Can't Understand What Constants Are
Apr 24, 2012i cant understand what constants are.
View 3 Repliesi cant understand what constants are.
View 3 RepliesI am calling this function when a button is CLICKED and received the error; The name "The" is not permitted in this context. Valid expression are constants, constants expression, and (in some contexts) variables. Column names are not permitted. Unclosed quotation mark after the character string 'True)'.
The function is as follows;
Private Sub Save()
Dim conn As SqlConnection = GetDbConnection()
Dim query As String
Dim cmd As New SqlCommand
I have been given an old dll and the assignment of accessing it through C# .NET 3.5. I believe the dll was originally built with VB6, but am not positive. There is no documentation or source for the dll aside from an example for how to use the it in VB6. I have been able to succesfully access it through VB.NET 3.5. Example code for accessing looks like this:
myLib = CreateObject("MyLib.api")
myConnection = myLib.CreateObject("NameOfConnectionObject")
myConnection.do_something("abc")
There are several different objects that are created from the library and all of those objects have different methods. I tried using different dll reading tools, but all the export methods show up as garbage. I also tried importing the dll in visual studio, but I get an error stating the dll is not accessible and/or not a COM object or assembly. So, I only know about the methods from the old documentation which is sparse. how to access in C# and/or find out more about this mystery dll?
Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click
Dim d As Integer
Dim price(20) As Double ' Adjusted close price
[code]....
What is the for ... next loops in the second subroutine doing? What is the sim() array meaning?
I have a modem that I've been trying to communicate with only to discover this....went to the modem properties and queried the modem.....
AT+FCLASS = 0,1,8
AT#CLASS = ? COMMAND NOT SUPPORTED
(And I had been trying to use AT#CLASS = 8 all day).So, what does this mean?That the modem is automatically in voice mode (or will automatically choose it's own mode) and forcing it isn't necessary?Still no luck with the connection response messages either -- RING, etc.All I can do is make a call and the called number will appear in a textbox.
I am getting a build error. If I try to build again after getting this error, it will build just fine.
View 9 Replies[code] I cannot seem to understand why left & lan isn't working in the vb 2008 edition
View 2 Replieshow to understand a msakeditbox in null?
View 4 RepliesI've been trying to understand classes and objects. Yes, I'm thick headed and slow, but I made the decision to go to .Net and I am determined to improve my coding skills to be more efficient. I have spoken to Atma several times on the topic and read most of his posts concerning classes and objects, but still came away a little baffled (He's really advanced for me yet). I needed a simplistic analogy for a reference point to begin understanding. I was reading about OOP written by MikeJ in the following thread/post ...[URL] and it all started to become clear in this statement , but I would like some reassurance that I'm getting it ..."A car IS-A vehicle, while a dog HAS-A tail. The car would be an object declared as type Vehicle, while the dog would have a member that IS-A tail. However, Fido IS-A dog. The dog class is the base template for all dog objects, so when we declare Fido as a dog, Fido is an object. Since Fido IS-A dog, Fido HAS-A tail."
From this I have taken the following understanding...
Vehicle ... ' Class
Car ....... ' Object
Truck ... ' Object
Van ....... ' Object
And from that can I infer that this is true?
Dog ....... ' Class
Fido ... ' Object
Tail .. ' Member of Fido
So to apply this to a program I wrote recently that tracks Generator service...
Generator ' Would be the class
Brand X ' Would be an object
Spark Plug ' Would be a member
Gas Tank ' Would be a member
Brand Y ' Would be an object
Brand Z ' Would be an object
This statement also helped ...
""Class" and "object" are sometimes used interchangeably. However, classes describe the structure of objects, while objects are instances of classes. Each instance is an exact copy of its base class. Because an object is an "instance" of a class, the act of creating an object is called instantiation. To describe it better, a class is a blueprint, and an object is a building based on that blueprint". I can understand this (I think) and it refers to a basic template such as ..."Generator" (my class or blueprint or template) Generators have an engine, powerplant, fuel tank, etc. These are basic requirements to be a generator. (Template or Blueprint) They can differ by Brand of engine, Size of powerplant, and type of fuel used. (Based on template or blueprint) Do I have it down now? MikeJ also made this statement ..."you can't access certain types of class members from outside of the class itself." From this I assume you would need to assign a Global variable the value of the class member if you needed to use it outside of the class?
I'm just getting back into VB and was never a pro. The last environment I was in, briefly, was VB6 but spent a good amount of time coding in early VB's back to QB.I'm trying to read RSS feeds and found a nice demo reader but now I want to understand the code I'm seeing:[code]
1. Why does the demo create a new XML to read through an existing XML or is this all in memory as I can't find an actually file? Is this even needed as what I want to do is read the RSS feed, grab some info from it (Source, Title of each story, Date stamp, author and the story text) and then process that in various ways (not actually view it... I want to e-mail specific stories directly to me that fit my search criteria). Or is this just opening the XML out on the web? That would explain why sending it "test" gives me an error saying it can't find "test" in the bin folder as without an HTTP address it goes local.
