When large number of records in Database, it throws error "Operation has been canceled by the user" in vb.net. I want to retrieve records from DB2 and display the records in DataGridView in VB.net. If number of records is less it works fine. But if the database tabe has large number of records it throws error "Operation has been canceled by the user". [code]
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I get this error while trying to add a printer driver.The operation was canceled by the user. (Exception from HRESULT: 0x800704C7)
Public Function AddDriver(ByVal DriverName As String, ByVal InfFile As String) As Boolean
Try
Dim PRNADMIN As New PRNADMINLib.PrintMaster
[code]....
UPDATE: The application requests administration rights in app.manifest (requestedExecutionLevel level="requireAdministrator")I get the same error with UAC On or even OFF.The driver is not digitally signed If i install the driver manually i get the windows security warning, with "Don't install this driver software" as the default option (And unfortunately, do not get that Message while running the code above).
I am handling many of the BindingNavigator tasks (MoveFirst, MoveNext, etc.)in code to ensure that I always ask the User to save his changes.
The one area I am have a problem is PositionItem. I would like to sense that the User has changed the Record Number in the BindingNavigatorPositionItem, handle my record Update, and move to the Record Number the User entered I have looked all over and have not found any way to do this.
use the following code to create a database in ms access
Code:
'reference: Microsoft ActiveX Data Objects 2.8 Library
'reference: Microsoft ADO Ext. 2.8 for DDL and Security
[code].....
There is newer code in a follow up post. I suggest using the code in the later post rather than the code in this one. You can still read this post though. When designing a user interface, one should be conscious of how many individual controls are required to implement the functionality. In some cases an initial design may begin with many buttons or textboxes (for example) but then further review of
the actual required functionality allows for a reduction in the number of unique controls.
But other times, there isn't a better way (which will still make sense to the user of the application) then to have a series of many repeated controls. So in the cases where one can be certain that the best UI implementation for an application will require the use of multiple copies of a given control, then it often becomes necessary to maintain some method of managing all of those controls at various points
throughout the application. Doing so typically requires that one build up some collection of controls which can then be accessed by index in order to work with any given control; but this can lead to a lot of clutter in the code file which handles these control's events. For instance there will be some kind of collection declaration, some recursive routine to find all of the controls of interest, and then any number of event handler methods with long lists of Handles clauses, or additional code loops to wire up the event handling for each control.
Purpose Since most of this functionality could be considered a requirement regardless of the type of control being managed, or its required functionality, it may make sense to wrap all of the control management functionality into a single class. And since our first requirement is a collection of controls, then a base collection class could be the perfect starting point for our control manager. There are a number of existing thread around this topic, with some recent (at the time of this writing) ones being:[URL]..In this, and related, threads I have posted examples of a simple TextBoxManager and ButtonManager control. But again, with so much similar functionality required regardless of the control being managed, it would be technically possible to create a generic ControlManager(Of T As Control) class which can manage any type of control.
[Code]...
So in summary, one can facilitate managing a large number of user interface controls by building a "control manager" class which both encapsulates the list of control instances, and deals with adding and removing defined event handlers for every control it manages. The generic control manager class itself can be inherited and extended into a more specific class on a per-application basis in order to provide more application-specific functionality. Reed Kimble - "When you do things right, people won't be sure you've done anything at all"
I've written a VB.NET program for a client that stores all of its data in XML files. I use the XMLReader to read the data into a dataset. When I run the sub to encrypt the XML file, I'll get the following message: Error: mscorlib: The requested operation cannot be performed on a file with a user-mapped section open.
It doesn't happen all the time, so I know it does work. But on occassion, I'll get this message. I've been all over the forums and I've tried everything I've read to try and stop this error.
I close the reader object and set it equal to Nothing. I've even tried using DoEvents to make sure the object finished closing before running the Encrypt sub. Nothing has helped.
I develop on a x32 PC. It works fine on the development machine. But then, when the client runs it on a x64 PC, he gets these errors. Could the x64 system really be running so fast that the .Close() and the = Nothing and evern the .DoEvents() can't keep up?
This work nicely
Public Const test As ULong = 1 << 30
This doesn't work nicely
Public Const test As ULong = 1 << 31
[code].....
I am trying to add a new record everytime i do my navigation gets all messed up I also need an update button... I would like so when i hit new record the record of will be(ex. If Im adding record number 30 it will say record 30 of 30, hit add new it will say record 31 of 31) my code is below.
'Class File
Module Class1
Public MasterConnection As New OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=db1.mdb;Persist Security Info=False;")
[code].....
My VB application is behaving strangley. I have form with fairly large number of controls. I am using case against radio buttons. after curtain number of buttons, it stops responding to more radio buttons.
