Checking Extbox Contains Null Value?
Feb 17, 2012checking im my textbox contains null valuefor example i have ten textbox how do i know if a textbox has no text in it?then gotfocus to that specific textbox?
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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?
Checking For Null Bytes?
Sep 6, 2011I'm using Visual Basic .NET to work with a USB HID device.Most of the time, I can receive data from it perfectly... but one out of every thousand transfers or so, my code will think it has received data when it actually hasn't.The device writes to an array of bytes. I wanted to check to see if the received packet is empty, by doing something like this:
If myDevice.dataPacket(1) <> Nothing then
myDevice.rxDataReady = False
[code].....
Checking For Null Return?
Nov 14, 2011ve a simple vb code similar to the below,
Function getvalue (ByVal Val as double) As string
Dim Num as Integer
Dim Prd as double
[code].....
Checking For XML NODE Null
Apr 11, 2012Is there anyway to check for a null here before it reaches this part of the code? tmpLabelData(0) = m_node.Item("CONTAINER_NAME").InnerText. Some XML has it while others do not. I cant seem to find a nice way to handle a null on these?
View 1 RepliesChecking If DB Query Is Null
Nov 15, 2011I'm querying a SQL DB and sometimes the result is Null, so I thought I would test this but my code results in an error "Data is Null. This method or property cannot be called on Null values."
Here is a snipet of my code:
For i = 5 To 6
cmd = New MySqlCommand(query2t & i, db)
rdr = cmd.ExecuteReader()
rdr.Read()
If Not IsDBNull(rdr.GetUInt32(0)) Then
[Code] ......
Length Checking In VBA With Null?
Jan 7, 2011I have some code that is meant to check the length of the values in the text boxes, and if any of the boxes has no content the length of the string is 0 (or null). Here is the code:
If (Len(Form_MainScreen.Ctl48.Value) Or Len(Form_MainScreen.Ctl49.Value) Or _
Len(Form_MainScreen.Ctl50.Value) Or Len(Form_MainScreen.Ctl51.Value) Or _
[code]....
When one string is blank, the length check becomes "null" and so does the whole statement.But if the length checks are all not null, the if statement becomes a "1" and then procedes to execute the Do X procedure again.
.net - Checking For Null In Date Field?
Oct 25, 2011I have an ASP.NET application that crashes when a null date value is returned.
The code line is:
excelWorksheet.Cells("A" & xlRowCounter).Value = IIf(IsDBNull(dRow("sysdate")), "", Format(dRow("sysdate"), "MM/dd/yyyy"))
Error message:
ERROR: System.ArgumentException: Argument 'Expression' is not a valid value.
How would I check for a null date, and replace it with "" in my app ?
Checking DataSet For Null Before Referencing?
Oct 15, 2010I keep getting the error "Object reference not set to an instance of an Object" on the below highlighted line of code and I understand why. It's because I'm checking for something that hasn't even been initialized yet. My question is, what's the best way to check a DataTables row count without getting that error before refilling it?
If Not ds.Tables("tblNotes").Rows(0).IsNull(0) Then
ds.Tables("tblNotes").Rows.Clear()
End If
adp.Fill(ds, "tblNotes")
Checking For Null Value In Specific Column
Mar 15, 2012I'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 null value 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 editor but it changes back automatically. Is there a way that I can work around this?
View 5 RepliesGeneric Function For Checking For A Value Of Null?
Aug 24, 2010I am trying to write a generic function that will check each database parameter to see if it is null, and if so, return DBNull; if not, return the object.So here is my function:
Public Shared Function CheckForNull(ByVal obj As Object) As Object
If obj <> Nothing Then Return obj Else Return DBNull.Value
End Function
[code].....
Nested If Loops Checking For Null And Empty
May 27, 2010I constantly find myself having to do code similar to the following.[code]Is there anyway to check for both on a single line? When i'm checking a condition for a great number of answers, I sometimes end up with conditionals 6-sets deep. If i check for null first, an error still pops up, even though VB shouldn't check since the first condition failed. i.e.[code]
View 8 RepliesVS 2005 Checking Null Excel Worksheet?
Jun 25, 2009how to check null excel worksheet?
View 2 RepliesVS 2008 DataGridView - Checking For Null Values
Apr 3, 2009I have a DataGridView1 populated by sql searches. On the rare occasion that nothing is returned, my app cannot make use of data so I'm trying to check for null values. My code below is not correct because IsDBNull is not a member of the of the DataGridView1.
If DataGridView1.SelectedRows(0).IsDBNull Then
MsgBox("Nothing to display")
Exit Sub
End If
VS 2008 Dataset - Checking If Date = Null?
Sep 7, 2009I need to check if a value from a date column is equal to null. I can't find how to do it.
Wat I got now is:
if ds.tblBooking(row).CancelledOn.compareTo(dbnull.value) = true then
But this doesn't seem to work, I think it's because I'm using a strongly typed database.
.net - Checking For Null Variable In Workflow 4.0 Transition Condition
Feb 27, 2012I'm implementing a State Machine in WF 4.0. In some transitions, I have added a condition where I check that some variables have the expected values. The variables are enums and booleans, and everything is fine.
However, now I tried to evaluate when a property is null. I have and argument in my workflow, let's say, 'MyArgument'. In a transition, I try to put a condition like 'MyArgument.MyProperty = Nothing'. I never developed in VB.NET, I don't know if I'm missing something here...
VS2010 gives the following error: "Error 4 Compiler error(s) encountered processing expression "MyArg.MyProp = Nothing".
