I am working on a program that has many integers (q1, q2, etc.), and each of them can be 0 or 1. This is dependent on which radiobuttons are selected. I need it to check and make sure that all of the integers have a value, but since "Null" is the same as "0",
View 8 RepliesI am using a GridView in asp.net 2.0 and I want to perform inline editing. I am using an object datasource. Because I want to use validation controls on the integer fields in my gridview, I have made them into <TemplateFields> and added a datatype validator and a range validator. This allows me to either have a blank field, or an integer value between 0 and 999.I am trying to display a "-" when the value of the property is not defined. There is no Null for an integer, so I have decided to use -1 as the value to indicate a Null.I am reformatting the to display the "-" if the value is -1. I do that as follows:
<ItemTemplate>
<asp:Label ID="lblPC" runat="server" Text='<%# FormatIntegerToText(Eval("PitchCount"),"-") %>'></asp:Label>
</ItemTemplate>
In the code behind I have defined the function FormatIntegerToText as follows:
Protected Function FormatIntegerToText(ByVal value As Object, ByVal nullvalue As String) As String
' Make sure value is not null... if so, return "-"
If value = Null.NullInteger() Then
Return nullvalue
[code]....
I though I could do the following to reformat the value that is placed in the text box:
<EditItemTemplate>
<asp:textbox ID="txtPC" runat="server" Text='<%# FormatIntegerToText(Bind("PitchCount")) %>' width="25" Columns="2"></asp:textbox>
but when I do this I get a compilation error that Bind is not a recognized function.why is this not allowed, and how can I work around it?
If I have a datatble column set as int16 but rows can contain null values for this column. How do i write the linq query. I keep getting an error null value exception. Dim query = From n In resultstable.AsEnumerable Where n.value is dbnull.value does n't work.
View 6 RepliesI have a class and method exposed to a client asp.net app. The class looks like
<DataContract()> _
Public Class Class1
Private v_string As String
Private v_integer As Integer
[code]....
The method is declared as
<OperationContract()> _
Function GetStuff(ByVal bar As Class1) As String
In the client code I create an instance of Class1 and set the values for v_string and v_integer, but using Wireshark to look at the xml being sent to the server only a value for v_string is being sent as part of Class1. I'm guessing this is because it considers the value of v_integer to be null/not set. Here is an example of the client code.
Dim MyService as New Service1.ServiceClient
Dim test as New Service1.Class1
test.P_integer = 1
[code]....
how different types are passed/used since Integer is a intergral type and String is a class, but can't seem to work out what to do to fix the problem.
How to check whether a column is null i use the following code but I got this error "Input string was not in a correct format."
[Code]....
How do you check if the division of two integers is a whole number, just answer with code, no links?
View 6 RepliesIn TSQ IF MyVal IN (1, 2, 3, 4, 14) BEGIN ... END .Is there a way to do this in VB.NET? Is it possible to check for the existence of an integer in a set of integers inline? Such as: If MyVal in (1, 2, 3, 4, 14) Then ... End If
View 2 Repliesanything wrong with using datatype object and determine datatype in class property? I have a typed dataset and it has several integers columns that are null in the db. and when I make a call it throws exception.is there anythign wrong with setting it as object in my dataset.. changing the throw exception property to Nothing and passing it to my property as integer?
for each row in myDS.DataTable
cRate.CustID = row.CustID
next row
and in my class
Public Property CustID() As Integer
Get
Return _custID[code].............
I tried coding for an application that will display the positive integers, negative integers and zero entered in a inputBox. for some reason it keeps crashing down.here is my code. paging all visual basic professionals. [code]
View 6 RepliesI have some code which gets child items for a menu via the GetChildren function which takes a list of menuData: Dim builtMenu As New List(Of MenuData)(_rawData.FindAll(Function(item) item.GroupingID = 0))
For Each menuData As MenuData In builtMenu
If menuData.Children IsNot Nothing Then
menuData.Children.AddRange(GetChildren(menuData))
End If
Next
If I check if menudata.children isnot nothing, it always is nothing because the GetChildren function is yet to run (providing the child items, which do exist). If I remove this check and just have this code:
Dim builtMenu As New List(Of MenuData)(_rawData.FindAll(Function(item) item.GroupingID = 0))
For Each menuData As MenuData In builtMenu
menuData.Children.AddRange(GetChildren(menuData))
Next
Then I am presented with a Object reference not set to an instance of an object error on menuData.Children.AddRange(GetChildren(menuData))
All I want to do is check if an object is null, but no matter what I do, if it compiles, it throws a NullReferenceException just trying to check! Here's what I've done:
[Code]...
