Is 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 RepliesI 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?
I was wondering how I would go about placing a check in the checkboxes for each child node of a parent node in a TreeView control, if I was to check the parent node.
For example:
Parent 1Child 1
Child 2
Child 3
If I was to check "Parent 1" how would I be able to make that event place a checkbox beside all of the child nodes of "Parent 1"? (Child1, 2, and 3.)
The code below works fine as long as there are values within an XML node (For example the <CPU>Intel</CPU> node below) but it throws an Exception error when the node value is blank/null whatever as in the example node <Monitor> </Monitor>.t's ok if the node value is blank, I just want to check for it and not throw an exception error.This question uses the following XML snippet below: Note: The tag <Monitor></Monitor> has no value in it.
<PCSettings>
<SystemSettings>
<CPU>Intel</CPU>
[code].....
New to XML. I have a 3rd party webservice that supplies an XML document that I have to update the element values and pass back. The core issue issue is I get an NullReferenceException error when calling the node.RemoveAll() method in the code below. I'm calling the RemoveAll() method because each element has the xsi:nil attribute when it is supplied to me, and if I don't remove it before updating the element value, the XML won't validate by the webservice.The XML document supplied by the 3rd party webservice is as follows:
<?xml version="1.0" encoding="utf-16"?>
<TaskData xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://schema.sample.com/application/1/520800B">
<Global>
[code]....
I've seen have used the XmlNamespaceManager, but I haven't been able to make it work. This xml document has a namespace specified for the TaskData element, and a different namespace for the RequestInfo element. I tried specifying the XmlNamespaceManager variable for each namespace, but got the same results....hovering over the nsmgr variable while in break mode reveals that the "children could not be evaluated" and that the DefaultNamespace property is an empty string.
Public Sub testxml()
Dim doc As New XmlDocument
doc.Load("c: empsample.xml")
[code]....
checking 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?
View 3 RepliesI'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].....
ve 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].....
I'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] ......
I 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.
I am attempting to grab an attribute from an XML file and place it in a VB Class as a string. However when i try to run the program, I get a Null Reference Exception on line 21. why I'm getting this and not the placeID (line 2 on XML code)
Private Shared roomDoc As XmlDocument
Private Shared rooms As XmlNode
Private Shared roomList As XmlNodeList
[Code]....
I 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 ?
I 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")
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 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 RepliesI 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].....
I 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 Replieshow to check null excel worksheet?
View 2 RepliesI 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
I 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.
I'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.
I am trying to implement a function for my SSRS report which will return a color value depending on the values of three dates.
[Code]...
I 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?
i have a treeview which has a bunch of parent and child nodes preset at design time, there is 1 parent node tho which is called developer, that i want to add child nodes to at runtime.When the form first loads im trying to have it check a text file and for each line in the text file add the text/string from that as a child node tot he 'developer' parent node.
vb
Dim reader As String = My.Computer.FileSystem.ReadAllText(Application.StartupPath() & "ConfigDevs.txt")
Dim strs() As String = Split(reader, Environment.NewLine)
For Each s As String In strs
[code]....
Thats what i have so far, how can i set it so 'Dim parentNode As TreeNode = ' points at the 'Developer' node?
I have a tree view in my project with a parent node and with theoretically speaking infinite child nodes.
Now I want to delete the last child node from the tree view when the user presses a certain button. I thought I could do this trick with this code:
Private Sub Bundo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Bundo.Click
Try
[Code]....
I have a treeview which have a listimage. And it has imageselectindex property (image is yellow ball)My problem is : When i click any node, the image of that node shows imageselectindex . I only want thirth child node will show it. I dont want when i click at first node (rootnode) or child of roodnode , the yellow ballon shows.
View 9 Repliesi need to check all child node when the parent node is checked and i had do research from the internet but it seem that i had a error which is Type 'MSComctlLib.Node' is not defined.do i need to import any reference? [code]
View 4 Repliesi got treeview with some root, parent and leaf node but when i create a foreach loop it alway read the 1st value with is 4
For Each node As TreeNode In Me.TreeView1.Nodes
'Label1.Text += node.Text & "</br>"
If (Not node.Checked) AndAlso (node.Value = module_id) Then
[code].....
My XML comes in like this:
<Document type="ContentPage">
<Fields>
<Field name="FaqCategory" type="dropdown" title="Select Category:" index="FaqCategory"
[code]....
How to add a child node to a specific node in treeview?
Say i have "Item1" in treeview already, How do i add "SubItem1" to "Item1" as it's child node?
I know its probably really simple, but i tried lots of stuff, i just cant get it working.
Basically, it refuses to find the node when the root node contains an attribute.
[code]...
When I do xml.SelectNodes("DataSet") with the xmlns in the root tag, it finds no nodes. If I remove the xmlns attribute, it works fine.How can I make it work while leaving the attribute?