Reg Data Connection & Null Contents?
Mar 10, 2012Reg Data Connection & Null contents
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Asp.net - Net Null Reference On Database Connection?
Jun 13, 2012I know I'm being an idiot here and I just can't work it out. But i'm trying to take some data back from a vb.net database. It's falling over with a Object reference not set to an instance of an object error. And before the code runs it's saying the variable is being used before it's set, but I can't see how. Code:
Private taNotifications As dsDataTableAdapters.NotificationsTableAdapter = New dsDataTableAdapters.NotificationsTableAdapter
Dim notification As dsData.NotificationsDataTable = taNotifications.GetDataByClientID(userrow.UserID)
If notification.Rows.Count > 0 Then
Dim notificationrow As dsData.NotificationsRow
Dim forwardURL As String = notificationrow.ForwardLocation
End If
It falls over on the Dim forwardURL As String = notificationrow.ForwardLocation
Null Exception Error Using Connection String In App.config
Sep 21, 2011I've moved my Database connection string into my app.config - however its causing a null exception error when i use it
App.Config
vb
<connectionStrings>
[Code].....
[2008] Error - Unable To Read Data From The Transport Connection: The Connection Was Closed
Mar 15, 2009I have a simple scraper. It works on some websites, but on some there is this Error:
Quote:
IOException was unhandled Unable to read data from the transport connection: The connection was closed
It is occuring at "Dim htmlresults As String = Urlcontents.ReadToEnd()".
'Create the HttpWebRequest object
Dim req As HttpWebRequest = WebRequest.Create(URL)
'Set the timeout to 1 second (or 1,000 milliseconds)
req.Timeout = 10000
[code]....
Dont Get Any Data From Socket When Data Should Be There And No Exeptions Raised, Connection Is Open. Using DataAvailable To Wait For Data
Mar 24, 2011I have a problem reading data from an RFID-reader. I connect to the reader by tcp and wait for DataAvailable to be true, then reading the data until I got a end of data character. Then I just go back and waiting for a new DataAvailable. This is done in a own thread for the function.
There seems to be some kind of timeout, If I don't got any data in a couple of minutes, then it just sits there in the do/loop waiting for DataAvailable. I hold the card to the RFID reader, it beeps, but there is no data available. I don't get any exeptions, and the information says that the clientsocket is still connected. Are there anything more I can check?
If I put the card to the reader in a minute-interval it seems as this will never occur. So 2-3 minutes idle:ing seems to do this.
Here are my code to read data from the socket, I have taken away some irrelevant code:
Sub test(ByVal ip As String, ByVal port As Integer)
' this sub is meant to run forever
[CODE]......................
VS 2008 Select From Excel Returning Null Data Instead Of Real Data?
Dec 22, 2010I typed this question once already, hit preview, and somehow never got the preview and lost what I typed. It has been that kind of a day.So here is my quick overview then I am going shopping. I am using OLE DB to select from an excel spreadsheet. It has over 15000 rows and 33 columns. Sometimes even when a cell is not null, it is returning a null value. If I just do a "select * where [termination date] is not null", for example, it will return no rows even though I can see with my own eyes that sometimes termination date is not null.
View 9 RepliesError - System.Data.SqlTypes.SqlNullValueException: Data Is Null
Jun 22, 2010I can't get past this error in my loop through the data reader specifically dr(12). I tried adding .To String but that doesn't seem to work either. Can someone help me with what need to do so it can read even if there is a Null value. My code is below:
While objDataReader.Read()
'Set up DataRow object
Dim dr As DataRow = DataReaderTable.NewRow
[code].....
Sends Data On A Networkstream Through A Tcp Connection - Error "An Established Connection Was Aborted By The Software In Your Host Machine"
Aug 18, 2009I have a program that sends some data on a networkstream through a tcp connection.
[Code]...
The Connection String Could Not Be Found Or Data Provider Associated With The Connection String Could Not Be Loaded
Mar 11, 2010I got this Error Message while I try to preview the records in Dataset Designer:"The connection string could not be found or Data provider associated with the connection string could not be loaded"
Here is my dataset.xsd code
<Connections>
<Connection AppSettingsObjectName="MySettings" AppSettingsPropertyName="loginConnectionString1" IsAppSettingsProperty="true" Modifier="Assembly" Name="loginConnectionString1 (MySettings)"
[code]....
