I needed one, and after scouring the net, I found this little bad boy:
Dim Expression As New System.Text.RegularExpressions.Regex("\S+@\S+\.\S+")
If Expression.IsMatch(strEmail) Then
' Email is valid
Else
' Email is not valid
End If
Volia!
.: Adam
Man, .net pisses me off when it comes to null values. I like the fact that I can test for them, but to have to account for them? lame.
Probably due to me coding at 5 in the morning than stoopid .net, but I implemented a new regex in a very commonly used function, and everything started throwing, "can’t parse null" errors. I was also working on a couple other areas of the site, so I wasn’t sure exactly what I did that broked everything. I wound up just saying, "fuck it" and going to bed.
First thing this morning, I throw a "If Not strValue Is Nothing Then" wrapper around my RegEx, and bam! All better.
That phrase doesn’t even make sense. Use of double-negatives in a stoopid order is stoopid. =)
If Not strValue Is Nothing Then strValue = System.Text.RegularExpressions.Regex.Replace(strValue, "RedExHere", String.Empty, RegexOptions.IgnoreCase) End If
.: Adam
For some reason, I wasn’t able to figure this simple little process out on my own with the help of Google. Everything I found was way over complicated. This is short, sweet, and works =)
Public Shared Sub SendMail(ByVal fromaddress As String, ByVal toaddress As String, ByVal body As String, ByVal subject As String)
Dim mailServer As String = "smtp.mailserver.com"
Dim message As MailMessage = New MailMessage(fromaddress, toaddress, subject, body)
Dim mailClient As SmtpClient = New SmtpClient
message.IsBodyHtml = True
mailClient.Host = mailServer
mailClient.Send(message)
message.Dispose()
End Sub
BAM! Thanks Joe!
.: Adam
For the longest time I’ve been struggling with an issue of browsers caching dynamic images that have the same name. Here’s my use case:
A user has a profile photo on their profile photo that’s called MyProfilePhoto.jpg. The user uploads a new image for their profile photo. When they load their profile page, the browser sees the request for MyProfilePhoto.jpg and just pulls from cache. But in reality, the image has changed. This causes the user to re-upload the photo and get super frustrated. The solution seems to be stupidly simple: Append a random querystring value.
So my new image source value is something like: MyProfilePhoto.jpg?r=1234
This causes the image to be reloaded every time the page is loaded. Another way that I’ve thought about attacking this and making it a little more controlled is to store a random value to the database when a new image is uploaded and just append that value to the querysting. This will ensure that the new image is always loaded, and that it will pull from cache until the image changes.
I’m just lazy, and don’t want to add more fields into my user tables =)
You can see this in effect on my profile page on bodymod.org. Just view the source of my profile image.
.: Adam
This may be simple for a lot of .NET developers out there, but for a person like me (coming from classic asp), this was a little tricky.
Problem, I need to know the # of days between 2 dates.
In ASP, I used to use the DateDiff function, and it worked (most of the time). But it’s pretty convoluted and a pain to remember. From just winging it, I’ve come up with this for .NET:
Dim arrThisSplitDate As Array Dim strThisDate As String = "" Dim intDaysDifference As Integer arrThisSplitDate = Split(CDate(strThisPremiumEndDate), "/") strThisDate = DateSerial(arrThisSplitDate(2), arrThisSplitDate(1), arrThisSplitDate(0)) iintDaysDifference = DateTime.Today.Date.Subtract(strThisDate).Days
This will return you an integer value for the difference in days.
.word.
Here’s the command to issue at a command prompt to enable database caching for a MS SQL 2005 server:
aspnet_regsql -S [servername] -U [username] -d [databasename] -ed -et -t [tablename]
Here’s some variables to throw into your Page Directives:
<%@ OutputCache Duration=”20″ VaryByParam=”none” VaryByCustom=”browser” SqlDependency=”CommandNotification” %>
Here’s a great article on formatting Time in asp.net
From Site:
If you have read any DateTime format string documentation, you will know that the .NET platform has two different styles of DateTime format string:
2-a. Standard Format String
This is basically built in short hand for custom format string. You pass in the one character string to denote which custom format you want.
i.e.
now.ToString(”d”); // “09/27/2006″
now.ToString(”D”); // “Tuesday, 27 September 2006″
now.ToString(”G”); // “09/27/2006 14:15:39″
All of the format string syntax I discussed in “.NET Format String 101″ is invalid here. Also, if you call now.ToString(), it is basically calling now.ToString(”G”);
I have included my own table mapping Standard Format String to Custom Format string in part 2-c below. MSDN actually has a pretty good table that describe what each item does, and DateTime.ToString() has a pretty good code example that shows what each format string specifier do. Also if you just want samples, MSDN has a “Standard Date Time Format String Output example” here. Because documentation is so good. I won’t go into this too much. 
