VS 2010 Using API Functions - Understand Data Types?
Sep 29, 2010I 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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Get A Compiler Warning For Functions Returning Value Types, Without Return Statement
Jul 21, 2009I've just been burned again by the fact that there is no compiler warning when you fail to return a result in a Function that returns a Value type. I wrote the function:
Public Function CompareTo(ByVal other As MessageIndex) As Integer Implements System.IComparable(Of MessageIndex).CompareTo
Me._messageIndex.CompareTo(other._messageIndex)
End Function
which performs the CompareTo Function for two integers, then throws the result away and returns 0, because I forgot to either assign a value to CompareTo, or use Return, and that isn't flagged by the compiler because it's valid VB for a Value type.
I happen never to use "FunctionName = ReturnValue" because it hides information from maintenance programmers and also because I think it's insane .
Is there any way I can get the compiler to issue a warning whenever my Functions are missing a Return, whether it's a Value type or not?
Converting Multiple Numerical Data Types In 2010?
May 7, 2011I'm having a bit of an issue with this program I have been working on for my class. It's a future values calculator, that takes a single data type, decimal data type and a integer data type does the formula and then spits back out the Future value. What i'm having difficulty with is converting the string over.
Public Class Form1
'Define the Module level variables
Dim FutureValueInteger As Integer
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VS 2010 Understand Shadowing Properties?
May 13, 2011I 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 RepliesVS 2008 : Have A Class Where The Functions Of The Same Name Are Both Instance Functions And Shared Functions?
Dec 6, 2010What I am trying to do is have a class where the functions of the same name are both instance functions and shared functions.
Public Shared Function Get...(byval xx as xx)
and
Public Function Get...
The Public Function uses a Property xx created in the constructor, whereas the Shared Function has the parameters (byval xx as xx).
Variables - Combining Multiple Data Types Into A Single Unified Data Structure
Mar 16, 2012In VB.NET I would like to create a complicated data structure with multiple types of data stored in an array like format (see below). I am trying to create a data structure that would look something like this: [Name; xLoc; yLoc; zLoc; [Jagged Array]] Note: Name needs to be dimensioned as a string, xLoc and so forth as integers. The Jagged Array would look like this:
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Data Types - Decimal - Move That Value Into A SQL Server Data Table Column Defined As A "Float"?
Aug 7, 2010SQL Server has a Data Type of "Float". Visual Studio has a Data Type of "Decimal". In other words, if I have a variable in a VB.Net app that is defined as a "Decimal" ...can I move that value into a SQL Server Data Table column defined as a "Float"?
View 4 RepliesVS 2008 - Choose Data Source - User To Easily Create A Connection To Any Installed Data Types They Have Installed
Jun 1, 2011I have been trying for days now how to create a process to the user to easily create a connection to any installed data types they have installed. I have found an example right inside vb2008. I never use this because I code my own connections, but this would be real nice if I could include it or duplicate it.
View 1 RepliesCalling C++ DLL In .NET - Data Types?
Mar 26, 2011I'm trying to call a C++ DLL from inside VB.NET and am having difficulty with the data types (I think), I understand VB.NET far more than I do C++...I think my main problem is differing data types and I don't understand enough C++?In C++ the DLL is called (I don't have the source for the DLL which would solve my problem, I only have a sample project written in C++) by this;
_InitSensor = (InitSensor)GetProcAddress(m_hInstLibrary, "InitSensor");
_FreeSensor = (FreeSensor)GetProcAddress(m_hInstLibrary, "FreeSensor");
_ReadTEMPsh10 = (ReadTEMPsh10)GetProcAddress(m_hInstLibrary, "ReadTEMPsh10");
_ReadType=(ReadType)GetProcAddress(m_hInstLibrary,"ReadType");
(Variables Declared Previously in other file like this;)
typedef char* (*InitSensor)(char ICType);
typedef void (*FreeSensor)();
typedef double* (*ReadTEMPsh10)(BYTE n);
typedef double (*ReadType)(BYTE address);
Data Types From External Dll
Feb 25, 2010I use Philip's MfRc500.dll for communicating with RFID chips. It contains a function for reading data, which is defined like this:[code]The second parameter in function Mf500PiccRead can returns "16 byte data block", so my long data type is too small. If I use byte() instead of long, then i get ExecutionEngineException Exception.
