I've been researching all over Google for how to Read/Write Floats, Doubles, Longs and String to memory. I believe I have the reading Longs, and Floats working properly. I'll post my Module (which contains all my Read/Writting).[code]
View 2 RepliesIs there a way to get the fraction parts of a Double without using string manipulations? Specifically in vb.net?
There are numerous examples for a decimal in various languages. One for vb.net is this one
Basically they all seem to use either a mod or Truncate method or they take advantage of casting to integer behavior. But none of those approaches will work for a double/float type due to the inherent inaccuracy of the double/float type. There is also the problem that doubles don't cast to decimals reliably. Below is a test case to show what I mean and expect.
<TestClass> _
Public Class BasicNumberTests
Function DecimalFractionalPart(ByVal number As Decimal) As Decimal
[Code]....
was wondering if it was possible to write/read from a programs memory inside of your visual basic 2008 application. I've done tons of research and "googled" everythingt to be able to read/write values of a running process from with my application.I did read somewhere that you can only read/write up to 4bytes in vb.net, That would be just perfect
View 6 RepliesDim x As Integer = 1.8 1
Error:
Option Strict On disallows implicit
conversions from 'Double' to 'Long'
What Long??
EDIT:
Apparently Visual Basic attempts to convert any floating-point numeric expression to Long. OK, this part is clear.
Now, I can use the
CType((Math.Round(myResultingSingle)), Integer)
but what for MSDN tells that operator supports all the types if in reality it supports only Long as expression1 ?!...
intLoginTime = txtLoginTime.Text
intLogoutTime = txtLogoutTime.Text
[CODE]..........
The problem is that the numbers seem to round after the decimal point, so if I entered a login-time of 8.15 and log-out 9.30, instead of showing 1.15 as the difference, it shows '1'. is there a way around this?
I am making the belated transition from VB6 to VB.NET (2008). I would appreciate some guidance on writing arrays to a file. I need to save and load large arrays of 4-byte floats (24 x 90,000 values is not uncommon). I can load or save them using nested for-next loops, but that's quite slow. I'd like to find a single operation that can read or write the binary data.In VB6 I could accomplish this (writing case shown) with Put #1 , , MyArray()I can read and write single variables from binary files without problems in .net. For example, [code]I have looked and looked, and Googled endlessly, but cannot find out how to accomplish a single-line numeric, floating-point array read or write in VB.NET.
View 3 RepliesIs there a easer way of coding in stead of wrighting long long paragraphs like this in one line [code]All of this is on one line and i got lots of info to put down.."The game will begin on your 16th birthday with your mother waking you up. Today you are to go to the castle for the first time. Leave your bed and open your dresser for a Strength Seed. "
View 2 RepliesI have created a string that holds the xml information that I need. I want to go through the xml in that string to go through each of the elements. I know how to do this if it is in a file like (books.xml) but how can you read it from a string?
View 3 RepliesI'm working on a way to authenticate users in my app, and what I've come up with is the following method.To write to a database, the user must have an account in SQL server 2008. However, I still want people to be able to view the application if they don't have access, but only read, they can't sync any changes. This is working well, as I have a string array hard coded containing approved users:
Dim Users() As String = {"BWANG", "EDASALLA", "ERICHARDSON", "HALONZO", "JCHAPMAN", "SKIM", "PMACK"}
The one problem with hardcoding is that if I need to ever add a user later on, I'd have to release an update to the program. (which isn't hard as I already have updating built into the app, and users can still download updates even if they can't sync.)
What I'd like to do, is use an encrypted .dat file that contains the user names, and store that with the application, so that i could always be added to, and only one file would need to be downloaded.
I have code in place to encrpt and decrypt the .dat file (called users.dat) and this code works for single text entries in the file. I need to figure out how to load a list however into the array in place.
Imports System
Imports System.IO
Dim userfile as String = "C:users.dat"
Dim Users() As String = Data.Decrypt(File.ReadAllLines(path))
Basically each line in the file will have an encrypted user name, and i want it to decrypt each line and store it back into that authorized user list.
