Wednesday, November 23, 2011

Clearing Another User's Checkout in TFS

A long gone coworker has left a few objects checked out in TFS, now you discover that you need to clear the checkout in order to incorporate new changes. How can this be done?

Clearing out another user's check out is NOT supported from the GUI, however there is a command line option to accomplish this:

- From Visual Studio Tools in the Start menu, open the Visual Studio Command Prompt
- If you use TFS, your workstation should have the TF command available, then type:

C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC>TF undo /workspace:WorkstationName;UserName $/ProjectName/ObjectName.cs /s:http://YourTFSServer:8080

Once the command completes, refresh the Source Control Explorer to see the changes, you may also need to  get the latest version of the project if multiple objects have been locked for a long period of time.

Hope this helps,

Tuesday, November 15, 2011

Using DotNetZip Library to Compress Data in ASP.Net

I recently worked on a project that involved creating encrypted Zip files. Data is captured on a web form and then written to a text file.
At first, the task sounded complex. However, if you are aware of the DotNetZip library existence, your task just got easier.

You can download the DotNetZip library from
Once you download and install the package, you will need to add a reference to Ionic.Zip.dll or copy the file to your \lib folder, this is all you need to start generating your own zip files.

The best part: DotNetZip is free!!

DotNetZip is well documented and is much easier to use than any other solutions out there including System.IO.Compression and SharpZipLib, after trying both methods I would highly recommend DotNetZip because is incredibly easy to use.

Below is a sample method to illustrate how to easily to compress content that is being passed as a string.
The method takes the file name and the content as arguments:

internal MemoryStream ZipString(string aZipFileName, string aContents, string aMode)
        //Add these to your AppSettings on Web.Config
        string sZipFilePassword = ConfigurationManager.AppSettings["ZipFilePassword"];
        string sZipFileEncryption = ConfigurationManager.AppSettings["ZipFileStrongEncryption"];

        //Stored the zippped data on this memory stream
        MemoryStream msZippedContent = new MemoryStream();
        // Creating Zip
        using (var zip = new ZipFile())
            // Add the password protection
            zip.Password = sZipFilePassword;
            if (sZipFileEncryption == "N")
                //PkZipWeak is not a string encryption method, but is supported by any UnZip utility
                zip.Encryption = EncryptionAlgorithm.PkzipWeak;
                //WinZipAes128 and WinZipAes256 is NOT compatible with Windows ZIP
                zip.Encryption = EncryptionAlgorithm.WinZipAes256;

            // Add the desired file to the Zip
            zip.AddEntry(aZipFileName, aContents, Encoding.ASCII);

            // Send the contents of the ZIP back to the output stream
            return msZippedContent;
    catch (Exception genEx)
        return null;


The method declares a variable of type ZipFile which is available once you add a reference: "using Ionic.Zip;" That declaration creates the shell of the zip file. After that, the process to save the file is simple, add a password if needed, add an encryption method and you can proceed to add an entry to the Zip file by using AddEntry.
Of course, you could add multiple files to the same Zip archive. Finally, you can Save the contents of the Zip which in this case are returned by the method as a MemoryStream that could be used for other purpose such as creating an e-mail attachment.

Be aware that if you need to encrypt the contents of the zip, choosing the encryption method is important because the built-in Windows unzip feature can only decrypt PkZip.Weak content. You would need to have WinZip or WinRar Installed on the target workstation to unzip contents encrypted with the WinZipAes128 or WinZipAes256 methods.

Hope this is helpful and feel free to contact me if you have any questions,

Saturday, November 12, 2011

Save the directory listing to a text file

Here is a useful and handy trick is to write the contents of a directory listing to a text file so you can create a report or execute a search in another tool, say Word or Excel.

I've used this in the past for other simple stuff for example, creating a spreadsheet out of a massive MP3 directory. Since I have music organized by album, each album being a directory I wanted to write the contents of My Music to a text file.

Go to CMD:
C:\User\My Music>dir *. >>Music.txt

This will list only directories and send the contents to the music.txt file. Of course you must have write permissions in the directory.

If you want a cleaner listing. Say only the directory names without any other information try:

C:\User\My Music>dir *. /b >>Music.txt

Hope it helps,

How to clear a String Builder?

How to clear a StringBuilder?
By now you probably realized that rhere is no Clear method.

You can use the two lines below, the assumption is that you are going to reuse the StringBuilder several times in your code and you want to temporarily clear it to ensure is empty and ready for a new assignment.

sbSQL.Length = 0;
sbSQL.Capacity = 0;

This trims the contents but also shortens the capacity to zero. I was surprised to noticed that both Length and Capacity properties are writable.

Hope it helps,

Thursday, November 3, 2011

Exporting Data as XML in a MemoryStream with Download Prompt

The below snippet demonstrates how to generate XML content on the fly and then storing the contents in memory. (MemoryStream)
This practice is useful if the output can't be saved on the server and avoids the hassle of dealing with permissions. Instead the XML is generated in memory and then the user will be automatically prompted to download the XML file to their local resource, similar to what happens when attempting to download a file.

protected bool GenerateExportFile()
            //Create Memory Stream to store XML Data
            MemoryStream ms = new MemoryStream();
            //Use a writer to greate the XML
            using (XmlWriter writer = XmlWriter.Create(ms))
                writer.WriteStartDocument(); //Header
                writer.WriteComment("Comment goes here");
                    writer.WriteStartElement("Root"); //<Root>
                            writer.WriteStartElement("Element1"); //<Element1>
                            writer.WriteAttributeString("Attribute1", "AtributeValue");

                            writer.WriteEndElement(); //<Element2>

                    writer.WriteEndElement(); //<Root>
                    //Closed the Root Tag

                //Convert Memory Stream to Byte Array
                byte[] data = ms.ToArray();
                //The Proposed FileName that will show when the user is prompted to save the file
                string xmlFileName = "OrdExp_" + DateTime.Today.Year.ToString() + DateTime.Today.Month.ToString("00") + DateTime.Today.Day.ToString("00");
                //Creating the Context
                //Heads up browser, here comes some XML
                HttpContext.Current.Response.ContentType = "text/xml";
                HttpContext.Current.Response.AddHeader("Content-Disposition:", "attachment;filename=" + HttpUtility.UrlEncode(xmlFileName));
                //Set the size of the file so the progress bar reports that correctly
                HttpContext.Current.Response.AddHeader("Content-Length", data.Length.ToString());
                //Download the file and prompt the user to save

                return true;
    catch (Exception exc)
        lblMsg.Text = "Error Generating File: " + exc.Message;
        return false;
    return true;  

This code was used to generate XML data output and then added the ability to automatically export the data to a local machine.
Hope this helps,