Check If A String Collection Is Empty?
Aug 19, 2009How can i check if a string collection is empty? I tried
VB.NET
My.Settings.IPBank.Count = 0
But it said
Quote:
Object reference not set to an instance of an object.
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Most Concise Way To Handle / Is Nothing / Empty String Check?
Apr 1, 2011What is the best way to checkt o see if the TelephoneNumber property has some string in it that does not Trim down to an empty string? I hate to use the Trim VB.NET function on Nothing just to give me an empty string whenever the TelephoneNumber is Nothing. [code] What puzzles me is that the "IsNullOrEmpty" function works as an extension method of a string instance even if the String is NOTHING. Why does this extension method work but the follow straight - .NET code raise an exception? [code]
View 4 RepliesCheck Object's Property For Null Or Empty String?
Jul 28, 2009I'm using FileHelper to generate object's property. Here is an example of one property:
<FieldOptional(), _
FieldTrim(TrimMode.Both)> _
<FieldNullValue(GetType(String), " ")> _
Public StoreNo As String
As you can see the StoreNo will either have a value or " ", one of the business policy is to check if the StoreNo is empty or nothing if the object's StoreNo is empty or null then the record will not create.
I though about creating an HasValue Function in the class to check the StoreNo and other properties in the object but I feel like it is a hack.
Public Function HasValue() As Boolean
Dim _HasValue As Boolean = True
If StringHelper.IsNullOrBlank(Me.StoreNo) Then
[Code]....
I don't think this approach is an ideal solution. what if the StoreNo is remove or change to something else. What's the best approach to check object's property?
Nothing Equals String.Empty, Null Does Not Equal String.Empty?
Jun 28, 2010This must've have been asked before but I couldn't locate it. In a mixed code project (VB and C#) we were debugging some old Visual Basic code where a statement as follows could be found:
If Request.Params("xxx") <> "" Then
'do something
I considered this a bug as Request.Params could be null, in which case the statement would've become false which wasn't the idea. So I thought. I just found out, -- probably for the tenth time and I will keep forgetting -- that the following two statements are not equal, while Nothing in VB should be equal to null in C# (thought I):
if(String.Empty == null) // always false
If String.Empty = Nothing Then ' always true
Should I dismiss this as a typical Microsoft backward compatibility effort, or should I consider this a huge error in the VB.NET compiler? Does anybody know the Microsoftean opinion on this oddity?
Arrays - If Not String.Empty Ignoring Empty String
Aug 11, 2010I have a array of strings and I am looping through them, but the string might be empty so I am trying this:
[Code]...
VS 2008 : Empty A Collection In .NET?
Apr 11, 2010How can I empty a collection in .NET? Let me specify that I don't want to destroy the collection , I just don't want it to have the objects it had before (so I can refill it from scratch) .
View 3 RepliesNunit Assertion For An Empty Intersection Between Collection
Dec 21, 2010I have a list of user names (we'll call 'original list') one object is returning. I have a list of user names (we'll call 'filtration list') another object is returning. I am testing a method that returns all of the items from the original list not in the filtration list. Ideally what I want is something like:
Assert.That(returnedList, Has.No.Members.In(filtrationList))
So far the only thing I can do is iterate over the filtrationList and do
Assert.That(returnedList, Has.None.EqualTo(filteredUser))
[2008] - Deserialize An Empty Arraylist Collection?
Mar 6, 2009the vars outside the procedure
Dim rentalRecords As New ArrayList() ' The arraylist containing the records
Dim carRecords As New ArrayList()
Dim currentRecordIndex As Integer ' The index of the current record
[code]....
TreeView.nodes Sometimes Returns An Empty Node Collection?
Jul 1, 2009treeView control which has been plaguing me for the last few days.
I'm not exactly sure what is causing this problem to arise, so I will just explain what my program is trying to do.
I am building an application which will have plugin support. I have created a Plugin interface, which is implemented by each plugin, as well as a host interface, which is implemented only by the host application.
