Code Change Throws Object Error
Sep 16, 2010I have a piece of code that I believe is the culprit in a "Object reference not set to an instance of an object" error being thrown.[code]
View 4 RepliesI have a piece of code that I believe is the culprit in a "Object reference not set to an instance of an object" error being thrown.[code]
View 4 RepliesI got the following code from the demo code samples and just changed the textbox names. But it throws an error:
Private Sub Fill_TextBox()
Dim Num As Integer
Dim DSet As DataSet
[code]....
The error is:
System.NullReferenceException:Object reference not set to an instance of an object.
I have an XML file that looks like
[Code]....
I am trying to delete the song node from the xml file but i can't figure out the cause of the error I'm getting. I'm still learning visual basics. Error: Object reference not set to an instance of an object. This is my code
[Code]....
with datagridview1
while looping through all the cells
i am trying to allot a cell value to another cell value basing on some conditions
& finally delete one column.my code is as fallows
Dim i, x As Integer
i = 0
x = Me.DataGridView1.Rows.Count[code]....
error i am getting is : Object reference not set to an instance of an object.it is extremely surprising for me the same code has worked nice for me but why & how the same line of code is generating this error.
Here is the code for the button click event;
Protected Sub CompetenciesButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles CompetenciesButton.Click
Dim con As String = WebConfigurationManager.ConnectionStrings("foo").ToString()
[code].....
#1 is C# Class Library, where I have my EF model defined (3.5 sp1) and some public methods.#2 is a VB winforms app.In the winforms app, I have referenced the C# library and added the connection string for the EF model. The problem I am having is that I have a form where the user selected a .txt file to import. On the VB side, I create a byte() from the file, then pass it to a public method cleverly called Process. In Process(), everything runs smoothly until I instantiate the EF model.
using (WorkersCompImportEntities context = new WorkersCompImportEntities()) { ....
Where I receive this error:
Could not load file or assembly 'System.Drawing, Version=1.0.3300.0,
[code]....
I created a typed dataset a day or so ago, then I added a whole bunch of tableadapter/tables with some relationships etc... suddenly out of nowhere it decides my dataset "is not defined". everywhere in my code where i use this dataset now has an error. I tried not to pull out my hair and do a Clean then Rebuild solution... out of nowhere it just refuses to generate code. Object reference not set to an instance of an Object. It would be nice if it was my object so i could find it but it's not.
Curiously I also lost the little database icon on the dataset in the solution explorer.I can still open it in the designer and preview my queries etc... it just wont make the code. it's driving me insane. anyone got a solution?
I am fairly new to programming and hence require some help and advice. Here goes my problem.I have an excel workbook with defined list of names and I want to change the cell reference for each name using macros. I then want to loop this so that it can change the cell reference for each of the names. I have written a statement to achieve the above but it is throwing object defined error.
View 1 RepliesI am trying to create a function that will return a pen(System.Drawing.Pen to be exact) that will have a random color and width. I thought that something like this should do the trick:
Public Function random_pen() As Pen
Dim clr As Color = Color.FromArgb(255, random_rgb_color_gen, random_rgb_color_gen, random_rgb_color_gen)
Dim pn As Pen = Pens.PeachPuff 'just a random color else i get a null exception...
pn.Color = clr ' the error is here
[Code].....
However when the code is run i get an Argument Exception with the error message:"System.ArgumentException was unhandled Message="Changes cannot be made to Pen because permissions are not valid.""
I'm currently building an application in C#, using a basic design I came up with in VB.net for applications involving openGL. Using the Tao framework in VB, I have the following method:
Private Sub checkForGlutInit()
If glut_initialized = False Then
Glut.glutInit()
[code].....
I have created an application using VB.NET in VS2008. When I run the app in the IDE on my development machine it works fine. It also works fine when I build it and run it as an exe on any machine that also has Visual Studio installed (at least 2005 and 2008 anyway) However, when I try to run the compiled executable on any machine without Visual Studio it throws up an error "[program name] has encountered a problem and will close..."
View 5 RepliesIs there a way to call a function everytime it throws an error? I could use try catch, but I need to do it with unexpected errors.