I have made this code and it does work with a normal string key, but with a multi-string value(REG_MULTI_SZ) key it does not.[code]The error is this : Conversion from type 'String()' to type 'String' is not valid.So how do i read from a multi-tring value registry key and list is all into the listbox ?
View 3 RepliesI have a problem to make the comparison from char to string array using Naive Algorithm in vb.net.[code]The problem is the system cannot compare the input from s1 to compare with s2.
View 15 RepliesI have an application in Electronics to communicate with serial port. With using VB I have succesfully read a character using
Serialport1.ReadByte
or
Serialport1.ReadChar
[code].....
I was just playing around with trying to set up a datacontract that returned a class that had a property that took/returned an enum value. I could set the class up so that it worked great, but the service contract seen by the client had the enum turned into a string, of all things. Had it been turned into an Integer, that would have been useable, but not a string
View 1 RepliesWe have a middle tier application which transfers data from one application to other.I need to write few values to a CSV file but every time the code runs it overwrites the prevoius line.How do I start with a new line every time
TextWriter tw =
new
StreamWriter("D:\parsII\Build\CCSDataProp\bin\server\smaple.csv");
[code]....
What I am trying to do is save a value (from a textbox) to the registry, and later retrieve the same:This is the code (not working) that I have at the moment:My.Computer.Registry.SetValue(My.Application.Info.Title, (TextBox1.Text), "MyFCA")
View 17 Repliesi have a vb project im getting a bit of trouble with.this is how it should work user input text in the textbox. the input text will be count as single character each one by one after been checked they will be writen to a text file but all in caps if use input symbols, there is a look up table to turn that symbol in charater and then write it to the text file. after all that are writen to the text file another part of the program will copy the text file to another location and delete the original one. so here is my problem because the text file will be deleted i need a code that will create a text file each time the programme runs.
[Code]...
How can I write and read a string array to a text file?
View 2 RepliesHow do I read all the text from a text file and save it as a string variable? For some reason I remembered it being something like this: IO.FromFile.ReadAllText("path") but thats not it.
View 3 RepliesI need help writting a Trivia Game for a school project. The teacher wanted us to get used to looking to forums and google for help so he refuses to help us for this particular summative.
What I want to know is.. how to use a streamreader to read questions randomly from a text document located in the debug folder (I have 10 questions all in 1 text file in the debug folder, and the same for all of my answers) how to use a streamreader and split function to read answers from a text document located in the debug folder to a combobox.
[Code]...
I have a text file containing the data in following format
12345 Abdt3 hy45d et45a 76huj agsj7
Now I want to replace hy45d with another sting that is created on run time. But I am not finding any way to do it. It keep replacing the firt item or append it in next line.Code that I am using is
Public Sub SaveToTextFile(ByVal PNR As String, ByVal CaseCount As Integer, ByVal Type As String)
'- Location of the Text files
Dim targetFile As String = "C:TestReportTextFilesPNR.txt"[code].....
I have a label that displays the result of a calculation, i.e lblTotalCost.Text = dTotalCost, where dTotalCost is a Double. When I try use FormatCurrenct(lblTotalCost.Text = dTotalCost), the program crashes and says unable to convert string to double.
View 2 RepliesI've got a heavily used web application that, for the first time in 2 years, failed doing an equality check on two doubles using the equality function a colleague said he'd also been using for years. The goal of the function I'm about to paste in here is to compare two double values to 4 digits of precision and return the comparison results. For the sake of illustration, my values are:
Dim double1 As Double = 0.14625000000000002 ' The result of a calculation
Dim double2 As Double = 0.14625 ' A value that was looked up in a DB
If I pass them into this function:
Public Shared Function AreEqual(ByVal double1 As Double, ByVal double2 As Double) As Boolean
Return (CType(double1 * 10000, Long) = CType(double2 * 10000, Long))
End Function
the comparison fails. After the multiplication and cast to Long, the comparison ends up being:
Return 1463 = 1462
I'm kind of answering my own question here, but I can see that double1 is within the precision of a double (17 digits) and the cast is working correctly. My first real question is: If I change the line above to the following, why does it work correctly (returns True)?
