Race Condition With GDI+?
Jan 21, 2012
I use a worker thread to do the procedure of query and fill the datasetAnd I use 3rd party component called DevExpress XtraGrid: GridControl to view the query outputI don't forget to use invoke and delegate to set the GridControl.datasourceOn Timer.Tick(), the thread is started and the procedure is called user has scrolled down the GridControl, even only one scroll value instead,and then the Timer.Tick() fired, I gottwo errors randomly. Mostly aNullReferenceException error and eventually anInvalidOperationException error
************** Exception Text **************
System.NullReferenceException: Object reference not set to an instance of an object.
at DevExpress.XtraGrid.Views.Grid.ViewInfo.GridViewInfo.UpdateCellAppearance(GridCellInfo
[code].....
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Mar 30, 2009
I have a legacy data table in SQL Server 2005 that has a PK with no identity/autoincrement and no power to implement one. As a result, I am forced to create new records in ASP.NET manually via the ole "SELECT MAX(id) + 1 FROM table"-before-insert technique.Obviously this creates a race condition on the ID in the event of simultaneous inserts.
What's the best way to gracefully resolve the event of a race collision? I'm looking for VB.NET or C# code ideas along the lines of detecting a collision and then re-attempting the failed insert by getting yet another max(id) + 1. Can this be done?
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Jun 7, 2012
im having problems with IP To country code, it checks country on .dat file, and it gives this error.Probable I/O race condition detected while copying memory. The I/O package is not thread safe by default. In multithreaded applications, a stream must be accessed in a thread-safe way, such as a thread-safe wrapper returned by TextReader's or TextWriter's Synchronized methods. This also applies to classes like StreamWriter and StreamReader.
My
Dim country As String = Me.geo.lookupCountryName(DataGridView1.Item(1, count).Value)
DataGridView1.Item(4, count).Value = country.ToString
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Aug 1, 2011
For a race, I am trying to evenly disperse the heats for smaller race groups within those of larger race groups. I do not want the smaller groups to finish too early and I am also trying to minimize groups running back to back heats.
As an example:
Group A has 4 heats
Group B has 2 heats
Group C has 1 heat
The resulting schedule would look something like this:
A1 B1 A2 C1 A3 B2 A4
To complicate things, there could be any number of race groups and each race group can have any number of heats.
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Dec 29, 2011
Basic out line connecting to an irc server. We connect to this server using a TCP client on a separate thread from the UI. Now the raw numeric for the MOTD is "372" so when our streamreader reads this value from the worker thread it raises it's value and displays it to a RTB. Now my issue. When i connect to a server i wait till raw "372" before i check to see if i need to join a channel. But a lot of servers have more then then one line MOTD each sending there own "372". So if a server has a long MOTD that could mean over 100 "372".
Now while it does not effect the UI of my app i wish to move the "372" to it's own thread from the current worker thread. But thats the problem. How do i move the MOTD to it's own thread when it's still being read.
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Jan 23, 2009
I have been given an assignment for my VB.Net class. Basically,given the race car's weight, horsepower and distance traveled,determine the time.I am going a couple of steps further...
(1) I am including two pictures of competing race cars at the staging area and a short track to travel (makes the assignment more interesting). I would like to know if it is possible to provide an animated light sequence of the Race Tree (staging lights, 3 sets of amber lights, and the green light) with a timer activating the start of the race.
(2) I would also like to incorporate a "sound" track of a race car as the two race cars proceed to the finish line. I realize that the user may enter any distance for the race. Regardless of the amount of time it takes to run the track (if given a long distance),I'm going to calculate the total time to span just 15 sec. Again, I would like to know if it's possible to incorporate these two
separate modules into my program using the Window's form application?Also, what resources should I study to gain knowledge on how to
execute the two modules?
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Aug 10, 2011
i mean for e.g., numbers are between 1 and 100 .i want to show messagebox for each number as text for example "One" for 1.
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Oct 18, 2010
I had posted this question before but didn't get the right answer -here's my code again with the if condition.
Dim provider As CultureInfo = CultureInfo.InvariantCulture
Dim a1 As DateTime = Nothing
If date1.selectedvalue isnot nothing Then
[code]....
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Sep 25, 2011
I have a problem. I have been programming an activation type of security protection for my software but i ran into problems when i try to generate an alphanumeric key with conditions. i cant seem to be able to make the keys to be valid with the condition. Basically i can get the 25 keys but all of them seem to be returning 1 (ones) instead of 0 (zero which what i want. below is my sample code may be someone can tell me what i am doing
[Code]...
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Dec 8, 2009
I have the following code which gives me an error at run time. The problem is when TxtSearch.Text - is not an integer a message box should be prompted saying- Only a numeric value is allowed in this field, otherwise continue with the sub.
Private Sub ButtonSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonSearch.Click
Dim query As String
[Code].....
The error I receive is showing ''saved_prac = cmd.ExecuteScalar()''..
First it brings the Message box - Only a numeric value is allowed in this field. When I OK it, then it brings another message box "error converting data type varchar to numeric". When you click OK the application crashes...
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Jun 20, 2010
What is the correct syntax to go to the next sequence in a loop if certain conditions are met bypassing the contents.
I am using goto and inserting a line number which is probably not the best way.
I.E. My syntax:
For i = 0 to 100
If i = myvariable goto 100
Functions to be performed
[Code]....
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Nov 15, 2010
When I am click a button every time adding +1 in a textbox but I want to give condition that it will add until the desite is 8 I am using the following code
If e.KeyCode = Keys.Down Then
textbox1.text = Val(textbox1.tex)+ 1
End If
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Sep 15, 2011
I'm trying to read data from database.