View 8 RepliesYes its me again with yet another problem Ok so I've now gotten round to trying to display some data from my database and displaying it in a DataGridView Heres the critical part
[Code]...
In our code base there is a function which should return either an object or nothing. The exact code is this : Return NothingThe calling method looks something like thismyObj = theClass.function()if myObj <> nothing then // fails
View 1 RepliesI am trying to get the selected rows from a listview. To achieve this, I did this:
Dim numsel As Integer
numsel = Me.ListView1.Items.Count
For countme As Integer = 0 To numsel
[Code]....
It does count the selected rows, but it always throws out the error saying "ArgumentOutOfRange Exception", or something along those lines. For example, if I selected a row, it will output the results of that row. But the loop goes on. I tried everything I can but to no avail. I specifically want to select multiple rows, and I can achieve that if someone can assist me with this simple "problem" I have.
I have a major problem. Things were going great until I came across this little bug(?) which has thrown a stick in my spokes. As I will demonstrate below, it seems that when defining certain numbers Visual Studio will throw an overflow error.
Dim T As ULong = 14774537964905701134 'Overflow error in the IDE
Dim M As ULong = ULong.MaxValue '(18446744073709551615) we are below the maximum value so it should work, right?
The one solution I have found is that we can use the following declaration instead.
Dim T As ULong = ULong.Parse("14774537964905701134")
However, to make matters even more complicated the value in question is unknown and must be compiled using CodeDOM so using the Parse method isn't an option. Unless there is some way I can determine if that value in particular will give me an overflow error.
I recently upgrade a project from vb 6 to 2008. Most of the code runs fine.I have a webbrowser form control that I use to navigate local files and display them with. (i have a file list box that you click which calls the navigate of the browser control). Most file types i have test work fine and display just as they would in a real browser window. Excel, PDFs, etc... so examples of files that utilize "plugins" like acrobat reader inside the browser work great. Tiff files are the exception. No error is thrown in vb, but the browser throws 2 runtime errors, included at the end here. After the browser errors are ignored the program continues execution but will just not display the file.
i can type the path to the file (eg c: estfielsfilename.tif) in a regular browser window and it displays just like it should, inside IE, using a plugin.Prior to upgrading, depending on what was installed on the computer, navigating to a tif would open the tif with picture and fax viewer, or display it with a tif viewer plugin.
Line:1
Error: Invalid Character
when click NO to debug it goes to
Line:0
Error:object expected
I've got a code sample below that will compile, but not run. Start it in the debugger by clicking the "step into" button on the toolbar, and an exception pops up before it reaches the first line of user code:
"Could not load type 'TestPrivileges.Win32Module+TOKEN_PRIVILEGES' from assembly 'TestPrivileges, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'."
Comment out either the 'Dim ... TOKEN_PRIVILEGES' line in the module or the 'Public Shared ... TOKEN_PRIVILEGES' at the end of the class, and the problem will stop occurring.Visual Studio 2008 as well as 2010 does it.
Module Module1
Sub Main()
Dim newState As Win32Module.TOKEN_PRIVILEGES = New Win32Module.TOKEN_PRIVILEGES
MsgBox("Here I am")
[code]....
I'm trying to compile a brand new 2010 windows forms application with a form and a single button that should display a msgbox with "hello" in it.When I try to compile I get the error message:
Unable to write to output file <filename>: This implementation is not part of the Windows Platform FIPS validated cryptographic algorithms.
The application that I am working on is a Service Desk App. I have a form there that uses a DropDownList that contains employees names coming from the Active Directory. Any employee can make a request and save it. Problem arises when an employee leaves the company and consequently his account is deleted from the Active Directory. When some other employee searches the DB to finds a relevant Service Ticket that could be of his use, when tries to open it an error is thrown that indicates that the name does not exist in the DropDownList items.
UPDATE:I am adding some code so that it can be more clear.
<asp:FormView ID="FormView1" runat="server" DataSourceID="SqlDataSource1"
DataKeyNames="ITRequestId">
<EditItemTemplate>
[code]....
