Using Reflection to set the value of an indexed property

问题

I am try to replicate the following c# code using reflection:

UserProfileManager userProfileManager = new UserProfileManager(ServerContextGoesHere);
UserProfile userProfile = null;

userProfile = userProfileManager.GetUserProfile(@"somedomain\someuser");

userProfile["PictureUrl"].Value = "This is where I want to update the value using reflection!";

userProfile.Commit();

Using reflection I can get everything to work except for the line where I'm trying to set the "PictureUrl" indexed property on the UserProfile object. That indexed property looks like this when using a decompiler:

public UserProfileValueCollection this[string strPropName]

And here is my code using reflection to achieve the same thing as the above, notice the TODO comment where I need to set the value of the PictureUrl indexed property:

   Assembly userProfileAssembly;

    var windowsFolderPath = Environment.GetEnvironmentVariable("windir");
    var pathToServerAssembly = string.Format(@"{0}\assembly\GAC_MSIL\Microsoft.Office.Server.UserProfiles\14.0.0.0__71e9bce111e9429c\Microsoft.Office.Server.UserProfiles.dll", windowsFolderPath);

    try
    {
        userProfileAssembly = Assembly.LoadFrom(pathToServerAssembly);
    }
    catch (FileNotFoundException)
    {
        // Assembly wasn't found, so eject.
        return;
    }

    var userProfileManagerClass = userProfileAssembly.GetType("Microsoft.Office.Server.UserProfiles.UserProfileManager");
    if (userProfileManagerClass == null) return;

    var userExistsMethod = userProfileManagerClass.GetMethod("UserExists");
    if (userExistsMethod == null) return;

    var getUserProfileMethod = userProfileManagerClass.GetMethod("GetUserProfile", new[]{typeof(string)});
    if (getUserProfileMethod == null) return;

    var instantiatedUserProfileManagerClass = Activator.CreateInstance(userProfileManagerClass);
    var result = (bool)userExistsMethod.Invoke(instantiatedUserProfileManagerClass, new object[] { SPContext.Current.Web.CurrentUser.LoginName });

    if (!result) return;

    var userProfileClass = userProfileAssembly.GetType("Microsoft.Office.Server.UserProfiles.UserProfile");
    var userProfile = getUserProfileMethod.Invoke(instantiatedUserProfileManagerClass, new object[] { SPContext.Current.Web.CurrentUser.LoginName });

    //userProfile["PictureUrl"].Value = userPictureUrl;
    //TODO: HOW DO I SET THE PICTUREURL PROPERTY USING REFLECTION?

    var commitMethod = userProfileClass.GetMethod("Commit");
    commitMethod.Invoke(userProfile, null);

Thanks in advance,

Ryan

回答1:

Assuming you only have one indexer on UserProfile:

PropertyInfo indexProperty = typeof(UserProfile)
    .GetProperties()
    .Single(p => p.GetIndexParameters().Length == 1 && p.GetIndexParameters()[0].ParameterType == typeof(string));

You can now get the value for the indexer and set its Value property:

object collection = indexProperty.GetValue(userProfile, new object[] { "PictureUrl" });

PropertyInfo valueProperty = collection.GetType().GetProperty("Value");
valueProperty.SetValue(collection, userPictureUrl, null);

If you have more than one matching index property you can find it with:

PropertyInfo indexProperty = (from p in t.GetProperties()
                              let indexParams = p.GetIndexParameters()
                              where indexParams.Length == 1 && indexParams[0].ParameterType == typeof(string)
                              select p).Single();

来源：https://stackoverflow.com/questions/12805792/using-reflection-to-set-the-value-of-an-indexed-property