Why Boolean True Is Equivalent To -1 If Identifier Type In Integer
Jan 24, 2012Dim method1 = Function(x As Integer, ByRef y As Integer) As Boolean
If x = y Then
Return True
Else
[code]....
Dim method1 = Function(x As Integer, ByRef y As Integer) As Boolean
If x = y Then
Return True
Else
[code]....
I am working with some VB.Net code that seems to be casting a boolean value to an integer using CInt(myBoolean). The odd thing that is happening is that it returns -1 if the value is true. For example:
CInt(True) // returns -1
CInt(False) // returns 0
Is this common in other languages? I thought that a boolean would be 1 if true and 0 if false. Also, is there a way to make VB assign 1 to true instead of assigning -1?
I'm just writing a bit of code to compare an id of integer with an id of integer? for example:
Dim id As Integer = 1
Dim nullId As Integer? = Nothing
Dim areEqual As Boolean
areEqual = nullId = id
When I try to compile the code I get a compiler error: Option Strict On disallows implicit conversions from 'Boolean?' to 'Boolean'. Whilst it's very simple for me to work around this, I was hoping that someone might be able to explain what's going in the compiler to give this warning.
i am using VS 2008 and just started to work with XAML and WPF. while opening in page(.xaml) in design mode i'm getting the error like this "Only TrueType fonts are supported and this is not a TrueType font".
View 7 RepliesI'm pretty new to Vb so I'm not sure of all the correct terminology etc.
Private Sub Add_mousedown(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Add.MouseDown
Dim Addition As Boolean
[code].....
I have a form which creates a new school talk appointment. In my database, there is a column called 'active' which is boolean (true or false). Then everytime I creates a new school talk appointment and added it to database, the active is automatically set to 'false'. how to make it set to 'true' instead?
View 10 RepliesI am trying to up a private sub routing based on the Text Changed Event for a listbox, inside of the event, I want to set a boolean variable to true. I have it set up, but for some reason it is not getting called.
Basically what I am doing is the user is being prompted to enter data in an input box. I am taking the data that is entered on the input box and populating it in a list box. I want to know if the text in the listbox has been changed, hence changing the blnIsChanged = True
Can I use text changed with a listbox???
I'm deserializing a custom object from a file to an object in my app using the XmlSerializer. My issue is that I want a field in the object to default to "True" rather than "False" for a new property that doesn't exist in the file that I am deserializing from.
By default, .Net is assigning this value to be false because it doesn't exist in the file and I want it to default to True if it doesn't exist. I used the System.ComponentModel.DefaultValue(True) attribute on the field in the definition of the object, but that didn't work. Does anyone know how to do this?
"In what circumstances will the following boolean expression evaluate to true?
strAlphabet.indexOf(StrCharacter) >= 0 And _
strAlphabet.indexOf(StrCharacter) < 0
Once you have answered that question, you should be able to complete this description: the expression indicates whether strCharacter is ..... but is not...."
I have a math program that I am working on. One of the exercises has a random word and 6 radiobuttons. The user has to select the radiobutton that displays the exact number of letters in the random word. What I am having trouble with is creating a Public Function to check if the answer selected is the correct one. The radio buttons are within a groupbox. The Public Function returns a boolean True or False.
View 4 RepliesI have a winform that is taking too long to load. The form has a gazillion of controls and I would like to see how much time each control takes to load.If it were a web app, I would have just turned the trace on, but I can not find anything similar in winforms.
View 3 RepliesPossible Duplicate: Is there a conditional ternary operator in VB.NET? C# has a shortcut like this:
cmd.Parameters.Add(new SqlParameter("@p2", ((supplierID > 0) ? (object)supplierID : DBNull.Value)));`
This is my
[Code]...
This is my error: Operator '=' is not defined for type 'FileInfo' and type 'Boolean'.
I am interfacing my pc to a device called a MiniBee which is basically a usb digital output adapter to allow electronic devices to be controlled by the pc. So, I need to be able to individually address the output channels of this device, the only problem is the DLL supplied with it will only accept an integer value which represents a binary instruction if that makes any sense. I have basically got 8 public boolean vars OUT1, OUT2 etc that I need to use to turn on/off the outputs by them being set to true/false.
So there are say 8 digital output channels to operate and it has to work like this:
SetOutputs(1) would turn on output 1 and turn all others off
SetOutputs(2) would turn on output 2 and all others off
SetOutputs(3) turns on 1 and 2 and all others off
How to turn my public bool vars into an integer based on what is set to true/false if you get my meaning as there must be an easy way but working it out individually there are far too many possible permutations.
i have code below...but i cannot run because this error..."Conversion from type 'DBNull' to type 'Boolean' is not valid."
CheckBox1.Checked = DataGridView2.CurrentRow.Cells(10).Value
CheckBox2.Checked = DataGridView2.CurrentRow.Cells(11).Value
CheckBox3.Checked = DataGridView2.CurrentRow.Cells(12).Value
CheckBox4.Checked = DataGridView2.CurrentRow.Cells(13).Value
CheckBox5.Checked = DataGridView2.CurrentRow.Cells(14).Value
how i have to set in my table to insert input 1 or 0..
