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  • Storing varchar(max) & varbinary(max) together - Problem?

    - by Tony Basallo
    I have an app that will have entries of both varchar(max) and varbinary(max) data types. I was considering putting these both in a separate table, together, even if only one of the two will be used at any given time. The question is whether storing them together has any impact on performance. Considering that they are stored in the heap, I'm thinking that having them together will not be a problem. However, the varchar(max) column will be probably have the text in row table option set. I couldn't find any performance testing or profiling while "googling bing," probably too specific a question? The SQL Server 2008 table looks like this: Id ParentId Version VersionDate StringContent - varchar(max) BinaryContent - varbinary(max) The app will decide which of the two columns to select for when the data is queried. The string column will much used much more frequently than the binary column - will this have any impact on performance?

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  • Algorithm to match list of regular expressions

    - by DSII
    I have two algorithmic questions for a project I am working on. I have thought about these, and have some suspicions, but I would love to hear the community's input as well. Suppose I have a string, and a list of N regular expressions (actually they are wildcard patterns representing a subset of full regex functionality). I want to know whether the string matches at least one of the regular expressions in the list. Is there a data structure that can allow me to match the string against the list of regular expressions in sublinear (presumably logarithmic) time? This is an extension of the previous problem. Suppose I have the same situation: a string and a list of N regular expressions, only now each of the regular expressions is paired with an offset within the string at which the match must begin (or, if you prefer, each of the regular expressions must match a substring of the given string beginning at the given offset). To give an example, suppose I had the string: This is a test string and the regex patterns and offsets: (a) his.* at offset 0 (b) his.* at offset 1 The algorithm should return true. Although regex (a) does not match the string beginning at offset 0, regex (b) does match the substring beginning at offset 1 ("his is a test string"). Is there a data structure that can allow me to solve this problem in sublinear time? One possibly useful piece of information is that often, many of the offsets in the list of regular expressions are the same (i.e. often we are matching the substring at offset X many times). This may be useful to leverage the solution to problem #1 above. Thank you very much in advance for any suggestions you may have!

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  • Web user expectations

    - by Ash
    When designing a good Web GUI what expectations can we expect from an end user? I've come up with the following, but I wonder if there are any others which can suggest.. If I click on a hyperlink it will take me to another page/part of this page If I tick/untick a checkbox it might alter the page state (enable/disable elements) If I click on a button I expect it to do something to data. If I click on a button I expect something to happen immediately (either to the current page, or for me to be taken to another page) If I have clicked on a hyperlink and it has taken me to another page, I expect to be able to use the Back button to get back to the previous page in a state similar to that which I left it in If I change something in a form, I can change it back to its previous value if necessary Unless I click on the 'Submit' button nothing should happen to my data. If I bookmark/favourite a page then it should show the same related data each time I visit it If text is underlined and looks like a link, it should be a link and act as one The reasoning behind this question is more a 'UI from hell' one. For example I have come across pages which checking a tickbox next to a record will delete it, straight away, via ajax. To me that just seems wrong, a checkbox is a toggle - something which a delete operation definitely isn't!

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  • Adding functionality to any TextReader

