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 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 RepliesDim method1 = Function(x As Integer, ByRef y As Integer) As Boolean
If x = y Then
Return True
Else
[code]....
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'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 wonder if this is not possible dim mystring as string="1" dim myint As Nullable(Of Integer) myint=0 myint=mystring It crashes on the last line why is that? mystring is already integer (1) , i dont have to cast using cint, i thought. option strict off- if this cause the problem
View 7 RepliesI'm trying to write a (WPF) program with Option Strict on, but I have a problem.
I have a Canvas with a background image, and I want to use the coordinates of where the canvas was clicked to determine what should happen next. (Something like this)
Dim p As Point = e.GetPosition(DirectCast(sender, Canvas))
Dim imgColorMap As System.Drawing.Bitmap = My.Resources.ColorMap
Dim c As System.Drawing.Color = imgColorMap.GetPixel(p.X, p.Y)
This gives me the error: "Option Strict disallows implicit conversion of 'Double' to 'Integer'" for p.X and p.Y I have tried several things, like Math.Round but strangely enough that also returns a double.
How do I cast/round these Double values to Integer, so I can use them in my GetPixel method?
VB
Dim pic2 As PictureBox
pic2 = snake.Item(0)
[Code].....
InvalidCastException was unhandled
Unable to cast object of type "System.Boolean' to type 'System.Windows.Forms.PictureBox'.
I am writing the code in the class to create the strings. I want the value to returns as true if the strings in the class are matched with two numbers or more, but if the if the strings in the class are not matched with first two numbers or not then returns the value as false.[code]....
View 4 RepliesIs there a fast way in VB.NET to take a 32-bit int and cast to a 32-bit float while preserving the underlying bit structure? BitConverter will do this, but I'd like to cast it directly without involving byte arrays.
View 1 RepliesSub pageload() Handles Me.Load
Dim bom As New List(Of Car)
Dim car1 As New Car With {.Name = "Pea", .Year = 2}[cod
WHY??? I mean the object has the exactly same data, so why does itee]..... say it is not contained?
I call a function (SaveChanges) to access my business / data layer and save any changes to fields that are marked as an Add or Update and are marked to be processed. This function used to work fine up until 60+ minutes ago. What is happening is that suddenly the function is returning false. After debugging through the code, when it hits Return the local boolean is set as True but when it gets back to the calling method (and uses the return value) it is now False. As I said I went through line by line and debugged it, then I added a watch to it. The funny part is that there is one spot that sets the Boolean to false, and when I put a breakpoint on that spot it is never reached.
Here is the function:
Private Function SaveChanges() As Boolean
Dim blnSaved As Boolean = True
Dim saveableRows As List(Of DataRow) = (From d As DataRow In _listData.Tables(0).Rows _
Where Not d("Marking") = "Duplicate" _
And d("Process") = True _
[Code] ....
I had a strange error in a VB6 app this morning and it all stems from the fact that IsNumeric is not working as I expected. To me this seems like a bug.
This code displays 4.15877E+62 in a message box:
Dim strMessage As String
strMessage = "0415877D57"
If IsNumeric(strMessage) Then
[Code]....
I am guessing that the runtime engine is incorrectly thinking that the D is in fact an E? I think this is a bug though as the exact same code in VB.NET outputs not numeric Is this a known issue with IsNumeric?
I want to check whether application is in debug mode/release mode to distinguish development & production application setting. I used custom attribute 'DebuggableAttribute' of currently executing assembly & its property IsJITTrackingEnabled to check application running mode.But this property always returns 'true' in both debug/release mode.
Can anybody let me know where is mistake or any alternative to achieve this?
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.
This 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)?
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 need top create a function that gets the next integer in the sequence of 1 to 60. Each time the function is called, I need it to increment from what the last value was and return the next number as the result. It also cannot return the same integer in 2 consecutive calls. When the count gets to 60, the sequence needs to reset back to 1. I would like to function to have no parameters.
I have created a function that does this using the cache to store the last value that was returned, but I am worried that with concurrent calls to the function that it might not work as I expect and 2 calls could get the same integer.
Is cache blocking the correct method to use in this instance or is there something other method I am not thinking about?
Also, stuck using .Net 3.5 and this is a web application.
I just wrote this function based on using SyncLock. Any obvious problems with it that I don't see? I am using the Cache to save the last value that was returned.
Private Shared Function GetNextNumber() As Integer
Dim o As Integer
Dim r As Integer
[Code].....
Is there any better performance by checking for a true value like this:
[CODE]..............
Than like this:
[CODE]..............
implement MOD(%) function without using the MOD or %. Function should take in two integers and return one integer.
View 2 RepliesI have a datagridview, and I want to get an array of rows, or rows indexes in which boolean column "Aktywny" is set to True.Obviously I can Do it using loop, but LINQ will be much faster for sure...
View 1 RepliesI have a project to make a "3x3 magic square" and I'm not quite sure how to begin. A magic square is a 3x3 table of 9 values where the sum of the values along any row, column, or either diagonal all add up to the same value.I have to use listboxes to create a form displaying a table of 3 rows and 3 columns whose elements can be individually updated. The solution should have the following features:
- a procedure that initializes a Listbox to hold the value "?", representing the value "undefined", in each of its locations. The number of locations should be provided as a n additional parameter.
- a procedure that will update the contents of a listbox by replacing the currently highlighted entry with a value provided as a second argument. The program should at most have at most one entry among the listboxes highlighted.
I am trying to use a Function that returns an integer value: -1 if not all the elements on the table contain values, 0 if the rows/columns/diagonals don't sum up to the same value, or the sum common to all the rows columns, and diagonals is returned if everything is alright.The user will enter a 3x3 set of numbers. The program will monitor the status of the table as values are entered and displays the status in a textbox that describes if a magic square currently exists. If not all the entries have been made to the table, then the textbox should display a message indicating so.
From what I read it is a good convention to name a method that returns a boolean value with the prefix of "is" or "has". So in keeping with this convention I am trying to name a method in my program with this prefix but I am running Specifically I have a class called Day. It is a simple class with a few data members and one method that returns a boolean value of true or false. The name of the boolean variable is isSpecialDay. This class has a method called isSpecialDay which takes the date of the day, applies some criteria to the date and then sets the variable isSpecialDay to true or false. My problem is that the boolean variable is named isSpecialDay and so it the method. What should I do?
Public Class Day
Private TheDate as String
Private DayName as String
[code].....