2. doc.load... what check can I perform here to be certain that the data entered by the user is actually a valid feed? It should, for example, have a first line header that is reliable but is that the best method?
3. Where or how are the elements stored that I can then refer back to pull the data out I want?
4. I don't understand how this part works: navigator.Select("/rss/channel/item/title") Can someone shed some lite on the 4 pieces at the end?
5. I'm assuming the clean-up isn't really needed for e-mail but I didn't remove it as it doesn't seem to harm anything.
I have Visual Basic 2010 and also bought a book to study and practice problems. I know how to add controls and assign properties but get confused with the coding part.understand this somewhat?
Here is one problem I am working on-
Write a program to make change for an amount of money from 0-99 cents input by the user. the output of the program should show the number of coins from each denomination used to make change.
Now I know what controls i need on the windows form but I am sorta lost on the coding to make this program work.
At the following cmd.ExecuteNonQuery() line, I get the following error message: [code] I have followed the example at page [code] as closely as possible, but it does not work.Additionally, I am not sure of the syntax for the length (64) that I have for the BigInt or if it should even have a length.All of the examples that I have found in MSDN uses only parameters with character rather than numberic type. [code]
View 6 Replies"write sub prototype for a procedure whcih is named my data and has first parameter as a string which can be changed and second parameter of an integer which cannot be change"
View 3 RepliesAre you familiar with prefix and postfix? I just wonder how to solve it especially if the expression is too long.
View 17 RepliesI want to make an application that will remind me to give a break once in 45-50 minutes. But I want it to determine if I am playing a game or not at the time that I have to give break. In short, if any application is in fullscreen mode (or maybe using graphic card) I want to know. Is there anything about that in .NET?
View 12 RepliesI have created a new usercontrol. My usercontrol contains several other controls like labels, buttons and so on ...When I set the Font property of the usercontrol I want that font property value to propagate down to the child controls.
View 2 RepliesCan someone explain to me what this is doing.
[code]...
My questions isn't really about a programming language but, since I did not find a general programming forum, I chose this one as I know VB.Net. There's this game, that you might already know, which is called Star Wars Galaxies (And is ending soon actually .. ). For each account and character, the game automatically saves chat logs in a .cht file. A player can have multiple chat channels that have different chat filters (group chat, public chat, etc) and they are all saved in this file. I'm thinking they are probably separated by some kind of a "flag" for the game to be able to detect them.
[Code]...
I am referring to this document on MSDN. I understand what ".BeginInvoke" does, however looking at the example code on the document.[code]The delegate myDelegate (and the DelegateMethod) accepts a control and a string, but, at the .BeginInvoke, a Label control is passed and an array.[code]Shouldn't a string be passed instead of the array? Am I missing something?
View 2 Repliesif a call to For Each starts by calling the Enumerator's MoveNext, then Current, then MoveNext, then Current, and so on until MoveNext returns a False then it exits, am i right to say that the Reset is never called?initially i thought that Reset would be called when MoveNext returns False, i tried this (a msgbox would come if it was ever called but i got no msgbox at all)
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if that's the case, what exactly is the use of the reset in an ienumerator, and is it ok to leave it empty, as such
I'm trying to understand ComboBox and the use of columns (or equivalent) in .NET For instance, I have a bound form with a combo box and a table that i want to feed it. In the table I have EmployeeID, LastName, FirstName. I want the "Bound Column" to be the EmployeeID, but the combo box to display the last and first name of the employee. This was very easily obtainable in VBA but is giving me some grief in VB.NET. I've played around with the datamember and valuemember properties of the combobox but have not had any luck.
View 2 RepliesI'm trying to understand the concept of Raise Events and threading, From this tutorial i've just read in the author example he wrote that you need to use an event when calling sub when using threading, but he didnt elaborate enough in this subject, why can't I just call the function/sub as i always do?
View 22 RepliesI freely admit that I tend to avoid using API calls as much as possible I wish to use this API call
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A number like 1,000,000.33 is written in another country as 1.000.000,33
which computer setting do I need to read to understand which type of number annotation is used on the current computer?
is there a way to convert those numbers in a neutral way??
There are a bunch of constants like vbTab in VB.Net, is there corresponding one in C# ?
View 1 RepliesSay I have some constants that depends one of other, and I decided to keep them together in a container instead of keeping it as individual constants in a class.I thought use a Structure for that scope, but compiler force me to declare a private member for that structure.
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How would you declare constants from a .dll, so you can use it in your program.
View 2 Repliesi was concerned if constants take up storage. if a class had 10 integer constants at class level, will that adds up to 40bytes of storage or is that actually not true because they are constants?
what i'm trying to do: find the best place to put the constants that i need to access at class scope, and whether its best to make them shared or not. [constants are private]
I want to define several constants of pens like SystemPens. How do I do that?
View 6 RepliesCan anyone explain what the following vbkey constants are as actual key presses? I've tried searching and really can't find any info other than vbKeyCancel = CANCEL key. Well, what's a cancel key? I dont have one on my keybaord...I read somewhere that CANCEL = Ctrl+C. Is that true? If so, what are the other few I have listed?
Constant
Value
Description[code].....