Then I tried to split controls in to 2 form but now my form.showdialog() too now working properly. It takes new from names but show the old form when running.
I am working on a project in which admin wants to send updates of website via email to all registered users on web site.How to do this.?
[Code]...
This is the backend code i am using for sending 1 email.How can i use this to send emails in bulk?
I am using VB Express 2008 and want to return the titlebar text of a window This is what I have:
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As String) As Long
Private Const WM_GETTEXT = &HD
Private Const WM_GETTEXTLENGTH = &HE
[code]....
This should simply return the window name I.e. "Calculator"But debugging it i get an "OverflowException" on:
strtmp = Space(length - 1)
If I look in the length variable it has "8975925931411505153" in it Why is it so big, and why is it not just "10" for the number of characters in calculator?
While I've previously many years of relational databases and procedural languages, I'm stumbling with Visual Basic. In this problem, the simple situation is that I have two files, parent and child. The primary key of the parent file (Area file) is linked by a relation to one of the two fields that makes up the primary key in the child file (Project file) (unique key is formed from 'area' and 'project'). I have the default table adapters created on both files. I have created two maintenance forms showing one each of the two files in datagrid view format.I can create some records in the Parent (Area) file, but when I try to create a record in the child (Project) file, using one of the valid key values from the Area file, I get the 'ForeignKeyConstraint [relation name] requires the child key values [actual value] to exist in the parent table' which I'm absolutely definitely sure it does.
I haven't done any actual coding for those two maintenance forms, just dragged-and-dropped the files from the data sources screen onto separate forms so it creates the controls itself. But I can't work out, if it already knows the data does exist because I can load it back in to the Area maintence form, why it can't check itself to find out the record does exist. Why does it think the record from the parent record doesn't exist? It does exactly the same thing, whether or not the database is in access or SQL Server Express. I have all the latest updates.
I've a situation where I am trying to extract a large number of URLs from a site, but the site which provides the URLs has an obstacle. Rather than the link directly to the site, they provide a link to an internal page, which automatically redirects me to the URL I need.
i.e.
<a href="www.StartingSite.com/outgoing/1234" ...> Example.com</a>
which passes me to an internal page, then automatically routes me to Example.com
I've suspected if I can do this, it would be through cookies.
Perhaps a little more work, I could create a page which calls each page, then I could acquire the URLs from my history, but my browser would crash for the # of URLs I'm extracting.
any means I could gather the end URL of this link?
I am using zipforge.net to archive files in a small backup program I am creating. Everything works fine however if I try to archive a large number of files the process of zipping them gets slower the further along in the job it gets.
Example: I have a directory that contains a little over 100,000 files in it. Each file is only about 200k of text. When I use the zipforge zip class it starts zip'ing very quickly but as it gets about 40% of the way through the directory it starts to slow down... at about 60% its working at a snails pace.
Memory usage for my solution also goes up proportionate to the archive file size as it grows. Currently it takes around 26hours to backup this directory which only contains 4 gigs worth of information.
If I use a program like winzip I can zip the folder in less than an hour. I am thinking there has to be a way to write to the end of the zip file without having to open it every time or without keeping it open. My backup software scans the specified folder and writes each file path and name into a text file. Then it reads the text file line by line and passes the path + file info to the zipforge addfile().
I know this is probably a stupid question. I am converting a huge string to a integer, it is not working.....saying the number is too large to handle. It is only a 10k character string.I figured this would be fine because 2^16 power is 18446744073709551616.
View 5 RepliesI'm working on a project that involves localizing a large number of Windows Forms. We're dealing with layout using the TableLayoutPanel control, which works nicely. One area we're striking problems with is when we set the Form.Localizable property to True, we then end up having to manage one .resx file per form per language.
That would be fine if the .resx files only contained the Localized text, but it also contains a vast amount of layout data for the form. Is there a way to separate the localizable text elements from the control layout information, that continues to work in the visual studio IDE? I've noticed that I can modify my the form's designer file to look at another resource file, but when I use the form designer, these changes are deleted:
'Label1
Me.Label1.AutoSize = True
Me.Label1.Dock = System.Windows.Forms.DockStyle.Top
Me.Label1.Location = New System.Drawing.Point(3, 0)
Me.Label1.Name = "Label1"
Me.Label1.Size = New System.Drawing.Size(61, 13)
Me.Label1.TabIndex = 1
Me.Label1.Text = My.Resources.ResourceManager.GetString("Form1_Label1_Text")
I am having a problem that I keep getting the following error when I try to run my program.I am trying to make a circle the size of the value of FrameSize.A first chance exception of type 'System.InvalidOperationException' occurred in System.Windows.Forms.dll
This is the details of the error:
System.InvalidOperationException was unhandled
Message=An error occurred creating the form. See Exception.InnerException for details. The error is: Cross-thread operation not valid: Control '' accessed from a thread other than the thread it was created on.