Return (CType(CType(double1, Decimal) * 10000, Long) = _
CType(CType(double2, Decimal) * 10000, Long))
Doesn't Decimal have even more precision, thus the cast to Long should still be 1463, and the comparison return False? I think I'm having a brain fart on this stuff...Secondly, if one were to change this function to make the comparison I'm looking for more accurate or less error prone, would you recommend changing it to something much simpler? For example:
Return (Math.Abs(double1 - double2) < 0.0001)
Would I be to try something like:
Return (double1.ToString("N5").Equals(double2.ToString("N5")))
I wonder, whats the proper, accepted way to convert doubles to strings? I've heard cstr(blah) is wrong (despite it working perfectly OK for me....), what is the proper way to do this say if I want to display the value of a double in a textbox (along with 'the answer is' or somesuch)?
View 1 RepliesHaving problem make last if an statement work in the code. the variables in the if statment are doubles but the ide keep telling i need a proceeding if statement. but is already there it is in the last if statement of the code
Public Class Form1
Dim Totals As New List(Of Double)
Private Sub btnclear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
[CODE].....................
I am tasked with the job of reading the X and Y coordinate of a Text label from a "save file" of a 2D CAD drawing. I found the exact position of the coordinates in the file, but I still don't understand how to read them 100%. They aren't simple ASCII characters.First, I read the file byte by byte, and load them into a textbox seperated by spaces as numbers from 0 to 255. Here is an example X and Y coordinate
View 1 RepliesI have a bunch of type Double variables in my program, say for example
Dim Area as Double = 0
Dim Perimeter as Double = 0
Somewhere in my program I want to calculate these values, so I define
Public Sub TheSquare(ByRef TheArea as Double, ByRef ThePerim as Double, ByVal TheSide as Double)
TheArea = TheSide^2
ThePerim = 4 * TheSide
End Sub
and somewhere in the program I'm collecting side lengths and calculating the area and perimeter; say
While True
S = GetSideValueFromSomewhere()
TheSquare(Area, Perimeter, S)
End
In my real program, I have, say, 20 quantities that I want to calculate. Obviously each one has a different equation. But in the end I want to output all 20 to a file, so to save typing, I create an array of the quantities, like this:
Dim TypingSaver() as Double = {Area, Perimeter}
so that I can dump values to file with a three-line for-loop instead of copying and pasting 20 variable names.
This does exactly what I want if Area and Perimeter were reference types like Objects. But since they are Doubles, TypingSaver contains only their values, not references to the actual variables. So after I use my TheSquare function the values of Area and Perimeter are correctly updated but TypingSaver just constains whatever the values of Area and Perimeter were when I declared the array.
how can I create an array of references to doubles in VB.NET?
I have a dataset (imported from a XML file) with double records (clientname), and I want only the records with the most recent date (datetime field) written to a SQL database. Now I sort the dataset ("clientname ASC, DateTime ASC"), so the newest entry is written to the database.
[Code]....
could anyone show me a code on how to transpose a two dimensional array of doubles (changing rows to columns and vice versa) ?
View 1 Repliesi have a string with the value = "/var/mobile/Media/iTunes_Control/Music/" i need to read the next 13 letter after this string in a text file i am also using a loop to do this multiple times
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim Header As String = "/var/mobile/Media/iTunes_Control/Music/"
[Code].....
I have the following code in vb.net that calculates the amount before tax was applied:
Public Shared Function CalculateRateBeforeTax(ByVal rate As Decimal, ByVal tax As Decimal) As Decimal
Dim base As Decimal = rate / (1 + (tax / 100.0))
Return Math.Round(base,2)[code]....
I put the above scenarios into some unit tests using c# and using the nunit testing framework. The first scenario passes, but the other fails and I am not sure how I can get it to pass. Here is are my tests:
[TestFixture]
class TaxTests
{[code].....
As I said before, the first test passes, but the results of the other tests are:
Second Test expected 305.1600000000000003d But was: 305.1643192488263d
Third Test expected 95.54999999999997 But was: 95.55555555555555557d