VB.Net MyExcel.Close(SaveChanges:=False) throws an Error
View 7 RepliesI am attempting to list files within a folder on an FTP site. When I run the debugger, I get a clean run the first time with no problems. Subsequent attempts lead to a 550 error: "The remote server returned an error: (550) File unavailable (e.g., file not found, no access)." However, If I step through the process in debugger, It works fine. I'm thinking this is a timeout issue because there are many files within the folder. Any suggestions?
Private Sub ListFTP(ByVal Directory As String)
Dim Req As FtpWebRequest = Nothing
Dim Response As FtpWebResponse = Nothing
[code]....
The application was previously using GlobalMemoryStatus() and MEMORYSTATUS structure to retrieve memory information. But since, the Physical memory of the hardware in which the application runs is more than 2GB, the code was changed to use GlobalMemoryStatusEx() and MEMORYSTATUSEX structure. When this function was implemented and the struture was used its thrown compilation error: "error C2501: 'MEMORYSTATUSEX' : missing storage-class or type specifiers"How to solve this issue???
View 1 RepliesI have an XML file where some of the elements have periods in their names. Using the code below, I receive the error:
"System.ArgumentException: Child list for field Stock cannot be created"It successfully reads the file if the periods are removed( i.e. StockAdjustment instead of Stock.Adjustment)
Dim myXMLfile As String = "C:file.xml"
Dim ds As New DataSet()
Dim fsReadXml As New System.IO.FileStream(myXMLfile, System.IO.FileMode.Open)
Try
[code]....
Is there a way to handle elements with periods in their names?
I have a project with multiple forms that are used to edit tables in a project data source (access DB). All the forms work fine, except the ones that use designer generated lookups.
When I am editing a row in a bound DGV on the lookup forms, they function fine, and the save button works fine. However, once I go to close the form it starts throwing "System.ArgumentException: DataGridViewComboBoxCell value is not valid." multiple times.
I've created applications similar to this in VS2008 without any issues.
I have created a very basic web service in vb.net using vs 2008. When I run the service within visual studio debugger, the service runs fine and gives me the expected results. When I deploy the service to the server and invoke it from a client, it always throws a NullReferenceException error when trying to access the data. More specifically when I call the DbConnection open() method within a dbhelper executeScalar method.
I'm using a custom dbhelper class I found on the web here: [URL] The only thing I've changed is the _factory at the top points to Providers.Odbc (since I'm using a ODBC connection). Like I said previously, the service (and the dbhelper class) work as expected within VS- it's only once I deploy it that it seems to bomb out. I've even tried hard coding the connection string in case it was having problems getting that but no difference there.
I've used this in a couple of places and it simply doesn't work. Despit the try event, VB.Net still crashes or throws up an error.
View 14 RepliesI am writing long text (1K to 2K characters long, plain xml data) into a cell in excel workbook.
The below statement throws COM error Exception from HRESULT: 0x800A03EC
range.set_Value(Type.Missing, data);If I copy paste the same xml manually into excel it just works fine ,but the same does not work progamatically.If I strip the text to something like 100/300 chars it works fine.
At the top of my code for the form I have the following statements (and some other unrelated ones to):
Dim LastDataRow As DataRow
Public Event RowChanged As DataRowChangeEventHandler
When my form loads I run the following line of code:
AddHandler dt.RowChanged, New DataRowChangeEventHandler(AddressOf Row_Changed)
After the form loads I have a FetchData button which connects to the database and brings the records into a datatable object. During this fill operation my Row_Changed event fires (for every record I think) and tries to run DataAdapter.Update(DataTable) (pseudocode) which ultimately fails because I haven't yet created commands. The error I get in my Row_Changed procedure is:
Update requires a valid InsertCommand when passed DataRow collection with new rows.I hadn't even planned to use an InsertCommand at all since I will not be allowing users to insert records from this form. I do plan to allow them to delete or modify existing records, but not insert new ones.run my AddHandler statement after filling the datatable. However, I'm trying to figure out how to rewrite my code so that I can refresh the datatable without closing out the form/application and having to open it up again. I think that's a problem for a separate discussion.
In a ASP.NET app from a procedure IN a VB code file a dynamic control is called. The first problem may solve the second. In the following line of code I am getting an "end of statement expected" error at the following line.
[Code]....