jheddings和AlexD都写了关于如何解析属性字符串的出色答案。我想把我的库也加入其中，因为我专门为此编写了一个库。

路径。CSharp的主类是Resolver。默认情况下，它可以解析属性、数组和字典条目。

举个例子，如果你有一个这样的物体

var o = new { Property1 = new { Property2 = "value" } };

想要获得Property2，你可以这样做:

IResolver resolver = new Resolver();
var path = "Property1.Property2";
object result = r.Resolve(o, path); 
//=> "value"

这是它可以解析的路径的最基本示例。如果你想看看它还能做什么，或者你可以如何扩展它，只需前往它的Github页面。

虽然最初的问题是关于如何仅使用一个字符串作为参数来获取属性的值，但是在这里使用Expression而不是简单的字符串来确保调用者永远不会使用硬编码的属性名是很有意义的。下面是一行的用法:

public static class Utils
...
    public static TVal GetPropertyValue<T, TVal>(T t, Expression<Func<T, TVal>> x)
        => (TVal)((x.Body as MemberExpression)?.Member as PropertyInfo)!.GetValue(t);

...
    var val = Utils.GetPropertyValue(foo,  p => p.Bar);

下面是一个在可读性方面稍微好一点的错误处理版本:

public static TVal GetPropertyValue<T, TVal>(T t, Expression<Func<T, TVal>> x)
{
    var m = (x.Body as MemberExpression)?.Member;
    var p = m as PropertyInfo;

    if (null == p)
        throw new ArgumentException($"Unknown property: {typeof(T).Name}.{(m?.Name??"???")}");

    return (TVal)p.GetValue(t);
}

简而言之，您传递了一个读取属性的lambda表达式。lambda的主体(胖箭头右边的部分)是一个成员表达式，您可以从中获取成员名称并将其转换为PropertyInfo，前提是该成员实际上是一个Property，而不是(例如)一个方法。

在简短的版本中，null宽恕操作符——the !-告诉编译器PropertyInfo不会为空。这是一个很大的谎言，你将在运行时得到一个NullReferenceException。较长的版本提供了属性的名称(如果它设法获得该属性的话)。

PS:感谢Oleg G.为这段代码的初始版本:)

看看Heleonix。反映图书馆。你可以通过路径获取/设置/调用成员，或者创建一个getter/setter (lambda编译成委托)，这比反射更快。例如:

var success = Reflector.Get(DateTime.Now, null, "Date.Year", out int value);

或者只创建一个getter并缓存以供重用(这样性能更好，但如果中间成员为空可能会抛出NullReferenceException):

var getter = Reflector.CreateGetter<DateTime, int>("Date.Year", typeof(DateTime));
getter(DateTime.Now);

或者如果你想创建一个List<Action<object, object>>的不同getter，只需要为已编译的委托指定基本类型(类型转换将被添加到已编译的lambdas中):

var getter = Reflector.CreateGetter<object, object>("Date.Year", typeof(DateTime));
getter(DateTime.Now);

下面的代码是一个递归方法，用于显示对象实例中包含的所有属性名称和值的整个层次结构。这个方法在这个线程中使用了AlexD的GetPropertyValue()答案的简化版本。多亏了这个讨论帖，我才知道该怎么做!

例如，我使用这个方法来显示WebService响应中所有属性的爆炸或转储，如下所示:

晚点属性(“响应”、“响应”、“错误”);

public static object GetPropertyValue(object srcObj, string propertyName)
{
  if (srcObj == null) 
  {
    return null; 
  }
  PropertyInfo pi = srcObj.GetType().GetProperty(propertyName.Replace("[]", ""));
  if (pi == null)
  {
    return null;
  }
  return pi.GetValue(srcObj);
}

public static void PropertyValues_byRecursion(string parentPath, object parentObj, bool showNullValues)
{
  /// Processes all of the objects contained in the parent object.
  ///   If an object has a Property Value, then the value is written to the Console
  ///   Else if the object is a container, then this method is called recursively
  ///       using the current path and current object as parameters

  // Note:  If you do not want to see null values, set showNullValues = false

  foreach (PropertyInfo pi in parentObj.GetType().GetTypeInfo().GetProperties())
  {
    // Build the current object property's namespace path.  
    // Recursion extends this to be the property's full namespace path.
    string currentPath = parentPath + "." + pi.Name;

    // Get the selected property's value as an object
    object myPropertyValue = GetPropertyValue(parentObj, pi.Name);
    if (myPropertyValue == null)
    {
      // Instance of Property does not exist
      if (showNullValues)
      {
        Console.WriteLine(currentPath + " = null");
        // Note: If you are replacing these Console.Write... methods callback methods,
        //       consider passing DBNull.Value instead of null in any method object parameters.
      }
    }
    else if (myPropertyValue.GetType().IsArray)
    {
      // myPropertyValue is an object instance of an Array of business objects.
      // Initialize an array index variable so we can show NamespacePath[idx] in the results.
      int idx = 0;
      foreach (object business in (Array)myPropertyValue)
      {
        if (business == null)
        {
          // Instance of Property does not exist
          // Not sure if this is possible in this context.
          if (showNullValues)
          {
            Console.WriteLine(currentPath  + "[" + idx.ToString() + "]" + " = null");
          }
        }
        else if (business.GetType().IsArray)
        {
          // myPropertyValue[idx] is another Array!
          // Let recursion process it.
          PropertyValues_byRecursion(currentPath + "[" + idx.ToString() + "]", business, showNullValues);
        }
        else if (business.GetType().IsSealed)
        {
          // Display the Full Property Path and its Value
          Console.WriteLine(currentPath + "[" + idx.ToString() + "] = " + business.ToString());
        }
        else
        {
          // Unsealed Type Properties can contain child objects.
          // Recurse into my property value object to process its properties and child objects.
          PropertyValues_byRecursion(currentPath + "[" + idx.ToString() + "]", business, showNullValues);
        }
        idx++;
      }
    }
    else if (myPropertyValue.GetType().IsSealed)
    {
      // myPropertyValue is a simple value
      Console.WriteLine(currentPath + " = " + myPropertyValue.ToString());
    }
    else
    {
      // Unsealed Type Properties can contain child objects.
      // Recurse into my property value object to process its properties and child objects.
      PropertyValues_byRecursion(currentPath, myPropertyValue, showNullValues);
    }
  }
}

下面是另一种查找嵌套属性的方法，它不需要字符串告诉您嵌套路径。感谢Ed S.的单一属性方法。

    public static T FindNestedPropertyValue<T, N>(N model, string propName) {
        T retVal = default(T);
        bool found = false;

        PropertyInfo[] properties = typeof(N).GetProperties();

        foreach (PropertyInfo property in properties) {
            var currentProperty = property.GetValue(model, null);

            if (!found) {
                try {
                    retVal = GetPropValue<T>(currentProperty, propName);
                    found = true;
                } catch { }
            }
        }

        if (!found) {
            throw new Exception("Unable to find property: " + propName);
        }

        return retVal;
    }

        public static T GetPropValue<T>(object srcObject, string propName) {
        return (T)srcObject.GetType().GetProperty(propName).GetValue(srcObject, null);
    }

public class YourClass
{
    //Add below line in your class
    public object this[string propertyName] => GetType().GetProperty(propertyName)?.GetValue(this, null);
    public string SampleProperty { get; set; }
}

//And you can get value of any property like this.
var value = YourClass["SampleProperty"];