    - by strager
    I have a Location class which represents a location somewhere in a stream. (The class isn't coupled to any specific stream.) The location information will be used to match tokens to location in the input in my parser, to allow for nicer error reporting to the user. I want to add location tracking to a TextReader instance. This way, while reading tokens, I can grab the location (which is updated by the TextReader as data is read) and give it to the token during the tokenization process. I am looking for a good approach on accomplishing this goal. I have come up with several designs. Manual location tracking Every time I need to read from the TextReader, I call AdvanceString on the Location object of the tokenizer with the data read. Advantages Very simple. No class bloat. No need to rewrite the TextReader methods. Disadvantages Couples location tracking logic to tokenization process. Easy to forget to track something (though unit testing helps with this). Bloats existing code. Plain TextReader wrapper Create a LocatedTextReaderWrapper class which surrounds each method call, tracking a Location property. Example: public class LocatedTextReaderWrapper : TextReader { private TextReader source; public Location Location { get; set; } public LocatedTextReaderWrapper(TextReader source) : this(source, new Location()) { } public LocatedTextReaderWrapper(TextReader source, Location location) { this.Location = location; this.source = source; } public override int Read(char[] buffer, int index, int count) { int ret = this.source.Read(buffer, index, count); if(ret >= 0) { this.location.AdvanceString(string.Concat(buffer.Skip(index).Take(count))); } return ret; } // etc. } Advantages Tokenization doesn't know about Location tracking. Disadvantages User needs to create and dispose a LocatedTextReaderWrapper instance, in addition to their TextReader instance. Doesn't allow different types of tracking or different location trackers to be added without layers of wrappers. Event-based TextReader wrapper Like LocatedTextReaderWrapper, but decouples it from the Location object raising an event whenever data is read. Advantages Can be reused for other types of tracking. Tokenization doesn't know about Location tracking or other tracking. Can have multiple, independent Location objects (or other methods of tracking) tracking at once. Disadvantages Requires boilerplate code to enable location tracking. User needs to create and dispose the wrapper instance, in addition to their TextReader instance. Aspect-orientated approach Use AOP to perform like the event-based wrapper approach. Advantages Can be reused for other types of tracking. Tokenization doesn't know about Location tracking or other tracking. No need to rewrite the TextReader methods. Disadvantages Requires external dependencies, which I want to avoid. I am looking for the best approach in my situation. I would like to: Not bloat the tokenizer methods with location tracking. Not require heavy initialization in user code. Not have any/much boilerplate/duplicated code. (Perhaps) not couple the TextReader with the Location class. Any insight into this problem and possible solutions or adjustments are welcome. Thanks! (For those who want a specific question: What is the best way to wrap the functionality of a TextReader?) I have implemented the "Plain TextReader wrapper" and "Event-based TextReader wrapper" approaches and am displeased with both, for reasons mentioned in their disadvantages.

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  • Which is the most memory leak safe approach.

    - by MattC
    I have a table of frequently updated information. This is presented using a container div with a div for each row, each row containing 10 divs. I am using setInterval to call a an asmx webservice that returns some json formatted information. On the success callback I call $("#myContainer").empty(); on the container div and recreate the rows and 10 nested divs for each row's columns. This page may be left to run for a whole day, so I am wary of updating the DOM like this as I have noticed that memory does rise for the browser over time (IE8). The other approach I am considering is to add an idea to the row div. When new results process each item of data, look for the corresponding row, if it exists overwrite the data in each div. If it doesn't exist (new data for example), append the row. What approaches have others used for this sort of long lived pseudo realtime information display. TIA

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  • To subclass or not to subclass

    - by poulenc
    I have three objects; Action, Issue and Risk. These all contain a nunber of common variables/attributes (for example: Description, title, Due date, Raised by etc.) and some specific fields (risk has probability). The question is: Should I create 3 separate classes Action, Risk and Issue each containing the repeat fields. Create a parent class "Abstract_Item" containing these fields and operations on them and then have Action, Risk and Issue subclass Abstract_Item. This would adhere to DRY principal.

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  • DDD and Client/Server apps

    - by Christophe Herreman
    I was wondering if any of you had successfully implemented DDD in a Client/Server app and would like to share some experiences. We are currently working on a smart client in Flex and a backend in Java. On the server we have a service layer exposed to the client that offers CRUD operations amongst some other service methods. I understand that in DDD these services should be repositories and services should be used to handle use cases that do not fit inside a repository. Right now, we mimic these services on the client behind an interface and inject implementations (Webservices, RMI, etc) via an IoC container. So some questions arise: should the server expose repositories to the client or do we need to have some sort of a facade (that is able to handle security for instance) should the client implement repositories (and DDD in general?) knowing that in the client, most of the logic is view related and real business logic lives on the server. All communication with the server happens asynchronously and we have a single threaded programming model on the client. how about mapping client to server objects and vice versa? We tried DTO's but reverted back to exposing the state of our objects and mapping directly to them. I know this is considered bad practice, but it saves us an incredible amount of time) In general I think a new generation of applications is coming with the growth of Flex, Silverlight, JavaFX and I'm curious how DDD fits into this.

