I am trying to create a UInt128 structure, based on some C code I found. The 128 bit number is stored as two UInt64's. All was going well until:
1.I tried to define MaxValue and MinValue.[code]
2. I tried to add. Apparently in C if you do the equivalent of this:[code]you do not get an overflow, the result "wraps".
I am trying to create a UInt128 structure, based on some C code I found. The 128 bit number is stored as two UInt64's. All was going well until:1. I tried to define MaxValue and MinValue. The code I found was
[code]...
Why does this not work ?
[code...]
I get "tostring cant be called without a narrowing conversion"
I'm trying to generate random dates in between two dates that are selected with a date and time selection control.Ideally, I would like to get the 'ticks' of each date, generate a random number between those, and then convert that back into a date.However I'm getting arithmetic overflow errors when I try to generate a random number from the between the ticks. I've tried many approaches - directly seeding with both the low and high date ticks, as well as subtracting.
Private Function randomDate() As ULong
Dim rand As New Random(Date.Now.Ticks Mod Integer.MaxValue)
Dim holder As ULong = DateTimePicker2.Value.Ticks - DateTimePicker1.Value.Ticks
[code].....
I have an application that deals with some rather large number values. I wanted the values to allow a roll over so I compiled the program with Remove Integer Overflow Checks turned on. The 32 bit numbers roll over just fine but the 64 bit unsigned integers still throw an over flow exception. Is this a bug in the compiler?
View 7 RepliesI have been trying to compute the checksum for a line of hex code. This is to create a hex file which will be loaded onto an embedded micro.Some of you guys may not know how this is done so very briefly:
a line of hex bytes:
: 10 01 00 00 21 46 01 36 01 21 47 01 36 00 7E FE 09 D2 19 01 40
The underlined bytes are taken and summed. (in this case the decimal 960). and the bold is the checksum Only the 8LSB (or single least significant byte) is needed to compute the checksum... which in this case, 960 = 03C0 in hex, so only C0 is needed.Two's complement is then taken:
step 1) logical not of C0 which is
step 2) add one (integer)
BIN...........DEC...HEX
[code]....
So here is the code I have been using: (quick mention that in the string passed, the hex bytes are all grouped together, there are no space characters)
Public Sub CreateLine(ByVal Data As String)
'Dim BDataArray(DataLength) As Byte
Dim IDataArray(Data.Length) As Integer
[code]....
where i get into trouble is where i commented 'i get into trouble'. My code works, but it's rather crude Now, in that line i first convert the hex value (string) "SChecksum" into an integer. I want to NOT this, so I get my step 2 from my explanation. However, the results appears to be a signed logical NOT. which gives me the wrong answer. My hashed togther version simply subtracts 256 before the not, in order to give me the correct answer.
Basically, I would love for someone to chime in and point out the flaws in my function, and push me towards figuring out the 'proper' way of doing this. Also I can't quite wrap my head around what would happen in the case a string were passed to my function that is over 16 bits, but I imagine I would have to subtract a larger value than 256, before doing the NOT in this case?(whilst we're on the subject of functions, I've used a 'sub', in which case should I used a sub, and which case should I use a function?).
i want to use an unsigned 32 bit integer. According to [URL]the rage of that type is
UInteger
UInt32
4 bytes
0 through 4,294,967,295 (unsigned)
[code].....
I am trying to write a VB.NET program that will call a function in an unmanaged C DLL passing the structure like this:[code]What I have not been able to figure out is how to handle the "unsigned char *msg" part. How would you define this in the VB.NET Structure?
View 2 RepliesI'm working with byte arrays and building and disassembling Int16/UInt16 and Int32/UInt32 from them. I'd like to not worry about the Sign bit until I return the final value and just have the code return the appropriate value for the data type that was requested to be converted to/from the byte array
View 3 RepliesI'm new to VB.Net. I'm using a library call setInstance(ByVal instance As UInteger) in my VB.Net code. The parameter I need to pass is an Integer. Is there anything I need to do to convert the integer parameter to an unsigned integer? The number is garunteed to be positive and less than 10.
