Xin Guo's Q&A profile

• .NET Development SqlConnection and thread safety

  I believe I know the answer to this, but I would like confirmation. I have been experiencing NullReferenceExceptions being thrown from a call to ExecuteScalar(). The occurence is intermittent, but only happens when two separate threads try to use the same pooled SqlConnection on synchronous schedule (i.e. every 5 seconds). I surmise that the cause of the NullReferenceException is a conflict between the two threads trying to simultaneously access the same SqlConnection object. I deduce from this that all calls to a pooled SqlConnection must be sychronized. This is not obvious from the ADO.NET documentation. ExecuteScalar() has no ref ...Show All

• Visual Studio 2008 (Pre-release) DataContext.GetQueryParameters?

  I have the ability to obtain the underlying sql select statement for a given expression. However, it has parameters instead of hardcoded values. I would need the possibility to get the underlying parameters as well in order to be able to execute the sql statement directly. Northwind db = new Northwind(...); Expression<Func<Customer, bool >> filter = customer => customer.City == "London"; Query<Customer> filteredCustomers = db.Customers.Where<Customer>(filter); string sqlSelect = db.GetQueryText(filteredCustomers); /*sqlSelect will have the form: "Select ... from Customers where City = @p0"*/ /* TODO Implement ...Show All

• Visual C# c# printing scale

  Hello, I have to print a label, and I have to ensure that the size is always the same, independently of the printer that has been used. Is there a scale factor between the grafic displayed in a form and the same printed grafic My label dimmensions are given in mm. What is the factor between the grafic scale and mm Many thanks in advance Redjo ...Show All

• Smart Device Development printing for pocket pc

  did dot net compact framework provide us any free wrapper code for printing in pocket PC currently i am developing smart device application for pocket PC using VB.NET from VS.NET 2003   Printing is not a native, supported feature of the Pocket PC platform. As the other answer points out, there are some third party products that do offer this support from Windows Mobile devices.   ...Show All

• Windows Forms fighting with framework 1.1 install

  I have visual studio (with 1.0 framework) installed. How do you add 1.1 with SDK NOTE: I removed framework 1.0, installed framework 1.1 update, then installed 1.1 samples and SDK--then, my compiler did not work!!!  Therefore, I had to do a complete re-install. The simple answer may be..."Don't uninstall 1.0 ... just install 1.1 and keep going." Could some one&n ...Show All

• Visual Studio Team System Organizing Projects

  We are getting started on Team System and would like some guidance on organizing projects. We are going to have a web based product and a smart client product with components that are going to be shared among them. If we are going to do project references among the two solutions we will have to go with one Team Project as source code cannot be shared among team projects according to this: http://msdn2.microsoft.com/en-us/library/ms242910(en-US,VS.80).aspx. Am I right in understanding this Having one team project for two different products might make it difficult to manage. Is our choice to go with dll references for the common stuff and then ...Show All

• Visual Studio Express Editions Were do i create a menu?

  Were do i create a menu |: tnx In the design view, you drag over a menu from the list of components in the toolbox. Then you just click on menu items and type to add them, and set their properties as you would any other item on a form. ...Show All

• Visual Studio Express Editions Getting files with specific extensions using FolderBrowserDialog

  Hi everyone. I'm making a media player using the BASS API Library and Direct-X. My problem is, I'm using the FolderBrowserDialog component and I know it can't filter files but I need only files with specific extensions to be added to the Listbox I have on the form. So far the code looks like this: Public Sub foldertoplaylist() Dim plug As Integer = 2 Dim playlistid3 As String Dim chosen As String Dim filInfo As IO.FileInfo AddFolder.Description = "Choose the folder you would like to add to Tray-Play" If addfolder.ShowDialog = Windows.Forms.DialogResult.Cancel Then ...Show All

• Windows Forms what control should i use?

  hi I need to create a simple list of items and i need to be able to group these items.. i need something that looks exactly like visual studio's Properties window (categorized) > a list of items that are divided into groups and those groups can either collapse or expand another example would be the Toolbox window, thats exactly what i would need to do and yet another example > icq instant messanger contactlist where you can group contacts.. Can you please help me with what component should I use I am sorry for this little newbie question but I've spent a whole afternoon on it and I havent found it. :-) thx in advance ...Show All

• Windows Live Developer Forums MSN Messenger - "The following message could not be delivered to all recipients"

  Hello, I've had masive problems with people trying to contact me getting the "The following message could not be delivered to all recipients" error messages. I am signed in, talking to other people but when some people talk to me they get that. What's worse, other times when people talk to me they don't get an error message and I never receive their messages. I have UPnP enabled through the router and the protocol installed on local computers. All firewalls are disabled and port forwarding enabled. Just the same, I never had to do any of this stuff and I could always use MSN fine. I have installed Windows XP Pro SP2 with t ...Show All

• Windows Forms Nox invasion

  Hi, I was just wondering what type of animal, and why the Nox 3.6 has totally invaded my ecosystem. Thanks  Well I am not sure about this, what I would really like to see is an advanced terrarium and a beginner terrarium. but you know that is only a wish and I know it would take an act of some higher ups to aprove  ...Show All

• Visual Studio 2008 (Pre-release) May CTP for Linq

  Yeah!!!! There appears to now be a May 2006 CTP for linq. Yes, it can be downloaded here: http://www.microsoft.com/downloads/details.aspx familyid=1e902c21-340c-4d13-9f04-70eb5e3dceea&displaylang=en Bye. ...Show All

• .NET Development io.networkstream encoding

  Hello, I'd like to ask how can i set the current encoding property to the streamreader I mean i am receiving a stream from a pop3 server and i would encode it into central european charset. how can i do this Dim respond As String respond = read.ReadLine() and i want respond to be encoded in unicode... how can i solve this thnx for ya help You can use System.Text.Encoding.Convert method to convert from one encoding to another Mariya ...Show All

• Visual Studio Team System TFS RC: Error loading Microsoft.TeamFoundation.WorkItemTracking.Server.EventFilter ...

  Even though the installation was successful, I am getting the following error four times in a row, every hour: Could not load file or assembly 'Microsoft.TeamFoundation.WorkItemTracking.Server.EventFilter' or one of its dependencies Is this a serious problem Should I be able to fix it or is it a problem with thr RC build Thanks in advance, here is the entire event log entry: Event Type: Warning Event Source: TFS Services Event Category: None Event ID: 3012 Date: 2/15/2006 Time: 8:05:13 AM User: N/A Computer: MyServer Description: TF53010: An unexpected condition has occurred in a Team Foundation component. The information contain ...Show All

• Windows Forms Colors and Brushes

  Alright, I have a color thats passed into a function. Now it would seem like an easy task (and it probably is but I'm having a blonde moment), how do i translate the System.drawing.color into a system.drawing.brush  I don't want to have to pass brushes around, so I'm at a loss here, how do I translate this Thanks!!! Oops, rechecking&nbs ...Show All