I have a dataset. I'd like to check if one item in the dataset is null or zero.
If IsDBNull(ds.Tables(0).Rows(0)("TotalCostPerUnit")) or CInt(ds.Tables(0).Rows(0)("TotalCostPerUnit") = 0 Then
Exit Sub
end if
Dim Conn As ADODB.Connection
Dim Null As String
Dim NullRecordset As ADODB.Recordset
[code]....
Im trying to check my database for a null value. If the database is null, then I want it to start the timer, otherwise I want it to skip over some stuff and automatically load the main form.
I am trying to check to see if a DataSet is null or not. If it is I would like to show a MessageBox. For some reason it is not recognizing null returns and skipping the message box and going right to the Else commands. [code]....
View 3 RepliesI have a problem with verifying db null value. Actually I don't know the syntax.
Here is the code.
If Not IsDBNull(Me.DeliveryReviewDataSet.Delivery(Me.CustomerIDListBox.SelectedIndex).Signature) Then
"Signature" is the image field (binary data).
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If MyBase.Dispose(disposing) <> DBNull.Value Then
Dispose() = DBNull.Value
[Code]....
I am getting error
1) Expression does not produce a value.
2)Expression is a value and therefore cannot be the target of an assignment.
I retrieve data from database like below. How do I check whether the value retrieved from database is null?
[Code]...
i'm working with a database application and i want to check if there is a null value in a specific column but it works only when its not null but if its null it throws an exception automatically
i tried to change the nullvalue property of this column but i'm not able it shows a message that its not a valid property
i tried to change the source code in the code editer but it changes back automatically
I have multiple textboxes that are saved using my settings and buttons to add them to the clipboard.
The problem is when the textbox is blank and I click on the copy button.
The saving to my.settings happens on close so when someone enters text that they plan on saving later and then clicks the copy button, whammo it crashes.
Here is the code that is failing and I need to check to make sure that there is a value before setting the text on the windows clipboard.[code]...
I just want to check and see if this object is null. if i do not and it is my applications closes.I have also looked into a null reference exception. I will do whatever as long as it handles "null".[code]
View 2 RepliesHow can I check if a datatable has never been set ? or Null or Nothing ? I don't mean empty Datatable ... For example,
[Code]...
[if me.textbox1.text= system.dbnull then msgbox("please inter a value")] it says system.dbnull can't be used as an expression so how can i check the if the textbox has a null value
View 13 RepliesTable contains 2 columns Tags10 and TU. Its values are:
NDX___________TUI48
JJI_________ NULL
CmdSelect.CommandText = "Select * From Tags Where Tags10='" & s_temp02 & "'" 'OK
ReaderSelect= CmdSelect.ExecuteReader() 'OK
[code]....
How to check this? If NULL there is nothing to do, if not NULL, we should put the value into s_temp03.
I want to display a message if the value of cell of my datagridview is Null.
View 1 RepliesWhat im trying to do is check a row for null values in my datagridview before saving the data back to my access database, in particular the first columns cell of the new row being added. This is the code I have so far'
Private Sub LatheprogramsBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LatheprogramsBindingNavigatorSaveItem.Click
Dim test As String = Me.LatheprogramsDataGridView.Columns(1).ToString()
[code]....
i hav two openfilefialogs(1 and 2). So i also have a listbox. the files opened with the openfiledialogs will be added to the listbox. and when i need to open the files i need to see if they are from which openfiledialog. so
it is like this.
Path.GetDirectoryName(OpenFileDialog1.FileName) & "" & Form3.ListBox1.SelectedItem.ToString
'if this returns a null then go to this
Path.GetDirectoryName(OpenFileDialog2.FileName) & "" & Form3.ListBox1.SelectedItem.ToString
Check multiple expressions for null?I have this bit here[code]...
View 8 Replies I am getting product id value some times null and empty from databasehere how i check if valule null and empty
productid = IIf(IsDBNull(TempDT.Rows(0).Item("productid")) =
True,
"", TempDT.Rows(0).Item("productid"))
[code].....
DataGridViewX.CurrentRow.Cells.Item(0).Value.ToString
If the item is blank and no data is entered it will throw a null exception, so the question is that how can I check if the item is null or not? Even using this:
If DataGridViewX.CurrentRow.Cells.Item(0).Value.ToString IsNot Nothing Then ...
Will throw the exception!
I have a sub that updates a form on certain occasions. Sometimes I need to update a form when some of the entries in my table will still have a NULL value. I used this code to prevent the sub from trying to fill the form fields with NULL data:
[Code]...