We Keep Coding

Why are some unintended symbols added to my string?

I wrote a console application which fetches strings from some fields in a Sharepoint list. Then I simply write the strings to console. This works fine for the most fields. There is one MultiLineTextField with RichText enabled where i had to remove all the html-tags, that causes this issue.
Even after all the tags are removed the strings seem to contain question marks which were never added to the string. The most weird thing about this is when I set a breakpoint and look into the string's value there are no question marks, but they suddenly appear on the console output.
The only thing I could think of was to Trim the string. Because sometimes they appear in front of the actual string sometimes they are at the and of it, but never in between.
So this is what I tried:
myString = myString.Trim();
myString = myString.Replace("?",string.Empty);
But this does not solve the issue. Besides this would not be a smart solution in case one of the strings would be supposed to contain question marks. For detailed code please see the link above.
Also Convert.ToBase64String(Encoding.UTF8.GetBytes(myString)) gives me the following output:
4oCLTWVobCwgRWllciwgV2Fzc2VyLCBIYWNrZmxlaXNjaCA=

There are probably some non-printing unicode (or possibly low ASCII) characters in the end of the string. The console has a different encoding, and will often render such as ?. Basically: use the indexer (yourString[n]) or yourString.ToCharArray() to investigate what is actually in the string aroung the location of the ?.
With the edit, we can see that the string has a zero-width space (decimal 8203) at the start:

Sounds like you're maybe having a problem with unicode characters. Chances are you're outputting the string as ASCII instead of Unicode. Take a look at this question as it sounds like you may be experiencing the same problem.

DevExpress EditMask

I'm using a Dev Express RepositoryItemTextEdit, and I'm looking to set the Edit Mask to help ensure the users input is in the correct format.
The desired behavior is to get the user enter on or more 6-digit numbers either comma separated or using a hyphen to specify a range.
eg:
000002, 000005-000025, 000029-00200, 999999
I'm sure I should be able to do this using the MaskType of RegEx, I'm having difficulty coming up with the correct RegEx.
Do any RegEx Experts know how to put that one together?

Your goal is easy to achieve if you have access to a full POSIX regex engine (for instance if you're using Perl or Python):
'\d{6}((,\s|-)\d{6})*$'
Accordingly to this Support Center thread end of string anchors are not supported by DevExpress editors but they are not required so you could try just:
'\d{6}((,\s|-)\d{6})*'
and see if it works for you (I can't test it myself as I don't use DevExpress editors).

Optimistic RegEx Matching for User Text Entry

I'm working on a text entry application that uses regular expressions to validate user input. The goal is to allow keypresses that fit a certain RegEx while rejecting invalid characters. One issue I've run into is that when a user starts inputting information they may create a string that doesn't yet match the given regex, but could cause a match in the future. These strings get erroneously rejected. Here's an example - given the following regex for inputting date information:
(0?[1-9]|10|11|12)/(0?[1-9]|[12]\\d|30|31)/\\d{2}\\d{2}
A user may begin entering "1/" which could be a valid date, but RegEx.IsMatch() will return false and my code ends up rejecting the string. Is there a way to "optimistically" test strings against a regular expression so that possible or partial matches are allowed?
Bonus: For this RegEx in particular there are some sequences which cause required characters. For example, if the user types "2/15" the only possible valid character they could enter next is "/". Is it possible to detect those scenarios so that the required characters could be automatically entered for the user to ease input?

What you can do is anchor your RegExp (i.e. adding ^ and $, as in start/end of line) and make some component optionnal for validation, but strictly defined if present.
Something looking like this:
^(0?[1-9]|10|11|12)(/((0?[1-9]|[12]\\d|30|31)(/(\\d{2}(\\d{2})?)?)?)?)?$
I do realize it looks horrible but as far as I know there is no way to tell the regexp engine to validate as long as the string satisfies the beginning of the regexp pattern.
In my opinion, the best way to achieve what you want to do is to create separate inputs for day/month/date and check their value when leaving the text field.
It also provides a better visibility and user-experience, as I believe no one likes to be prevented from typing certain characters into a text field with or without noticing them disappear as they type or having slashes inserted automatically and without notice.

Have you ever used and app or form that worked that way, simply refusing to accept any keypress it didn't like? If the answer is Yes, did it blow an electronic raspberry each time you pressed a wrong key?
If you really need to validate the input before the form is submitted, use a passive feedback mechanism like a red border around the textfield that disappears the regex matches the input. Also, make sure there's a Help button or a tooltip nearby to provide constructive feedback.
Of course, the best option would be to use a dedicated control like a date-entry widget. But whatever you do, don't do it in such a a way that it feels like you're playing guessing games with the user.

Use of MaskedTextBox with text

I'm facing a simple problem that bugs me...
I have a MaskedTextBox and I want the user to be able to enter 3 numbers at the end :
"My Masked Text Box : XXX"
This text will be translated. The problem is, this control uses Microsoft's recipe to validate the input and in this example, the final display will look like this :
"My M_sked Text Box : _"
The letter 'a' is considered like a control caracter instead of a simple text caracter. I can backslash it but when the text is translated I have to do it again and I think it's ridiculous to have to do something like that...
I hope I'm being clear...
Thanks in advance for your help !

The 'a' needs to be quoted as a literal. The Mask should be something like:
My M\asked Text Box : 000
You should use '9' rather than '0' as the placeholder for an optional numerical character.
Of course any other of the characters that match mask options should be 'literal' too.
http://msdn.microsoft.com/en-us/library/system.windows.forms.maskedtextbox.mask.aspx
After reading the comments I'd like to add another suggestion (you clearly understood about literals -- the problem is your translation.)
Would it be feasible to run the translated text strings through a filter that put literal-quotes in where possible? It's not that nice a solution, because if Microsoft added new control characters it'll break your filter, but I think it would work.

formatting strings with backslash

I'm a newbie to c# so hopefully this one isn't too hard for a few of you.
I'm trying to build a string that has a \ in it and I am having difficulty getting just one backslash to show up even though I am adding additional escape chars or ignoring them all together. Can someone show me what I am doing wrong?
What I want my string to look like:
"10.20.14.103\sql08"
What I've tried so far:
I added an additional character to make the compiler happy but it did not escape it.
ip = string.Format("{0}\\\\{1}", ip, instancename); // output has 2 \'s
I told it to ignore escapes, it decided to ignore me instead
string temp = #"192.168.1.200\sql08"; // output has 2 \'s
Can someone help me make sense of this? (The richtext editor here seems to do a better job with it than VS2010 is doing, lol)

I'm guessing you're getting confused by the debugger.
If you hover your mouse over a local variable in VS, strings will be escaped so a single \ will display as \\.
To see what your string really is, output it somewhere for display (e.g., to the console) or hover your mouse on the variable, click on the arrow next to the little magnifying glass that appears, and select "Text Visualizer."

If you're looking at these strings in the debugger (i.e., by hovering the mouse over the variable or using a watch), the debugger adds escape characters to the display string so that it's a valid string expression. If you want to view the string verbatim in this fashion, click on the magnifying glass on the right side of the tooltip or watch entry with the string in it.

I'm guessing you're looking at the values in the debugger and seeing that they have two slashes.
That's normal. The debugger will show two slashes even though the actual string representation will only have one. Just another hump to get over when getting used to the debugger.
Be assured that when you actually use your strings, they will still only have a single slash (using either of your methods).

string requiredString = string.Format(#"{0}\\{1}",str1,str2);