VS2008: Error while setting the property of a custom web control - An unhandled exception has occurred

You might see this error when you create a custom web control which has a property that you would like to set in the web page that consumes the control.
An unhandled exception has occurred. 'value' could not be set on 'propertyName'

I had created lots of custom controls in VS 2005 and creating custom properties for these controls was pretty straight forward. So I was surprised when i saw this error. I tried various things to find the reason and why the value was not getting set. Finally i gave up and started searching the net and finally got this link
http://www.west-wind.com/Weblog/posts/484172.aspx

this seemed to a bug with VS 2008 and SP1 and till date there is no solution. The only option is to close VS and open it again. But again this is a problem with the IDE, you can still compile the project and run it and it will not throw any compilation error nor show any error while accessing those properties you set on your custom control.

For those who are interested, Rick (whose blog I have referenced above) also has a issue ticket raised with microsoft which is marked as resolved, but the patch mentioned also seems to be buggy (read the comments in the link given below)
https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=361826

Comments from the above link

>>>> Hi, I installed the hotfix: KB961847 - "Error creating control- [text] property" ASP.NET server cntls in VS the problem still there? can anyone tell me if i got the wrong hotfix? or is there any hotfix i need to install as well?
Posted by NatureNZ on 4/23/2009 at 2:56 PM

>>>> and the hotfix seems broke the web user control as well, i had a web user control uses standard asp controls and ajax control. it was working well in design time and now it is got the same error again.
Posted by NatureNZ on 4/23/2009 at 3:38 PM

Active directory queries

I had to spend lot of time trying to figure how to write queries on active directory using SSIS. I searched the internet for quite some time with no concrete examples. I did find examples using scripts but none for querying using ADO objects in SSIS. So I thought there might be others like me out there who might need some help .. so here goes

some of the Field names
- givenName = First name of user
- sn = Last name of user
- memberof = list of groups that the user belongs to
- cn = Display name
- objectGUID = Unique value for each record
- samAccountName = windows Login Name

The "FROM" clause would need to contain the complete domain controller name
so if you domain is called "corp.company.us.com", then your from clause would be like this
select field1, field2 from
FROM 'LDAP://DC=corp,DC=commpany,DC=us,DC=us'

if you want to fetch only the users you will need to specify a where clause like WHERE objectClass='user'

I had a requirement where I had to fetch users belonging to a particular group. I had a lot of problem finding this query. I finally learned that your where clause needs to have the whole heirarchy of the group specified. For eg, If you want to find all users in a Group called "Finance" your where clause needs to include

> memberOf = 'CN=Finance,DC=corp,DC=commpany,DC=us,DC=us'

Now if the department is within a Orgnization unit or OU called "AllUsers", then qour query needs to specify that too
> memberOf = 'CN=Finance,OU=AllUsers,DC=corp,DC=commpany,DC=us,DC=us'

Similarly you need to first check how the groups, users are created within your active directory and make changes to your query .. do remember to add the domain controller information too ..

Sample query finding all users within finance group where the finance group is plaed within a OU=Allusers

select cn
FROM 'LDAP://DC=corp,DC=commpany,DC=us,DC=us'
WHERE objectClass='user'
and memberOf = 'CN=Finance,OU=AllUsers,DC=corp,DC=commpany,DC=us,DC=us'

Hope this helps someone out there ..

Querying Active directory - how to fetch more than 1000 records

I had developed and tested a SSIS package which queried active directory and imported the users into a SQL server table. This was working fine till I deployed this on the client server. Some of the AD users were not getting imported. The users that were not been imported also has the same attributes and belonged to the same OU and domain as the users that were successfully imported. So I got confused and started investigating.

After some hours of various changes to the package and testing, I noticed that only 1000 records were been fetched every time. This surprised me and so I changed the query to fetch only one user which was not getting imported earlier (realised later, that this should have been my first thing I should have tested). This user now got successfully imported. So I concluded that issue was indeed with the records been limited to just 1000.

So now I started searching the internet for a solutions to this wierd problem. There were various solutions where the pagesize could be set when you user directory service objects but I could not find a solution on how to set the pagesize when queried through SSIS. So I started looking whether there is any policy that is set on active directory server and whether it is defaulted to 1000. This is when I found this article
http://support.microsoft.com/default.aspx?scid=kb;en-us;315071&sd=tech

Using the instructions in that article, I did the following
1. At the Ntdsutil.exe command prompt, type LDAP policies, and then press ENTER.
2. At the LDAP policy command prompt, type connections, and then press ENTER.
3. At the server connection command prompt, type connect to server , and then press ENTER.
4. At the server connection command prompt, type q, and then press ENTER to return to the previous menu.
5. At the LDAP policy command prompt, type Show Values, and then press ENTER.

You will see all the values set and can confirm whether the MaxPageSize is set to 1000

This is what Microsoft says about "MaxPageSize"
MaxPageSize - This value controls the maximum number of objects that are returned in a single search result, independent of how large each returned object is. To perform a search where the result might exceed this number of objects, the client must specify the paged search control. This is to group the returned results in groups that are no larger than the MaxPageSize value. To summarize, MaxPageSize controls the number of objects that are returned in a single search result.
Default value: 1,000

We can change this value by running the command
Set MaxPageSize

I am yet to test this on the client's server and will get back whether this helped in solving the problem or not. But this looks promising :-)

WCF - "The client was unable to retrieve service metadata. Make sure the service is running and exposing metadata."

So as you can see, not I have moved onto writing code in framework 3.5 and learning the way around WCF, WPF etc ..

I am in the processes of designing and developing a application using SOA and for that purpose, trying to create the data layer as service. Now why this is been planned has a service has its own reasons and maybe I can explain it sometime later. After creating a simple WCF service, I tried to test it using the default client tool provided by VS2008, I kept getting this error "The client was unable to retrieve service metadata. Make sure the service is running and exposing metadata."

I looked and cross-checked every detail and could not locate the issue. After a couple of trial and error, I noticed that one of the contract defined for the endpoint did not have the complete namespace. I had changed the namespace of contract class and I think I had reassigned the contract using the WCF configuration tool and suprisongly, it had not added the complete namespace. Anyway, correcting this namespace cleared the issue.

So you get a similar error, check the namespace for each of the component within the app.config by opening it within the VS IDE and not within the WCF configuration tool.