I have following code (obtained from online tutorial). The code is working but I suspect the way to dispose the Excel com object is somewhat not proper. Do we need really need to call GC.Collect? Or what is the best way to dispose this Excel com object?
Public Sub t1()
Dim oExcel As New Excel.Application
Dim oBook As Excel.Workbook = oExcel.Workbooks.Open(TextBox2.Text)[code]............
I have a problem with the Timer class in that there is a chance that a timer would fire right before you call Dispose() since you will probably call Dispose() from some other thread. You may have something like:
Public Sub TimerTick() Handles itsTimer.Elapsed
Do Something
End Sub
And then from somewhere else in the code, when your app is done, you call
itsTimer.Dispose()
The only way I can think of doing this is:
Public Sub SomeMethod()
SyncLock(itsTimer.SynchronizingObject)
itsTimer.Dispose()[code]...
This is not a great thing to do esp. since I am holding a lock on an object I am disposing. I can create my own lock and syncLock on that but is there a simple way?
From code analysis (Visual studio), I got this warning:
[Code]...
The warning disappear but then the literal control isn't anymore being displayed on the page... EDIT Note that the code come from a Microsoft web page: [URL]
I have a custom settings file that I designed using the designer. In my form, I have a function that creates a new instance of this settings by using a dim statement. Then I add this new settings object to a hashtable. After I exit this function, I no longer have access to the settings object without using the hashtable to retrieve it. If I want to remove the object from the hashtable, I can do a simple remove but the settings object still exists somewhere in memory. How can I dispose of this object as well since it inherits from ApplicationSettingsBase and does not have a built in Dispose() function?
View 5 RepliesIs there any sense to set custom object to null(Nothing in VB.NET) in the Dispose() method?Could this prevent memory leaks or it's useless?!Let's consider two examples:
public class Foo : IDisposable
{
private Bar bar; // standard custom .NET object
public Foo(Bar bar) {
[code]....
I am getting the following Exception when calling MyBase.Dispose ()ObjectDisposedException was unhandled.I tried adding a Try Catch around the call but it doesn't catch the exception.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
[code]....
FYI: The value of disposing is False
I'm playing an audio file like so:
VB.NET Dim audio As New Audio(Application.StartupPath & "est.wav", True) audio.Balance = 10000 audio.Play()
Which works great. But if I need to change that file, I get an UnauthorizedException because the I haven't disposed of it. But, if I add a dispose after .Play, it won't play.
I looked at the Dispose() method in System.Data.SqlClient.SqlTransaction (using a decompiler):
[Code]....
Why does everyone say in forums that it is Rolling back in the dispose? Where does it rollback?
I am using VS .net 2003 and developing a program that calls Excel. The development computer only has Excel 2003, and the target machine only has Excel 2007. Would it be possible to install Excel 12 Object Library in the development computer without installing Excel 2007?
View 4 RepliesI'm trying to upgrade a VB6 app to VB 2008. I have read the article in the tutors corner about automating Excel from VB but I cannot get it to work. Heres what I have done:
1) set a reference to the Microsoft Excel 12.0 Object Library
2) Added "Imports Excel = Microsoft.Office.Interop.Excel" to the top of the module
3) in a routine I have added: Dim X As New Excel.Application Here's where I get an error: Error 75 'Application' is ambiguous in the namespace 'Microsoft.Office.Interop.Excel'.
I use the following code snippet
Dim exlapp As New Microsoft.Office.Interop.Excel.Application
Dim xlWorkBook_new As Microsoft.Office.Interop.Excel.Workbook
Dim strOriginal As String
strOriginal = Server.MapPath(Request.ApplicationPath & "/Attachments/") & "abc.xls"
xlWorkBook_new = exlapp.Workbooks.Open(strOriginal)
The code hangs in the last line. It works fine in the development environment. i deployed in windows server 2000 ,where I get this issue. the browser goes half way and throws the below exception after some time
[Code]...
I have set the identity impersonate to true in web config. This should be mostly an access rights issue.I have even provided access rights for the "everyone " user in the excel file and as well for the interop component. Please post ur valuable comments.
I'm trying to create a pivot table by opening an Excel file from my drive.But I'm receiving the error saying "Object reference not set to an instance of an object".[code]
View 1 RepliesBasically I've coded an Excel 2007 project in VB.NET 2010 that allows you to create charts with a fair amount of interactivity. I want the user to be able to save and reopen this workbook and still have that interactivity in any already-created charts, so they don't have to re-create them.
When I create the charts, I use Sheet1.Controls.AddChart(...), which returns a Microsoft.Office.Tools.Excel.Chart with which I can handle events and such. However, when I reopen the file and look through the Sheet1.Controls collection, there are no Chart objects. Accessing the charts through Sheet1.ChartObjects.Chart gives me Interop Charts, when I need the Tools Charts.
following error message:
Method not found: Void Excel.Range.set_Value(System.Object,System.Object)
I am using VB Express 2008, and I am trying to create a COM object to use in Excel. I have looked at the walkthroughs, but it seems they only apply to Visual Studio.
Is there a way to create a COM object in VB Express?
