Copying an object instance instead of a reference [modified] - C# Discussion Boards

Hi

Is it possible to get hash value of user's password form Active directory.

You MAY be able to get your hands on the "Unicode-Pwd" field of a Person object, but that's about it. Every other password field I've seen is write-only.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

What do you need the hash for? If you're just trying to do user verification via active directory, afaik the it's all done on in the API and all you need to provide are the users credentials.

Today's lesson is brought to you by the word "niggardly". Remember kids, don't attribute to racism what can be explained by Scandinavian language roots.
-- Robert Royall

Hi
From SQL procedure, I need to call a .NET function (which is part of .NET assembly and loaded in SQL Server 2005).
1. What is the maximum length of STRING which can be passed as parameter?
2. I only saw the samples of basic types (like int, string) but can we pass XML datatype or other complex custom objects?

Please advise. Thanks
Pankaj

pankazmittal wrote:
1. What is the maximum length of STRING which can be passed as parameter?

I wouldn't expect there to be a max. There is no limit on the size a string can be apart from the physical limit of how much memory you have available.

pankazmittal wrote:
2. I only saw the samples of basic types (like int, string) but can we pass XML datatype or other complex custom objects?

Don't see any reason why not. Give it a try. Let me know what happens.

Simon

pankazmittal wrote:
1. What is the maximum length of STRING which can be passed as parameter?

I don't know exactly, but it would be something like 2 or 4 million characters. If you have a 32 bit operating system, the limit would be that no process can use more than 4 GiB of memory.

pankazmittal wrote:
2. I only saw the samples of basic types (like int, string) but can we pass XML datatype or other complex custom objects?

I don't see how you could create any object like than in T-SQL?

Despite everything, the person most likely to be fooling you next is yourself.

Yes we can what you need to do is to add your assembly under the database programmability folder in assemblies and then call it in your query.

This may be a stupid question, which may be easily solved if I just study the C# programming guide thoroughly, yet I expect help from Codeproject members as I don't have enough time.

I've a library with a class called RegistryBrowser, that simply encapsulates the Microsoft.Win32.Registry and Microsoft.Win32.RegistryKey classes to provide a simple stateful access mechanism to the windows registry. This is a code fraction from the class:

public class RegistryBrowser
    {
        RegistryKey currentKey, regRoot, tempKey;
        bool writable;
        string temp;

        public string FullPath
        {
            get
            {
                return currentKey.Name;
            }
        }

        public int SubKeyCount
        {
            get
            {
                return currentKey.SubKeyCount;
            }
        }

        public int ValueCount
        {
            get
            {
                return currentKey.ValueCount;
            }
        }

        public RegistryBrowser(RegistryKey root, bool writable)
        {
            regRoot = root;
            currentKey = regRoot;
            this.writable = writable;
        }

        public RegistryBrowser(RegistryKey root, string subKey, bool writable)
        {
            regRoot = root;
            currentKey = regRoot.OpenSubKey(subKey, true);
            this.writable = writable;
        }

        public bool BrowseTo(string subKey)
        {
            tempKey = currentKey;
            currentKey = currentKey.OpenSubKey(subKey);
            if (currentKey == null)
            {
                currentKey = tempKey;
                return false;
            }
            else if(tempKey != regRoot)
                tempKey.Close();
            return true;
        }
        .
        .
        .

Now the problem is that both the constructors simply copy the object reference 'root'. What if the calling method calls the .Close method on the same instance. I need to secure my library against this. So how do I copy the object, instead of just copying the reference, or maybe I need a better design. If so, please suggest.

I encounter this problem very often and it's the source of most of bugs in my programs. Please suggest at the earliest.

modified on Friday, November 7, 2008 10:08 AM

Write a copy constructor[^] or implement ICloneable[^] interface.

*jaans

ICloneable is generally not recommended[^].

It is ambiguous as to weather the call to clone will be a deep or shallow copy, so can introduce bugs if the caller makes the wrong assumptions. Recommendation is to define your own clone semantics and implement the required interfaces.

Simon

Ankit Rajpoot wrote:
I just study the C# programming guide thoroughly, yet I expect help from Codeproject members as I don't have enough time.

You can expect all you like, does not mean you'll get. And with an attitude like that im certainly not helping.

I said that just to glorify the helping nature of Codeproject members. I'm not a professional programmer working for some company. I'm a student who also need to study the academic course. I program just for the sake of my hobby. So what I mean by not having enough time is that I don't have time to study the guide and read the concepts. If someone can (please) tell me some straightforward way of doing that, I'd be very grateful. And if my attitude was bad, I'd not have said 'please'.