Way To Create Empty Data Table / Update Its Contents Based On Columns Not Add Data Based On Addition Of New Rows
Apr 6, 2011I am creating a project in VB.NET in which one of the reports require that the name of employees should be displayed as column names and whatever work they have done for a stated period should appear in rows below that particular column.Now as it is clear, the columns will have to be added at runtime. Am using an ODBC Data source to populate the grid. Also since a loop will have to be done to find out the work done by employees individually, so the number of rows under one column might be less or more than the rows in the next column.Is there a way to create an empty data table and then update its contents based on columns and not add data based on addition of new rows.
View 1 RepliesDB/Reporting :: Cannot Find In The Data Toolbox The Connection And Data Adapters
Sep 27, 2009I recently switched to V.Studio 2008 and using VB. I can not find in the data toolbox the connection and data adapters. Should I do something else to make this appear so I can drag them in my form.
View 2 RepliesPrint Contents Of Data Grid
Jul 2, 2011How can we print all the contents of data grid???
View 5 RepliesData Grid Contents To Access Database?
Mar 1, 2012how to get my data out of access and to a data grid. What i want to do is, edit this data in the the data grid and save all alterations to the data grid back to access. There must be a command which copies all the contents of the data grid back to the access database??
View 6 RepliesDisplaying The Contents Of Pixel Data Onto A Picture Box?
Nov 11, 2010I have a code found in Internet which does the job of displaying the contents of pixel data onto a picture box. The Code goes as given below:
HTML
Protected Overrides Sub WndProc(ByRef m As Message)
Dim myBMP As Image
Dim pal As System.Drawing.Imaging.ColorPalette
[Code].....
Exporting Contents From Data Grid To Excel?
Apr 4, 2011I'm trying to export the content of a data grid to an Excel file. But here is my problem:
1. If I use a Data Grid which was set to allow Adding and Editing of columns ( this appeared the first time I add the control to the form) , the resulting excel file will show all the content of the data grid, except for the Headers ( Column names) .
2. If I use a Data grid which was set to disabled adding and editing of columns, the resulting excel file is lacking the bottom-most row of the data grid content. The Headers are also not included.
I cannot choose Option 1, since the data grid must not be editable by the user. I cannot choose option 2 since the last row is being omitted. Another thing is that the Column Names ( the data are coming from a MS Access File) are not added into the Excel File for both Option 1 and 2.
Here is the code I'm using. I found it from the net and tried changing the values of i and j but still I can't get the result I wanted.
For i = 0 To dgreport3.RowCount - 2
For j = 0 To dgreport3.ColumnCount - 1
xlWorkSheet.Cells(i + 1, j + 1) = _
dgreport3(j, i).Value.ToString()
Next
Next
View The Data Contents Of A Datagridview On Screen?
May 13, 2010is there a way to view the data contents of a datagridview on screen? i mean if i have a dgv with 7 columns and 7 rows, and i can only view 5 columns and 5 rows of it when i run the program cause i have a small form,(regardless of the scrollbars) is there a way that when i click the button 'viewonscreen', the whole datagridview will be viewed on screen?
View 3 RepliesNULL DateTimePicker Text, If There Is No Data
Jan 7, 2010I have about 7 different DateTimePickers that I populate with data from my database. In my database there are Date fields that are actually NULL like a date hasn't been set. I have allowed for this to happen but every time I load up the information into the DateTimePickers, a default date appears even if no data is there in the database. If there is no data, I want the DateTimePickers text to be nothing. Is there anyway around this annoying problem?
View 11 RepliesCopy Contents Of One Array Of Booleans To Another, Preserving Contents But Adding Additional Boolean Values?
Nov 11, 2010i have an array of booleans whose current boolean values I want to preserve but add additional length to the array? How can I achieve that? My code looks like this:
Dim Array() As Boolean
Dim ArrayInterimShort() As Boolean
ReDim Array(119)
[code]....
Export Data To Excel And Update File Contents?
Jun 2, 2010This is the code that I have to export data to Excel.
Dim oExcel As Object
Dim oBook As Object
Dim oSheet As Object
oExcel = CreateObject("Excel.Application")
oBook = oExcel.Workbooks.Add
[Code] ....
I can create and save the excel file, but I can't update the contents.
Check Money Data Type Null In Net?
Aug 4, 2010I usually have a check to see if a certain database column is DBNull and if it is convert it. Current with a datatype of money in SQL 2008 with the row column containing
Null, i declare the equivalent value as Decimal (in .Net) then get the error "'DBNull' to type 'Decimal' is not valid".... How could i check this column for null and convert it?
Validate The Contents Of A MaskTextBox With Contents From An Array Or List?
May 10, 2011I am trying to create a code where I placed sets of numbers in an array.I'll use a masktextbox to have the user enter the numbers to match what's in the array. If the user enters the number, ex: social, and the data is correct (matches the numbers in the array), something happens if the number entered in the masktextbox does not match any of the number sets in an array then another thing happens.The masktextbox so far only validates format and gets number only, however, I want the number entered to match whats in the array.
