ASP.NET - GridView - EditItem - Null Value For Integers?
Jul 16, 2009
I 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:
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:
Error Dropdownlist has a SelectedValue which is invalid because it does not exist in the list of items. Parameter name: value I have been banging my head over this error for about a week now. I have searched posted on other forums and still no solution to my issue. I have seen the FindControl being suggested but do not know how to implement this.
Basically I have 2 webmethods that reference 2 datasets which then populate my ajax cascading dropdownlist. In insertmode they work great however in editmode i get the above error.I have removed the selectedvalue and added
DataSource='<%# Bind("intRoom") which works sort of except for the fact that when you click edit it does not retain the original value of that particular record. Other things i have tried are as following:adding the items to the itemcollection of the dropdownlist turning appenddataitems to true on also tried to use the findcontrol but dont understand that punching my monitor and slamming my keyboard
Now I know i could get this to work by using a sqldatasource with some t-sql to get my dropdownlist to work however I thought by reusing my webmethods my code would be more professional. So if there is anyone out there that can help me understand why the value for my dropdownlist is not being populated or does not exist during gridview editing Also will post code if asked not sure what you would like to see rather than posting everything.
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",
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.
I 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.
anything 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]
I have this code:Dim Result As New DataTable DataAdapter.Fill(Result)
'bind data to visible surname/name grid If Result.Rows.Count = 0 Then NoInputBottom.Text = "No Results. Please widen your search criteria and try again" NoInputTop.Text = "No Results. widen your search criteria and try again" Else GV.DataSource = Result GV.DataBind() End If
I have also tried moving the check to the gridview like so:
If GV.Columns.Count = 0 Then NoInputBottom.Text = "No Options Selected: Please select your search criteria and try again" NoInputTop.Text = "No Options Selected: Please select your search criteria and try again" End If
When I run the code. the noinput labels do not have value, the null check seems to be failing? Please can you tell me how to display a message if the search returned no reults.
Basically I have and array of integers that vary in size. I need to compare each number to each other number and display which number is repeated. For example:
Dim ints() As Integer = {1,2,2,5,4,6}
The number that shows up more than once is 2.
How can I run through the array and compare each integer with the numbers in the array. I tried a for loop but it didn't return the value I was looking for.
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?
When I put a break point to the last if clause in the sub ("If (backOrder < 0) Then", see below) it runs until the break point, if I put the break point further below, I get the following error:
Cannot insert the value NULL into column 'OrderID', table 'WHM.dbo.OrderDetails'; column does not allow nulls. INSERT fails. The statement has been terminated.
I've discovered first hand that it only happens when prodqty is bigger then qtyOnStock, thus executing the if clause.
The code:
Private Sub NCOSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NCOSubmit.Click Dim sqlText As String = ""
How to show pop up menu from database in gridview on each gridview row items ?Example of this is : http:[url].....Move your cursor to Departure time and arrival time...a want this type of popup in gridview items....which fetch entries from database..
In my application,i have a gridview in which columns are created at runtime.Actually these columns are created when i am entering data in a database table.[code]where Column1,Column2,column3 may vary during runtime.i need to enter values to these columns during runtime.But i cant bind these columns because these are created during runtime.The first column "Description" will not change.It will remain constant.For each description, there will be values for each column.At last these data will be saved to the database.How to add columns in the gridview during runtime?
I am able to export a gridview to excel, my problem is that I cannot figure out how to remove the formatting from coming over from the girdview. Here is the code I am using to export the gridview: Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
I have a modal popup that contains a gridview. On the click of a button inside of a grid i reload the gridview with the data that depends on the id of the row clicked in the gridview. I would have like to reload the gridview onclientclick but I couldn't find a way to do that. Is it possible to reload a gridview client-side without the user even knowing the page partially loaded?
I am trying to create a treeview in VB.net, the data has to be loaded from MSAccess 2010 database. When I try to run this program I get error : Argument Null Exception was unhandled, 'column' argument cannot be null and the program crashes. I have pasted the code as under:
Imports System.Data.OleDb Public Class frmRating Private Sub frmRating_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles
I'm making a program that will use .split and I only want to split every other instance. The way I want to do this is by splitting by only odd integers, how do I do this?
I would like to know if there is a command to make a program choose between certain integers. For example, I would like my program to make a random choice between the numbers 12, 118,224 and 300.
Id like to use 4 integers in a For, Next loop. The integers are 1, 3, 7, 9. Is it possible to pass just these integers to the loop without putting them in an array or something similar?
What is the formula in VB for finding the average of two integers?I know in normal math it is e.g. (4 + 6) / 2 it only needs to be the average of two values.
So I am making a file crypter so that I can encrypt my VB.NET Application that I am making so that people can't decompile it. I had made this in C# and am transfering it to VB.NET, Everything worked fine in C# but once I had re-written the code in VB.NET i get this error inside of my RC4 Encryption method:
'Arithmetic operation resulted in an overflow.'
The error is occuring here:
Dim t As Int64 = (s(i) + s(j)) Mod 256
This is the same code above in c#:
int t = (s[i] + s[j]) % 256;
Is there anyway to make that calculation with it erroring? And why does it work in C# but not VB.NET?
I need to add integers in a listbox, using for next. Dim intCount As Integer Dim dblTotal As Double ' here are the lines of code that will perform the calculations ' to create a grand total. For intCount = 1 To lstCosts.Items.Count dblTotal += dblSubTotal += intCount Next intCount lblTotal.Text = dblTotal.ToString("C")
The amount of items in the list box is not seso I used the items.count. I have been getting the wrong result. Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click ' Declarations. Dim intCount As Integer Dim dblTotal As Double ' here are the lines of code that will perform the calculations to create a grand total. [Code] .....
I have a group of 25 labels named Label1, Label2, Label3, ... Label25 in a square of 5 per row, 5 per column and I wanted to assign the backcolor to all of them on a loop and assign a value of "True" or "False" to a matrix of 25 boolean values representing them.
But I was getting errors on the pattern created.
My approach was to use a substring containing a number copied from the label names:
Num = Val(sender.name.substring(5))
And the subindexes of the matrix:
p = (Num - 1) / 5 q = (Num - 1) Mod 5
The values for the lower corner of the matrix were rouded to 5 instead of being 4. Instead of (4,0) ,(4,1), (4,2), (4,3) (4,4) I was getting (5,0),(5,1)...(5,5)
So I solved the problem by creating two single variables "A" and "B", doing the divission and MOD operations on them, finding the floor of them and then converting to integer:
Private Sub Label1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles _ Label1.Click, Label2.Click, Label3.Click, Label4.Click, Label5.Click, _
I have made a simple program for invoices, e.g. The total amount is coming 48,950/$, How to appear this amount in words "Forty Eight Thousand Nine Hundred and Fifty, through MODULE.
I have a method that I want to check to make sure that both integers entered are both positive: Public Function BothPositive(ByVal num1 As Integer, ByVal num2 As Integer) As Boolean If (num1 And num2) > 0 Then Return True Else Return False End If End Function
Now if I were to enter some numbers in BothPositive(1,1) = True BothPositive(1,2) = False BothPositive(-10, 10) = True
Why is this? What is going on with the order of operations in the comparison statement or what is the "And" trying to compare? I don't see why this wouldn't work.