Operator '=' is not defined for types 'XXXX' and 'XXXX'
The type names are exactly the same, and I have debugged VS2010 to ensure that my assembly is not loaded from 2 different locations.
How can I check if the property is null or not?
BTW, I'm using VS2010 SP 1, with .NET Platform Update 1 installed, on W7 64 bits.
Checking For NULL Dates In SSRS Custom Code Function
Feb 7, 2012I am trying to implement a function for my SSRS report which will return a color value depending on the values of three dates.
[Code]...
Checking For NULL Dates In SSRS Custom Code Function?
Jul 7, 2009I am using following code in rowdatabound fn.
Protected Sub gvwMileStone_RowDataBound(ByVal sender As System.Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs)
[code]...
ddlEProjectLevels is dropdownlist in edititemtemplate.Whwn i click edit in 1st row ddlEProjectLevels gets loaded with data from database.But in 2nd row dropdownlist does not contain values.Again in 3rd it gets loaded from db.Means in alternate rows,when i click edit dropdownlist(ddlEProjectLevels) doesnot load values.Can anybody help?
VS 2005 - Boolean Checking - Better Performance By Checking For A True Value
Aug 4, 2010Is there any better performance by checking for a true value like this:
[CODE]..............
Than like this:
[CODE]..............
Linq To Sql Null - Check Whether A Column Is Null
Jul 15, 2011How 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]....
SQL Exception (adding A Null Value To A Non-null Column)
Aug 12, 2009When 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 = ""
[Code]....
Error 'Arguement Null Exception Was Unhandled, Column Arguement Cannot Be Null'?
Oct 20, 2011I 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
[code].....
Null Check Always Returns Null, If Removed Returns Object Reference Not Set To An Instance Of An Object
Jun 24, 2010I 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))
.net - Checking For Comments?
Jun 2, 2011i am writing a vb.net program which gets a c program as an input and checks it for errors,now i want my program to skip the comments in the c program,i have written some code but its not working
For Each line In TextBox1.Lines
sample = TextBox1.Lines(k)
Dim len As String
len = sample.Length
[code]....
.net SQL Checking Dates?
Mar 28, 2011Basically, I have a list of dates in a SQL table with some statistics next to each of them. I want to compare the dates in the table with a certain date I choose. However, my dates in my table are stored as Varchar(50) (and have to be). Apparently I can convert the date in the table into date type but I don't know. Does anyone know how? My current code can be seen below.
[Code]...
Asp.net - .NET Checkboxes Checking?
May 14, 2012I have a form which contains a checkbox field. On page load I want to create a separate checkbox for each customer in my Database. The code I have to create the checkboxes for each customer works fine. However, I also want to check in the database if the customer is set to unauthorized if they are then I want to check there box. I also have code for the case where the user checks a box. If a box is checked I update the database setting the unauthorized attribute to true. My problem is when I check a box it works fine and the box is checked, however if I reload the page all the boxes are unchecked. So either my database update is not updating the database or the way I check on page load for checked boxes is incorrect. Any ideas?
The code for the asp checkbox field:
<asp:CheckBoxList id="check1" AutoPostBack="True" TextAlign="Right" OnSelectedIndexChanged="Check" runat="server">
</asp:CheckBoxList>
The Code for the page load:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim sql As String = "SELECT Name, unauthorized, ID FROM Customer ORDER BY Name"
Dim dt As DataTable = db.execDataTableQuery(sql, "Customer")
[code]....
Asp.net - Checking If Row Was Inserted?
Apr 19, 2011I am trying to check whether a row is getting inserted into my database. It is throwing an error even when it does insert (it's a database issue that will get resolved later when I get a newer version of Microsoft Access), so I can't check whether the insert is successful based on whether there's an error or not. I think I need to check the AffectedRows of something, but I'm not sure what. I've been looking for info on how to do this but I can't figure out how to make it work for my exact situation. Here's a general idea of what my code looks like:
Protected Sub Wizard1_FinishButtonClick(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.WizardNavigationEventArgs) Handles Wizard1.FinishButtonClick
[Code]...
But the numInserted is coming out as 0 every time even though the insert is successful. It may have to do with the fact that myIns1.ExecuteNonQuery() throws an error even though the insert is successful.
-EDIT- I discovered that the "duplicate values" error is because it is somehow attempting to insert the record twice. I have no idea why it's doing that though.
Best Way Of Checking If A Value Is Present
Nov 11, 2011The following line of code gives a warning with Resharper: 'Comparison of floating point numbers with equality operator. Possible loss of precision while rounding values.'
Dim samples() As Single
If samples(i) = Nothing Then
samples(i) = _mPreviousSamples(i)
End If
What is the best way of checking if a value is present?
Checking A String Contains A Value?
Jul 7, 2010I am trying to figure out how to check a string can contain a certain value.In the begining I had a checkbox and wanted to hide a ceratin field depending upon which checkboxes were selected.The problem with this is that the value is always = to the first value.
I got around this by writing these values into a hidden textBox and using a loop.So now I have a textbox and if the user selected the 1st and 3rd choice the textBox would = "AC" If they selected all choices it would = ABCD etc...How can I determine if the values in my textBox contains just letter 'B' ?
I tried this:
--------------------------
Dim values As String = [String].Empty
For Each item As ListItem In section2List.Items
If item.Selected Then
[code]....
but this doesn't work.
Checking For A SQL Result?
Dec 2, 2009I need to check if my SQL statement returned any results from the Access db I'm using to store my data.
I have this code atm:
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=D:Computing Projectdatabase.mdb;")
cn.Open()
[Code]....
I would like to be able to check (maybe via a boolean value or something) that this result returned a query. I'm using VB.net.