You just started your post rather badly. You basically said that the problem was easy to solve and that if you could be bothered you would do it your self, but you can't be bothered so you expect someone here to do the work for you. If you can't be bothered to put the effort it, why should you expect someone else to do it for you.

I'm sure you didn't mean it like that, it was just worded badly.

Ankit Rajpoot wrote:
I'm not a professional programmer working for some company

Remember that people here aren't professionals paid to answer questions, we just do it because we are being generous. Don't expect an answer quickly every time.

Looks like you've got some good answers to your question though. Personally, Dave's sounds like the best solution.

Simon

Thanks,

And I agree, I started my post rather badly. That was, may be because I'm not a native English speaker & so I've difficulties fluently understanding the emotions that a statement conveys. Another reason is that I wanted my post to be extra polite and for the sake of it, I wrote that "it's a stupid question and can be solved by reading the guide", because I just thought that it's not worth bothering the geniuses for.

Ankit Rajpoot wrote:
Now the problem is that both the constructors simply copy the object reference 'root'. What if the calling method calls the .Close method on the same instance.

An object passed in is not copied. You only get a copy of the reference. Why don't you just create an internally used RegistryKey object, using the passed in object as a guide to the key to open??

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

Exactly my thought as well Smile | :)

, like this...

static RegistryKey CopyKey(RegistryKey k, bool writeable)
{
    string[] pathParts = k.Name.Split(new string[] { @"\" }, StringSplitOptions.None);
    RegistryKey currentKey = null;
    // get the root key
    switch (pathParts[0].ToUpper())
    {
        case "HKEY_CLASSES_ROOT":
            currentKey = Registry.ClassesRoot;
            break;
        case "HKEY_CURRENT_CONFIG":
            currentKey = Registry.CurrentConfig;
            break;
        case "HKEY_CURRENT_USER":
            currentKey = Registry.CurrentUser;
            break;
        case "HKEY_DYN_DATA":
            currentKey = Registry.DynData;
            break;
        case "HKEY_LOCAL_MACHINE":
            currentKey = Registry.LocalMachine;
            break;
        case "HKEY_PERFORMANCE_DATA":
            currentKey = Registry.PerformanceData;
            break;
        case "HKEY_USERS":
            currentKey = Registry.Users;
            break;
    }
    if (pathParts.Length == 1)
        return currentKey;

    // walk the path of the original key to create a copy
    for (int pathPartIndex = 1; pathPartIndex < pathParts.Length; pathPartIndex++)
    {
        currentKey = currentKey.OpenSubKey(pathParts[pathPartIndex], writeable);
    }
    return currentKey;
}

Keep It Simple Stupid! (KISS)

Many thanks Ben Smile | :)

I didn't expect anyone to post the complete method.

Once again, many many many thanks, I'm really obliged.

My son would like to get into game programming. Are there any good C# game programming references that anyone can recommend? Thanks.

The thing to start with is XNA[^]. It's a dedicated gaming framework from MS. It's entirely .net based (no need to get dirty with directx), and there is a Visual Studio "XNA game studio" express edition available for free.

Check out the creators club[^] for guides and competitions and stuff. There's a bunch of getting started guides, tutorials and sample code under the "education" tab.

Simon

I suggest starting out with something like Gamemaker. That way you get an idea of how the logic flows and how things can be set up, before actually having to write the code yourself.

My current favourite word is: Nipple!

-SK Genius

Game Programming articles start -here[^]-

Hi there

How can I draw and image with a transparency and an alpha bending ?

many thx

It's done the same as any other image. Since you're asking this question, I take it your not getting the results you were hoping for?? You might want to explain what you're ultimately trying to do with this.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

Before asking such question you could have searched the web. The first link I got from Google itself will answer you.
DrawTransparentImageUsingAB[^]

*jaans

I am working on an SDK. Obviously I am very happy with the ability to create documentation from code comments. This is useful for both Intellisense and Documentation. We are using Sandcastle to produce the chm file. Sandcastle allows me to filter out internal and private elements. Unfortunately they are in the XML generated by csc.exe which means they show up in Intellisense. I don't see anyway to filter the output of csc. Can I use Sandcastle to filter the docs? How do other people do this?

Tanks for your support
Pat O
<a href="http://currentchaos.blogspot.com/">Blog</a>

  _      _      _
 /*\==  /*\==  /*\==
&lt;ooo&gt;  &lt;ooo&gt;  &lt;ooo&gt;

Don't write any.

Your classes should be small enough that you don't need to anyway. Just use regular comments.