Good day,
I need to make function that will iterate on Dictionary that stores variable name and variable`s new value. After that, I need to update class variable with that value.
void UpdateValues(Type type, Dictionary<string, string> values)
{
foreach (var value in values)
{
var fieldInfo = selected.GetComponent(type).GetType().GetField(value.Key);
if (fieldInfo == null) continue;
fieldInfo.SetValue(selected.GetComponent(type), value.Value);
}
}
It works but I want little improvement and I absolutely don't know if it is possible.
As you can see, that function can accept any class, not just one specific.
If I have class like this
class test
{
public string age;
}
And I would use function this way, it would work.
UpdateValues(typeof(test), new Dictionary<string, string>{{"age", "17"}});
Problem is if I have class like this and I would like to update "subfield" (field in field)
class test
{
public string age;
}
class test2
{
public test data;
}
I was thinking that syntax could be something like this, but I have no idea how could I do it.
UpdateValues(typeof(test2), new Dictionary<string, string>{{"data.age", "17"}});
To sum it up, I need to make function that will take class that is stored in another class. Function will iterate trough the dictionary and update fields of class and even her subfields.
I would propose to add a recursive call to your method, to set the properties. I have changed your method a little bit, because i don't have selected object, it takes an object as a parameter
void UpdateValues<T>(T obj, Dictionary<string, string> values)
{
foreach (var value in values)
{
SetProperty(obj, value.Key, value.Value);
}
}
public void SetProperty<T>( T obj, string valueKey, string value, Type type= null)
{
var typeToUse = type ?? typeof(T);
var pointIndex = valueKey.IndexOf(".");
if (pointIndex!=-1)
{
var subKey = valueKey.Substring(0, pointIndex);
var fieldInfo = typeToUse.GetField(subKey);
var propObj = fieldInfo.GetValue(obj)
?? Activator.CreateInstance(fieldInfo.FieldType);
SetProperty(propObj, valueKey.Substring(pointIndex+1), value, fieldInfo.FieldType);
fieldInfo.SetValue(obj, propObj);
}
else
{
var fieldInfo = typeToUse.GetField(valueKey);
if (fieldInfo != null)
fieldInfo.SetValue(obj, value);
}
}
It works even if you define
class test3
{
public test2 data;
}
and call
UpdateValues(t, new Dictionary<string, string>{{"age", "17"}});
UpdateValues(t2, new Dictionary<string, string> { { "data.age", "17" } });
UpdateValues(t3, new Dictionary<string, string> { { "data.data.age", "17" } });
The third parameter of SetProperty method is not really nice, i would avoid it, but i don't know how to solve it with generics, after creating with Activator you get object as a Type, and object doesn't have field age
You are using Dictionary<string, string> as a parameter that allows you to set only string fields, so you must assume that you don't have any other. Actually this will work even if you will use Dictionary<string, object>, that i would suggest to do.
First of all you will need to change your Dictionary variable to use
Dictionary<string, object> if you want to pass a class as a parameter in here.
Secondly Here is an example of how to make it work.
class test
{
public string age;
}
class test2
{
public test data;
}
Lets suppose i have created an instance of test class and added it in a dictionary, to get the fields with reflection and then update the instance of test2 accordingly.
public void UpdateValues(object test2, Dictionary<string, object> dict)
{
var fieldValues = test2.GetType()
.GetFields()
.ToList();
foreach (var value in dict)
{
foreach (var field in fieldValues)
{
if (value.Key == field.Name)
{
bool obj = field.FieldType == typeof(test);
if (obj)
{
if (dict.ContainsKey("data"))
{
var prop = test2.GetType().GetField("data", System.Reflection.BindingFlags.Public
| System.Reflection.BindingFlags.Instance);
prop.SetValue(test2, dict["data"]);
break;
}
}
else
{
var prop = test2.GetType().GetField(value.Key, System.Reflection.BindingFlags.Public
| System.Reflection.BindingFlags.Instance);
prop.SetValue(test2, value.Value);
break;
}
}
}
}
}
In the end call you function i have created a Dictionary<string,object> instance to send it as a parameter to the function
object test2 = new test2();
test t = new test();
t.age = "10";
Dictionary<string, object> dict = new Dictionary<string, object>();
dict.Add("data", t);
UpdateValues(test2, dict);
Related
I want to take an anonymous object as argument to a method, and then iterate over its properties to add each property/value to a a dynamic ExpandoObject.