View 3 RepliesHow can I implement a two's complement in VB.NET using unsigned integer types such as Byte, UShort, UInteger and ULong? Can I cast a UInteger to an Integer?
View 1 RepliesIn VB .Net this code:
Dim t As UInt64
t = UInt64.MaxValue
t += 2UL
causes an overflow. It is my understanding that in C it "wraps". Assuming that is true, is there a way to mimic this in VB? I need this for an implementation of UInt128 I am trying to write.
VS 2010 Adding whole numbers between a number and a number
View 3 RepliesI need to parse a binary stream in .NET to convert a 16 byte unsigned integer. I would like to use the BinaryReader.ReadUIntXX() functions but there isn't a BinaryReader.ReadUInt128() function available. I assume I will have to roll my own function using the ReadByte function and build an array but I don't know if this is the most efficient method?
View 3 RepliesHow do I pull off an unsigned left shift in VB.Net while using Option Strict? Maybe I am doing it wrong, but while trying to implement my own IP2Long function (I have my reasons), I'm testing things to make sure I have my head wrapped around the conversion process properly. Tried a few tests, all seem to cause errors.
Dim a As Int32
a = CUint(172 << 24) 'Constant expression not representable in type 'UInteger'
a = DirectCast((172 << 24), UInt32) 'Value of type 'Integer' cannot be converted to 'UInteger'
a = Convert.ToUInt32(172 << 24) 'Compiles, but throws an OverflowException
The last one is especially befuddling. 172 << 24 is a mere 2,885,681,152, well under the limit imposed by the UInt32 data type. My assumption is .NET is doing the left-shift in signed mode, then tries to convert, to unsigned, and this tosses up some kind of error. Basically, my question boils down to this: why do unsigned numeric have to act like such hacks to the .NET framework at times? Is it really that hard for Microsoft to make Unsigned data types intrinsic to the framework?
I'm making a "wrapper" for an unmanaged DLL (written, I'm fairly certain in C). I have a c++ "wrapper" that I'm trying to convert to VB.net. I've got most of the program working, but I've hit a brick wall.
I'm trying to convert the following two structures from their c++ versions to their vb.net versions. I cannot be sure which is the problem because both must be passed at the same time. The error I am getting is thrown by the object and indicates "Invalid structure size specified". I can cause this error on other objects when I either don't set the dwSize variable, leave off a parameter or change the parameter type incorrectly. Note that the dwSize parameter is supposed to contain the size of each structure. I'm successfully calculating that for my other structures and I'm using the same method on these and the results appear correct, so I do not believe the problem is found there. The object uses a lot of structures and the rest of them are working. These two are the only ones with a) an unsigned character pointer b) an unsigned long array and c) doubles.
C++ versions:
CODE:
I don't think I'm missing any parameters - the help file seems to agree with me on this, but it's theoretically possible that there is something missing (though I don't think so for other reasons as well). My suspicion is that it's dwPalette, pImageData or pMaskData with (in my uninformed opinion) more suspicion on the pImageData and pMaskData.
I need to read signed and unsigned 8 bit, 16 bit and 32 bit values from a file stream which may be little-endian or big-endian (it happens to be a tiff file which carries the byte order indicator at the start).I initially started by writing my own functions to read the values and was able to do so for unsigned values. e.g.
Public Function ReadUInt32() As UInt32
Dim b(4) As Byte
input.Read(b, 0, 4)
[code]....
But then I started looking at signed values and my brain broke.As an alternative, I found the IO.BinaryReader which will let me read signed values directly but doesn't seem to have any way to indicate that the data is big-endian or little-endian.Is there a nice way of handling this? Failing that, can someone tell me how to convert multiple bytes into signed values (in both byte orders)?
how can i, for example add a datum from the rs232 with other variable here is my code:
Dim ii As Byte
Dim c(100) As Char
c = Me.SerialPort1.ReadExisting()
[Code]....
