyType), null);
        }
    }
}

Answer 1

EDIT用int, bool, double和string测试它，它工作了，还添加了一个检查，以确保该属性存在并抛出它不存在的异常(可能想要改变异常类型)

EDIT 2:临时解决方案，将添加更多的类型名转换方法，或者如果有人可以建议一个更动态的方式来转换它(如果不是，那么我认为你将不得不知道所有将使用的类型)?

EDIT3从另一个问题的答案(克里斯泰勒)偷了转换方法，谢谢:-)

public void setProperty(object containingObject, string propertyName, object newValue)
    {
        if (containingObject.GetType().GetProperties().Count(c => c.Name == propertyName) > 0)
        {
            var type = containingObject.GetType().GetProperties().First(c => c.Name == propertyName).PropertyType;
            object val = Convert(type,(string)newValue);
            containingObject.GetType().InvokeMember(propertyName, BindingFlags.SetProperty, null, containingObject, new object[] { val });
        }
        else
        {
            throw new KeyNotFoundException("The property: " + propertyName + " was not found in: " + containingObject.GetType().Name);
        }
    }
    public object convert(System.Type type, string value)
    {
        return Convert.ChangeType(value, type);
    }

摘自http://www.haslo.ch/blog/setproperty-and-getproperty-with-c-reflection/

有兴趣看看这是否有效，创建一个快速测试:

class testSettings
{
    public bool SetBool { get; set; }
    public void setProperty(object containingObject, string propertyName, object newValue) 
    {
         if (containingObject.GetType().GetProperties().Count(c => c.Name == propertyName) > 0)
        {
            containingObject.GetType().InvokeMember(propertyName, BindingFlags.SetProperty, null, containingObject, new object[] { newValue });
        }
        else
        {
            throw new KeyNotFoundException("The property: " + propertyName + " was not found in: " + containingObject.GetType().Name);
        }
    }
}
static void Main(string[] args)
{
    testSettings ts = new testSettings();
    ts.SetBool = false;
    ts.setProperty(ts, "SetBool", true);
    Console.WriteLine(ts.SetBool.ToString());
    Console.Read();
}

输出为true，但不能完全确定它是否会正确转换所有类型。

Answer 2

正如其他人提到的，您应该考虑将SettingsLib类设置为静态。您可能还需要处理从字符串到目标类型的值转换。下面是一个简单的示例:

namespace Service
{
  class Program
  {
    static void Main(string[] args)
    {
      string[] splitSettings = { "SettingsLib.Settings", "EncodeAudio", "False" };
      SetProperty(splitSettings[0], splitSettings[1], splitSettings[2]);  
    }
    static void SetProperty(string typeName, string propertyName, object value)
    {
      var type = Type.GetType(typeName);
      if (type == null) 
      {
        throw new ArgumentException("Unable to get type", "typeName");
      }
      var pi = type.GetProperty(propertyName);
      if (pi == null) 
      {
        throw new ArgumentException("Unable to find property on type", "propertyName");
      }
      object propertyValue = value;
      if (propertyValue != null)
      {
        // You might need more elaborate testing here to ensure that you can handle 
        // all the various types, you might need to special case some types here 
        // but this will work for the basics.
        if (pi.PropertyType != propertyValue.GetType())
        {
          propertyValue = Convert.ChangeType(propertyValue, pi.PropertyType);
        }
      }
      pi.SetValue(null, propertyValue, null);
    }
  }
}
namespace SettingsLib
{
  public static class Settings
  {
    public static bool EncodeAudio { get; set; }    
  }
}

Answer 3

也许你应该将你的可设置属性标记为static，然后尝试使用反射设置值:

namespace SettingsLib
{
  public static class Settings
  {
    public static bool EncodeAudio { get; set; }
  }
}
namespace Service
{
   void SetSettings()
   {
     string[] splitSettings = { "SettingsLib.Settings", "EncodeAudio", "False" };
     dynamic property = Type.GetType(splitSettings[0]).GetProperty(splitSettings[1]);
     property = splitSettings[2];
   }
}