So what I need is to go from
new { Prop1 = "first value", Prop2 = SomeObjectInstance, Prop3 = 1234 }
to knowing names and values of each property, and being able to add them to the ExpandoObject.
How do I accomplish this?
Side note: This will be done in many of my unit tests (I'm using it to refactor away a lot of junk in the setup), so performance is to some extent relevant. I don't know enough about reflection to say for sure, but from what I've understood it's pretty performance heavy, so if it's possible I'd rather avoid it...
Follow-up question:
As I said, I'm taking this anonymous object as an argument to a method. What datatype should I use in the method's signature? Will all properties be available if I use object?
foreach(var prop in myVar.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public))
{
Console.WriteLine("Name: {0}, Value: {1}",prop.Name, prop.GetValue(myVar,null));
}
Reflect on the anonymous object to get its property names and values, then take advantage of an ExpandoObject actually being a dictionary to populate it. Here's an example, expressed as a unit test:
[TestMethod]
public void ShouldBeAbleToConvertAnAnonymousObjectToAnExpandoObject()
{
var additionalViewData = new {id = "myControlId", css = "hide well"};
dynamic result = new ExpandoObject();
var dict = (IDictionary<string, object>)result;
foreach (PropertyInfo propertyInfo in additionalViewData.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public))
{
dict[propertyInfo.Name] = propertyInfo.GetValue(additionalViewData, null);
}
Assert.AreEqual(result.id, "myControlId");
Assert.AreEqual(result.css, "hide well");
}
An alternative approach is to use DynamicObject instead of ExpandoObject, and that way you only have the overhead of doing the reflection if you actually try to access a property from the other object.
public class DynamicForwarder : DynamicObject
{
private object _target;
public DynamicForwarder(object target)
{
_target = target;
}
public override bool TryGetMember(
GetMemberBinder binder, out object result)
{
var prop = _target.GetType().GetProperty(binder.Name);
if (prop == null)
{
result = null;
return false;
}
result = prop.GetValue(_target, null);
return true;
}
}
Now it only does the reflection when you actually try to access the property via a dynamic get. On the downside, if you repeatedly access the same property, it has to do the reflection each time. So you could cache the result:
public class DynamicForwarder : DynamicObject
{
private object _target;
private Dictionary<string, object> _cache = new Dictionary<string, object>();
public DynamicForwarder(object target)
{
_target = target;
}
public override bool TryGetMember(
GetMemberBinder binder, out object result)
{
// check the cache first
if (_cache.TryGetValue(binder.Name, out result))
return true;
var prop = _target.GetType().GetProperty(binder.Name);
if (prop == null)
{
result = null;
return false;
}
result = prop.GetValue(_target, null);
_cache.Add(binder.Name, result); // <-------- insert into cache
return true;
}
}
You could support storing a list of target objects to coalesce their properties, and support setting properties (with a similar override called TrySetMember) to allow you to dynamically set values in the cache dictionary.
Of course, the overhead of reflection is probably not going to be worth worrying about, but for large objects this could limit the impact of it. What is maybe more interesting is the extra flexibility it gives you.
