Ravi Subramanian's Q&A profile

• Visual Basic What is Boxing

  I am a newbie learning VB 2005. can anyone explain it to me with an example what is boxing The only thing I foudn in the book is boxing refers to treating value type (int) as reference type. Why do we ever need to refer a value type to a reference type.   Boxing and unboxing is a  essential concept in VB’s type system. With Boxing and unboxing one can link between value-types and reference-types by allowing any value of a value-type to be converted to and from type object. Boxing and unboxing enables a unified view of the type system wherein a value of any type can ultimately be treated as ...Show All

• Visual C# Avoid duplicate data

  Hi, I want to insert data in a database. How is it possible to avoid inserting duplicate data If I want to insert a row which also is in my database, I get an Exception and my program stops running. How can I tell my programm to go on without stoppng even if there was an Exception Or has anybody a better and faster solution ! Thank you! Your best bet for ignoring those exceptions and continueing is to create a function that wraps your insert in a try...catch block.  You'll need to catch the specific duplicate key exception that is thrown, and just ignore the exception.  The function would be called ...Show All

• Visual C++ Works in 2003 but not in 2005

  I am trying to get some code to work in 2005 that is working in 2003 and VC6 and I am getting the following errors when I use templates. 1st error: error C2664: 'std::_Vector_iterator<_Ty,_Alloc> std::vector<_Ty>::erase(std::_Vector_iterator<_Ty,_Alloc>)' : cannot convert parameter 1 from 'std::basic_string<_Elem,_Traits,_Ax> *' to 'std::_Vector_iterator<_Ty,_Alloc>' with [ _Ty=std::wstring, _Alloc=std::allocator<std::wstring> ] and [ _Elem=wchar_t, _Traits=std::char_traits<wchar_t>, _Ax=std::allocator<wchar_t> ] and [ _Ty=std::wstring, _Alloc=std::allocator<std::wstri ...Show All

• Windows Forms How to mark UserControl to do that behavior in InitializeComponent

  I have a question of user control. I want to create a user control as same as some build control behavior in InitializeComponent. For example. The following property of TextBox control only in InitializeComponent mehtod will be initialize. this.textBox1.Location = new System.Drawing.Point(456, 44); this.textBox1.Name = "textBox1"; this.textBox1.Size = new System.Drawing.Size(100, 20); this.textBox1.TabIndex = 31; But font property never initial in this method........ I want to know how to do it as same as Font property ...Show All

• Visual Studio Team System Team Explorer - red cross on "documents"-folder

  Since installation of TFS I am unable to see the content of the documents-folder (teamexplorer) on a client-machine. There is always a red cross on the folder! If I start the team explorer on the server the documents folder is shown correctly. I tried to copy the http-url ( http://[servername]/sites/[Project ]) to an IE on a client and there the sharepoint site is shown without any problems. I did the changes required after installation of Sharepoint Portal Services SP2 ( http://blogs.msdn.com/robcaron/archive/2005/10/07/478336.aspx ). I think I also configured the users like mentioned in the install guide (TFSInstall-v50926.chm - Manag ...Show All

• Visual C++ pow(2,31)

  In Microsoft visual studio .net 2003 C++ it seems that pow(2,31) returns a negative number and pow(2.0,31.0) returns a positive number Is there a service pack that corrects this problem Thanks, Tom I’d wager good money that you are capturing the return value of pow(2,31) in an int... the return value of which is a 1 followed by 31 zero’s and that a signed int as being negative... which is what you are seeing. To avoid this problem, capture the value into an unsigned int, not an int ala:       unsigned int x = pow(2,31); The reason you are not seeing ...Show All

• Windows Forms Multi-threading problem with Windows Forms (possibly SerialPort too)

  I've been having a problem when updating a windows form from a different thread. Data is received on using a SerialPort class which fires the DataReceived event (on a different thread). This thread then calls a method on a form which updates a text box. The code used in the method is just like the sample from the MSDN below, which reroutes the call so that the textbox update is done from the same thread. private void SetText(string text) { // InvokeRequired required compares the thread ID of the // calling thread to the thread ID of the creating thread. // If these threads are different, it returns true. if (this.textBox1.In ...Show All

