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  • Does the chunk of the System.Collections.Concurrent.Partitioner need to be thread safe?

    - by Scott Chamberlain
    I am working with the Parallel libraries in .net 4 and I am creating a Partitioner and the example shown in the MSDN only has a chunk size of 1 (every time a new result is retrieved it hits the data source instead of the local cache. The version I am writing will pull 10000 SQL rows at a time then feed the rows from the cache until it is empty then pull another batch. Each partition in the Partitioner has its own chunk. I know every time I call to the IEnumerator in from the SQL data-source that needs to be thread safe but for use in a Parallel.ForEach do I need to make every call to the cache for the chunking thread safe?

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  • Forcing a checkbox bound to a DataSource to update when it has not been viewed yet.

    - by Scott Chamberlain
    Here is a test framework to show what I am doing: create a new project add a tabbed control on tab 1 put a button on tab 2 put a check box paste this code for its code (use default names for controls) public partial class Form1 : Form { private List<bool> boolList = new List<bool>(); BindingSource bs = new BindingSource(); public Form1() { InitializeComponent(); boolList.Add(false); bs.DataSource = boolList; checkBox1.DataBindings.Add("Checked", bs, ""); this.button1.Click += new System.EventHandler(this.button1_Click); this.checkBox1.CheckedChanged += new System.EventHandler(this.checkBox1_CheckedChanged); } bool updating = false; private void button1_Click(object sender, EventArgs e) { updating = true; boolList[0] = true; bs.ResetBindings(false); Application.DoEvents(); updating = false; } private void checkBox1_CheckedChanged(object sender, EventArgs e) { if (!updating) MessageBox.Show("CheckChanged fired outside of updating"); } } The issue is if you run the program and look at tab 2 then press the button on tab 1 the program works as expected, however if you press the button on tab 1 then look at tab 2 the event for the checkbox will not fire untill you look at tab 2. The reason for this is the controll on tab 2 is not in the "created" state, so its binding to change the checkbox from unchecked to checked does not happen until after the control has been "Created". checkbox1.CreateControl() does not do anything because according to MSDN CreateControl does not create a control handle if the control's Visible property is false. You can either call the CreateHandle method or access the Handle property to create the control's handle regardless of the control's visibility, but in this case, no window handles are created for the control's children. I tried getting the value of Handle(there is no public CreateHandle() for CheckBox) but still the same result. Any suggestions other than have the program quickly flash all of my tabs that have data-bound check boxes when it first loads? EDIT-- per Jaxidian's suggestion I created a new class public class newcheckbox : CheckBox { public new void CreateHandle() { base.CreateHandle(); } } I call CreateHandle() right after updating = true same results as before.

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  • WCF high instance count: anyone knows negative sideffects?

    - by Alex
    Hi there! Did anyone experience or know of negative side effects from having a high service instance count like 60k? Aside from the memory consumption of course. I am planning to increase the threshold for the maximum allowed instance count in our production environments. I am basically sick of severe production incidents just because "something" forgot to close a proxy properly. I plan to go to something like 60k instances which will allow the service to survive using default session timeouts at a call rate average for our clients. Thanks, Alex

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  • What is the difference between MVC model 1 and model 2?

    - by Alex Ciminian
    I've recently discovered that MVC is supposed to have two different flavors, model one and model two. I'm supposed to give a presentation on MVC1 and I was instructed that "it's not the web based version, that is refered to as MVC2". As the presentations are about design patterns in general, I doubt that this separation is related to Java (I found some info on Sun's site, but it seemed far off) or ASP. I have a pretty good understanding of what MVC is and I've used several (web) frameworks that enforce it, but this terminology is new to me. How is the web-based version different from other MVC (I'm guessing GUI) implementations? Does it have something to do with the stateless nature of HTTP? Thanks, Alex

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  • "Circuit breaker" for net.msmq?

    - by Alex
    Hi, The Circuit Breaker pattern, from the book Release It!, protects a service from requests while it is failing (or recovering). The net.msmq binding used with transactions give us nice retry and poison message capabilities. But I am missing the implementation of such a "Circuit breaker" pattern. A service is put under even heavier load by retries while it is already in a failure condition (like DB connectivity issues causing loads of blocked threads etc.). Anyone knows about a behavior extension or similar that explicitly closes the service host when defined failure thresholds have been exceeded? Cheers, Alex

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  • Data table columns become out of order after changing data source.

    - by Scott Chamberlain
    This is kind of a oddball problem so I will try to describe the best that I can. I have a DataGridView that shows a list of contracts and various pieces of information about them. There are three view modes: Contract Approval, Pre-Production, and Production. Each mode has it's own set of columns that need to be displayed. What I have been doing is I have three radio buttons one for each contract style. all of them fire their check changed on this function private void rbContracts_CheckedChanged(object sender, EventArgs e) { dgvContracts.Columns.Clear(); if (((RadioButton)sender).Checked == true) { if (sender == rbPreProduction) { dgvContracts.Columns.AddRange(searchSettings.GetPreProductionColumns()); this.contractsBindingSource.DataMember = "Preproduction"; this.preproductionTableAdapter.Fill(this.searchDialogDataSet.Preproduction); } else if (sender == rbProduction) { dgvContracts.Columns.AddRange(searchSettings.GetProductionColumns()); this.contractsBindingSource.DataMember = "Production"; this.productionTableAdapter.Fill(this.searchDialogDataSet.Production); } else if (sender == rbContracts) { dgvContracts.Columns.AddRange(searchSettings.GetContractsColumns()); this.contractsBindingSource.DataMember = "Contracts"; this.contractsTableAdapter.Fill(this.searchDialogDataSet.Contracts); } } } Here is the GetxxxColumns function public DataGridViewColumn[] GetPreProductionColumns() { this.dgvTxtPreAccount.Visible = DgvTxtPreAccountVisable; this.dgvTxtPreImpromedAccNum.Visible = DgvTxtPreImpromedAccNumVisable; this.dgvTxtPreCreateDate.Visible = DgvTxtPreCreateDateVisable; this.dgvTxtPreCurrentSoftware.Visible = DgvTxtPreCurrentSoftwareVisable; this.dgvTxtPreConversionRequired.Visible = DgvTxtPreConversionRequiredVisable; this.dgvTxtPreConversionLevel.Visible = DgvTxtPreConversionLevelVisable; this.dgvTxtPreProgrammer.Visible = DgvTxtPreProgrammerVisable; this.dgvCbxPreEdge.Visible = DgvCbxPreEdgeVisable; this.dgvCbxPreEducationRequired.Visible = DgvCbxPreEducationRequiredVisable; this.dgvTxtPreTargetMonth.Visible = DgvTxtPreTargetMonthVisable; this.dgvCbxPreEdgeDatesDate.Visible = DgvCbxPreEdgeDatesDateVisable; this.dgvTxtPreStartDate.Visible = DgvTxtPreStartDateVisable; this.dgvTxtPreUserName.Visible = DgvTxtPreUserNameVisable; this.dgvCbxPreProductionId.Visible = DgvCbxPreProductionIdVisable; return new System.Windows.Forms.DataGridViewColumn[] { this.dgvTxtPreAccount, this.dgvTxtPreImpromedAccNum, this.dgvTxtPreCreateDate, this.dgvTxtPreCurrentSoftware, this.dgvTxtPreConversionRequired, this.dgvTxtPreConversionLevel, this.dgvTxtPreProgrammer, this.dgvCbxPreEdge, this.dgvCbxPreEducationRequired, this.dgvTxtPreTargetMonth, this.dgvCbxPreEdgeDatesDate, this.dgvTxtPreStartDate, this.dgvTxtPreUserName, this.dgvCbxPreProductionId, this.dgvTxtCmnHold, this.dgvTxtCmnConcern, this.dgvTxtCmnAccuracyStatus, this.dgvTxtCmnEconomicStatus, this.dgvTxtCmnSoftwareStatus, this.dgvTxtCmnServiceStatus, this.dgvTxtCmnHardwareStatus, this.dgvTxtCmnAncillaryStatus, this.dgvTxtCmnFlowStatus, this.dgvTxtCmnImpromedAccountNum, this.dgvTxtCmnOpportunityId}; } public DataGridViewColumn[] GetProductionColumns() { this.dgvcTxtProAccount.Visible = DgvTxtProAccountVisable; this.dgvTxtProImpromedAccNum.Visible = DgvTxtProImpromedAccNumVisable; this.dgvTxtProCreateDate.Visible = DgvTxtProCreateDateVisable; this.dgvTxtProConvRequired.Visible = DgvTxtProConvRequiredVisable; this.dgvTxtProEdgeRequired.Visible = DgvTxtProEdgeRequiredVisable; this.dgvTxtProStartDate.Visible = DgvTxtProStartDateVisable; this.dgvTxtProHardwareRequired.Visible = DgvTxtProHardwareReqiredVisable; this.dgvTxtProStandardDate.Visible = DgvTxtProStandardDateVisable; this.dgvTxtProSystemScheduleDate.Visible = DgvTxtProSystemScheduleDateVisable; this.dgvTxtProHwSystemCompleteDate.Visible = DgvTxtProHwSystemCompleteDateVisable; this.dgvTxtProHardwareTechnician.Visible = DgvTxtProHardwareTechnicianVisable; return new System.Windows.Forms.DataGridViewColumn[] { this.dgvcTxtProAccount, this.dgvTxtProImpromedAccNum, this.dgvTxtProCreateDate, this.dgvTxtProConvRequired, this.dgvTxtProEdgeRequired, this.dgvTxtProStartDate, this.dgvTxtProHardwareRequired, this.dgvTxtProStandardDate, this.dgvTxtProSystemScheduleDate, this.dgvTxtProHwSystemCompleteDate, this.dgvTxtProHardwareTechnician, this.dgvTxtCmnHold, this.dgvTxtCmnConcern, this.dgvTxtCmnAccuracyStatus, this.dgvTxtCmnEconomicStatus, this.dgvTxtCmnSoftwareStatus, this.dgvTxtCmnServiceStatus, this.dgvTxtCmnHardwareStatus, this.dgvTxtCmnAncillaryStatus, this.dgvTxtCmnFlowStatus, this.dgvTxtCmnImpromedAccountNum, this.dgvTxtCmnOpportunityId}; } public DataGridViewColumn[] GetContractsColumns() { this.dgvTxtConAccount.Visible = this.DgvTxtConAccountVisable; this.dgvTxtConAccuracyStatus.Visible = this.DgvTxtConAccuracyStatusVisable; this.dgvTxtConCreateDate.Visible = this.DgvTxtConCreateDateVisable; this.dgvTxtConEconomicStatus.Visible = this.DgvTxtConEconomicStatusVisable; this.dgvTxtConHardwareStatus.Visible = this.DgvTxtConHardwareStatusVisable; this.dgvTxtConImpromedAccNum.Visible = this.DgvTxtConImpromedAccNumVisable; this.dgvTxtConServiceStatus.Visible = this.DgvTxtConServiceStatusVisable; this.dgvTxtConSoftwareStatus.Visible = this.DgvTxtConSoftwareStatusVisable; this.dgvCbxConPreProductionId.Visible = this.DgvCbxConPreProductionIdVisable; this.dgvCbxConProductionId.Visible = this.DgvCbxConProductionVisable; return new System.Windows.Forms.DataGridViewColumn[] { this.dgvTxtConAccount, this.dgvTxtConImpromedAccNum, this.dgvTxtConCreateDate, this.dgvTxtConAccuracyStatus, this.dgvTxtConEconomicStatus, this.dgvTxtConSoftwareStatus, this.dgvTxtConServiceStatus, this.dgvTxtConHardwareStatus, this.dgvCbxConPreProductionId, this.dgvCbxConProductionId, this.dgvTxtCmnHold, this.dgvTxtCmnConcern, this.dgvTxtCmnAccuracyStatus, this.dgvTxtCmnEconomicStatus, this.dgvTxtCmnSoftwareStatus, this.dgvTxtCmnServiceStatus, this.dgvTxtCmnHardwareStatus, this.dgvTxtCmnAncillaryStatus, this.dgvTxtCmnFlowStatus, this.dgvTxtCmnImpromedAccountNum, this.dgvTxtCmnOpportunityId}; } The issue is when I check a button the first time, everything shows up ok. I choose another view, everything is ok. But when I click on the first view the columns are out of order (it is like they are in reverse order but it is not exactly the same). this happens only to the first page you click on, the other two are fine. You can click off and click back on as many times as you want after those initial steps, The first list you selected at the start will be out of order the other two will be correct. Any ideas on what could be causing this?

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  • Concatenating a string and byte array in to unmanaged memory.

    - by Scott Chamberlain
    This is a followup to my last question. I now have a byte[] of values for my bitmap image. Eventually I will be passing a string to the print spooler of the format String.Format("GW{0},{1},{2},{3},", X, Y, stride, _Bitmap.Height) + my binary data; I am using the SendBytesToPrinter command from here. Here is my code so far to send it to the printer public static bool SendStringPlusByteBlockToPrinter(string szPrinterName, string szString, byte[] bytes) { IntPtr pBytes; Int32 dwCount; // How many characters are in the string? dwCount = szString.Length; // Assume that the printer is expecting ANSI text, and then convert // the string to ANSI text. pBytes = Marshal.StringToCoTaskMemAnsi(szString); pBytes = Marshal.ReAllocCoTaskMem(pBytes, szString.Length + bytes.Length); Marshal.Copy(bytes,0, SOMTHING GOES HERE,bytes.Length); // this is the problem line // Send the converted ANSI string + the concatenated bytes to the printer. SendBytesToPrinter(szPrinterName, pBytes, dwCount); Marshal.FreeCoTaskMem(pBytes); return true; } My issue is I do not know how to make my data appended on to the end of the string. Any help would be greatly appreciated, and if I am doing this totally wrong I am fine in going a entirely different way (for example somehow getting the binary data concatenated on to the string before the move to unmanaged space. P.S. As a second question, will ReAllocCoTaskMem move the data that is sitting in it before the call to the new location?

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  • Invert the 1bbp color under a rectangle.

    - by Scott Chamberlain
    I am working with GDI+, the image I am working with is a 1bbp image. What i would like to do is draw a rectangle on the image and everything under that rectangle will be inverted (white pixels will become black and black pixels become white). All of the sample code I have seen is for 8 bit RGB color scale images, and I don't think the techniques they use will work for me. Here is the code I have so far. This is the parent control, one of the Epl2.IDrawableCommand's will be the command that does the inverting. protected override void OnPaint(PaintEventArgs e) { base.OnPaint(e); if (Label != null) { using (Bitmap drawnLabel = new Bitmap((int)((float)Label.LabelHeight * _ImageScaleFactor), (int)((float)Label.LableLength *(int) _ImageScaleFactor), System.Drawing.Imaging.PixelFormat.Format1bppIndexed)) { using (Graphics drawBuffer = Graphics.FromImage(drawnLabel)) { drawBuffer.ScaleTransform(_ImageScaleFactor, _ImageScaleFactor); foreach (Epl2.IDrawableCommand cmd in Label.Collection) { cmd.Paint(drawBuffer); } drawBuffer.ResetTransform(); } drawnLabel.RotateFlip(Rotation); pbLabelDrawArea.Size = drawnLabel.Size; using (Graphics drawArea = pbLabelDrawArea.CreateGraphics()) { drawArea.Clear(Color.White); drawArea.DrawImage(drawnLabel, new Point(0, 0)); } } } } What should I put in the Paint(Graphic g) for this command?

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  • Mixing .NET versions between website and virtual directories and the "server application unavailable" error Message

    - by Doug Chamberlain
    Backstory Last month our development team created a new asp.net 3.5 application to place out on our production website. Once we had the work completed, we requested from the group that manages are server to copy the app out to our production site, and configure the virtual directory as a new application. On 12/27/2010, two public 'Gineau Pigs' were selected to use the app, and it worked great. On 12/30/2010, We received notification by internal staff, that when that staff member tried to access the application (this was the Business Process Owner) they recieved the 'Server Application Unavailable' message. When I called the group that does our server support, I was told that it probably failed, because I didn't close the connections in my code. However, the same group went in and then created a separate app pool for this Extension Request application. It has had no issues since. I did a little googling, since I do not like being blamed for things. I found that the 'Server Application Unavailable' message will also appear when you have multiple applications using different frameworks and you do not put them in different application pools. Technical Details - Tree of our website structure Main Website <-- ASP Classic +-Virtual Directory(ExtensionRequest) <-- ASP 3.5 From our server support group: 'Reviewed server logs and website setup in IIS. Had to reset the application pool as it was not working properly. This corrected the website and it is now back online. We went ahead and created a application pool for the extension web so it is isolated from the main site pool. In the past we have seen other application do this when there is a connection being left open and the pool fills up. Would recommend reviewing site code to make sure no connections are being left open.' The Real Question: What really caused the failure? Isn't the connection being left open issue an ASP Classic issue? Wouldn't the ExtensionRequest application have to be used (more than twice) in the first place to have the connections left open? Is it more likely the failure is caused by them not bothering to setup the new Application in it's own App Pool in the first place? Sorry for the long windedness

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  • Does my TPL partitioner cause a deadlock?

    - by Scott Chamberlain
    I am starting to write my first parallel applications. This partitioner will enumerate over a IDataReader pulling chunkSize records at a time from the data-source. protected class DataSourcePartitioner<object[]> : System.Collections.Concurrent.Partitioner<object[]> { private readonly System.Data.IDataReader _Input; private readonly int _ChunkSize; public DataSourcePartitioner(System.Data.IDataReader input, int chunkSize = 10000) : base() { if (chunkSize < 1) throw new ArgumentOutOfRangeException("chunkSize"); _Input = input; _ChunkSize = chunkSize; } public override bool SupportsDynamicPartitions { get { return true; } } public override IList<IEnumerator<object[]>> GetPartitions(int partitionCount) { var dynamicPartitions = GetDynamicPartitions(); var partitions = new IEnumerator<object[]>[partitionCount]; for (int i = 0; i < partitionCount; i++) { partitions[i] = dynamicPartitions.GetEnumerator(); } return partitions; } public override IEnumerable<object[]> GetDynamicPartitions() { return new ListDynamicPartitions(_Input, _ChunkSize); } private class ListDynamicPartitions : IEnumerable<object[]> { private System.Data.IDataReader _Input; int _ChunkSize; private object _ChunkLock = new object(); public ListDynamicPartitions(System.Data.IDataReader input, int chunkSize) { _Input = input; _ChunkSize = chunkSize; } public IEnumerator<object[]> GetEnumerator() { while (true) { List<object[]> chunk = new List<object[]>(_ChunkSize); lock(_Input) { for (int i = 0; i < _ChunkSize; ++i) { if (!_Input.Read()) break; var values = new object[_Input.FieldCount]; _Input.GetValues(values); chunk.Add(values); } if (chunk.Count == 0) yield break; } var chunkEnumerator = chunk.GetEnumerator(); lock(_ChunkLock) //Will this cause a deadlock? { while (chunkEnumerator.MoveNext()) { yield return chunkEnumerator.Current; } } } } IEnumerator IEnumerable.GetEnumerator() { return ((IEnumerable<object[]>)this).GetEnumerator(); } } } I wanted IEnumerable object it passed back to be thread safe (the .Net example was so I am assuming PLINQ and TPL could need it) will the lock on _ChunkLock near the bottom help provide thread safety or will it cause a deadlock? From the documentation I could not tell if the lock would be released on the yeld return. Also if there is built in functionality to .net that will do what I am trying to do I would much rather use that. And if you find any other problems with the code I would appreciate it.

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  • Does my GetEnumerator cause a deadlock?

    - by Scott Chamberlain
    I am starting to write my first parallel applications. This partitioner will enumerate over a IDataReader pulling chunkSize records at a time from the data-source. TLDR; version private object _Lock = new object(); public IEnumerator GetEnumerator() { var infoSource = myInforSource.GetEnumerator(); //Will this cause a deadlock if two threads lock (_Lock) //use the enumator at the same time? { while (infoSource.MoveNext()) { yield return infoSource.Current; } } } full code protected class DataSourcePartitioner<object[]> : System.Collections.Concurrent.Partitioner<object[]> { private readonly System.Data.IDataReader _Input; private readonly int _ChunkSize; public DataSourcePartitioner(System.Data.IDataReader input, int chunkSize = 10000) : base() { if (chunkSize < 1) throw new ArgumentOutOfRangeException("chunkSize"); _Input = input; _ChunkSize = chunkSize; } public override bool SupportsDynamicPartitions { get { return true; } } public override IList<IEnumerator<object[]>> GetPartitions(int partitionCount) { var dynamicPartitions = GetDynamicPartitions(); var partitions = new IEnumerator<object[]>[partitionCount]; for (int i = 0; i < partitionCount; i++) { partitions[i] = dynamicPartitions.GetEnumerator(); } return partitions; } public override IEnumerable<object[]> GetDynamicPartitions() { return new ListDynamicPartitions(_Input, _ChunkSize); } private class ListDynamicPartitions : IEnumerable<object[]> { private System.Data.IDataReader _Input; int _ChunkSize; private object _ChunkLock = new object(); public ListDynamicPartitions(System.Data.IDataReader input, int chunkSize) { _Input = input; _ChunkSize = chunkSize; } public IEnumerator<object[]> GetEnumerator() { while (true) { List<object[]> chunk = new List<object[]>(_ChunkSize); lock(_Input) { for (int i = 0; i < _ChunkSize; ++i) { if (!_Input.Read()) break; var values = new object[_Input.FieldCount]; _Input.GetValues(values); chunk.Add(values); } if (chunk.Count == 0) yield break; } var chunkEnumerator = chunk.GetEnumerator(); lock(_ChunkLock) //Will this cause a deadlock? { while (chunkEnumerator.MoveNext()) { yield return chunkEnumerator.Current; } } } } IEnumerator IEnumerable.GetEnumerator() { return ((IEnumerable<object[]>)this).GetEnumerator(); } } } I wanted IEnumerable object it passed back to be thread safe (the MSDN example was so I am assuming PLINQ and TPL could need it) will the lock on _ChunkLock near the bottom help provide thread safety or will it cause a deadlock? From the documentation I could not tell if the lock would be released on the yeld return. Also if there is built in functionality to .net that will do what I am trying to do I would much rather use that. And if you find any other problems with the code I would appreciate it.

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  • Is a line formed by two points greater than 90 degrees off of the horzontal.

    - by Scott Chamberlain
    I am trying to find out if a line defined by two points is greater than or equal to 90 degrees compared to the horizontal. Here is the code I used bool moreThan90 = false; double angle = Math.Atan((double)(EndingLocation.Y - Location.Y) / (double)(EndingLocation.X - Location.X)); if (angle >= Math.PI / 2.0 || angle <= -Math.PI / 2.0) moreThan90 = true; Did I do this correctly or is there a better built in function in .Net that will find this?

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  • How to make a program not show up in Alt-Tab or on the taskbar.

    - by Scott Chamberlain
    I have a program that needs to sit in the background and when a user connects to a RDP session it will do some stuff then launch a program. when the program is closed it will do some housekeeping and logoff the session. The current way I am doing it is like this I have the terminal server launch this application. I have it set as a windows forms application and my code is this public static void Main() { //Do some setup work Process proc = new Process(); //setup the process proc.Start(); proc.WaitForExit(); //Do some housecleaning NativeMethods.ExitWindowsEx(0, 0); } I really like this because there is no item in the taskbar and there is nothing showing up in alt-tab. However to do this I gave up access to functions like void WndProc(ref Message m) So Now I can't listen to windows messages (Like WTS_REMOTE_DISCONNECT or WTS_SESSION_LOGOFF) and do not have a handle to use for for bool WTSRegisterSessionNotification(IntPtr hWnd, int dwFlags); I would like my code to be more robust so it will do the housecleaning if the user logs off or disconnects from the session before he closes the program. Any reccomendations on how I can have my cake and eat it too?

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  • Lock thread using somthing other than a object

    - by Scott Chamberlain
    when using a lock does the thing you are locking on have to be a object. For example is this legal static DateTime NextCleanup = DateTime.Now; const TimeSpan CleanupInterval = new TimeSpan(1, 0, 0); private static void DoCleanup() { lock ((object)NextCleanup) { if (NextCleanup < DateTime.Now) { NextCleanup = DateTime.Now.Add(CleanupInterval); System.Threading.ThreadPool.QueueUserWorkItem(new System.Threading.WaitCallback(cleanupThread)); } } return; } EDIT-- From reading SLaks' responce I know the above code would be not valid but would this be? static MyClass myClass = new MyClass(); private static void DoCleanup() { lock (myClass) { // } return; }

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  • Convert a image to a monochrome byte array

    - by Scott Chamberlain
    I am writing a library to interface C# with the EPL2 printer language. One feature I would like to try to implement is printing images, the specification doc says p1 = Width of graphic Width of graphic in bytes. Eight (8) dots = one (1) byte of data. p2 = Length of graphic Length of graphic in dots (or print lines) Data = Raw binary data without graphic file formatting. Data must be in bytes. Multiply the width in bytes (p1) by the number of print lines (p2) for the total amount of graphic data. The printer automatically calculates the exact size of the data block based upon this formula. I plan on my source image being a 1 bit per pixel bmp file, already scaled to size. I just don't know how to get it from that format in to a byte[] for me to send off to the printer. I tried ImageConverter.ConvertTo(Object, Type) it succeeds but the array it outputs is not the correct size and the documentation is very lacking on how the output is formatted. My current test code. Bitmap i = (Bitmap)Bitmap.FromFile("test.bmp"); ImageConverter ic = new ImageConverter(); byte[] b = (byte[])ic.ConvertTo(i, typeof(byte[])); Any help is greatly appreciated even if it is in a totally different direction.

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  • Template engine recommendations

    - by alex
    I'm looking for a template engine. Requirements: Runs on a JVM. Java is good; Jython, JRuby and the like, too... Can be used outside of servlets (unlike JSP) Is flexible wrt. to where the templates are stored (JSP and a lot of people require the templates to be stored in the FS). It should provide a template loading interface which one can implement or something like that Easy inclusion of parameterized templates- I really like JSP's tag fragments Good docs, nice code, etc., the usual suspects I've looked at JSP- it's nearly perfect except for the servlet and filesystem coupling, Stringtemplate- I love the template syntax, but it fails on the filesystem coupling, the documentation is lacking and template groups and stuff are confusing, GXP, TAL, etc. Ideas, thoughts? Alex

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  • Using combo boxes with a binding source and multiple tables

    - by Scott Chamberlain
    I have two data tables in a data set for example lets say Servers: | Server | Ip | Users: | Username | Password | ServerToConnectTo | and there is a foreign key on users that points to servers. How do I make a combo box that list all of the servers. Then how do I make the selected server in that combo box be saved in the data set in the ServerToConnect to column.

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  • DataGridView validating old value insted of new value.

    - by Scott Chamberlain
    I have a DataGridView that is bound to a DataTable, it has a column that is a double and the values need to be between 0 and 1. Here is my code private void dgvImpRDP_InfinityRDPLogin_CellValidating(object sender, DataGridViewCellValidatingEventArgs e) { if (e.ColumnIndex == dtxtPercentageOfUsersAllowed.Index) { double percentage; if(dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].Value.GetType() == typeof(double)) percentage = (double)dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].Value; else if (!double.TryParse(dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].Value.ToString(), out percentage)) { e.Cancel = true; dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].ErrorText = "The value must be between 0 and 1"; return; } if (percentage < 0 || percentage > 1) { e.Cancel = true; dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].ErrorText = "The value must be between 0 and 1"; } } } However my issue when dgvImpRDP_InfinityRDPLogin_CellValidating fires dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].Value will contain the old value before the edit, not the new value. For example lets say the old value was .1 and I enter 3. The above code runs when you exit the cell and dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].Value will be .1 for that run, the code validates and writes 3 the data to the DataTable. I click on it a second time, try to leave, and this time it behaves like it should, it raises the error icon for the cell and prevents me from leaving. I try to enter the correct value (say .7) but the the Value will still be 3 and there is now no way out of the cell because it is locked due to the error and my validation code will never push the new value. Any recommendations would be greatly appreciated. EDIT -- New version of the code based off of Stuart's suggestion and mimicking the style the MSDN article uses. Still behaves the same. private void dgvImpRDP_InfinityRDPLogin_CellValidating(object sender, DataGridViewCellValidatingEventArgs e) { if (e.ColumnIndex == dtxtPercentageOfUsersAllowed.Index) { dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].ErrorText = String.Empty; double percentage; if (!double.TryParse(dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].FormattedValue.ToString(), out percentage) || percentage < 0 || percentage > 1) { e.Cancel = true; dgvImpRDP_InfinityRDPLogin[e.ColumnIndex, e.RowIndex].ErrorText = "The value must be between 0 and 1"; return; } } }

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  • Convert Yes/No/Null from SQL to True/False in a DataTable

    - by Scott Chamberlain
    I have a Sql Database (which I have no control over the schema) that has a Column that will have the varchar value of "Yes", "No", or it will be null. For the purpose of what I am doing null will be handled as No. I am programming in c# net 3.5 using a data table and table adapter to pull the data down. I would like to directly bind the column using a binding source to a check box I have in my program however I do not know how or where to put the logic to convert the string Yes/No/null to boolean True/False; Reading a null from the SQL server and writing back a No on a update is acceptable behavior. Any help is greatly appreciated. EDIT -- This is being developed for windows.

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  • What to use to wait on a indeterminate number of tasks?

    - by Scott Chamberlain
    I am still fairly new to parallel computing so I am not too sure which tool to use for the job. I have a System.Threading.Tasks.Task that needs to wait for n number number of tasks to finish before starting. The tricky part is some of its dependencies may start after this task starts (You are guaranteed to never hit 0 dependent tasks until they are all done). Here is kind of what is happening Parent thread creates somewhere between 1 and (NUMBER_OF_CPU_CORES - 1) tasks. Parent thread creates task to be run when all of the worker tasks are finished. Parent thread creates a monitoring thread Monitoring thread may kill a worker task or spawn a new task depending on load. I can figure out everything up to step 4. How do I get the task from step 2 to wait to run until any new worker threads created in step 4 finish?

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  • Simulate stochastic bipartite network based on trait values of species - in R

    - by Scott Chamberlain
    I would like to create bipartite networks in R. For example, if you have a data.frame of two types of species (that can only interact across species, not within species), and each species has a trait value (e.g., size of mouth in the predator allows who gets to eat which prey species), how do we simulate a network based on the traits of the species (that is, two species can only interact if their traits overlap in values for instance)? UPDATE: Here is a minimal example of what I am trying to do. 1) create phylogenetic tree; 2) simulate traits on the phylogeny; 3) create networks based on species trait values. # packages install.packages(c("ape","phytools")) library(ape); library(phytools) # Make phylogenetic trees tree_predator <- rcoal(10) tree_prey <- rcoal(10) # Simulate traits on each tree trait_predator <- fastBM(tree_predator) trait_prey <- fastBM(tree_prey) # Create network of predator and prey ## This is the part I can't do yet. I want to create bipartite networks, where ## predator and prey interact based on certain crriteria. For example, predator ## species A and prey species B only interact if their body size ratio is ## greater than X.

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  • Allow a new line anywhere in the regex?

    - by Scott Chamberlain
    I am having a find a replace in a bunch of RTF documents, The basic pattern I need is \{(?:\\\*)?\\field\\fldlock\{\\\*\\fldinst ?MERGEFIELD ?((?:\\.*?)?[\w\[\]]+?)(?:\\.*?)?\}(?:\{\\fldrslt\})?\} However I then found out there could potentialy be a newline before each slash, so it turned in to this. \{(?:\s*\\\*)?\s*\\field\s*\\fldlock\s*\{\s*\\\*\s*\\fldinst\s*MERGEFIELD\s*((?:\\.*?)?[\w\[\]]+?(?:\s*\\.*?)?)?\s*\}(?:\s*\{\s*\\fldrslt\s*\})?\s*\} But then I hit this it fails fees totaling $\protect {\field\fldlock{\*\fldinst MERGEFIELD ENTEROUTSTANDINGVETERINARYF EES}}\plain\f0\fs24\prot Is there way have to have it match a new line anywhere in the search too without adding (?:\r?\n)? everywhere? EDIT To clear up confusion on the new lines. I need to keep the newlines in the document, I only want to remove the newlines if they are inside my match, so in the final example I posted it should replace fees totaling $\protect {\field\fldlock{\*\fldinst MERGEFIELD ENTEROUTSTANDINGVETERINARYF EES}}\plain\f0\fs24\prot with fees totaling $\protect ENTEROUTSTANDINGVETERINARYFEES\plain\f0\fs24\prot

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  • Foreach loop and tasks.

    - by Scott Chamberlain
    I know from the codeing guidlines that I have read you should not do for (int i = 0; i < 5; i++) { Task.Factory.StartNew(() => Console.WriteLine(i)); } Console.ReadLine(); as it will write 5 5's, I understand that and I think i understand why it is happening. I know the solution is just to do for (int i = 0; i < 5; i++) { int localI = i; Task.Factory.StartNew(() => Console.WriteLine(localI)); } Console.ReadLine(); However is something like this ok to do? foreach (MyClass myClass in myClassList) { Task.Factory.StartNew(() => myClass.DoAction()); } Console.ReadLine(); Or do I need to do the same thing I did in the for loop. foreach (MyClass myClass in myClassList) { MyClass localMyClass = myClass; Task.Factory.StartNew(() => localMyClass.DoAction()); } Console.ReadLine();

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  • Creating a image viewer window controll.

    - by Scott Chamberlain
    I am learning GDI+ and I am trying to make a display window with scroll bars (so I can only see part of the image at a time and I can scroll around it). I have read through the basics of GDI+ from several books but I have not found any good tutorials online or in books available to me about doing more advanced things like this. Any recommendations on guides or example code on how do do this? Here is what I have so far protected override void OnPaint(PaintEventArgs e) { base.OnPaint(e); if (Label != null) { using (Bitmap drawnLabel = new Bitmap(Label.LabelHeight, Label.LableLength, System.Drawing.Imaging.PixelFormat.Format1bppIndexed)) using (Graphics drawBuffer = Graphics.FromImage(drawnLabel)) { drawBuffer.ScaleTransform(_ImageScaleFactor, _ImageScaleFactor); foreach (Epl2.IDrawableCommand cmd in Label.Collection) { cmd.Paint(drawBuffer); } drawBuffer.ResetTransform(); } } } I would like to paint this in to a PictureBox I have on the control and control what is shown by a VScrollBar and HScrollBar but I don't know how to do that step. P.S. Label is a custom class that I have in my namespace, it is a object that represents a label you would print from a label printer.

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