This is an old question, but now you should be able to do this with the following code:
dynamic expObj = new ExpandoObject();
expObj.Name = "James Kirk";
expObj.Number = 34;
// print the dynamically added properties
// enumerating over it exposes the Properties and Values as a KeyValuePair
foreach (KeyValuePair<string, object> kvp in expObj){
Console.WriteLine("{0} = {1} : Type: {2}", kvp.Key, kvp.Value, kvp.Value.GetType());
}
The output would look like the following:
Name = James Kirk : Type: System.String
Number = 34 : Type:
System.Int32
you have to use reflection.... (code "borrowed" from this url)
using System.Reflection; // reflection namespace
// get all public static properties of MyClass type
PropertyInfo[] propertyInfos;
propertyInfos = typeof(MyClass).GetProperties(BindingFlags.Public |
BindingFlags.Static);
// sort properties by name
Array.Sort(propertyInfos,
delegate(PropertyInfo propertyInfo1, PropertyInfo propertyInfo2)
{ return propertyInfo1.Name.CompareTo(propertyInfo2.Name); });
// write property names
foreach (PropertyInfo propertyInfo in propertyInfos)
{
Console.WriteLine(propertyInfo.Name);
}
Use Reflection.Emit to create a generic method to fill an ExpandoObject.
OR use Expressions perhaps (I think this would only be possible in .NET 4 though).
Neither of these approaches uses reflection when invoking, only during setup of a delegate (which obviously needs to be cached).
Here is some Reflection.Emit code to fill a dictionary (I guess ExpandoObject is not far off);
static T CreateDelegate<T>(this DynamicMethod dm) where T : class
{
return dm.CreateDelegate(typeof(T)) as T;
}
static Dictionary<Type, Func<object, Dictionary<string, object>>> cache =
new Dictionary<Type, Func<object, Dictionary<string, object>>>();
static Dictionary<string, object> GetProperties(object o)
{
var t = o.GetType();
Func<object, Dictionary<string, object>> getter;
if (!cache.TryGetValue(t, out getter))
{
var rettype = typeof(Dictionary<string, object>);
var dm = new DynamicMethod(t.Name + ":GetProperties", rettype,
new Type[] { typeof(object) }, t);
var ilgen = dm.GetILGenerator();
var instance = ilgen.DeclareLocal(t);
var dict = ilgen.DeclareLocal(rettype);
ilgen.Emit(OpCodes.Ldarg_0);
ilgen.Emit(OpCodes.Castclass, t);
ilgen.Emit(OpCodes.Stloc, instance);
ilgen.Emit(OpCodes.Newobj, rettype.GetConstructor(Type.EmptyTypes));
ilgen.Emit(OpCodes.Stloc, dict);
var add = rettype.GetMethod("Add");
foreach (var prop in t.GetProperties(
BindingFlags.Instance |
BindingFlags.Public))
{
ilgen.Emit(OpCodes.Ldloc, dict);
ilgen.Emit(OpCodes.Ldstr, prop.Name);
ilgen.Emit(OpCodes.Ldloc, instance);
ilgen.Emit(OpCodes.Ldfld, prop);
ilgen.Emit(OpCodes.Castclass, typeof(object));
ilgen.Emit(OpCodes.Callvirt, add);
}
ilgen.Emit(OpCodes.Ldloc, dict);
ilgen.Emit(OpCodes.Ret);
cache[t] = getter =
dm.CreateDelegate<Func<object, Dictionary<string, object>>>();
}
return getter(o);
}
Are there any elegant quick way to map object to a dictionary and vice versa?
Example:
IDictionary<string,object> a = new Dictionary<string,object>();
a["Id"]=1;
a["Name"]="Ahmad";
// .....
becomes
SomeClass b = new SomeClass();
b.Id=1;
b.Name="Ahmad";
// ..........
Using some reflection and generics in two extension methods you can achieve that.
