I am trying to count Acad Blocks and then write the block references to the modelview using vb.net (VB 2010 Express).I have been scanning the forums for the error I am getting and before I post the code, I thought I would check and see if anyone is experienced with AutoCad and would be able to give some insight. Have not found much to do with AutoCad on the forums as of yet.I have comments on the debugging process, that might help out somewhat but I can't figure out where the first value is not being assigned (or better yet why).
I'm trying to add a new record to my database but i keep getting the message - "conversion from type DBnull to type string is not valid". I think its something to do with the Employee ID when VB attempts to save it to the database my code is below
Imports System.Data.OleDb Public Class Add Private Sub DisplayRow()
I now have SQL Parameters set up and I'm using them to save/delete/add my data. This all works well, except when it's trying to save a combobox to the datatable it appears with the error above.Majority of my comboboxes have datasources, and the valuemembers of these are the actual list items, not the ID's of the list items.I'm not sure why this error could be happening, I'm fairly sure I've connected everything to the binding source correctly; I've checked it a few times.Does anybody know what the cause of this could be? I've looked around a bit and I haven't found much
Error 1Server Error in '/ Application. -------------------------------------------------------------------------------- Conversion from type 'DBNull' to type 'String' is not valid. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.InvalidCastException: Conversion from type 'DBNull' to type 'String' is not valid. Source Error: Line 64: Line 65:
I am getting the error "Conversion from type 'DataGridViewTextBoxCell' to type 'String' is not valid." When trying to display a cell from DGV in a listbox.I have my variable for the cell reference as follows:
Dim a As Object a = DataGridView1(4,1)
To insert it in the listbox as follows:
This will not actually display the entry inside the referenced cell, it shows this in my listbox instead:
I was tried to get quantity from db make use of the selection in list box. I got answered with listbox1. If i selected the item in listbox1 the quantity would appear in textbox1. But in this same code will not work for listbox2 with textbox4.. Here i given the code...
$Con.open() $Dim cd as new oledb.oledbcommand("Select Quantity from tlist where tool_name"& "'"listbox2.selecteditem & "'" & "", con)
Here i got the error as "Conversion from type DBNull to type string is not valid"
I've been getting this error when pulling data from a recordset. It is coming from a null entry and as a newbie to VB2008 I'm not sure how to get around this.
here is my code lblShipping.Text = reader("CARRIERCODE")
the error:Conversion from type 'DBNull' to type 'String' is not valid. Basically what i'm attempting to accomplish is to see if there is anything in that field. If so put it into the text box if not leave it blank.
We get this error: Conversion from type 'InternalField' to type 'String' is not valid. When we get to this in our Dim fname2 = fname args.Graphics.DrawString(fname2, New Font("arial", 8), Brushes.Black, 5, 5) fname is a nvarchar variable from a recordset. It's just a name.
I am importing an Excel spreadsheet, turning it into a dataset and inserting the results into SQL Server (only 100 rows).
I am having an issue with one of the date columns in Excel, which can have a value or not. The "F" column is the one that may be blank and this is the error I get: Conversion from type 'DBNull' to type 'String' is not valid.
How can I add a check to the Dim F As Date = CDate(row(5)) to handle a null?
VB ' The use of letters instead of ' more descriptive variables is ' strictly for this sample peice
At run time my application gives an error of "Conversion from type "DBNull" to type "String" is not valid. In my form only one field - Add_info is an optional field which might be filled or not by the user. Before, I had an error when an apostrophe was used so i updated the code as highlighted below. This in return removed the apostrophe error but generated an error whenever there is an empty additional field. [code]
I am pulling records from an access database onto my form and have a "Next" button to get to the next record, but every time it gets to the 5th record, the error msg, "Conversion from type DBNull to type String is not valid." because one of the text boxes (fields) from the database is empty.
a user will enter a number, n, which ranges from 1 to 30. they will also enter a "P" or an "S" (sum or product). depending on which was selected, it will calculate the sum or product of the numbers from 1 to n.i'm having a conversion error on line 5 stating "Conversion from string "S" to type 'Double' is not valid." [code]
I created an application in vb.net 2005. It works fine on my machine. I tested several different test machines and all were working fine. As for the client, it's generating an error. My application reads from an excel sheet and imports the values to an oracle database. the error being generated is: "conversion from type string to type double is not valid". Why is it generating only on the client's computer and not mine?
i have a text box and i want to insert the textbox value to my sql procedure in server and then generate record in the datagrid view ... the parameter in sql server i declare as varchar and actua database column item datatype is nchar.. anyway in what suitable datatype that i have to put in my visual basic for the textbox in order to transfer the vlaue to sql procedure and generate result
I have this program i have to do for my Intro class. The assignment is to have the user enter a pay code(A,B or C) and the amount of hours worked. If the hours is more than 40hrs, they will receive time 1/2. And it must also calculate a 22% Tax.I was getting this error: Conversion from string to type 'double' is not valid. But some how i eliminated it.[code]
I am trying to update MS-Access database where one field is boolean and updating a string. I am getting a error message "Conversion from string "Update Claims set appointed=" to type double is not valid".