有没有一种简单的方法可以将对象属性转换为字典<string, string>

Question

I have a database object (a row), that has lots of properties (columns) that map to form fields (asp:textbox, asp:dropdownlist etc) . I would like to transform this object and properties into a dictionary map to make it easier to iterate.

Example:

Dictionary<string, string> FD = new Dictionary<string,string>();
FD["name"] = data.name;
FD["age"] = data.age;
FD["occupation"] = data.occupation;
FD["email"] = data.email;
..........

How would I do this easily, without manually typing out all the various 100s of properties?

Note: FD dictionary indices are same as database column names.

Answer 1

Assuming that data is some object and that you want to put its public properties into a Dictionary then you could try:

Original - here for historical reasons (2012) :

Dictionary<string, string> FD = (from x in data.GetType().GetProperties() select x)
    .ToDictionary (x => x.Name, x => (x.GetGetMethod().Invoke (data, null) == null ? "" : x.GetGetMethod().Invoke (data, null).ToString()));

Updated (2017) :

Dictionary<string, string> dictionary = data.GetType().GetProperties()
    .ToDictionary(x => x.Name, x => x.GetValue(data)?.ToString() ?? "");

Answer 2

The HtmlHelper class allows a conversion of Anonymouns Object to RouteValueDictonary and I suppose you could use a .ToString() on each value to get the string repersentation:

 var linkAttributes = System.Web.Mvc.HtmlHelper.AnonymousObjectToHtmlAttributes(linkHtmlAttributes);

The down side is this is part of the ASP.NET MVC Framework. Using a .NET Reflector, the code inside of the method is as follows:

public static RouteValueDictionary AnonymousObjectToHtmlAttributes(object htmlAttributes)
{
   RouteValueDictionary dictionary = new RouteValueDictionary();
  if (htmlAttributes != null)
  {
     foreach (PropertyDescriptor descriptor in TypeDescriptor.GetProperties(htmlAttributes))
     {
            dictionary.Add(descriptor.Name.Replace('_', '-'), descriptor.GetValue(htmlAttributes));
       }
 }
    return dictionary;
 }

You'll see that this code is identical to the answer Yahia gave you, and his answer provides a Dictonary<string,string>. With the reflected code I gave you you could easily convert a RouteValueDictionary to Dictonary<string,string> but Yahia's answer is a one liner.

EDIT - I've added the code for what could be a method to do your conversion:

EDIT 2 - I've added null checking to the code and used String.Format for the string value

    public static Dictionary<string, string> ObjectToDictionary(object value)
    {
        Dictionary<string, string> dictionary = new Dictionary<string, string>();
        if (value != null)
        {
            foreach (System.ComponentModel.PropertyDescriptor descriptor in System.ComponentModel.TypeDescriptor.GetProperties(value))
            {
                if(descriptor != null && descriptor.Name != null)
                {
                     object propValue = descriptor.GetValue(value);
                     if(propValue != null)
                          dictionary.Add(descriptor.Name,String.Format("{0}",propValue));
            }
        }
        return dictionary;
    }

And to go from a Dictionary to an object check http://automapper.org/ which was suggested in this thread Convert dictionary to anonymous object

Answer 3

var myDict = myObj.ToDictionary(); //returns all public fields & properties

.

public static class MyExtensions
{
    public static Dictionary<string, object> ToDictionary(this object myObj)
    {
        return myObj.GetType()
            .GetProperties()
            .Select(pi => new { Name = pi.Name, Value = pi.GetValue(myObj, null) })
            .Union( 
                myObj.GetType()
                .GetFields()
                .Select(fi => new { Name = fi.Name, Value = fi.GetValue(myObj) })
             )
            .ToDictionary(ks => ks.Name, vs => vs.Value);
    }
}

Answer 4

Take a look at System.ComponentModel.TypeDescriptor.GetProperties( ... ) . This is the way the normal data binding bits work. It will use reflection and return you a collection of property descriptors (which you can use to get the values). You can customize these descriptors for performace by implementing ICustomTypeDescriptor .