Right, others did mostly the same solution, but this uses less reflection which is more performance-wise and way more readable:
public static class ObjectExtensions
{
public static T ToObject<T>(this IDictionary<string, object> source)
where T : class, new()
{
var someObject = new T();
var someObjectType = someObject.GetType();
foreach (var item in source)
{
someObjectType
.GetProperty(item.Key)
.SetValue(someObject, item.Value, null);
}
return someObject;
}
public static IDictionary<string, object> AsDictionary(this object source, BindingFlags bindingAttr = BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.Instance)
{
return source.GetType().GetProperties(bindingAttr).ToDictionary
(
propInfo => propInfo.Name,
propInfo => propInfo.GetValue(source, null)
);
}
}
class A
{
public string Prop1
{
get;
set;
}
public int Prop2
{
get;
set;
}
}
class Program
{
static void Main(string[] args)
{
Dictionary<string, object> dictionary = new Dictionary<string, object>();
dictionary.Add("Prop1", "hello world!");
dictionary.Add("Prop2", 3893);
A someObject = dictionary.ToObject<A>();
IDictionary<string, object> objectBackToDictionary = someObject.AsDictionary();
}
}
Convert the Dictionary to JSON string first with Newtonsoft.
var json = JsonConvert.SerializeObject(advancedSettingsDictionary, Newtonsoft.Json.Formatting.Indented);
Then deserialize the JSON string to your object
var myobject = JsonConvert.DeserializeObject<AOCAdvancedSettings>(json);
Seems reflection only help here.. I've done small example of converting object to dictionary and vise versa:
[TestMethod]
public void DictionaryTest()
{
var item = new SomeCLass { Id = "1", Name = "name1" };
IDictionary<string, object> dict = ObjectToDictionary<SomeCLass>(item);
var obj = ObjectFromDictionary<SomeCLass>(dict);
}
private T ObjectFromDictionary<T>(IDictionary<string, object> dict)
where T : class
{
Type type = typeof(T);
T result = (T)Activator.CreateInstance(type);
foreach (var item in dict)
{
type.GetProperty(item.Key).SetValue(result, item.Value, null);
}
return result;
}
private IDictionary<string, object> ObjectToDictionary<T>(T item)
where T: class
{
Type myObjectType = item.GetType();
IDictionary<string, object> dict = new Dictionary<string, object>();
var indexer = new object[0];
PropertyInfo[] properties = myObjectType.GetProperties();
foreach (var info in properties)
{
var value = info.GetValue(item, indexer);
dict.Add(info.Name, value);
}
return dict;
}
I'd highly recommend the Castle DictionaryAdapter, easily one of that project's best-kept secrets. You only need to define an interface with the properties you want, and in one line of code the adapter will generate an implementation, instantiate it, and synchronize its values with a dictionary you pass in. I use it to strongly-type my AppSettings in a web project:
var appSettings =
new DictionaryAdapterFactory().GetAdapter<IAppSettings>(ConfigurationManager.AppSettings);
Note that I did not need to create a class that implements IAppSettings - the adapter does that on the fly. Also, although in this case I'm only reading, in theory if I were setting property values on appSettings, the adapter would keep the underlying dictionary in sync with those changes.
I think you should use reflection. Something like this:
private T ConvertDictionaryTo<T>(IDictionary<string, object> dictionary) where T : new()
{
Type type = typeof (T);
T ret = new T();
foreach (var keyValue in dictionary)
{
type.GetProperty(keyValue.Key).SetValue(ret, keyValue.Value, null);
}
return ret;
}
It takes your dictionary and loops through it and sets the values. You should make it better but it's a start. You should call it like this:
SomeClass someClass = ConvertDictionaryTo<SomeClass>(a);
Reflection can take you from an object to a dictionary by iterating over the properties.
To go the other way, you'll have to use a dynamic ExpandoObject (which, in fact, already inherits from IDictionary, and so has done this for you) in C#, unless you can infer the type from the collection of entries in the dictionary somehow.
So, if you're in .NET 4.0 land, use an ExpandoObject, otherwise you've got a lot of work to do...
Building on MatÃas Fidemraizer's answer, here is a version that supports binding to object properties other than strings.