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  • Best practices for managing limited client licenses/login

    - by MicSim
    I have a multi-user software solution (containing different applications, i.e. EXEs) that should allow only a limited number of concurrent users. It's designed to run in an intranet. I dont have a really good, satisfactory solution to the problem of counting the client licenses yet. The key requirements are: Multiple instances (starts) of the same application (= process) should count as only one client licence Starting different applications of the software solution should also count as only one (the same) client licence Application crash should not lead to orphaned used licences The above should work also for Terminal Server environments (all clients same IP, but different install folders) I'm looking for estabilished patterns, solutions, tips for managing used client licenses. Specific hints for the above sitaution are also welcome.

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  • C# Setting Properties using Index

    - by Guazz
    I have a business class that contains many properties for various stock-exchange price types. This is a sample of the class: public class Prices { public decimal Today {get; set} public decimal OneDay {get; set} public decimal SixDay {get; set} public decimal TenDay {get; set} public decimal TwelveDay {get; set} public decimal OneDayAdjusted {get; set;} public decimal SixDayAdjusted {get; set;} public decimal TenDayAdjusted {get; set;} public decimal OneHundredDayAdjusted {get; set;} } I have a legacy system that supplies the prices using string ids to identify the price type. E.g. Today = "0D" OneDay = "1D" SixDay = "6D" //..., etc. Firstly, I load all the values to an IDictionary() collection so we have: [KEY] VALUE [0D] = 1.23456 [1D] = 1.23456 [6D] = 1.23456 ...., etc. Secondly, I set the properties of the Prices class using a method that takes the above collection as a parameter like so: SetPricesValues(IDictionary<string, decimal> pricesDictionary) { // TODAY'S PRICE string TODAY = "D0"; if (true == pricesDictionary.ContainsKey(TODAY)) { this.Today = pricesDictionary[TODAY]; } // OneDay PRICE string ONE_DAY = "D1"; if (true == pricesDictionary.ContainsKey(ONE_DAY)) { this.OneDay = pricesDictionary[ONE_DAY]; } //..., ..., etc., for each other property } Is there a more elegant technique to set a large amount of properties? Thanks, j

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  • Sub-Schemas in SQL Server 2005/2008

    - by Maushu
    This is a simple question yet I was unable to find any information at all about this. Is it possible to have sub-schemas in SQL Server 2005/2008? Example: Having a HR (Human Resources) schema with a sub-schema called Training (with tables related to this). It would end up like HR.Training.* where * would be the tables.

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  • Collaboration Diagrams: how to represent setting a variable's and attribute's value to a specified v

    - by devoured elysium
    Let's assume I have a class called MyClass with an attribute called MyAttribute and a method called MyMethod(). Inside that method I'd like to have a variable called MyVariable. I'd like to set the value of MyVariable to "MyVariable" and MyAttribute to "MyAttribute" inside the call to MyMethod(). How can I do this in a Collaboration Diagram? I can't find any info of this kind on the internet and the book I'm studying from (Applying UML and Patterns) is very vague in the details. Thanks

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  • Objective-C partial implementation of classes in separate files

    - by Aran Mulholland
    I am using core data and am generating classes from my data model. I implement custom methods in these classes, however when i regenerate i generate over the top so i end up copying and pasting a bit. What i would like to do is split my implementation files ('.m') so i can have one header file with multiple '.m' files. then i can keep my custom methods in one and not have to worry about erasing them when i regenerate. I use this technique in .NET a lot with its partial keyword. Is there anything similar in objective-C

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  • Java: initialization problem with private-final-int-value and empty constructor

