Declare And Define An Object Dynamically?
Apr 19, 2009I have the following situation, can anybody help me in that?Following is a "pseudo" code of what I want to do in VB using VB.NET 2005:
[Code]...
I have the following situation, can anybody help me in that?Following is a "pseudo" code of what I want to do in VB using VB.NET 2005:
[Code]...
below is my code to use binarywriter it work fine on class form1 level
[code]...
This is a VB.Net newbie question. I'm confused at the different ways to declare and define variables.Here's an example:
Dim URL As String = http://www.c-sharpcorner.com/default.asp
Dim request As HttpWebRequest = WebRequest.Create(URL)
Dim response As HttpWebResponse = request.GetResponse()
[code]......
Imports Microsoft.Office.Interop.Excel
[Code]...
Is it at all possible to declare variables dynamically? Something like Dim Answers & i As ArrayList. What I'm trying to achieve is putting one or more answers to a question into an array. Or should I really be looking at a mult-dimensional array to store the question number and answer? How would I add to and access a multi-dimentional array? Anyway, here's the section of code:[code].......
View 4 RepliesI have searched online for a few hours to try to figure out how to do this, but nothing I found really makes sense, so could someone please tell me, in a simple way, how to do this?
Let's say I have a text box that the user fills out, named textbox1. And I have a combo box, named combobox1, which contains the choices A, B, C. And then I have a button named submit_button.
Each time that the user clicks submit_button, I would like to dynamically create a new variable. This variable should be named the same as textbox1.text, and should contain the value of combobox1.
For example, if the user types "blue" into textbox1, and chooses value "C" from combobox1, and then clicks submit_button... then the following variable should be dynamically created, like..Dim blue as String = "C"
And then, after that, if the user types "red" into textbox1, and chooses value "B" from combobox1, and then clicks submit_button... then another variable should be dynamically created, like...
Dim red as String = "B"
And each time the user submits new information into the textbox and combobox, a new variable should be created.Is it possible to have the program automatically create variables like this? If so, how?
My actual project is much more complicated than this, of course, so the above is just an example. But if I could figure out how to solve the problem in this example, I could figure out how to solve the entire project.
How can I define the datatype of an variable dynamically. I read out data from a file. In the file it is specified, if the raw-data is interpreted as single, integer or .... So my idea is: To check, what datatype is in use and then declare an array with this datatype to store the data there.
View 2 RepliesI am trying to figure out how to use variables to define which object to update. I could of course use a case statement to pick the object based on a variable, but it seems to me like there should be a more direct way. Here is a smaller example of what I would like to do.In my form I have 4 picture boxes (pbox1, pbox2, pbox3, and pbox4). I then want to change the image in one of the boxes, but the box I want to change will be determined by a variable (say maybe a randomly generated number). Is there some way to dynamically concatenate the "pbox" with the number that VB would understand it and use it as an object?In this example I could easily build a case statement to handle the selection, but in my real program there will be many more than 4 options.
View 7 RepliesI've created a private sub which enables me to move to the next object when I press enter in the textbox or any input controls... What I want to do is to create a universal sub procedure for moving to next object. this is my code
[Code]...
In the following code as you see I am defining myFile inside the timer sub; which of course is not a good idea. The FilePath is derived in form load before the timer kicks in. How can I declare myFile globally so it can be used in timer sub as well as in form load?
Private Sub tmrInterval_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tmrInterval.Tick
Dim myFile As New IO.FileInfo(FilePath)
If myFile.Exists Then
...
...
I want something like this:
Public Class Form1
private myFile As New IO.FileInfo()
'but I do not have strMessageFilePath value yet, that will be achieved in form load.
I am having a problem with a and OOP class i made that contains a sub that creates random integers.
Problem is if i define two instances of this class and configure them(name in this case) then they both display different names but the random integers are ALWAY the same. in this case having the integers the same kinda kills the idea of the program.
Is it possible that the random part only every works for one class, but if .NET is fully OOP then this should not be possible... right?
Some of my Code (broken down to something smaller) i will display for obvious reasons.
Code:
I have a class library that contains a number of classes. I would like to dynamically create an instance of one of these classes, set its properties, and call a method.
Example:
Public Interface IExample
Sub DoSomething()
End Interface
Public Class ExampleClass
[Code].....
In C# we do
byte[] imageData = new byte[];
SqlCom.Parameters.Add(new SqlParameter("@ImageData", (object)imageData));
which makes the imageData variable as an object.But How do i do this in Visual Basic??
Dim imageData As byte() = new Byte()
SqlCom.Parameters.Add(new SqlParameter("@ImageData", ?? ) <-----What Should i do here?
My code is like this
conn.Open()
Dim cmd As SqlCommand = New SqlCommand("SELECT PhotoID From Photo " & str8 & " And Photo = @Photo", conn)
cmd.Parameters.AddWithValue("@Photo", CType(Photo, Object))[code]....
It comes out error like this:The data types image and varbinary are incompatible in the equal to operator. What should I do?
To declare an object in JS i can simply do the following:
var house = new Object();
house.window="square"
house.color="green"
In asp.net (VB) if i try doing the same
Dim house = new Object()
house.window="square"
i get an error: System.MissingMemberException: Public member 'window' on type 'Object' not found.