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
namespace WebOpsApi.Shared.Helpers
{
public static class MappingExtension
{
public static T ToObject<T>(this IDictionary<string, object> source)
where T : class, new()
{
var someObject = new T();
var someObjectType = someObject.GetType();
foreach (var item in source)
{
var key = char.ToUpper(item.Key[0]) + item.Key.Substring(1);
var targetProperty = someObjectType.GetProperty(key);
//edited this line
if (targetProperty.PropertyType == item.Value.GetType())
{
targetProperty.SetValue(someObject, item.Value);
}
else
{
var parseMethod = targetProperty.PropertyType.GetMethod("TryParse",
BindingFlags.Public | BindingFlags.Static, null,
new[] {typeof (string), targetProperty.PropertyType.MakeByRefType()}, null);
if (parseMethod != null)
{
var parameters = new[] { item.Value, null };
var success = (bool)parseMethod.Invoke(null, parameters);
if (success)
{
targetProperty.SetValue(someObject, parameters[1]);
}
}
}
}
return someObject;
}
public static IDictionary<string, object> AsDictionary(this object source, BindingFlags bindingAttr = BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.Instance)
{
return source.GetType().GetProperties(bindingAttr).ToDictionary
(
propInfo => propInfo.Name,
propInfo => propInfo.GetValue(source, null)
);
}
}
}
public class SimpleObjectDictionaryMapper<TObject>
{
public static TObject GetObject(IDictionary<string, object> d)
{
PropertyInfo[] props = typeof(TObject).GetProperties();
TObject res = Activator.CreateInstance<TObject>();
for (int i = 0; i < props.Length; i++)
{
if (props[i].CanWrite && d.ContainsKey(props[i].Name))
{
props[i].SetValue(res, d[props[i].Name], null);
}
}
return res;
}
public static IDictionary<string, object> GetDictionary(TObject o)
{
IDictionary<string, object> res = new Dictionary<string, object>();
PropertyInfo[] props = typeof(TObject).GetProperties();
for (int i = 0; i < props.Length; i++)
{
if (props[i].CanRead)
{
res.Add(props[i].Name, props[i].GetValue(o, null));
}
}
return res;
}
}
If you are using Asp.Net MVC, then take a look at:
public static RouteValueDictionary AnonymousObjectToHtmlAttributes(object htmlAttributes);
which is a static public method on the System.Web.Mvc.HtmlHelper class.
public Dictionary<string, object> ToDictionary<T>(string key, T value)
{
try
{
var payload = new Dictionary<string, object>
{
{ key, value }
};
} catch (Exception e)
{
return null;
}
}
public T FromDictionary<T>(Dictionary<string, object> payload, string key)
{
try
{
JObject jObject = (JObject) payload[key];
T t = jObject.ToObject<T>();
return (t);
}
catch(Exception e) {
return default(T);
}
}
I am having a tough time figuring out a way to add objects into an array without knowing the type of either object...so basically, we are populating objects using data we import from a text file. The objects we are populating will vary, we identify the objects using reflection to find the object with the same class type as the string provided in the txt file. The string representation of the class is the ONLY knowledge of the class we have during the entire process. The issue occurs when we have objects that need to be created and then put into an array. I'm able to identify the array it belongs to fine, but storing the object in the collection is another story.
This is as far as I've gotten:
UPDATE:
public bool Populate(Dictionary<string, string> nameValuePairs, object obj)
{
return obj.GetType() == typeof (Array) ? PopulateList(nameValuePairs, obj) : PopulateObject(nameValuePairs, obj);
}
private bool PopulateObject<T>(Dictionary<string, string> nameValuePairs, T obj) where T : new()
{
foreach (var kvp in nameValuePairs)
{
var itemName = kvp.Key;
var value = kvp.Key;
try
{
var property = obj.GetType().GetProperty(itemName, BindingFlags.Public | BindingFlags.Instance);
property?.SetValue(obj, value);
}
catch (Exception e)
{
try
{
var field = obj.GetType().GetField(itemName, BindingFlags.Public | BindingFlags.Instance);
field?.SetValue(obj, value);
}
catch (Exception e1)
{
return false;
}
}
}
return true;
}
private bool PopulateList<T>(Dictionary<string, string> itemProperties, List<T> list)
where T : new()
{
var baseObj = new T();
var lookup = new NameLookupHandler();
Populate(itemProperties, baseObj);
list.Add(baseObj);
return true;
}
private bool PopulateList(Dictionary<string, string> itemProperties, ref object list)
{
Type baseType = list.GetType().GetElementType();
var baseObj = Activator.CreateInstance(baseType);
//Code here populates the object that will be added to the collection.