    - by HH
    $ javac InitInt.java InitInt.java:7: variable right might not have been initialized InitInt(){} ^ 1 error $ cat InitInt.java import java.util.*; import java.io.*; public class InitInt { private final int right; InitInt(){} public static void main(String[] args) { // I don't want to assign any value. // just initialize it, how? InitInt test = new InitInt(); System.out.println(test.getRight()); // later assiging a value } public int getRight(){return right;} } Initialization problem with Constructor InitInt{ // Still the error, "may not be initialized" // How to initialise it? if(snippetBuilder.length()>(charwisePos+25)){ right=charwisePos+25; }else{ right=snippetBuilder.length()-1; } }

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  • Best way to represent Gender in a class library used in multilingual applications

    - by Hauge
    I'm creating class library with some commonly used classes like persons, addresses etc. This library will be used in an multilingual application, and I am looking for the most convenient way to represent a persons gender. Ideally I would like to be able to code like this: Person person = new Person { Gender = Genders.Male, FirstName = "Nice", LastName = "Dude" } if (person.Gender == Genders.Male) Console.WriteLine("person is Male"); Console.WriteLine(person.Gender); //Should output: Male Console.WriteLine(person.Gender.ToString("da-DK")); //Should output the name of the gender in the language provided List<Gender> genders = Genders.GetAll(); foreach(Gender gender in genders) { Console.WriteLine(gender.ToString()); Console.WriteLine(gender.ToString("da-DK")); } What would you do? An enumeration and a specialized Gender class, but what about the localization then? Regards Jesper Hauge

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  • Accessing the Private Constructor

    - by harigm
    I am java developer, went for an interview. I have been asked a question about the Private constructor 1) Can I access a Private Constructor of a Class and Instantiate the class. I was thinking and gave the answer directly--- "NO" But its wrong, can any one help Why NO? and How we can achieve this

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  • Making a DateTime field in SQLExpress database?

    - by Mike
    I'm putting together a simple test database to learn MVC with. I want to add a DateTime field to show when the record was CREATED. ID = int Name = Char DateCreated = (dateTime, DateTime2..?) I have a feeling that this type of DateTime capture can be done automatically - but that's all I have, a feeling. Can it be done? And if so how? While we're on the subject: if I wanted to include another field that captured the DateTime of when the record was LAST UPDATED how would I do that. I'm hoping to not do this manually. Many thanks Mike

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  • DRY programming dilemma

    - by fayer
    the situation is like this: im creating a Logger class that can write to a file but the write_to_file() function is in a helper class as a static function. i could call that function but then the Log class would be dependent to the helper class. isn't dependency bad? but if i can let it use a helper function then what is the point of having helper functions? what should one prioritize here: using helper functions and have to include this helper class everywhere (but the other 99 methods wont be useful) or just copy and paste into the Log class (but then if i have done this 100 times and then make a change i have to change in 100 places). share your thoughts and experience!

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  • ASP-style tags for Perl web development?

    - by Alex R
    I feel like I'm traveling 10 years back in time by asking this, but... Are there any modules, patches, or any "new" version of Perl (released in the last 10 years) to enable writing web-oriented Perl scripts using ASP-style tags? e.g. from ASP/JSP some html <% some code %> more HTML e.g. from PHP some html <? some code ?> more HTML Please don't worry about "why" I'm asking this... It's related to programming language research.

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  • What are some funny error pages websites have?

    - by Dean
    This question is along the same lines as What are some funny loading statements to keep my users amused, I want screenshots of all the coolest "error" pages site's throw up when something's broken. I know pandora.com talks about a panda ravaging it's way through the office, twitter's has the little birds floating around or something, sourceforge had one with some funny robots the other day. I'm sure I saw a blog once that had a bunch of them, but it's kinda hard to google "error pages". Community Wiki, of course :)

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  • looking for automated modeling tool for ASP.Net class diagramming

    - by alchemical
    I'm walking into a project with 500+ classes, and am wondering if anyone has had good experiences with automated modeling tools that can import from ASP.Net /C#? It would be a bonus if I could get an automated model based on all the objects called to completely load a single ASP.Net page, with relationships indicating which objects are calling out to which other ones, etc. Thanks for sharing your thoughts or recomendations.