2-b. Custom Format String
Custom format string gives you the flexibility to build your own formatting. When using a single character format string specifier, you will need to prepend it with a “%”, otherwise it will be interpreted as a Standard Format String. Here are the basics for building your own string:
DateTime now = new DateTime(2006, 9, 07, 15, 06, 01, 08, DateTimeKind.Local);
now.ToString(); //”09/27/2006 15:06:01″
Year
now.ToString(”%y”); //”6″
now.ToString(”yy”); //”06″
now.ToString(”yyy”); //”2006″
now.ToString(”yyyy”); //”2006″
Month
now.ToString(”%M”); //”9″
now.ToString(”MM”); //”09″
now.ToString(”MMM”); //”Sep”
now.ToString(”MMMM”); //”September”
Day
now.ToString(”%d”); //”7″
now.ToString(”dd”); //”07″
now.ToString(”ddd”); //”Thu”
now.ToString(”dddd”); //”Thursday”
Hour
now.ToString(”%h”); //”3″
now.ToString(”hh”); //”03″
now.ToString(”hhh”); //”03″
now.ToString(”hhhh”); //”03″
now.ToString(”%H”); //”15″
now.ToString(”HH”); //”15″
now.ToString(”HHH”); //”15″
now.ToString(”HHHH”); //”15″
Minutes
now.ToString(”%m”); //”3″
now.ToString(”mm”); //”03″
now.ToString(”mmm”); //”03″
now.ToString(”mmmm”); //”03″
Seconds
now.ToString(”%s”); //”1″
now.ToString(”ss”); //”01″
now.ToString(”sss”); //”01″
now.ToString(”ssss”); //”01″
Milliseconds
now.ToString(”%f”); //”0″
now.ToString(”ff”); //”00″
now.ToString(”fff”); //”008″
now.ToString(”ffff”); //”0080″
now.ToString(”%F”); //”"
now.ToString(”FF”); //”"
now.ToString(”FFF”); //”008″
now.ToString(”FFFF”); //”008″
Kind
now.ToString(”%K”); //”-07:00″
now.ToString(”KK”); //”-07:00-07:00″
now.ToString(”KKK”); //”-07:00-07:00-07:00″
now.ToString(”KKKK”); //”-07:00-07:00-07:00-07:00″
// Note: The multiple K were just read as multiple instances of the
// single K
DateTime unspecified = new DateTime(now.Ticks, DateTimeKind.Unspecified);
unspecified.ToString(”%K”); //”"
DateTime utc = new DateTime(now.Ticks, DateTimeKind.Utc);
utc.ToString(”%K”); //”Z”
TimeZone
now.ToString(”%z”); //”-7″
now.ToString(”zz”); //”-07″
now.ToString(”zzz”); //”-07:00″
now.ToString(”zzzz”); //”-07:00″
Other
now.ToString(”%g”); //”A.D.”
now.ToString(”gg”); //”A.D.”
now.ToString(”ggg”); //”A.D.”
now.ToString(”gggg”); //”A.D.”
now.ToString(”%t”); //”P”
now.ToString(”tt”); //”PM”
now.ToString(”ttt”); //”PM”
now.ToString(”tttt”); //”PM”
2-c. Additional Resources
Now that you understand what Standard and Custom format strings are, here is a table of Standard Format String to Custom Format String mapping:
Year Month Day Patterns:
d = “MM/dd/yyyy”
D = “dddd, dd MMMM yyyy”
M or m = “MMMM dd”
Y or y = “yyyy MMMM”
Time Patterns:
t = “HH:mm”
T = “HH:mm:ss”
Year Month Day and Time without Time Zones:
f = “dddd, dd MMMM yyyy HH:mm”
F = “dddd, dd MMMM yyyy HH:mm:ss”
g = “MM/dd/yyyy HH:mm”
G = “MM/dd/yyyy HH:mm:ss”
Year Month Day and Time with Time Zones:
o = “yyyy’-'MM’-'dd’T'HH’:'mm’:’ss.fffffffK”
R or r = “ddd, dd MMM yyyy HH’:'mm’:’ss ‘GMT’”
s = “yyyy’-'MM’-'dd’T'HH’:'mm’:’ss”
u = “yyyy’-'MM’-'dd HH’:'mm’:’ss’Z'”
U = “dddd, dd MMMM yyyy HH:mm:ss”
All other single characters will throw an exception.