return true;
}
Updated Method:
private bool PopulateList<T>(Dictionary<string, string> itemProperties, List<T> list)
where T : new()
{
var baseObj = new T();
var lookup = new NameLookupHandler();
Populate(itemProperties, baseObj);
list.Add(baseObj);
return true;
}
Why not make it generic?
private bool PopulateList<T>(Dictionary<string, string> itemProperties, List<T> list)
where T : new();
{
var baseObj = new T();
//Code here populates the object that will be added to the collection.
list.Add(baseObj); <--- This obviously doesn't work.
return true;
}
Note that the list parameter does not need to be ref unless you're changing what list references. It does not need to be ref to add items to the list.
I have the following class:
public class foo
{
public Dictionary<string, string> data = new Dictionary<string, string>();
public foo(params object[] args)
{
foreach (object arg in args)
{
data.Add(arg.ToString(), "..");
}
}
}
I need get the value of dictionary using the dot operadotor it's because the class that I set the class as arguments use the dynamic keyword to "walk" on the class.
for example:
var args = new[] {"a","b","c"};
var Foo = new foo(args);
var baa = Foo.data.a;
Console.Write(baa); // ..
if exists an way to make dynamic variables, something like:
public foo(params object[] args) {
foreach (object arg in args) {
var name = (string) arg;
var value = "..";
MakeVariable(name, value);
}
}
makes an variable named of arg and the value .. as public member of foo class.
anyway differents to solve this is very appreciated. Thanks in advance.
You can have Foo inherit from DynamicObject:
public class Foo : DynamicObject
{
private Dictionary<string, string> data = new Dictionary<string, string>();
public Foo(params object[] args)
{
foreach (object arg in args)
{
data.Add(arg.ToString(), "..");
}
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
if (data.ContainsKey(binder.Name))
{
result = data[binder.Name];
return true;
}
return base.TryGetMember(binder, out result);
}
}
To use it you can use dynamic to hold an instance of Foo:
var args= new[] { "a", "b", "c" };
dynamic foo = new Foo(args);
var myA = foo.a; //returns ".."
Keep in mind that you will lose type safety since you have to use dynamic - your use case should really justify this disadvantage - usually there is a better approach.
I think you should use DynamicObject. If you are using an older version of the framework the only option is Reflection.Emit
The dynamic works something like this
// If you try to get a value of a property
// not defined in the class, this method is called.
public override bool TryGetMember(
GetMemberBinder binder, out object result)
{
// Converting the property name to lowercase
// so that property names become case-insensitive.
string name = binder.Name.ToLower();
// If the property name is found in a dictionary,
// set the result parameter to the property value and return true.
// Otherwise, return false.
return dictionary.TryGetValue(name, out result);
}
// If you try to set a value of a property that is
// not defined in the class, this method is called.
public override bool TrySetMember(
SetMemberBinder binder, object value)
{
// Converting the property name to lowercase
// so that property names become case-insensitive.
dictionary[binder.Name.ToLower()] = value;
// You can always add a value to a dictionary,
// so this method always returns true.
return true;
}
Another option is to use the ExpandoObject class if you want to directly expose the Data member, as in your example. This keeps the code simpler if you don't need to define specific operations that would require inheriting DynamicObject.
public class Foo
{
public dynamic Data = new ExpandoObject();
public Foo(params object[] args)
{
var dataDict = (IDictionary<string, object>)Data;
foreach (var obj in args)
{
dataDict.Add(obj.ToString(), "..");
}
}
}
Usage:
var foo = new Foo("a", "b", "c");
Console.WriteLine(foo.Data.a);
((IDictionary<string, object>)foo.Data).Add("d", "!");
foreach (var item in foo.Data)
{
Console.WriteLine("{0} : {1}", item.Key, item.Value);
}
Notice that I cast to a dictionary and added "d" although I could've also assigned it directly: foo.Data.d = "!". The only difference is you may not know ahead of time what field names you have, and the former example allows you to setup the ExpandoObject based on dynamic input, whereas the latter is useful when you already know what field name to use.