I'm creating an emulator for a device to simulate wave forms. My challenge is that when I try to convert the output of the following code, I can't convert the Math.Sin's double output into byte values that lend themselves to the byte array format required by an existing graphing control as listed at bottom below. I''m not sure how to handle this when the sin function creates negative values but the byte values will need to be positive and basically 'shifted up' so that anything over 127 is negative. (0 - 255) unsigned. BitConverter.GetBytes has been suggested but THIS is the result of that attempt.
[Code]....
I am working on a UDP Client/Server, and currently i have them sending back and forth strings, which i convert to bytes, and then open the bytes to read. I want to now send an Object instead of those strings, which includes multiple unsigned integers and strings.
View 39 RepliesI am doing a bar cash register and I want to use a if statement to see if fosters button and number 1 on the number pad are both pressed then multiply constant by quantity number
View 1 RepliesI would like to know how to convert a unisgned byte to signed byte
Atm I got this
a
Function readSignedByte() As SByte
'-128/127
Dim b As SByte
[Code]....
it doesn't work one that well works for numbers positive over 127 if lets say ReadByte() has 128 it would give overflow error which I don't want it to give I would like it to overflow the number to negivate value aka its signed value.
How can I know if the number is Down or up? For example: i have textbox with the nubmer "5" now if i write "6" the program will display a message like "The nubmer is up" and if i write "4" the program will display a message like "The nubmer is down"
View 13 Repliesi have this as my code goal is tocreate a application that displays counts of occurences of each digit in a number entered by a user , is their another way without doing it with the case statement?
For x = 0 To userInput.length - 1
Select Case userInput(x)
Case "0"
[code].....
I've written an app - that use httplisteners to talk to other winforms (they will be services but are now simple form apps so I can easily show stats as they communicate). One UI app talking to three other "service" apps - all talking to each other as well...Everything uses multi-threading...At any rate - how many threads do I have available - I see that most of the apps seem to run "two or three" consecutive threads - but not more than that.Is that just a byproduct of running in the IDE - or is there a max of number of threads available?When more threads are asked for than are available - do they simply wait to get started for a free thread to become available?
View 4 RepliesI've been trying to solve this for couple of days now, I have tried with regex, split command and I have this string: Temp: 21�-9�hum: 45%-100%probable something: 14%-32%
characters after numbers are always the same as above same as the text all numbers can go from 0 to 999 I need to get only numbers, so output would be array of (21, 9, 45, 100, 14, 32)
I'm analyzing several log files obtained by drive test. I need of an information called "Cell information" and I extract it using analyzer tool. Issue is that this tool extracts this information in DWORD 11214032. So I need to use calculator to convert it to WORD. See image: and after conversion:So I want to convert 11214032 to 7376 number that identifies my cellid. I must repeat this operation for all informations (around 30)
Can someone know how to convert number 11214032?
Would it be possible to list the number of items in a rich text box? Each item starts on a new line. Something like the following but obviously for a rtb.
TextBox1.Text = ListBox1.Items.Count
i need a simple way to get a random number from 2 numbers. This means that for example if my 2 numbers are 3 and 7, i don't need a random number between 3 and 7 that would be like 3,4,5,6,7 but only a random that is either 3 or 7. Meaning not all the numbers between x and y, but either x or y.
View 7 RepliesI am working on a printing kiosk and it should handle PDF.When printing PDF I need to get the number of pages the PDF has, so that I can charge the user accordingly.The kiosk will support Word*, PowerPoint*, and Excel* (2010) and I print these files to PDF by Microsoft.Office.Iterop.* namespace.And then print the resulting PDF file to a physical printer. If the file is already a PDF then just print. What would be the best way to get the number of pages the PDF has. Also Printing via code and setting parameters such as paper_size.
View 4 Replies