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  • Python - help on custom wx.Python (pyDev) class

    - by Wallter
    I have been hitting a dead end with this program. I am trying to build a class that will let me control the BIP's of a button when it is in use. so far this is what i have (see following.) It keeps running this weird error TypeError: 'module' object is not callable - I, coming from C++ and C# (for some reason the #include... is so much easier) , have no idea what that means, Google is of no help so... I know I need some real help with sintax and such - anything woudl be helpful. Note: The base code found here was used to create a skeleton for this 'custom button class' Custom Button import wx from wxPython.wx import * class Custom_Button(wx.PyControl): # The BMP's # AM I DOING THIS RIGHT? - I am trying to get empty 'global' # variables within the class Mouse_over_bmp = None #wxEmptyBitmap(1,1,1) # When the mouse is over Norm_bmp = None #wxEmptyBitmap(1,1,1) # The normal BMP Push_bmp = None #wxEmptyBitmap(1,1,1) # The down BMP Pos_bmp = wx.Point(0,0) # The posisition of the button def __init__(self, parent, NORM_BMP, PUSH_BMP, MOUSE_OVER_BMP, pos, size, text="", id=-1, **kwargs): wx.PyControl.__init__(self,parent, id, **kwargs) # The conversions, hereafter, were to solve another but. I don't know if it is # necessary to do this since the source being given to the class (in this case) # is a BMP - is there a better way to prevent an error that i have not # stumbled accost? # Set the BMP's to the ones given in the constructor self.Mouse_over_bmp = wx.Bitmap(wx.Image(MOUSE_OVER_BMP, wx.BITMAP_TYPE_ANY).ConvertToBitmap()) self.Norm_bmp = wx.Bitmap(wx.Image(NORM_BMP, wx.BITMAP_TYPE_ANY).ConvertToBitmap()) self.Push_bmp = wx.Bitmap(wx.Image(PUSH_BMP, wx.BITMAP_TYPE_ANY).ConvertToBitmap()) self.Pos_bmp = self.pos self.Bind(wx.EVT_LEFT_DOWN, self._onMouseDown) self.Bind(wx.EVT_LEFT_UP, self._onMouseUp) self.Bind(wx.EVT_LEAVE_WINDOW, self._onMouseLeave) self.Bind(wx.EVT_ENTER_WINDOW, self._onMouseEnter) self.Bind(wx.EVT_ERASE_BACKGROUND,self._onEraseBackground) self.Bind(wx.EVT_PAINT,self._onPaint) self._mouseIn = self._mouseDown = False def _onMouseEnter(self, event): self._mouseIn = True def _onMouseLeave(self, event): self._mouseIn = False def _onMouseDown(self, event): self._mouseDown = True def _onMouseUp(self, event): self._mouseDown = False self.sendButtonEvent() def sendButtonEvent(self): event = wx.CommandEvent(wx.wxEVT_COMMAND_BUTTON_CLICKED, self.GetId()) event.SetInt(0) event.SetEventObject(self) self.GetEventHandler().ProcessEvent(event) def _onEraseBackground(self,event): # reduce flicker pass def _onPaint(self, event): dc = wx.BufferedPaintDC(self) dc.SetFont(self.GetFont()) dc.SetBackground(wx.Brush(self.GetBackgroundColour())) dc.Clear() dc.DrawBitmap(self.Norm_bmp) # draw whatever you want to draw # draw glossy bitmaps e.g. dc.DrawBitmap if self._mouseIn: # If the Mouse is over the button dc.DrawBitmap(self, self.Mouse_over_bmp, self.Pos_bmp, useMask=False) if self._mouseDown: # If the Mouse clicks the button dc.DrawBitmap(self, self.Push_bmp, self.Pos_bmp, useMask=False) Main.py import wx import Custom_Button from wxPython.wx import * ID_ABOUT = 101 ID_EXIT = 102 class MyFrame(wx.Frame): def __init__(self, parent, ID, title): wxFrame.__init__(self, parent, ID, title, wxDefaultPosition, wxSize(400, 400)) self.CreateStatusBar() self.SetStatusText("Program testing custom button overlays") menu = wxMenu() menu.Append(ID_ABOUT, "&About", "More information about this program") menu.AppendSeparator() menu.Append(ID_EXIT, "E&xit", "Terminate the program") menuBar = wxMenuBar() menuBar.Append(menu, "&File"); self.SetMenuBar(menuBar) self.Button1 = Custom_Button(self, parent, -1, "D:/Documents/Python/Normal.bmp", "D:/Documents/Python/Clicked.bmp", "D:/Documents/Python/Over.bmp", wx.Point(200,200), wx.Size(300,100)) EVT_MENU(self, ID_ABOUT, self.OnAbout) EVT_MENU(self, ID_EXIT, self.TimeToQuit) def OnAbout(self, event): dlg = wxMessageDialog(self, "Testing the functions of custom " "buttons using pyDev and wxPython", "About", wxOK | wxICON_INFORMATION) dlg.ShowModal() dlg.Destroy() def TimeToQuit(self, event): self.Close(true) class MyApp(wx.App): def OnInit(self): frame = MyFrame(NULL, -1, "wxPython | Buttons") frame.Show(true) self.SetTopWindow(frame) return true app = MyApp(0) app.MainLoop() Errors (and traceback) /home/wallter/python/Custom Button overlay/src/Custom_Button.py:8: DeprecationWarning: The wxPython compatibility package is no longer automatically generated or actively maintained. Please switch to the wx package as soon as possible. I have never been able to get this to go away whenever using wxPython any help? from wxPython.wx import * Traceback (most recent call last): File "/home/wallter/python/Custom Button overlay/src/Main.py", line 57, in <module> app = MyApp(0) File "/usr/lib/python2.6/dist-packages/wx-2.8-gtk2-unicode/wx/_core.py", line 7978, in __init__ self._BootstrapApp() File "/usr/lib/python2.6/dist-packages/wx-2.8-gtk2-unicode/wx/_core.py", line 7552, in _BootstrapApp return _core_.PyApp__BootstrapApp(*args, **kwargs) File "/home/wallter/python/Custom Button overlay/src/Main.py", line 52, in OnInit frame = MyFrame(NULL, -1, "wxPython | Buttons") File "/home/wallter/python/Custom Button overlay/src/Main.py", line 32, in __init__ wx.Point(200,200), wx.Size(300,100)) TypeError: 'module' object is not callable I have tried removing the "wx.Point(200,200), wx.Size(300,100))" just to have the error move up to the line above. Have I declared it right? help?