In .NET 4 this exact behavior is implemented by ExpandoObject class:
public class Foo
{
private readonly ExpandoObject _dict = new ExpandoObject();
public dynamic Data
{
get { return _dict; }
}
public Foo(params object[] args)
{
foreach (var arg in args)
_dict.Add(arg.ToString(), "..");
}
}
var foo = new Foo("a", "b", "c");
foo.Data.x = 3.14;
Console.Write(foo.Data.a);
From the world of PHP I have decided to give C# a go. I've had a search but can't seem to find the answer of how to do the equivalent to this.
$object = new Object();
$vars = get_class_vars(get_class($object));
foreach($vars as $var)
{
doSomething($object->$var);
}
I basically have a List of an object. The object could be one of three different types and will have a set of public properties. I want to be able to get a list of the properties for the object, loop over them and then write them out to a file.
I'm thinking this has something to do with c# reflection but it's all new to me.
Any help would be greatly appreciated.
This should do it:
Type myType = myObject.GetType();
IList<PropertyInfo> props = new List<PropertyInfo>(myType.GetProperties());
foreach (PropertyInfo prop in props)
{
object propValue = prop.GetValue(myObject, null);
// Do something with propValue
}
void Test(){
var obj = new{a="aaa", b="bbb"};
var val_a = obj.GetValObjDy("a"); //="aaa"
var val_b = obj.GetValObjDy("b"); //="bbb"
}
//create in a static class
static public object GetValObjDy(this object obj, string propertyName)
{
return obj.GetType().GetProperty(propertyName).GetValue(obj, null);
}
Yes, Reflection would be the way to go. First, you would get the Type that represents the type (at runtime) of the instance in the list. You can do this by calling the GetType method on Object. Because it is on the Object class, it's callable by every object in .NET, as all types derive from Object (well, technically, not everything, but that's not important here).
Once you have the Type instance, you can call the GetProperties method to get the PropertyInfo instances which represent the run-time informationa about the properties on the Type.
Note, you can use the overloads of GetProperties to help classify which properties you retrieve.
From there, you would just write the information out to a file.
Your code above, translated, would be:
// The instance, it can be of any type.
object o = <some object>;
// Get the type.
Type type = o.GetType();
// Get all public instance properties.
// Use the override if you want to classify
// which properties to return.
foreach (PropertyInfo info in type.GetProperties())
{
// Do something with the property info.
DoSomething(info);
}
Note that if you want method information or field information, you would have to call the one of the overloads of the GetMethods or GetFields methods respectively.
Also note, it's one thing to list out the members to a file, but you shouldn't use this information to drive logic based on property sets.
Assuming you have control over the implementations of the types, you should derive from a common base class or implement a common interface and make the calls on those (you can use the as or is operator to help determine which base class/interface you are working with at runtime).
However, if you don't control these type definitions and have to drive logic based on pattern matching, then that's fine.
well, in C# it's similar.
Here's one of the simplest examples (only for public properties):
var someObject = new { .../*properties*/... };
var propertyInfos = someObject.GetType().GetProperties();
foreach (PropertyInfo pInfo in propertyInfos)
{
string propertyName = pInfo.Name; //gets the name of the property
doSomething(pInfo.GetValue(someObject,null));
}
One line solution using Linq...