Source=DreamCatcher[code]......
I am using the folowing logic to create an event that can be canceled...
Code:
Public Class ParentClass
Private WithEvents MySubClass As New SubClass
Public Sub DoSomething()
[Code].....
It is my opinion that if you needed multiple things to happen either you would implement some coordination between your event handlers as to who chould cancel when, or have one handler that calls the multiple methods and decides the cancel in one place?
I have to export the data from the database to .txt file, I have the code below that does export it to .txt file but I'm having problems with this code because the data that I'm exporting is about 5 000000 records, it is quite slow and sometimes the pc can't handle it and stops the exporting.
Dim saveFile As New SaveFileDialog
If saveFile.ShowDialog = Windows.Forms.DialogResult.OK Then
command = New SqlCommand
[Code]....
In my application, every time a button is pressed a complex interface is built, it requires few seconds to be built.All works well till someone press the button too quickly and the application lag behind.Is there a way to read how manu times a button has been pressed so I can jump to build the last interface number equivalet to the sum of the last few click avaoind to try to build the interfaces in the middle.
View 7 RepliesIf you are working on a large record in database. How you manage to use the INSERT,,UPDATE? I mean when selecting a record base on two tables or more and those tables consist of 20 columns it hazard to put all those columns in one query.
[code]...
How to lessen the code without typing all those queries over and over again ?
I want to load 2 crore records in a treeview control with parent child Hierarchy order
for example
- Groupa
- a1
- a2
[Code[....
This is probably a stupid question, but how do you make a function which takes a number then does an operation to it again and again until it gets a vlue which it already has seen, when it returns all of its values? I have this function:
Private Function fractal(d as string) As double
Fractal = Val(D) * (Val(D) - 1)
Fractal = FormatNumber (Fractal, 2)
[code].....
Dim lv As Integer
For lv = 1 To 33
picPileCard(lv.ToString).visible = False
Next
That's the code but its saying the name hasn't been declared.
I wrote last week about a problem with an MDI program that had a large number of forms (each with a large number of controls on it) that was "sluggish" in loading and in switching between the child forms.I've attached an example program in VS2008 (though the actual app is VB2010)Rather than show the hardware control application with all of the text fields, and picture boxes acting as indicators, I made a simple program to show the point. This is exaggerated as this just loads 2000 or so text boxes on a form. In the real app I have ~ 200 assorted controls per form of picture boxes, scroll bars, text boxes, labels etc. Also, there is a large full screen .jpeg as the back ground of each form. All are generated at run time and are placed on the form in the New call of each form. (as in the sample attached)main issue seems to be the methodology I use to switch between child forms. I make the current form .visible = false, and the next.visible = true. I have used this as it "keeps the place" on each page if the user has scrolled or is looking at one section of the form. When the next form .visible = true happens I see the controls added in a "machine gun" fashion instead of all at once.
View 28 RepliesI always make back ups of my projects in case I'll really really mess up on the way and want to go back to more stable version. I've tried running one of my back ups few days ago and ended up with importing pfx key canceled. What exactly is pfx key? And what do I do to have my code compiled?
View 2 RepliesWe have a customer, who prints a large number of a batch job to a reporting service. When printing large batches of jobs, occasionally he would get a WebException from reporting services saying "The underlying connection was closed".What is the work around for this? Somebody added this portion in the code [code]It doesn't seem to fix the issue though. The customer still notices the Web Exception when she prints a large job to reporting service.
View 8 RepliesOur current solutions/projects have several classes combined into one file, I'm told this was done due to the slow compile times in VS
View 6 Replieshow to create an error message by message box to tell the user to enter a number only if they key in a character value?
I MEAN AFTER THEY PRESS THE CALCULATE BUTTON
Private Sub btnCalcFat_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalcFat.Click
Dim intFat As Integer
intFat = Integer.Parse(txtFat.Text)
lblResultDisplay.Text = txtFat.Text * 9
End Sub
My text box is call txtFat
Running VS2008 working on a customized DotNetNuke version. This issue has come up a couple of times figured I'd see if it's unique to this installation or if it's a IDE bug.
In short I have files that get locked as Readonly and the only way to unlock them is to do a build.
The app I'm working with takes > 60 secs. to build on my box. This error seems to reproduce fairly regularly but you'll need an app that takes a while to build to try it.
During a build try to edit a file.
You should get the error "Cannot currently modify the text in the editor. It is read-only." and a little lock should appear on the tab.
If you wait till the build completes the lock disappears and the file can be edited.
However if instead you cancel the build the file stays Read-Only until such a time as you either restart the IDE or run a build and let it complete.
Looks to me like someone forgot to call the unlock files method in the cancel event handler.