While looking into ASP.NET caching techniques, I ran across this little gem on IIS page compression using gzip.
IIS 6 has a built-in capability of compressing pages and / or content through gzip before sending it to the requesting client to cut down on bandwidth usage and overall network performance.
It’s also a smart process. First, there’s two types of compression that it will do. If it’s a static file (no dynamic content), it’ll zip up the file and store it in a temp space to send every time the page is requested. This way the CPU overhead is very minimal because it only has to compress the page once. The other is for dynamic pages. For these, it’ll compress the page as requested on the fly. This has a higher CPU usage, but worth it overall.
On top of that, it also checks the users browser for gzip compatibility before it even compresses the file. If it’s compatible (IE, Firefox, etc), it’ll send the compressed version. If the browser can’t handle compressed content, it’ll send the non-compressed version. Rock!
The downer is that it’s not very easy to setup (kinda). Meaning that there’s no checkbox anywhere to enable this and configure it. The guy over at AngryHacker.com (article above), wrote a great batch file that enables it and sets it up in one quick swoop. Make sure to save the BAT file in C:\Inetpub\AdminScripts
IISreset.exe /stop cscript adsutil.vbs set w3svc/filters/compression/parameters/HcDoDynamicCompression true cscript adsutil.vbs set w3svc/filters/compression/parameters/HcDoStaticCompression true cscript.exe adsutil.vbs set W3Svc/Filters/Compression/GZIP/HcFileExtensions "htm" "html" "txt" "ppt" "xls" "xml" "pdf" "xslt" "doc" "xsl" "htc" "js" "css" cscript.exe adsutil.vbs set W3Svc/Filters/Compression/DEFLATE/HcFileExtensions "htm" "html" "txt" "ppt" "xls" "xml" "pdf" "xslt" "doc" "xsl" "htc" "js" "css" cscript.exe adsutil.vbs set W3Svc/Filters/Compression/GZIP/HcScriptFileExtensions "asp" "dll" "exe" "aspx" "asmx" "ashx" cscript.exe adsutil.vbs set W3Svc/Filters/Compression/DEFLATE/HcScriptFileExtensions "asp" "dll" "exe" "aspx" "asmx" cscript.exe adsutil.vbs set W3Svc/Filters/Compression/GZIP/HcDynamicCompressionLevel "9" cscript.exe adsutil.vbs set W3Svc/Filters/Compression/DEFLATE/HcDynamicCompressionLevel "9" IISreset.exe /restart
If you’re not familiar with IIS, this script will stop your web server while it implements this and then start it back up once it’s done. Also, the default compression level is 0 (0-10), and this script sets it to 9. I have mine set at 9 and didn’t really notice much difference in CPU utilization.
Good stuff eh?
I was installing Visual Studio 2008, when all of a sudden I saw him. Wait, let me back up. You know how when you install an app, and you are shown all those lame screens of people smiling at work and a little blurb about how awesome the app is that your installing flip by. Well, whoever this guy is takes the cake. It’s just not natural…
What I learned today:
1. .net tracing is freaking awesome. Talk about being able to pinpoint your problems! Sheesh! I wish I had this a looooong time ago.
2. My db server needs more ram. I guess 512 isn’t enough 
All this time, I figured it was my code, or possibly something with the web server that was causing my site (BodyMod.org) to run so slow. Nope… DB server. I ran some trace events tight around all the DB calls, and low and behold, that’s where all the time was coming from. Up to 15+ seconds for a DB call!
So I head on over to my db server to check out whats up. I pull up my task manager and see cpu at 60-70% ( not great, but not bad ), and my ram usage at about 615 out of 1024. Not bad either. So wtf?
Oops… only 512 of that is physical. the other 100 is virtual. Crap.
So, I sent an IM to my server guy (it’s 5am, so I doubt he’s up) that I wanted to buy some more ram. I figure with prices the way they are, I’ll bump it up to 2gb =)
Better be the miracle fix I was looking for.
So to all you bmod members out there, hold tight, it’s about to get crazy fast! (probably not, but I dream big =)