Do i have to create a house class before i can reference house.window? Is there no way to do it without creating a class?
How do I:
--declare and create a new mortgage data object
--invoke this class's displayPayment method
--invoke this class's displayAmoritizationTable method
Here is a block of my code:
Private Sub findMortgagePayment()
Dim prompt As String
Dim validPV As Boolean = False
[Code].....
I would like to declare a list above Sub procedure and to be able to add/modify it. I would like to have something like this:
[Code]....
When i run the above example i get an error like: Object reference not set to an instance of an object.
can i do some thing like this in .net? and how?
Code:
dim object1 as new clsDatadim object2 as object
object2 = getobject("object1")
"getobject" function is my "needed function"
the purpose is to set object2 to have same memory address with object1 so if i change the properties of object2 then the properties of object1 also changes..
How can I do this:
Dim oMyObject As New MyObject
oMyObject.DoSomething("Parameter1","Parameter2")
The "DoSomething" and the two parameters are dynamically provided from another script. They are stored in a string object in this script: sAction & sParameters. My question is how can I dynamically pass the "sAction" to the object oMyObject.For example oMyObject.sAction (where sAction should be the value stored in the sAction string). The example will probably not work. Is there a way to do this? The idea behind is to avoid having to write each function hardcoded, like:
If sAction = "DoSomething" then
oMyObject.DoSomething(sParameters)
ElseIf sAction = "AnotherThing" then
[code]....
I am trying to create an object dynamically with CreateObject function. The code is below but it gives error:"ActiveX object can't be created" while calling the CreateObject function.
Public Class Form1
Public Delegate Sub DButtonClick(ByVal sender As System.Object, ByVal e As System.EventArgs)
Private Sub DButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
MsgBox("You hit me")
[code]....
I'm trying to reference a public property from a string. How can this be done in vb.net?I have the text value of "FirstName" stored in strucParam(i).TxtPropertyName.[code]...
View 1 RepliesI am coding a public sub routine that clears all textbox fields in a form. I want to call/reuse this sub routine everytime i want to clear all textfields in any form in my program.
I can create a collections of all textbox objects in a form and loop on each of them to clear their textfields.
I'm making a little program in where i'm trying to invoke a method from a class dynamically with so called Reflection.
The class I'm trying to call is called ContactList and i try to invoke the property in this class called count. The assembly itself is called Contact.Exe
Now I have the following code where I make an instance of the ContactList class in the Contact.exe assembly:
[code]...
Below is some code that I'm using to create objects with Visual Basic:
For indexCounter As Integer = 1 To TotalParticipants Step 1
participantClock = New Label
participantClock.Size = New Size(100, 20)
participantClock.Name = "participantClock" & indexCounter
[code]....
I'm creating a label, a button, Timer, and Stopwatch. (Though I have sinking feeling I don't need BOTH a timer and stopwatch since I'm counting time.)What I would like to do, is create the label and set that label's text to be the value from the stopwatch. The button that will be created will stop THAT stopwatch.
The problem that I'm having is that I cannot call the stopwatch by name since it wasn't created yet and VB throws a hissy fit at me for it. (After all it wasn't really declared.)So the question becomes, how do you call the most recently dynamically created control and assign events using that control. If it's not possible to do, I do not mind dumping the form and starting over creating 30 stopwatches instead (but I'd like to avoid that, if possible).
I'm not sure if the question properly asks what I want, because I'm a bit new, but what I am trying to do is write a sub or function that I can run when a label is clicked, and I want to to be reusable on multiple labels. There will be 12 in total, and I don't wish to write the same thing over and over, with slightly different characters. A programmer never wants to write the same thing twice, right? Also, something else is making it a necessity to do it dynamically.
So, how I was trying to accomplish that was by using a string, and adding the name of the label to the string on click.
click1 = "Label1"As it turns out, you can't just say click1.Text and return the text of Label1. The reason it's important to do it implicitly is because I need to somehow remember the one I clicked before, to compare the first click and second click, and if they match, do A, and if they don't match, do B.
I have this code.
Code:
Public Class Form1
Dim NPB As Button
Dim x As Integer
[code]....
As you can see, when I open a program from my menu, a new button will be created with text similar to this, "C:Program ". The button it self will not do anything. How can I create the method at the same time the button it is for is created? Also how can I change the text do that it gives me, for example, CCleaner.exe instead of the whole target path?
This Image shows type-safe method of defining the Actionlinks ,how to define it in VB.NET
View 1 RepliesThis image shows how to define the RouteTable in C#, using the Route Class. How to define it in VB.NET?
View 1 RepliesI want to define several constants of pens like SystemPens. How do I do that?
View 6 RepliesI am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj
Inherits baseObj
Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
I am using System.Reflection to load a type that I cannot otherwise load during design time. I need to pull all controls within a collection of this type, however, i the OfType command doesn't seem to like the reflection Syntax. here is "close to" what I got.
Dim ControlType As Type = System.Reflection.Assembly.GetAssembly( _
GetType(MyAssembly.MyControl)) _
.GetType("MyAssembly.MyUnexposedControl")
Dim Matches as List(Of Control) = MyBaseControl.Controls.OfType(Of ControlType)
So that code is bogus, it doesn't work, but you get the idea of what I am trying to do. So is there a way to use reflection and get all of the controls that are of that type?