• Visual Studio Express Editions Cannot create a new project that opens startup form

  Have been using vb 2005 express final now for a week or too.  Have had no problems using and modifying example code and connecting to a MySQL database.  However i am now trying to create a new project and no matter what form is selected under startup form nothing displays when code f5 is pressed.  Message that build is ok in status bar screen refreshes and back to IDE.  However existing projects work ok.  Even creating a simple one form app leaving default form name as form1 the form will not display.  Any ideas please!    step by step 1 new project windows app 2 add button to form 3 add ...Show All

• Visual Basic IDE

  When I am in break mode, I cannot update code. I receive message "Cannot currently modify this text in the editor. It is read only." Can anyone explain why I get this message All the Best, Charlie In VisualStudio 2005, Edit & Continue is back, so in many cases you are able to edit the source code. Things that may cause this to happen include: - You attached to the process (didn't start it from within Visual Studio) - You have disabled Edit & Continue (Tools->Options->Debugging->Edit and Continue) Are you debugging a Web project Best regards, Johan Stenberg ...Show All

• Visual Studio Multiple checkouts dont work for me

  i allowed multiple checkouts (SS 8) via sourcesafe administrator. Me and my teammates restarted visual studio (2005), but it seems we cant checkout one file for more than one person. I think it is because of database has been created with default 'Lock-Modify-Unlock' Model which doesnt support multiple checkouts. Hence the question, can i change existing model "Lock Modify Unlock" is basically equivalent to disabling SSadmin/Tools/Options/General "Allow multiple checkouts" and enabling "Only allow checkouts of latest version". "Copy Modify merge" is set to "Allow multiple che ...Show All

• Visual Basic html editor in visual basic

  Hello everyone, I would like to know how to build an HTML editor with (drag and drop) in Visual Basic. I'm just looking for drag and drop into html editor and autoamtic write code themself. Does anyone know how to build that in Visual basic or is there is any sample website where i can learn more about the drag and drop html editor! Alidad   There is a pretty interesting control for this on your system. if you go to tools Menu and select Choose Toolbox items and select the Com Components and check - DHTMLEDIT Control for IE5 it will add this control to your tool box. Make a form ...Show All

• Visual C++ How to decide the errors

  hoh to decide the error C2039 a exist... i have 2 forms, form1 and form2. in form1 i have a button, and when i click in this button, will open form2. whats the code to do this ...Show All

• .NET Development Using IXmlLineInfo without XmlReader

  I have a recursive method that cycles through an XmlDocument.  The document is built using an XmlReader, but at the time I'm spinning through the document, I am not using the reader (it's used just for loading).  When I display line information (number and position) from any validation exceptions that occur, they all have the last line and position of the file (because I set LineInfoProvider property after the reader loaded the doc). So, is there a way to get line number and position without using an XmlReader to cycle through my document   Specifically, is there a way to keep the line information updated while processing a ...Show All

• Windows Forms .Net 2 Progressbar not working in Win2000?

  Hi all, Hope you can help me. I've ported a Windows Forms app to .Net2 and VS2005. In one form, I am using the progressbar control in Marquee style with animation speed set to 200. In this form, I'm running a backgroundworker. As soon as the backgroundworker completes, the form closes itself. Everything works just fine on Windows XP. On Windows 2000, the actual processing does work, but the progressbar is not animating! It's just empty. Quotes from MSDN: "Windows XP Home Edition, Windows XP Professional x64 Edition, Windows Server 2003 Platform Note: The Marqu ...Show All

• Game Technologies: DirectX, XNA, XACT, etc. Vector3.Project() doesn't work.

  I guess I posted this in the wrong forum the first time... I'm trying to project the location of a mesh in world space back to screen coords. I've been searching around with no real luck. I've seen people say that you should use Matrix.Identity instead of your world matrix, but that makes no difference for me at the moment. It's not that the code causes an error, it doesn't. It's just that after projecting pos, it remains almost identical to what it was, off by about 0.5. Considering my values are typically in the hundreds, this is a minor rounding error. I get the exact same results using Unproject(). I would have expected that proje ...Show All