I would like to serialize the properties of the HttpBrowserCapibilities object so that it may be returned via a web method call. Currently the object cannot be serialized:
Cannot serialize member System.Web.Configuration.HttpCapabilitiesBase.Capabilities of type System.Collections.IDictionary, because it implements IDictionary.
...which is understandable. However, I would like to simply copy out the properties and their values to a hierarchy, i.e.
<HttpBrowserCapabilities>
<IsMobile>true</IsMobile>
</HttpBrowserCapabilities>
I'm starting to think I would need to use reflection to copy this object, but I haven't reached a conclusion. Does anyone have any suggestions to keep this simple?
Thanks,
George
Originally I posted an answer using XmlDocument, but I glossed over some of the web method stuff and didn't realize you were really trying to map a DTO.
Reflection sounds complicated but it really isn't. The following snippet will do what you want:
public static void Populate(object dest, IDictionary dictionary)
{
Type t = dest.GetType();
foreach (object key in dictionary)
{
PropertyInfo prop = t.GetProperty(key.ToString(),
BindingFlags.Instance | BindingFlags.Public);
if ((prop != null) && prop.CanWrite)
{
object value = dictionary[key];
prop.SetValue(dest, value, null);
}
}
}
Then invoke this as:
BrowserCapsDto dto = new BrowserCapsDto();
Populate(dto, Capabilities); // Capabilities is the real BrowserCaps
It's pretty easy because you already have an IDictionary and thus you already know all of the possible names you can map; you don't actually need to use any reflection on the source, just the destination.
Related
I have a method with this signature
public IEnumerable<T> GetAll<T>() where T : new()
{
// Orm Lite Version
return Connection.LoadSelect<T>();
}
At compile time I don't know the Type T. I only know the class name at runtime is it possible to call this method using reflection with something like this?
string TargetTBLName = ...;//TargetTBLName get's it's value at runtime
Type ParentTableClass = Type.GetType(TargetTBLName);
IEnumerable<Type.GetType(TargetTBLName)> test = Repository.GetAll<Type.GetType(TargetTBLName)>();
Any Ideas?
I'd give a Dynamitey library a go. You can do that in many different ways, but I prefer this one because of its simplicity. You can find it here.
var name = InvokeMemberName.Create;
var test = Dynamic.InvokeMember(Repository, name("GetAll", new[]{ParentTableClass }));
foreach(var obj in test)
{
obj.SomeMethodFromMyType();
}
Keep in mind, that if Repository is static, than you have to tweak it a bit to use static invocation context (look up the link).
Now you have a test object, which is a dynamic - you can use it with duck typing (which has some implications on speed, for example), but in general you can do whatever you want to do with a normal IEnumerable<YourType>.
If you want to use reflection:
MethodInfo getAll= typeof(Repository).GetMethod("GetAll");
MethodInfo getAllGeneric= getAll.MakeGenericMethod(ParentTableClass);
object result = getAllGeneric.Invoke(this, null);
//or null, null is Repository is static
var finalObject = result as IEnumerable;
Mind that since this ParentTableClass is an unknown during compilation, you won't have access to anything that the actual type provides - unless you use dynamic approach.
I want to pass a object to workflow as input parameter, without creating instance of it, as this object is already filled up with lot of sub-objects, and I want to run lot of rules on that object. I want to use
WorkflowInvoker.Invoker(this); Is this possible in Windows Workflow Foundation 4.0, If so, what should I keep in InArguments as the type?
Thanks In Advance,
Thanks for your input....
Sorry, I think I haven't kept the question correctly, I had a business class used by bank customers, class is like this,
public partial class BankName.DTOS.clsCardDetails : BaseClass
{
public string _mBankStatusCode;
protected override string IsCreditCard(HttpContext ctx)
{
Status = ctx.Request.Form["Trans_Status"];
_mBankStatusCode = Status.ToString();
}
}
Now, I have to pass this class object to workflow foundation, I should not create new instance of this class in workflow again. Because in workflow, I want to get the status, so ideally what I thought of passing to workflow is object of "BankName.DTOS.clsCardDetails". That is my question.
InArguments<> to workflow is object of BankName.DTOS.clsCardDetails
Arguments passed into a workflow need to be put into a dictionary and the dictionary is passed into the workflow.
var dictionary = new Dictionary<string, object> { { "BankName", _bankNameObject } };
WorkflowInvoker.Invoke(this, dictionary);
The key must have the same name as your InArgument and your object must have the same type as your InArgument.
You can pass as many arguments as you like into the workflow via the dictionary.
See http://blogs.msdn.com/b/rjacobs/archive/2011/05/26/passing-arguments-to-workflow-activities-again.aspx
Pardon me if this question has already been asked. HttpContext.Current.Session["key"] returns an object and we would have to cast it to that particular Type before we could use it. I was looking at various implementations of typed sessions
http://www.codeproject.com/KB/aspnet/typedsessionstate.aspx
http://weblogs.asp.net/cstewart/archive/2008/01/09/strongly-typed-session-in-asp-net.aspx
http://geekswithblogs.net/dlussier/archive/2007/12/24/117961.aspx
and I felt that we needed to add some more code (correct me if I was wrong) to the SessionManager if we wanted to add a new Type of object into session, either as a method or as a separate wrapper. I thought we could use generics
public static class SessionManager<T> where T:class
{
public void SetSession(string key,object objToStore)
{
HttpContext.Current.Session[key] = objToStore;
}
public T GetSession(string key)
{
return HttpContext.Current.Session[key] as T;
}
}
Is there any inherent advantage in
using
SessionManager<ClassType>.GetSession("sessionString")
than using
HttpContext.Current.Session["sessionString"] as ClassType
I was also thinking it would be nice
to have something like
SessionManager["sessionString"] = objToStoreInSession,
but found that a static class cannot have an indexer. Is there any other way to achieve this ?