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  • How do I load SciLexer.dll in Visual Studio 2008 Designer, on Windows 7 64-bit?

    - by Filini
    We develop a WinForm application using Scintilla.NET (1.7) component, which uses SciLexer.dll (unamnaged). At run-time, we distribute both 32bit and 64bit SciLexer.dll, and we load the correct one when the application starts (everything works fine). On our new development environments (Windows 7 64-bit), all our solutions build and run just fine, but the WinForm visual designer does not load our forms/controls which use Scintilla.NET, because it cannot load the correct SciLexer.dll: Window class name is not valid. at System.Windows.Forms.NativeWindow.WindowClass.RegisterClass() at System.Windows.Forms.NativeWindow.WindowClass.Create(String className, Int32 classStyle) at System.Windows.Forms.NativeWindow.CreateHandle(CreateParams cp) at System.Windows.Forms.Control.CreateHandle() at System.Windows.Forms.Control.get_Handle() at Scintilla.ScintillaControl.SendMessageDirect(UInt32 msg, IntPtr wParam, IntPtr lParam) at Scintilla.ScintillaControl.SendMessageDirect(UInt32 msg) at Scintilla.ScintillaControl.get_CodePage() at Scintilla.ScintillaControl..ctor(String sciLexerDllName) at Scintilla.ScintillaControl..ctor() Where does Visual Studio 2008 look for unmanaged libraries? I tried putting the 64-bit SciLexer.dll in SysWOW64, in the folder where ScintillaNET.dll is referenced, adding a folder in PATH system variable, adding a folder reference in the project, but I keep getting this error. Any help is appreciated.

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