Take the below example. I would expect the IsInterned method to return null, because this string can't possibly be in the intern pool having started up the test app for the first time? I would also expect, that if I did something like string.intern("this112233StringCan'tPossiblyBeInTheInternPool!£$%") first, then this would legitimately be returned by IsInterned from the pool. I've also done the same in c# and the behaviour is the same.
Whenever I use strings in code, I tend to do something like textbox.text = string.intern("someValue") etc or if (textbox.text = "someValue") etc. Infact, whever strings are being used, I've gotten in to the habbit of using string.intern. Is this a bad habbit rather than using constants or the resources file?
I am currently using a sql data reader (in vb.net) to extract an article object via a stored proc from a SQL Server 2008 database. Part of this object includes the two properties shown below:
My problem is that the Truthfulness and Relevance may return a null value and this is causing the function to fall over.I think I understand why. I am asking for an integer value (getin32) and because null is returned it fails.How do I accommodate the null value from the database so it does not fall over?
I'm having trouble figuring out what to do with the bolded part, when there are no nodes to return.If there are no image tags inside the <images> tag, i get an "Object reference is not set to an instance of an object".I have been searching and searching for an answer but can't find one.
Dim orders = From o In xmlLinq.Descendants("order") Select New With { _ .orderID = o.Attribute("id").Value, _
i am retrieving data using data reader. Whenever a null value fetches from the column, the compiler encountering an error. The error occurs when column value contains NULL. I am using Visual Basic 2005.
Please look at the following error which is in red color:
DEVNA11.Checked = IIf(IsDBNull(dr("dev_serv_desc_final_na")), 0, dr("dev_serv_desc_final_na")) txtPlanServDesFinal.Text = IIf(IsDate(dr("dev_serv_desc_final_planned")), Format(dr("dev_serv_desc_final_planned"), "dd/MM/yyy"), dr("dev_serv_desc_final_planned")) System.ArgumentException: Argument 'Expression' is not a valid value.
I want to retrieve total value from sales table in sqlcommand object. Below is my sample code.I will get error if there was no data in the tabel that matched my query saying that null could not be converted into decimal.
I would not get error if there was data that matched my query and returned the total value in tmpSales variable.My question is what is the best way to deal with this situation?
Dim CmdTmp As System.Data.SqlClient.SqlCommand
Dim tmpSales As Decimal
CmdSales = New System.Data.SqlClient.SqlCommand("SELECT SUM(Total) FROM Sales WHERE Date>= '1 Jan 2011' And Date<= '30 Jan 2011", ConDB)tmpSales = CmdSales.ExecuteScalar
How can i return null values in if statement above. This statement is not working if condtion is false its retruning me 0 value even if condition is false
dim d as nullable(0f Decimal) d=(if(_dr("value") isnot dbnull.value,Convert.toDecimal((_dr("value")),Nothing)
I have a datetimepicker and combobox on my form. If a user does not change the date on dtpicker or does not change text on combo box, these controls return null value, and the save operation fails. The controls are bound to data in a database.
Is there any sense to set custom object to null(Nothing in VB.NET) in the Dispose() method?Could this prevent memory leaks or it's useless?!Let's consider two examples:
public class Foo : IDisposable { private Bar bar; // standard custom .NET object public Foo(Bar bar) {
Dim myRow As BurnerService.OEBSContractBatchesRow Dim myDate As Nullable(Of DateTime) myRow = Me.BurnerService.OEBSContractBatches.AddOEBSContractBatchesRow( _
I have already defined in my SELECT statement in TableAdapter to tell it what to do if the parameters are Null:
SELECT a.ID, a.NameID, b.BNameID FROM a INNER JOIN b ON a.ID = b.ID WHERE ((@NameID IS NULL) OR (a.NameID = @NameID)) AND ((@BNameID IS NULL) OR (b.BNameID = @BNameID))
I have a Web Service with one WebMethod for which return value is boolean.It accepts XML file as string and process data. How can I first return status as true and then call the ProcessData method.
