Overcome "Conversion From 'Byte' To 'String' Cannot Occur In A Constant Expression." In VB?
Apr 27, 2012
I have this code:
Public Class Beryllium
Public Const AtomicNumber As Byte = 4
Public Const Symbol As String = "Be"
[Code]....
I want to make a list out of all the constants (AtomicNumber, Symbol, Name and AtomicMass). I want to make the list also a constant. When I run the code above, I get an error highlighting AtomicNumber (on line on which I commented on "This line"). I tried .ToString() and CStr() but I get errors on both. Maybe there is a different way to make these constants one string or list (must be public and have new lines)?
I have written a small program to aide my business and the program works fine. But while compiling the code it shows a lot of warnings like the following."late bound resolution; run time errors may occur""implicit conversion from 'Object' to 'String'." Where am i going wrong. Even though the options strict off removes the warning I want to correct the warnings.
Private Function ledgerMasterFullName(ByVal i As Integer) As String Dim fullName As String Dim vObj As Object
I'm writing a C# application that reads data from an SQL database generated by VB6 code. The data is an array of Singles. I'm trying to convert them to a float[]
Below is the VB6 code that wrote the data in the database (cannot change this code):
Set fso = New FileSystemObject strFilePath = "c: emp emp.tmp" ' Output the data to a temporary file
[Code]....
The problem here is the VB6 binary to string conversion. The VB6 string char is 2 bytes wide and I don't know how to transform this back to a binary format I can handle.
Below is a dump of the temp file that the VB6 code generates:
And here is the dump of the data as I read it from the database in (=the VB6 string):
I'm trying to make following subroutine work. The problem is this part of the statement.[code]I've tried everything and can't seem to come up with a constant to use here.[code]
I have created a program that creates a blank database in a users account (each user has a seperate folder when registered) by pressing a command button, i have got it to create the database but when i try to populate it with a table to go to the correct folder i get an error
Constant expression is required the code im using for this is: Const strConnection As String = ("Provider=Microsoft.Jet.OLEDB.4.0;" & _
I need to read a named range into an array. Then if the value in the 1st position matches a static value, read the value in the second position. I've been looking into array's and this is what I think will work, however I get a compile error on the columns.count "constant expression required". Is it because in the DIM statement I'm attempting 2 things? This is a macro in Excel. The range name is Data1 and the string comparison is "AnyString". The second value will be an integer.
Sub macro1() Dim rng As Range Dim x As Integer Dim y As Integer rng = Range(Data1) [Code] .....
I m new to this forum and also to VB.net programming. In an application Modbus protocol is used and I have generate LRC checksum for that. But I am stuck at conversion of a Long type data to Byte type. The long type data is for example : 4294967197. I tried all the following functions:
<DefaultValue(Guid.Empty)> _ Public Property KeyValue() As Guid
I get an error on Guid.Empty "Constant expression is required."
What I'm trying to accomplish is to get rid of this line that shows up in the Designer file,
Me.TestUserControl1.KeyValue = New System.Guid("00000000-0000-0000-0000-000000000000")
I can avoid running the property's Set code with some conditionals on the Value sent when the form instances. I was just wondering if there's a way to deal with it similar to other data types.
I'm trying to make to do a widening conversion from a byte to an integer. form has a text box for both Input, and Output, plus a conversion button. [Code] I'm trying to use a catch block, but I'm not certain how it works exactly, and also tried to use an If statement to avert the issue, but that didn't work either. When ever user inputs a number greater than what can be held within the Byte data type the program crashes from the run time error. [Code] and an error message pops up in the compiler saying overflow exception was unhandled.
I am totally new with VB.NET. I have started coding for Modbus protocol. The response that I receive from the slave is as below -
01 = byte slave id 03 = byte function code 04 = byte -no. of bytes sent by slave 00 = byte(8 bits) (Lower Register MSB) 00 = byte(8 bits) (Lower Register LSB) 64 = byte(8 bits) (Upper Register MSB) 00 = byte(8 bits) (Upper Register LSB) 2bytes for crc
Now I want the value of 64 00 00 00 into floating point number in Vb.net . I think in vb.net its single as its 32bit floating precision number. Now the bytes that I need are 00 64 00 00 but if i process in this way the output is different, so I tried manually putting the data into the byte array and found out that I need 64 00 00 00 to be processed so that i can get desired output.
I have a byte array that I convert into a string like so Dim byt As Byte() = New Byte(255) {} s = New String(Encoding.ASCII.GetChars(byte))My question is when I look at the string in a debuger its clearly a normal string but when I compare it to what I know its supposed to be it doesnt equal. So i did a quick check and for some reason its return a string thats the length of 256 characters. So i did a s.trim and it still is 256 characters long.
i changed a class variable to shared so i can access it in all instances of the class, but it caused an error. what is causing this, and how can i fix it?
I want to pass an optional parameter to a function of type System.Drawing.Color. The problem I am having is that when I declare the function it says "Constant expression is required" but I have tried variations of the following, including integers, full qualified indentifiers, even old vbWhite constants to no avail.
a user will enter a number, n, which ranges from 1 to 30. they will also enter a "P" or an "S" (sum or product). depending on which was selected, it will calculate the sum or product of the numbers from 1 to n.i'm having a conversion error on line 5 stating "Conversion from string "S" to type 'Double' is not valid." [code]
In the following code i get a warning at line 59:Warning 1: Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.and.. At line 78 I get this Warning:
Warning 2 Property 'SelectedCustomer' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.
The program compiles and runs well, but i cant' undesrtand the reason for these warnings. Any Idea ?
1: Public Class Form1 2: 3: 'Form level members 4: Private objCustomers As New ArrayList
I have strMyColor = "Red".I would like to make lblMyLabel.BackColor to be red.Without using a variable the code would be this:
lblMyLabel.BackColor=Color.Red
I tried using the variable like this: lblMyLabel.backcolor="Color." & strMyColor
But the error is that a string can't be converted to System.Draw.Color. I understand that, as the string "Color.Red" is not the same as the VB constant Color.Red.Is there a way I can construct a valid vbConstant from a string?
When building a class library which contains many classes, all classes uses a lot of common constants and functions, what is the best to do:
1- Declare these constants and functions as public in a module.
2- In each class declare constants and functions used by individual class as private.
The first choice is good for easy and fast implementation, but re-using a class in a different project will require importing the module to the other project.The second choice require a lot of copy/paste for code snippet but a class can be re-used in different project easily.
I'm making a call to my DLL file (prototyping 30+ functions), and want to be able to switch between different versions of the DLL quickly while in development. Thus, i want to replace the literal string constant that follows the "Lib" key word, with a variable string constant. In case there's any confusion in my use of the jargon. I am currently able to do this:
