I am trying to display a basic clock from system time. I don't understand why this is crashing. I am hoping someone can help me to understand my error here.   At this point the form is just a label with short time displayed. I am trying to just make it update the label text on its own.   The label shows the time just fine on load. But when the timer_elapsed occurs the error is thrown  private void Form1_Load(object sender, EventArgs e) {     lblClock.Text = DateTime.Now.ToShortTimeString();     timer = new System.Timers.Timer();     timer.Interval = 1000;     timer.Elapsed += timer_Elapsed;     timer.Enabled = true;     timer.Start(); }   void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) {     lblClock.Text = DateTime.Now.ToShortTimeString(); }   The error is   InvalidOperationException was unhandled by user code  Why does this work on load but not on update?    This was marked as a duplicate, but I have to disagree. Based on the linked duplicate thread the questions aren't the same. This question refers to why the exact same method works on load but not on call. The other thread is simply asking in general how to update a UI.
12750
Which is the simplest way to update a Label from another Thread?   I have a Form running on thread1, and from that I'm starting another thread (thread2).  While thread2 is processing some files I would like to update a Label on the Form with the current status of thread2's work.   How could I do that?
94927
I tried to execute some code in a sandbox and I got an odd error message:     System.UnexpectedException: Invalid parameter value '****' for   parameter "Decryption Exception".    Looks like it happened immediately following a callout attempt...
102736
I'm looking into writing a simple synchronization ability into my app and one of the concerns that has popped up is synchronization of time between two remote computers, each with their own clock (in particular concerning the modification dates of files/objects).  I'm sure a lot of research has been done on this topic and don't want to get too theoretical, but I'm wondering if there are any accepted best practices for minimizing temporal discrepancies between remote clocks?  For example, a start is to always use universal time (UTC) as that avoids timezone problems, but there is no guarantee that two computers will have exactly the same system time. Luckily the work I'm doing isn't very fine-grained, so it's not a terribly important concern, but I'm still curious nonetheless.  One solution would be to always use the same clock on both ends, such as a global time server, rather than the local system clock. Presumably this (combined with shared resource locks) could guarantee no accidental overlap of synchronized time, but it's not very practical.  One thought that just popped into my head would be to synchronize each node (each client) with an offset calculated at some point prior, perhaps by calculating the offset of the system clock with a global time server. This would only need to be done occasionally as the offset itself would not likely change greatly over a short period of time.  Update: Let me just add that I'm not interested in actually synchronizing the system clocks of two computers--I'll presume that the operating system will handle this in most cases. This is just a question of how to ensure two instances of an application are using synchronized times, though in this day and age I suppose the system clocks would almost assuredly be synchronized to within some very small delta anyway.
115907
I am trying to addError on the opportunities based on one condition. But getting System.FinalException: SObject row does not allow errors error while saving the record. Below I have given the code snippet. Please let me know how I can resolve the issue.  if(Trigger.isUpdate &amp;&amp; Trigger.isBefore){         map&lt;Id,Opportunity&gt; newOpptyMap = (map&lt;Id,Opportunity&gt;)trigger.newMap;         OpportunityTriggerHelper.checkforStageDuration(newOpptyMap,Trigger.OldMap);     }   The function is below where I am adding the error statement  public static void checkforStageDuration(Map&lt;Id,Opportunity&gt; oldMap, Map&lt;Id,Opportunity&gt; newMap){         Map&lt;Id,Opportunity&gt; recordsToCheck = new Map&lt;Id,Opportunity&gt;();         for(Id oppId : newMap.keyset()){             if(newMap.get(oppId).StageName != oldMap.get(oppId).StageName){                 recordsToCheck.put(oppId,newMap.get(oppId));             }         }         List&lt;Opportunity_Stage_History__c&gt; oppStageHistory = [select Id,Expected_Stage_Duration__c,Opportunity__c,Duration__c,Reason_For_Delay__c from Opportunity_Stage_History__c where Opportunity__c IN :recordsToCheck.keyset()];         for(Opportunity_Stage_History__c oppHistory : oppStageHistory){             if(oppHistory.Duration__c&gt;oppHistory.Expected_Stage_Duration__c &amp;&amp; oppHistory.Reason_For_Delay__c==null){                 newMap.get(oppHistory.Opportunity__c).addError('The Opportunity has crossed it\'s Stage Duration, Please fill the Reason for Delay !!');             }         }     }
439
Consider:  namespace WindowsApplication1 {     public partial class Form1 : Form     {         public Form1()         {             InitializeComponent();         }          private void button1_Click(object sender, EventArgs e)         {             //int[] val = { 0, 0};             int val;             if (textBox1.Text == "")             {                 MessageBox.Show("Input any no");             }             else             {                 val = Convert.ToInt32(textBox1.Text);                 Thread ot1 = new Thread(new ParameterizedThreadStart(SumData));                 ot1.Start(val);             }         }          private static void ReadData(object state)         {             System.Windows.Forms.Application.Run();         }          void setTextboxText(int result)         {             if (this.InvokeRequired)             {                 this.Invoke(new IntDelegate(SetTextboxTextSafe), new object[] { result });             }             else             {                 SetTextboxTextSafe(result);             }         }          void SetTextboxTextSafe(int result)         {             label1.Text = result.ToString();         }          private static void SumData(object state)         {             int result;             //int[] icount = (int[])state;             int icount = (int)state;              for (int i = icount; i &gt; 0; i--)             {                 result += i;                 System.Threading.Thread.Sleep(1000);             }             setTextboxText(result);         }          delegate void IntDelegate(int result);          private void button2_Click(object sender, EventArgs e)         {             Application.Exit();         }     } }   Why is this error occurring?     An object reference is required for the nonstatic field, method, or property 'WindowsApplication1.Form1.setTextboxText(int)
102384
I am still not able to get the correct difference, really struggling to make it working. The business hour set from 10 AM to 7 PM  BusinessHours bh = [SELECT FridayEndTime,FridayStartTime,Id,MondayEndTime,MondayStartTime,                     FROM BusinessHours where Name='Test Business Hour'                     LIMIT 1]; Time startTime = bh.MondayStartTime;        Time endTime = bh.MondayEndTime;  Date d = Date.today(); Datetime monTodaystart = Datetime.newInstance(d.year(),d.month(),d.day(),startTime.hour(), startTime.minute(),startTime.second()); Datetime monTodayend = Datetime.newInstance(d.year(),d.month(),d.day(),endTime.hour(), endTime.minute(),endTime.second()); System.debug('monTodaystart :: '+monTodaystart);     System.debug('monTodayend :: '+monTodayend);   Long diff = BusinessHours.diff(bh.Id, monTodaystart, monTodayend); System.debug('diff  :: '+diff);   I tried this simple example, but still its not working why ? How we can manipulate it ?  Datetime monTodaystart = Datetime.newInstance(2017,8,20,10,0,0); Datetime monTodayEnd = Datetime.newInstance(2017,8,20,17,0,0); System.debug('ID : '+bh.Id);  Long diff = BusinessHours.diff(bh.Id, monTodaystart,monTodayEnd); System.debug('diff  :: '+diff);   I dont think I should used the API here, instead I should use my custom logic, looks like some bug in the API still exists.
23661
Context Around this Code: I am making a schedulable class run each Sunday to track a couple of metrics important to the team.   Question: I am looking to consolidate DML operations and a big part of this is understanding pass by reference vs pass by value.  I want to pass the salesOps user object to the method SDREfficiencyLastWeek. I made the return type void, because I figured that I will be passing this by reference and I can make all the updates in the method without having to anything.   Why I am confused:    I read the above article and am thrown off by the following statement:  "Non-primitive data type arguments, such as sObjects, are also passed into methods by value. "   If the object is indeed passed by reference, then the query for the salesOps user in my code should be sufficient enough to edit all fields on that object without actually having to state each field in the query.  global class SDREfficientMetricsSchedulable implements Schedulable  {     global void execute(SchedulableContext sc)      {         User salesOps = [SELECT ID FROM USER WHERE id = '0056A000002Z3p9QAC'];         List&lt;String&gt; queries = new List&lt;String&gt;();          String contactsWorked_lastWeek  = 'select count(id) results from contact where LastActivityDate = last_week';         queries.add(contactsWorked_lastWeek);          String demosSet_lastWeek            = 'select count(id) results from form__c where CreatedDate = last_week';         queries.add(demosSet_lastWeek);          String demosCompleted_lastWeek  = 'select count(id) results from opportunity where (stagename = \'Unqualified Demo Completed\'  OR stagename = \'Qualified Demo Completed\' )  and RecordTypeId = \'0126A000000yudDQAQ\' and CloseDate = last_week';         queries.add(demosCompleted_lastWeek);          String qualifiedDemos_lastWeek  = 'select count(id) results  from opportunity where RecordTypeId = \'0126A0000004Ao6QAE\' and isclosed = false and  SDR_Owner__c != null and CreatedDate = last_week';         queries.add(qualifiedDemos_lastWeek);          String closedWon_lastWeek       = 'select count(id) results  from opportunity where RecordTypeId = \'0126A0000004Ao6QAE\' and iswon = true and  SDR_Owner__c != null and CloseDate = last_week';         queries.add(qualifiedDemos_lastWeek);            SDREfficiencyLastWeek(queries, salesOps);          update salesOps;     }       public void SDREfficiencyLastWeek(List&lt;String&gt; queries, User salesOps )     {        }  }
57036
When I used to create the record in Event object it is showing error like:     Error: Invalid Data.   Apex trigger General_Event_Trigger caused an unexpected exception, contact your administrator: General_Event_Trigger: execution of BeforeINsert caused by: System.NullPointerException: Attempt to de-reference a null object: Class.EventClass.updateNewCustomFieldsEvent: line 369, column 1   Trigger code:  trigger General_Event_Trigger on Event (...) {     if (trigger.isBefore)     {         if (trigger.isInsert)         {             EventClass.updateNewCustomFieldsEvent(trigger.new);         }         else if (trigger.isUpdate)         {             EventClass.updateNewCustomFieldsEvent(trigger.new);         }     } }   Apex class:  public static void updateNewCustomFieldsEvent(List&lt;Event&gt; eventList) {     for (Event eve : eventList)     {         if (Administrators__c.getInstance().Update_field_Last_Modified_End_User__c)         {             String userIdString = eve.LastModifiedById;             eve.Last_Modified_By_End_User__c = userIdString.subString(0, 15);             eve.Last_Modified_Date_End_User__c = eve.LastModifiedDate;         }     } }
121529
I've just installed 64-bit Ubuntu 11.04 and after I updated it, the clock stopped displaying the right time. It's now 8 hours behind my normal time. I've checked the Time and Date settings and the Location field is correct. What's even weirder is that the time displayed in Time and Date Settings adjusts itself after a few seconds and is correct. The time displayed in the task bar remains the same, however.  Any ideas?
87780
I have a legacy WinForms Mdi App in VB.Net 2.0 which I am adding functionality to. One of the additions is a warning which needs to be raised when the current time nears a specified value (a deadline). My intention is to check the time once an hour until there is less than an hour until the deadline, then display warnings at specified intervals until the time's up.  The user needs to be able to continue to use the app up to and even after the deadline, but they need to periodically be made aware of the deadline's proximity.   The app does not use System.Threading yet and my knowledge of it is limited at this time. I do know that there are 3 different Timer() methods available:    System.Threading.Timer(), Windows.Forms.Timer() and  System.Timers.Timer()   My question is, which is the best way to go with this? I attempted to use the threaded timer, but since WinForms are not thread safe I got a run time error trying to access another class. Is it worth making the class/form thread safe? Am I completely off track?  Thanks.
858
Is there a way to get the text displayed for the "Recurrence" field on the View Item screen for an OOB "Event" list item through the object model?  For example, I see:  "Every 1 month(s) on the first Tuesday"  Is there maybe a calculated field that I can reference using an SPListItem to get at this string (ensuring it's localized correctly)?  For example:  lblRecurrence.Text = item["RecurrenceText"].ToString();   Response targeted for SP2007, but interested if this carries over to 2010?  Or if there is a way to get at it in 2010 that wasn't there before?
61917
I want a splash screen to show while the application is loading. I have a form with a system tray control tied to it. I want the splash screen to display while this form loads, which takes a bit of time since it's accessing a web service API to populate some drop-downs. I also want to do some basic testing for dependencies before loading (that is, the web service is available, the configuration file is readable).  As each phase of the startup goes, I want to update the splash screen with progress.  I have been reading a lot on threading, but I am getting lost on where this should be controlled from (the main() method?). I am also missing how Application.Run() works, is this where the threads for this should be created from? Now, if the form with the system tray control is the "living" form, should the splash come from there? Wouldn't it not load until the form is completed anyway?  I'm not looking for a code handout, more of an algorithm/approach so I can figure this out once and for all :)
78
We all know you can't do the following because of ConcurrentModificationException:  for (Object i : l) {     if (condition(i)) {         l.remove(i);     } }   But this apparently works sometimes, but not always. Here's some specific code:  public static void main(String[] args) {     Collection&lt;Integer&gt; l = new ArrayList&lt;&gt;();      for (int i = 0; i &lt; 10; ++i) {         l.add(4);         l.add(5);         l.add(6);     }      for (int i : l) {         if (i == 5) {             l.remove(i);         }     }      System.out.println(l); }   This, of course, results in:  Exception in thread "main" java.util.ConcurrentModificationException   Even though multiple threads aren't doing it. Anyway.  What's the best solution to this problem? How can I remove an item from the collection in a loop without throwing this exception?  I'm also using an arbitrary Collection here, not necessarily an ArrayList, so you can't rely on get.
38621
I am not sure what the problem is but I keep receiving this error when I try to use a while statement in my code.     Invalid token 'while' in class,   struct, or interface member   declaration   I want to use a while loop to have something continuously update while a statement is true.  The rest of my code is rather long but whenever I type in the syntax:  while(a&lt;b) { //do whatever i want it to do here }   It gives me that compiler error right off the bat. Not quite sure what the problem is. I am doing this in a C# windows application under the Form1.cs file with all the other event handlers (for buttons and such).  Thanks!    I was unaware that loops had to be placed within a method (fairly new to c#), but I tried it and no errors were returned. Thanks for your help everybody!  Previously, I just had the loop within the main class of the program.
51297
I moved a method that sets addError() from a trigger into a Helper class. As I started writing test code for it it seems like the addError() is not actually preventing DML operations for the records that get modified in the helper class.  The information from the SF  states: Marks a trigger record with a custom error message and prevents any DML operation from occurring.  Does this mean that addError() will not work outside of a trigger class?  EDIT  Adding some sample code.  public class MyHelperClass() {     public static void someMethod(Opportunity opp) {         opp.My_Field__c.addError('Some error');         insert opp;     } }   And sample test for it without any asserts:  @IsTest private class MyHelperClass_Test() {     @IsTest     static void someTest() {         Opportunity opp = new Opportunity();         opp.Name = 'Some Name';         opp.StageName = 'Prospect';         opp.CloseDate = Date.today().addDays(30);          MyHelperClass.someMethod(opp);     } }   The above inserts the opportunity and does not trigger an exception. Am I doing something wrong?
47851
What does InitializeComponent() do, and how does it work in WPF?  In general first, but I would especially be interested to know the gory details of order of construction, and what happens when there are Attached Properties.
90255
I want to create a countdown timer in a Unity game I am creating. Up until now my game was running for a specific time but I was using InvokeRepeating to end the game after the set time.  But now I want to display the time left in a GUI text. One approach could be to use InvokeRepeating again but this time call it every second to decrement the timer. With this approach though it would mean do extra calculations for when a minute passes in order to display time appropriately and not just display the whole time in seconds.  Is there a different approach? Does Unity have any timers built in? Also which is the more efficient method?