As the processing data takes time I need to return true first and then process the data.
[webmethod] Public function receiveData(ByVal xmlstr as string) as boolean dim status as boolean=false try
I'm trying to search a generic list of 'User' business objects which has a property called 'Username': If (From u In colUsers Select u.Username Where Username.Equals(strUsername)).Count > 0 ThenI keep getting:Delegate to an instance method cannot have null 'this'.
Use the "new" keyword to create an object instance & Check to determine if the object is null before calling the method. I'm reading text from a text file using the following [Code]
I'm using VB6 and trying to get an instance of a Type Library object.After i retrieved the object and i'm trying to invoke a method. I'm getting this exception. However, i've checked with the parameters and its type. it is correct.I found something fishy, that method doesnt have return value. But it is throwing a compiler error whenever i'm trying to call the function and the compiler error went off when i get a return value from that method.I don't know,
Dim data As DataTable = DataAccess.ExecuteDataSet("AuthenticateWebServiceClient" _ , New SqlParameter("@ClientID", ClientId) _ , New SqlParameter("@Password", Password) _[code]....
Except PrepareSPCommand isn't recognized by VS. Does anyone know the correct way to convert this function to C#.
I know there is a function Contains that returns true if string has a certain substing in it. But is there a function that returns the count of instances of that substring inside another string.
i'm using powershell 2.0 on win 7, does anyone know where to find what the non-zero return values from the rename method of win32_computersystem mean?i get a 5 every time i execute it, & have no idea where to find what that means.it's a HUGE brick wall on a project i'm working on
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.
If we format a value for percent "{0:#%}" then it will become 400%, and this also applies to all the 3rd party controls I've tried. I've used custom format as a workaround for this but perhaps you guys could enlighten me on this one. If a user inputted 4 for example then did the user intended 4% or 400%? If it were me that I would expect the 4 to be 4% rather than 400%.
Dim myDialog As frmTestDialog myDialog = New frmTestDialog myDialog.Show()
you'd expect some dialog window to appear in a non-modal state. For some reason, this isn't the case with a program I am working on. Most of the dialogs use ShowDialog() to open them, and one uses Show(). The second I try to show another non-modal dialog, the dialog appears in a modal state. Another strange thing is, before I show the dialog, there is code to shift the dialog location to centre it on the main form - this isn't executed either: the dialog appears at 0,0.
My usual trend is to blame myself for errors (usually the case), then I blame the software; I have checked every single line of code (including the generated code), and it all checks out - the dialog should be non-modal. But ... it's not. I've come across other errors in VB.net 2003; is this another instance?
I'll try creating a new dialog and displaying this non-modal, and see what happens. If it works, I can just transplant the code but this shouldn't be happening, just like if I go to a shop, ask for a cola, I expect a cola not a Chinese panda; more annoying, I return the panda, ask for a cola, and they give me the panda back do loop until I give up The system does using threading, but none of that code connects to the display dialog routines all dialogs are opened with more-or-less the above code (a few have simple validation routines).
After right clicking on the form Context Menu give option to see 'View Code Window' which opens the the view code window and shows from the first line of code in the file, where actually it should show Event handlers related to the control on which Mouse was right clicked. right now we have to go through the line of codes to locate the event related to particular control.Also after double clicking on the control, VB inserts a default event handler to Code file which should happen only when there is no Event Handlers added for that control previously & if a previously added Event Handler present, double clicking controls should locate that procedure.[code]after dragging dataset table to the form vb assigns 'field name' concatinated with 'TextBox' to TextBox Control likewise 'field name' concatinated with 'ComboBox' for ComboBox Control where it is difficult to locate them in Controls Member list into code..Instead why don't you prefix them with 'txt' for TextBox, 'cbo' for ComboBox etc. It is then easy to find one in code. Or make the original Optional.
Public Class userDefClass private b as integer = 1 End class Public Class Form1 private SomeClass as new userDefClass Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) [Code]...