var obj = new {Property1 = 1, Property2 = 2};
var property1 = obj.GetType().GetProperties().First(o => o.Name == "Property1").GetValue(obj , null);
To get specific property value from property name
public class Bike{
public string Name {get;set;}
}
Bike b = new Bike {Name = "MyBike"};
to access property value of Name from string name of property
public object GetPropertyValue(string propertyName)
{
//returns value of property Name
return this.GetType().GetProperty(propertyName).GetValue(this, null);
}
You can use GetType - GetProperties - Linq Foreach:
obj.GetType().GetProperties().ToList().ForEach(p =>{
//p is each PropertyInfo
DoSomething(p);
});
Here's something I use to transform an IEnumerable<T> into a DataTable that contains columns representing T's properties, with one row for each item in the IEnumerable:
public static DataTable ToDataTable<T>(IEnumerable<T> items)
{
var table = CreateDataTableForPropertiesOfType<T>();
PropertyInfo[] piT = typeof(T).GetProperties();
foreach (var item in items)
{
var dr = table.NewRow();
for (int property = 0; property < table.Columns.Count; property++)
{
if (piT[property].CanRead)
{
var value = piT[property].GetValue(item, null);
if (piT[property].PropertyType.IsGenericType)
{
if (value == null)
{
dr[property] = DBNull.Value;
}
else
{
dr[property] = piT[property].GetValue(item, null);
}
}
else
{
dr[property] = piT[property].GetValue(item, null);
}
}
}
table.Rows.Add(dr);
}
return table;
}
public static DataTable CreateDataTableForPropertiesOfType<T>()
{
DataTable dt = new DataTable();
PropertyInfo[] piT = typeof(T).GetProperties();
foreach (PropertyInfo pi in piT)
{
Type propertyType = null;
if (pi.PropertyType.IsGenericType)
{
propertyType = pi.PropertyType.GetGenericArguments()[0];
}
else
{
propertyType = pi.PropertyType;
}
DataColumn dc = new DataColumn(pi.Name, propertyType);
if (pi.CanRead)
{
dt.Columns.Add(dc);
}
}
return dt;
}
This is "somewhat" overcomplicated, but it's actually quite good for seeing what the outcome is, as you can give it a List<T> of, for example:
public class Car
{
string Make { get; set; }
int YearOfManufacture {get; set; }
}
And you'll be returned a DataTable with the structure:
Make (string)
YearOfManufacture (int)
With one row per item in your List<Car>
This example trims all the string properties of an object.
public static void TrimModelProperties(Type type, object obj)
{
var propertyInfoArray = type.GetProperties(
BindingFlags.Public |
BindingFlags.Instance);
foreach (var propertyInfo in propertyInfoArray)
{
var propValue = propertyInfo.GetValue(obj, null);
if (propValue == null)
continue;
if (propValue.GetType().Name == "String")
propertyInfo.SetValue(
obj,
((string)propValue).Trim(),
null);
}
}
I haven't found this to work on, say Application objects. I have however had success with
var serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
string rval = serializer.Serialize(myAppObj);
You can try this:
string[] arr = ((IEnumerable)obj).Cast<object>()
.Select(x => x.ToString())
.ToArray();
Once every array implements IEnumerable interface
public Dictionary<string, string> ToDictionary(object obj)
{
Dictionary<string, string> dictionary = new Dictionary<string, string>();
Type objectType = obj.GetType();
IList<PropertyInfo> props = new List<PropertyInfo>(objectType.GetProperties());
foreach (PropertyInfo prop in props)
{
object propValue = prop.GetValue(obj, null);
dictionary.Add(prop.Name, propValue.ToString());
}
return dictionary;
}
/// get set value field in object to object new (two object field like )
public static void SetValueObjectToObject (object sourceObj , object resultObj)
{
IList<PropertyInfo> props = new List<PropertyInfo>(sourceObj.GetType().GetProperties());
foreach (PropertyInfo prop in props)
{
try
{
//get value in sourceObj
object propValue = prop.GetValue(sourceObj, null);
//set value in resultObj
PropertyInfo propResult = resultObj.GetType().GetProperty(prop.Name, BindingFlags.Public | BindingFlags.Instance);
if (propResult != null && propResult.CanWrite)
{
propResult.SetValue(resultObj, propValue, null);
}
}
catch (Exception ex)
{
// do something with Ex
}
}
}