If objReader.Read = True Then
If objReader("cell") IsNot DBNull.Value Then
Me.txtContact.Text = Trim(objReader("cell"))
[code]....
Problem is, no data displays if cell is empty.
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May 21, 2011
my problem is that i want to put if condition on textbox for example i want if key board keypress on textbox then enter no in textbox
[Code]...
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Aug 16, 2011
Scenario: I need to create a report for the auditors for an ASP.Net application. I have a program that parses the XML of the web.config files in a directory for the authorization tag and creates a report providing which users have access to which folder in the site structure. The report is shown below.
UserName, Firstname, LastName, Directory, Roles, Access,
LastLoginDate
Problem: As you can see from the report some directories (the middle column with GISMO in it) show up twice, with both allow and deny for a user. I am wondering if there is a way to group the results in such a way that if there is a row that has allow for a directory then the deny's are not shown but otherwise they are.
Alternatively if this can be manipulated in VB.net/C# that is also an option. It comes back there and is pumped into an Excel spreadsheet.Edit: I should have explained better. I still need the deny rows to show if the user isn't allowed in the directory. But if they are allowed then there is no point showing the deny rows.
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May 14, 2010
I am developing an application to my official use. In which I have one combo box for selecting the customerName.When I select the custName from the combobox I want to retrieve data from a particular field of a table and sum it within a selected date value. i.e: When the user selects a custName from the combobox the field within the date value should be summed up and grouped by custName. I think it is possible but I dont know how it is to be done.
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Jun 16, 2010
I think im going mad but can some show me what im missing, it must be some stupidly simple i just cant see the wood for the trees.BOTH side of this if then else statement are being executed?
Ive tried commenting out the true side and moving the condition to a seperate variable with the same result. However if i explicitly set the condition to 1=0 or 1=1 then the if then statement is operating as i would expect. i.e. only executing one side of the equation...
The only time ive seen this sort of thing is when the compiler has crashed and is no longer compiling (without visible indication that its not) but ive restarted studio with the same results, ive cleaned the solution, built and rebuilt with no change?
Dim dset As DataSet = New DataSet
If (CboCustomers.SelectedValue IsNot Nothing) AndAlso (CboCustomers.SelectedValue <> "") Then
Dim Sql As String = "Select sal.SalesOrderNo As SalesOrder,cus.CustomerName,has.SerialNo,
[code]....
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Sep 16, 2011
I have one datagridview with first column may contain checkbox or could be empty space depending upon data in second column. How can I put checkbox or keep it empty in first column whever required ? Checkbox column puts check box in all cells of first column.
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Jul 29, 2010
In aspx page:
if (<%= Not Me.ThisVisa.PassportExpirationDate.IsNull %>){
Returns error:Microsoft JScript runtime error: 'True' is undefined
I tried this:
if ("<%= Me.ThisVisa.PassportExpirationDate.IsNull.ToString %>" != "True"){
..but I get a compile time error:
Error 5 Option Strict On disallows implicit conversions from 'String' to 'Long'
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Nov 1, 2009
I've got this function which converts wav files to mp3. I call this from my button_click handle. The thing is, when the conversion is started, the rest of the code in the button_click handler continue, while the conversion is happening in a different thread. Now, I need the rest of the code in the button_click handle so continue to try until a boolean is true, so that I know that the conversion is done before the rest of the code continues. I've tried using Do While but it didn't seem to do the trick. Perhaps it's just me though..
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Feb 21, 2011
as the title says , for example i want to say if the first letter in textbox1 is "d" then do a specific command ,so what is the code for this ?
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Aug 12, 2009
I have form on VB2008 and Mysql as Database which have 24 textfields on a form.I want to impose certain condition that when ever user adds/updates/modifies data into database for example You may have entered text in a numeric fied or a number that is larger than the fieldsize setting permitts. if violates message box should appear with Invalid entries
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Oct 6, 2010
So I have case statements grouped together here, but I have a few case statements that need extra decision based on a second variable after the original case is confirmed. [code] And then just have 3 case statements instead of one but the code wouldn't look ugly. By the way Condition is declared instead the same select.Is there any reason why I shouldn't use this if it does work?
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Feb 17, 2011
How Can I Row Filter with a condtion on colam where Coloum1 = > 0
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Jan 17, 2012
I have a String variable in this page named "a".I wanted the scenario to be.When the page is started "a" will be null.But when the user selected an entry from the DetailView Control "a" will become "have".The following is my code. But i keep getting "a" = null even though i have selected an entry from the detailView control.[code]
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Jan 30, 2010
My problem consist in show values into a cell of a DGV control, for example:MySQL Table:
ID - Name - Price - Type
1 Mouse Pad 2.85$ - a
2 Keyboard 10.50$ - a
[code].....
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Mar 3, 2011
I'm trying to format a label based on it's value and I'm having difficulty making the font bold. All other formats work apart from the "bold" part. Here is my code:
Private Sub SchoolTxt_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles SchoolTxt.TextChanged
If SchoolTxt.Text = "Invalid DfE Number!" Then
[code].....
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Sep 20, 2011
i set this code in my mainform form_load Tabcontrol.Tabapages.clear()when i close all the open tabpage from the tabcontrol. there is still a window left of tabcontrol although its empty. it annoys me because i cannot see my mainform wherein it has a design, i cant see it bcoz of that empty tabpage window from tabcontrol.
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Aug 30, 2010
i want to validate many textboxes with same condition....Do i need to write code for each text boxes.
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May 28, 2012
i have 1 query with aggregate with condition using access
SELECT
HD.No,
SUM(IIf(DT.Status = 'A', 1, 0)) AS One,[code]...
i can run it in access but not in .Net QueryBuilder
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