View 3 RepliesUse UniqueIdentifier Data Types?
Jul 14, 2010I'm torn between using UniqueIdentifiers(UID) or some other field as my primary key for my new web app. I have two tables. I need to be able to find the UID on one record in Table1 and put that UID in a new record in Table2. I also need to be able to create a brand new UID for the new record in Table2 on the fly.
View 3 RepliesWhen Is It Necessary To Convert Data Types
Feb 25, 2011Visual Basic 2010 (Express). If I take a string from a textbox and assign it to an integer variable, I'm under the impression that you're supposed to use CInt to explicitly convert the contents to an integer.intMyCount = CInt(txtUserInput.Text)However, if I don't do that, it still seems to work. Similarly, if I have an integer and concatenate it into a label's text property, it still works: lblResults.Text = intMyCount & " number of times."
rather than using intMyCount.ToString.Why does it work? Is VB doing implicit conversions when possible? Are there examples where not explicitly converting with .ToString or using CInt would cause unexpected results?
Wrapping A C++ Dll And Data Types
Dec 25, 2009I am trying to wrap a c++ dll and can use system.runtime.interopservices.dllimport and declare function to call functions from the dll. But how do i wrap the data types and everything else?
View 1 RepliesPassing Data Between Functions?
Jun 8, 2012I would like to have custom methods to pass data between function, or to keep it in memory throughout the program.
Example:
Private function info()
Addr1 = addr1.text
Addr2 = addr2.text
City = city.text
[code]....
Could I run this function towards the beginning of the program and use it throughout until the form is disposed? I can't seem to get the information to stick once I get out of the function, I will need to use the same information multiple times throughout the application so I figured if I could make a function to keep the info rather than declaring the 5 lines in every option but anytime I call the method, it fills it correctly then when I get back to the main function the info goes back to 'nothing'. is it possible to pass data around between functions like you could in Java?
C# - Compare Two Objects Regardless Of Data Types?
Oct 12, 2010I want to compare two objects whose type may be diffrent.
For eg, I expects 'true' for comparing 1000.0(Decimal) with 1000(Double) . Similary, it should return true if I compare 10(string) and 10(double) .
I tried to compare using Object.Equals() , but it did NOT work.It return false if two objects have different data types.
Dim oldVal As Object ' assgin some value
Dim newVal As Object 'assgin some value
If Not Object.Equals(oldVal,newVal) Then
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Calling TIME Data Types?
Oct 12, 2009I am create a mysql table with TIME data type Field. And then store time type data into that field. But can't view in datagridview ( not show in other controls, like LABEL,TEXT,LISTBOX etcc..) . Using method is:
(LEAVEFROM TIME DATA TYPE, LEAVETO TIME DATA TYPE)
Dim cmd As New MySqlCommand
Dim adapter As New MySqlDataAdapter
Dim table As New DataTable
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Run time display error:ArgumentException was unhandled Argument 'Prompt' cannot be converted to type 'String'
Data Types Don't Match In SQL Statement?
Mar 31, 2011I have a table that has a "date" column and an "amount" column. I also have a form with two DateTimePickers ("dtp1" and "dtp2"), a button and a label. The label should show the total amount calculated from the rows whose "date" value is between the dates picked by the user with the DateTimePicker controls.
I keep getting an error with my SQL statement, and I don't know what to try. My code is as follows:
Private Sub getData(ByRef total As Double)
Dim connection As OleDbConnection
connection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\proyectogestion.mdb")
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Delphi To VB: Define Data Types?
Aug 11, 2011in Delphi I have:
type osVer = (
osVerUnknown,
osVerWin95,
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I need to translate to VB...
Handle The Different Data Types That Could Be Returned?
Sep 7, 2010I tend to use
If Not IsDBNull(dr("data")) Then
myData = dr("data")
End If
to catch nulls. Is there a better way? It seems I use this over and over again? Anyone write a function to check this something like
mydata = IfNotNull("data")
I don't know how to handle the different data types that could be returned.
Python To VB: Unknown Data Types
Mar 3, 2010I never thought I'd say this, but I am getting pissed at how easy it is to just plop down a variable in python without any declaration. I have an existing python script which interfaces with a server, and it builds its own messages to be communicated via sockets. What I am trying to do is take the command line python script and convert it into a VB GUI app that is more user friendly.
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VS 2008 : Native Sql Data Types?