My thought was create a SessionObject which would store the Type and the object, then add this object to Session (using a SessionManager), with the key. When retrieving, cast all objects to SessionObject ,get the type (say t) and the Object (say obj) and cast obj as t and return it.
public class SessionObject { public Type type {get;set;} public Object obj{get;set;} }
this would not work as well (as the return signature would be the same, but the return types will be different).
Is there any other elegant way of saving/retrieving objects in session in a more type safe way
For a very clean, maintainable, and slick way of dealing with Session, look at this post. You'll be surprised how simple it can be.
A downside of the technique is that consuming code needs to be aware of what keys to use for storage and retrieval. This can be error prone, as the key needs to be exactly correct, or else you risk storing in the wrong place, or getting a null value back.
I actually use the strong-typed variation, since I know what I need to have in the session, and can thus set up the wrapping class to suit. I've rather have the extra code in the session class, and not have to worry about the key strings anywhere else.
You can simply use a singleton pattern for your session object. That way you can model your entire session from a single composite structure object. This post refers to what I'm talking about and discusses the Session object as a weakly typed object: http://allthingscs.blogspot.com/2011/03/documenting-software-architectural.html
Actually, if you were looking to type objects, place the type at the method level like:
public T GetValue<T>(string sessionKey)
{
}
Class level is more if you have the same object in session, but session can expand to multiple types. I don't know that I would worry about controlling the session; I would just let it do what it's done for a while, and simply provide a means to extract and save information in a more strongly-typed fashion (at least to the consumer).
Yes, indexes wouldn't work; you could create it as an instance instead, and make it static by:
public class SessionManager
{
private static SessionManager _instance = null;
public static SessionManager Create()
{
if (_instance != null)
return _instance;
//Should use a lock when creating the instance
//create object for _instance
return _instance;
}
public object this[string key] { get { .. } }
}
And so this is the static factory implementation, but it also maintains a single point of contact via a static reference to the session manager class internally. Each method in sessionmanager could wrap the existing ASP.NET session, or use your own internal storage.
I posted a solution on the StackOverflow question is it a good idea to create an enum for the key names of session values?
I think it is really slick and contains very little code to make it happen. It needs .NET 4.5 to be the slickest, but is still possible with older versions.
It allows:
int myInt = SessionVars.MyInt;
SessionVars.MyInt = 3;
to work exactly like:
int myInt = (int)Session["MyInt"];
Session["MyInt"] = 3;
I need to log all the function parameters in a dozen functions.
Is there a way to pro grammatically determine all the parameters and their values (or at least their .ToString() value)? Perhaps via reflection?
Here is an example of how to do this with PostSharp
http://consultingblogs.emc.com/merrickchaffer/archive/2009/08/04/using-postsharp-to-log-method-entry-and-exit-in-net-code.aspx
You can also roll your own
http://www.developerfusion.com/article/5307/aspect-oriented-programming-using-net/3/
To the best of my knowledge there's no way to use reflection to dynamically list and determine value of local variables. You can use reflection to get type information about the parameters of a method, but only the declared type - you can't automatically get information about the actual arguments, because the reflection metadata gives information about the method definition, not the specific values passed to it at runtime.
You can, however, do something like this:
static class Extensions
{
public static string GetTypeAndValue(this object obj)
{
return String.Format("{0}: {1}", obj.GetType().Name, obj.ToString());
}
}
Then, from within each method in which you want to perform logging, do something like
private void SomeMethodToBeLogged(string some_string, int some_int, bool some_bool)
{
Logger.Log(String.Format("SomeMethodToBeLogged({0}, {1}, {2})",
some_string.GetTypeAndValue(),
some_int.GetTypeAndValue(),
some_bool.GetTypeAndValue()));
}
I have a list of error codes I need to reference, kinda like this:
Code / Error Message
A01 = whatever error
U01 = another error
U02 = yet another error type
I get the Code returned to me via a web service call and I need to display or get the readable error. So I need a function when passed a Code that returns the readable description. I was just going to do a select case but thought their might be a better way. What is the best way / most effieient way to do this?
Use a Dictionary, (in C#, but the concept and classes are the same):
// Initialize this once, and store it in the ASP.NET Cache.
Dictionary<String,String> errorCodes = new Dictionary<String,String>();
errorCodes.Add("A01", "Whatever Error");
errorCodes.Add("U01", "Another Error");
// And to get your error code:
string ErrCode = errorCodes[ErrorCodeFromWS];
You would use a dictionary. A dictionary uses a hashmap internally for performance, so it is good in that regard. Also, because you want this to go as quickly as possible by the sounds of it, I would statically initialize it in its own class instead of, for example, in an XML file or slimier. You would probably want something like:
public static class ErrorCodes
{
private static Dictonary<string, string> s_codes = new Dicontary<string, string>();
static ErrorCodes()
{
s_codes["code"] = "Description";
s_codes["code2"] = "Description2";
}
public static string GetDesc(string code)
{
return s_codes[code];
}
}
That way, if you wanted to move the back end to a file instead of being static, then you could.