Each plugin has an Action subroutine, and when finished, it is supposed to call the ExecutionComplete subroutine in the host interface.
Now, onto the problem. I have a treeView on the host form, which has several nodes in it. If I create a button on the form which displays a message box with treeView.nodes.count, it shows up fine, and everything works as expected. If I attempt to display the same messagebox from the ExecutionComplete subroutine, it also gives the correct number of nodes.
This is where things get a little weird. I have implemented a save feature into my program, so you can save and load data. For some weird reason, if you have loaded the data from a file, rather than adding each node manually, it now returns an empty node collection ONLY if I try to access it from ExecutionComplete. If I try to access the nodes from a button, it still returns the correct values!
What could it possibly be about the ExecutionComplete subroutine that makes it return a value any different than what is returned when the exact same code is placed in a button click event? And why does it only happen when I've loaded the data from a file? I just don't understand how loading it from a file is any different than them adding the nodes manually. The nodes are definitely being added, as I can see them, and the button click event can also see them. Also, ExecutionComplete is obviously able to read the contents of the treeView, because it works just fine if the user has set up the treeView manually.
VB Check If Int Is Empty?
Nov 22, 2010A really boring question, sorry, but I really don't know that yet ;) I've tryed always string.empty, but with a decimal, there is an error.
View 3 RepliesCheck Datagrid Is Empty?
Aug 25, 2011[code]... Check Datagrid Is Empty?
View 1 RepliesCheck Empty Dataset
Oct 4, 2011i have a dataset that takes results from a select to a sql database. the select returns rows and sometimes returns no rows. how can i check if the dataset has no rows from the select? [Code]
View 4 RepliesCheck If A Txt File Is Empty?
Jun 30, 2011I need to check if a .txt file is empty, if it's not, the code will read the file and process the information.I know how to read .txt file. Is there a way to check if the .txt file is empty? not an empty line just completely empty?
View 3 RepliesCheck If Array Is Empty?
Apr 12, 2009On a button click I need to test whether or not an array has been filled, if it has the user gets linked to a new form otherwise they receive a message box telling them to first assign values to the array.
I've tried 'If MyArray Is Nothing Then....' and 'If MyArray.Length < 1 Then...' but neither seemed to have worked.
Check Listbox Is Not Empty?
Jan 14, 2009I was wondering how to check if a list box is not empty I have inserted my code I want t check if there if text in the listbox and if there is no text do some thing. I have put the line of code i am having trouble with in red
result = MsgBox("Are you sure you wish to make the required number of lockers", MsgBoxStyle.YesNo, "Confirm Order")
If (result = MsgBoxResult.Yes) Then
CheckLevels()
If lstOrder.NoItems = True Then
[Code]...
Check When SqlDataAdapter Is Empty?
Oct 15, 2009I've done an internet search to determine if I can detail if a SQLDataAdapter is empty after running an SQLCommand? My research so far point I can't check if the SQL dataAdapter is empty until I bind it to a dataset/datatable. Ideally would not like to run another SQL command to do a row count to determine if query retruns rows or not. I'm populating a datagridview and would like to alert the user that there is no data to view. What's the most efficent way to check if an SQLDataAdapter is empty?
View 4 RepliesCheck Whether The Table Is Empty?
Jun 22, 2011i want to insert the data into the table only if the table is empty, so for that i need to check the condition to check whether data already exists in the table, if present then i want to empty the table before inserting the the fresh value.
i know how to insert and delete the data only prob is to check the condition. so please can any help me out in this.
TO INSERT
Dim comUserSelect As OleDbCommand
myDateTime(i) = DateTime.Parse(arr_dateTime(i))
' Console.WriteLine(r("P1"))
[Code].....
How To Check A PicrureBox If It Is Empty
Feb 12, 2012In Visual Basic 2010 I have a PictureBox control which i need to check in code to see if it does not contain an image.
View 2 RepliesHow To Check Stacks If Already Empty
Oct 22, 2008How to test the stacks if it is already empty? I tried Stacks.IsEmpty but unfortunately I have an error says:
IsEmpty is not declared..
Is there any way to test if the stack is empty? When I'm typing (after dot) there is no IsEmpty properties of the stack.
SQL - How To Check If Table Is Empty
Jun 4, 2010Possible Duplicate: Checking for an SQL result in VB.NET
I have login form which is redirect user for their levels but before to that if there is no any user on the data table I would like to redirect to create admin form. I have all the forms but I didn't manage to redirect them because I don't know how to create statement.
Dim con As SqlCeConnection
Dim command As SqlCeCommand
con = New SqlCeConnection("Persist Security Info=False;Data Source=.database.sdf;Password=********;File Mode=shared read")
con.Open()
[Code] .....
I have this code is working. What to write for
Private Sub frmlogin_Load(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
Three Folders - To Check If They Are Empty Or Not
Jul 27, 2011Here is my problem-> I have three folders that I need to check if they are empty or not, if one of them is empty, I would like to keep checking the other two, if they are not empty I want to do something and then check the other two, but not all the time all three will be empty or not empty there might be times where one folder has something and the other two not and so on. I just want to check a folder and if its empty go to the next one but if not do something and still g to the next one to check if it empty or not, an so on.
View 3 Replies.net - Check For Empty TextBox Controls?
Feb 28, 2012Ive got a Form application in VB.NET.I have many text boxes on one form (about 20). Is there anyway to check them all at once to see if they are empty instead of writing out a massive line of code to check each one individually such as
If txt1.text = "" Or txt2.text="" Then
msgbox("Please fill in all boxes")
Check Column Empty In .net Using MSaccess?
Aug 25, 2009i want to check the table column null or empty......in vb.net iam using ms access in backend.....
View 2 RepliesCheck For Empty Dynamic TextBoxes?
Aug 8, 2011I have a code in Save Button, and part of it, a code that checks if the dynamic text boxes that has been created is empty. But when the system runs, it only check the first set of text box and an an message appears "Collection was Modified; enumareation operation may not execute.".
Here's the code:
Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
Try
For Each txt As TextBox In TextBoxes2
If String.IsNullOrEmpty(txt.Text) Then
[Code]...
Check For Empty Record In Recordset?
Jun 16, 2011I'm trying to retrieve some data from an Excel with the following [code]...
At some point the Recordset encounters an empty cell which it can't assign as a to Recordset.Fields("BG").Value. VB2010 will then throw an error: When casting from a number, the value must be a number less than infinity.
correct syntax for checking on an empty cell?
Check If Query Result Is Empty
Oct 10, 2011First time poster and new to ASP programming.I have a functional database to where i am trying to add new functionality.I'm trying to add the idea to check if a returned string is empty, if so get value from a backup table which holds historical information. Here is what i have got for the specific part:
[Code]...
Check If The Masked Text Box Is Empty?
Sep 18, 2009I have a mask of : 00/00/0000
I need to check if the masked text box is empty,I tried MaskedTextBox1.Text
it returns --/--/--
How can I check whether the user has entered a value to the maskedTextBox or not?
Check Null And Empty Both At A Time?
Jun 17, 2009 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].....
Check Numerous Textboxes As Empty?
Nov 6, 2011I have numerous textboxes which I use to gather data to be placed into an array. But I want to ensure, before I place them to the array,that there is at least one character (letter or number, no space) in each textbox. Seeing as I have about two dozen, it would seem tedious to write an If...Then statement for each of them. And I cannot use a custom textbox class for this. So how can this be done?
View 3 RepliesCheck When Contents Of File Is Empty?
Jun 20, 2012I've used System.IO to check if files exists/copy/delete in the past but I have not been able to check if the file is empty?
I have two text files, and i want to add a check to see if both files are empty, if they are empty then I want to exit the application.