View 1 RepliesClear The Contents Of The Datagridview So That When Each Option Is Selected Only That Data Is In The Grid?
Jun 22, 2009Public
Class LoanCalc
Private Sub butCalc_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butCalc.Click
'This procedure executes when the user clicks the Calculate
'button to produce a loan payment based on the requirements
'as stated in the service request.
'Variable Declarations
Dim douPrincipal As Double = Me.txtPrincipal.Text
Dim douInterest() As Double = {5.35, 5.5, 5.75}[CODE]......
File I/O And Registry :: Analyzing Contents And Writing Manipulated Data
Jul 25, 2009I am basically reading a text file with info like this:
"S1($=""ChW System Pressure"",V=134.00,%=""Pa""),S2($=""UPS_Batt Rm 1to4 Circ A Flow "",V=9.17,%=""DegC""),S3($=""UPS_Battery Rm Sec ChW Rtn"",V=-38.38,%=""DegC""),S4($=""Buffer Vessel BV-02 High Temp"",V=9.08,%=""DegC""),...
And I'm trying to write a program that read the data, filters the sections so that per line it does the bit before the brackets i.e. "S1" then a comma then the sections inside the brackets as comma separated values removing the double quotes and symbols I don't want etc. Basically dividing the separate S*'s onto different lines and separating the values with comma's. There are also other points which are a different letter than "'S" and the same to do with them to.
Assign Data To An Array From A Text Box - Null Reference?
Apr 24, 2011when i try to assign data to an array from a text box, i get a null reference exception, stating "Object reference not set to an instance of an object".
View 5 RepliesCode Read The Excel Cell As Null When It Contains Data?
Mar 29, 2012Using VB.Net, I am reading an Excel spreadsheet does anyone know what might cause a cell to be read as VBNull when it contains data?the cell clearly contains data. and what is extra weird is all the same cells in the rows before and after the bad one have the little green triangle in the upper left corner, indicating an error - but they all read fine the cell that reads as NULL is the cell in row 4 above
View 1 RepliesCurrent Date Returned If Data In Dataview Is Null?
Aug 2, 2011I have the following code to bind data to my form controls:
dateFromDate.DataBindings.Add("Value", dvUpdateCME, "From Date")
dateToDate.DataBindings.Add("Value", dvUpdateCME, "To Date")
[code].....
[2008] Insert Data Into Sql Table With Filtering Null Value?
Jan 14, 2009my table is:
CREATE TABLE [dbo].[VarianceReport](
[ID] [int] IDENTITY(1,1) NOT NULL,
[FN] [nvarchar](50) NOT NULL,
[Fdate] [nvarchar](50) NOT NULL,
[code]....
But inserted null value when all textbox is temp!?!How to resolve this problem and best way for this action?
Pulling SQL Data Into Text File - Some Fields Null / Blank
Apr 2, 2010I am trying to pull sql data into a text file. The code works just fine, until some new data comes in from lazy employees and a couple fields (used for notes/comments) are now left blank. Originally I've never seen them blank so I didn't think anything of it.
col2 = myreader.GetString(1)
It will error if the field is ever null - I even tried using a case when:
case when note is null then '" & empty & "' else note end and set the variable emtpy = '', but vb still thinks that it's null and errors?
Null Reference Exception In Line Checking For Null?
Dec 15, 2011I have a fairly simple piece of code:
Private _PurchaseDelivery as PurchaseDelivery
Protected Overrides Sub InsertItem(ByVal index As Integer, ByVal item As PurchaseDeliveryItem)
[Code]....
Which is inside a class which overrides a custom list base. The code is occassionaly throwing an unhandled exception, System.NullReferenceException, on this line when used in production:
If _PurchaseDelivery IsNot Nothing AndAlso _PurchaseDelivery.DefaultSKUBinID.HasValue Then
DeafultSKUBinID is declared as an Integer? (Nullable Int) in the PurchaseDelivery class. I cannot see what might be causing this error, why would this be returning an error?
Database Binding And Data Navigation Project Error - Null Reference?
Mar 4, 2012I am trying not to become intimidated or give up.I created a simple database and added stored procedures to read the data on a Windows form using Visual Basic in VS 2010.First I tried the Data Grid Example and all worked, I was able to view the data using a connection string to call the Stored procedure.I have stepped it up a notch by trying to bind data to form controls and I am getting this error message when I try to navigate through the data.
System.NullReferenceException was unhandled
[code].....