Jun 2, 2011I'm creating a VB.Net Windows Form Application. Apologies if this is not clear as I'm still new to .Net. This consists of a text box and a gridview.The user is able to write SQL code in the textbox, click run and see the results in the gridview.It uses a SQL DataAdapter and the fill method to a datatable to populate the gridview.My problem is that I need to know the SQL datatypes for each column in the data table (NOT the .net ones). I.E SQL Server 2008 data type 'Date' is stored as System.Datetime in the datatable. I need to know if the SQL Server datatype is 'Date' or 'Datetime'.
View 2 RepliesVS 2010 Get All Types In A Structure?
Jun 27, 2011Basically I have a system that will take an unknown structure (that should be marked serializable) and attempt to serialize it to a stream. However, before the system will do that, I want to know if there's a way to check every single variable/property to make sure that all the types are serializable.Anyone know a way?
EDIT: For now, I was able to do this:
Private Function IsSerializable(ByVal obj As [Object]) As [Boolean]
If obj.GetType.IsSerializable Then
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VS 2010 Add Subs / Functions To Subs / Functions?
Oct 26, 2009When you refrence a Function like this one:[code]You may want to be able to get more out of that, like this.[code]So how would I be able to add subs or functions onto a sub or function like that?
View 4 RepliesC# :: Determining Object Equivalence For Value Types, Reference Types And ILists?
Nov 1, 2009I have a class with a Property called 'Value' which is of type Object.Value can be of any type, a structure, a class, an array, IList etc.My problem is with the setter and determining whether the value has changed or not.This is simple enough for value types, but reference types and lists present a problem.For a class, would you assume that the Equals method has been implemented correctly, or just assume that the value has changed every time the setter is called?If I did assume it's changed, then perhaps I should assume it for value types as well, so that the behaviour is consistent.
View 2 RepliesFlexible Data Sets For Functions
Nov 12, 2009I have only 2 sets of "fixed" numbers used, that I need to be able to toggle between. Particularly, for array sizes/for loops. Is it best to use "Collections" in VB.NET to accomplish this?
View 5 RepliesMathematic Functions As A Data Type?
Dec 11, 2009I want to be able to have the user type in a function, say ,x^2 + 1, and have the computer store this such that it can be recalled and plug in a given value for x. For example, say they type in x+4, the program will then (in a bunch of different text boxes) return the value of x+4 when x = 1, x = 2, and so on up to x = 10. But how can I get it so that it will store x+4, be able to recall it and replace x with it's given value
View 2 RepliesVS 2010 Alternatives For The Old Functions?
Sep 21, 2010When I try to code in VB2010, I usually unmark the reference to Microsoft.VisualBasic. Because I do not want to use the legacy functions of VB6. I want to complete walk in .Net path. And I have found some alternatives for the old VB6 functions. But the rest not. Where can I find the list of those methods or classes (alternatives for the VB6 functions) ?(For eg: when I tried to find the difference of 2 dates, I couldn't find any other alternatives. So, I came back and used the Microsoft.VisualBasic reference for using DateDiff())?
View 24 RepliesVS 2010 Converting Hex Functions From VB6
Jan 9, 2011I came about these two functions (ReadHEX and WriteHEX) that, obviously, read a hex offset or write a hex offset of a file. However, these functions were written in VB6. The main thing I'm not understanding is how to open a file (in a filestream I presume) and then to either read or write a certain offset from the file. I'd also need to convert the string I'm writing to hex before I actually right it, but I've got that under control. Here's the current functions as they were written:
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VS 2010 Using Functions From Reflection Var?
Dec 13, 2011how to use a function from an assembly reference.when using:
Dim __asm As System.Reflection.Assembly
__asm = System.Reflection.Assembly.LoadFrom("c: estsomedll.dll")
this dll should have a few public methods, lets say it has a helloworld() with no args and a hellowworld2(byval x as string). How to call them?
.net - Double Or Integer : What To Use With BIG Or SMALL Data Types
Jul 26, 2011I have a value of: "2.54334881002458E-37" and i keep getting "overflow" exception when i'm using a double.what should i use to make this work?
code snippet:
Dim curries, act, cat As Double
For Each dataRow As DataRow In dt.Rows
curries = dataRow("Activity")
getting the error when i try to assign Activity to curries.but "activity" is a string in the database....