The following code at run time gives the error - Opearator '=' is not defined for type DBNull and type 'Boolean'.
The reason is the data at the table is set as NULL value.. How can I change it to accomodate the error.
Dim irowNo As Integer
For irowNo = 0 To DgvReturns.Rows.Count - 1
If DgvReturns.Rows(irowNo).Cells(2).Value = True Or
[Code]......
In my application when i click the button i'm getting this" Operator '=' is not defined for type 'Char' and type 'Boolean'." But when i test it locally there is no problem at all!
View 2 RepliesThis is probably a really basic (no pun intended) question, but I can't seem to find an answer anywhere.Why does the result of func1 return False and func2 returns True? On every other test I have done, integer 1 is converted to boolean true and 0 to false. Works ok if I just set rtnValue to 1 or 0.
Is there anyway to customize a variable to use both an integer and a boolean value?For example. I am kind of making a simulation engine and using GDI as a visual aid, I am generating a grid of tiles for objects to be displayed, but I do NOT want to repaint all the tiles just the ones that have changed, so that I can save fps.So I thought if I could set a variable for the "tile number", "how many objects there are on a tile", and a boolean value for whether or not the tile needs repainted.[code]
View 2 RepliesI am looking to convert an integer into a boolean array where each item in the array corresponds to a bit in the binary representation of the integer.
MyInteger = 3 '011 in binary
to
MyArray(2) = False
MyArray(1) = True
MyArray(0) = True
Also is there anyway to assign a value to an Integer in binary or hex (like MyInteger = 1010b or MyInteger = A7h)?
I faced an error when upgrading VB6 code to VB.NET. The error occurs at AddressOf WindowProc
AddressOf expression cannot be converted to 'Integer' because 'Integer' is not a delegate type
My declaration for SetWindowLong is:
Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA"(
ByVal hWnd As Integer,
ByVal nIndex As Integer,[code]....
What is the reason for the error I get?
How come both intellisense and compiler accepts If 3 = True Then ... in VB.NET? Even with option strict on.Does it in actuality treat Booleans as Integers, or what's the deal?
View 4 RepliesWhile testing some code i found something strange how vb.net (2005) is handling integer representation of true and false (or yes and no). Or at least i dont understand the reason for this.Im used to C or Java where 0 is false and everything else is true. To get to the point, here is the code: [code] And the out put is:X: 1 Y: 2x is truey is truex and y is false.If x and y or both individually true, why does it return false when you evaluate x And y.However, change the values of x and y to 4 and 5 you get this:X: 4 Y: 5x is truey is truex and y is trueJust another example, which seems to work how it should to me:X: 4 Y: 0x is truey is falsex and y is false.
View 7 RepliesI am a newbie in VB and I got a piece of code which can display the current running program. I need to use that in VB2005 and I got the below error message. Can anyone help how to fix it?[code]
View 18 RepliesI'm trying to convert a VB6 project to .NET, but I get problems with some callback functions, and the following message comes up: "AddressOf' expression cannot be converted to 'integer' because integer is not a delegate type" I've seen several solutions to similar problems like this, but I am not able to understand this issue with delegates.
After the conversion, the code look like this:
Declare Function vsmsgwSetDataPackageCB Lib "vsmsgwW.dll" (ByVal PACKAGE As Integer, ByRef arg As Integer) As Integer
Dim arginitP As Integer
[Code]...
Which gives the error: Method 'Public Function PackageCB(HisNodeID As Integer, ByRef data() As Byte, ByVal length As Integer, ByRef arg As Integer) As Integer' does not have the same signature as delegate 'Delegate Function DelegatePackageCallback(hwnd As Integer, lparam As Integer) As Integer
I am new to EF Linq and I have been struggling with this query for a few days. From reading this forum, I have managed to get this far:
Dim noPic = (From f In myEntities.FriendLists
Where (f.UserID = Profile.ID)
Select f.FriendID).Except(From g In myEntities.GuestLists
Where g.EventID = _id
Select g.FriendID)
[Code]...
I am trying to get everybody from the FriendList who is not already on the GuestList to display in a Repeater control. After reading the forum I was able to append .First() to noPic at the myNoPic declaration and finally get a result but that only gave me the first element. Does anybody have any advice on how to accomplish this?
Is there any better performance by checking for a true value like this:
[CODE]..............
Than like this:
[CODE]..............
Imports System
Imports System.Data
Imports System.Data.SqlClient[code]....
This my working method to send a email
Sub emailConfirm()
Dim email As String = txtMail.Text
Dim name As String = txtPrenom.Text + txtNom.Text[code]....
note:I want to send Link contains a unique identifier and verify the unique identifier in the login.aspx.I don't know when to do this...I found nothing interesting on the net ...
I've got a routine that checks a website my my external address. What I'd like to do is loop through the string just to get the first 15 numbers and full stops (periods). But that isn't my question, my problem is I've got this routine that isn't building because of a string conversion issue. I don't know how to correct it.
[Code]...