I wrote this little AddIn sample to show you a performance issue and how to avoid it?It is just a parse of an excel workbook and runned in the main excel process (0) and a random thread created by the timer.
Public Class ThisAddIn
Dim a As System.Windows.Threading.Dispatcher = System.Windows.Threading.Dispatcher.CurrentDispatcher()
Dim t As New Threading.Thread(New Threading.ParameterizedThreadStart(AddressOf threadTest))
Dim tm As New System.Timers.Timer(20000)
[code].....
For some reason I get "Exception from HRESULT: 0x800A01A8" from the following code only if I open the XLS file outside of the application I'm coding while this code is being ran. Can anyone advise as to what might be occurring and how to fix this? Right now when my application launches I just output a messagebox informing the user not to open Excel while the data is being loaded. I'd like to correct this problem.Another thing is that when I open the XLS file externally after my application loads an instance of the file, it doesn't prompt to open it as read-only.
[Code]...
Can anyone tell me how to assign an excel spreadsheet as the datasource for an axspreadsheet object?
View 4 RepliesI have written Code for Excel File Create via ASP.Net with VB Code, I want Kill the process Explictly..I already used GC.Collect(), But it takes more time.
View 4 Repliesto have Microsoft Excel 12.0 Object Library when I click on Add Reference... in Visual Studi 2005, do I need to have Excel installed on my PC or is it ok if I gac Microsoft.Office.Interop.Excel.dll
My company is currently in the process of upgrading from Office 2000 to Office 2010. The upgrade won't take place until October, but I am currently testing it on my PC. I have some applications that reference Microsoft Excel 14.0 Object Library VERSION 1.3.0.0 and export DataGridView results to Excel. Since I upgraded my PC to Office 2010, my version of Microsoft Excel 14.0 Object Library was upgraded to 1.7.0.0. Now, Office 2000 users are having issues when trying to export data. They get the following error:"Attempted to read or write protected memory. This is often an indication that other memory is corrupt."I can't debug to find out the issue because I am running Office 2010 and it works perfectly fine for me. Has anyone else encountered this? I think it's happening right around when it starts to save the file.[code]
View 2 RepliesWell, I've searched numerous threads and I'm stumped. Though my VB.net experience is newb status.I'm interacting with Excel Workbooks/worksheets with:
Imports Excel = Microsoft.Office.Interop.Excel
Now I'm fairly adept with getting data from the excel sheet with no problem.But each and every time I quit my widows form, or execute a new command_button click to repeat an operation, in the task manager, excel.exe then opens up a new instance.Releasing the the Excel COM object seems to offer a bit of head scratching.I realize that you can get your form to activate and retrieve data from whatever spreadsheet has been directed to be opened, but I can't seem to put it back and close it correctly.I have read about the Marshal. release object methods and garbage collection with no luck so far.Do I need to import another liberary that completes this operation? I would asssume this would be taken care of as apart of the:
Imports Excel = Microsoft.Office.Interop.Excel
close excel instances opened up by my windows form? Somethig like this:
Dim xlApp As Excel.Application
Dim xlWorkBook As Excel.Workbook
Dim xlWorkSheet As Excel.Worksheet
[code]....
(so that it is no longer looked at as "read only" when the spread sheet is opened up from directly from excel)As A minor work around, I've teminated it from the task Bar with proc.kill() but this does not help because my ultimate goal is to just simply realease the excel sheet when my windows form is finished getting its data.This following code does not seem to work.
releaseObject(xlApp)
releaseObject(xlWorkBook)
releaseObject(xlWorkSheet)
Using the Office 2010 Object Library to create Excel documents from code. Is there a way to deploy the project without having Office installed on the target machine? I have a 2000 Server that Office 2010 is incompatible with.
View 2 RepliesI am trying to manipulate an excel 2000 spreadsheet in visual basic 2010 express with the following code but cannot get it to work
Imports Excel = Microsoft.Office.Interop.Excel
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[code]....
I have : Dim cell As Excel.Range = sheet.Range("A2") Console.WriteLine("Cell references to = " + ????? ) What should I replace ????? with to get A2 printed in its place?
View 2 RepliesI have a datagrid on a silverlight 4 application that I am trying to export to excel by calling the COM component for Excel in silverlight. It keeps error-ing out and tells me that the functionality is not supported. I can't quite figure out what is wrong and believe my code is solid, obviously not though.[code]
View 1 RepliesI've tried this[code]...
and it throws me an exception. I'm feeling that I'm doing something wrong with the object access, but this method worked in embedded VB, and do not works in .net.
How do I link data in an Excel spreadsheet to a chart object in Visual Basic 2010? Really basic here, I just want to draw a single simple line chart from a single column of data. Is it easier just to read the data into an array (which I can do) and somehow get it into the chart?
View 1 Repliesi made this program some time ago. it finds all numerics in an excel program and changes their formatting and it works ok. [code] my problem is, there are some alphanumeric values where i need to change the formatting of the number part of the cell example: [code] but it gives me an "Object reference not set to an instance of an object." error is there another way to solve my problem?
View 3 RepliesI need to add a reference for excel. But to do that i need to remove an earlier version i added.
How do i remove what i have already added so i can add another version?