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..
I'm trying to create 3 instances of the the Workshop selector form for the 3 individuals that I have inthe listbox to appear when I first run the program.
View 4 RepliesIs it possible to look for all current instances of a specified object without specifically IDing each instance as it's created?
View 12 Repliesthis is probably something I should know, but I'm puzzled by this.I'm trying to create some objects and being able to access and modify these globally. I tried to create a Public Module and declare a few objects in this.I am able to access these from another sub, but I get an exception error when after building and runing the process and trying to modify these object. The same thing happens if I declare the object in the Public Class Form1. For example like this:
Public Class Form1
Public appWord = New Microsoft.Office.Interop.Word.Application
Public wordDoc as Microsoft.Office.Interop.Word.Document
[code]....
I am just getting started with VB.NET - what I couldn't find in my book is whether a new instance of an object with the same variable-name will delete the previously stored values - or will that somehow remain in memory?This is the scenario:
I open a data file and load the contents in 'Dim var As New dataObject'what happens when I again open another file and the same line is encountered:Dim var As New dataObject'
Hope the question is clear p.s. the dataObject is a simple structure with a bunch of variables in it - nothing fancy.
Like i have. Dim MainWindow as new Classic.
But i have another i need to Access.
Is there a Way. Ive Tried and Tried. But i can't find a Way to Load another.
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].....
having difficulty with understanding object lifetime / instantiation.I have a windows from with a datagridview and a panel. The datagridview has a checkbox column and a list of names which is populated from a database.The panel has a few text boxes (e.g. name, age, favourite sports team) and a 'save changes' button.
The idea is that when the user selects a person in the datagridview by checking the appropriate checkbox then the panel shows the relevant data for that person (name, age, fav sports team) by pulling the data from a database. If the user would like to update the person's details they can do so by typing in the textboxes and then clicking the 'save changes' button. All quite simple so far.
The way I have designed this is to have a 'panel' class and to create an instance when the user checks a checkbox.(NB - the reason I have created a 'panel' class is that I intend to replicate the datagridview and panel on other tabpages within my form and thought it would be useful to have a generic 'panel' class that I could re-use.)
My code looks a bit like this:
If CheckBoxClicked Then
Dim UpdatePanel As New UpdatePanel(MyForm.NameTextBox, MyForm.AgeTextBox, MyForm.FavSportTeamTextBox, MyForm.SaveButton)
UpdatePanel.GetData()
...
When the user clicks the SaveButton the data is updated to the database and I have a display message (simple textbox) which says "Update successful" and displays for 5 seconds before hiding itself.
Here is the problem:Suppose a user checks a checkbox, reviews the data and does not make any changes, and then checks another checkbox and decides to update the data by clicking the 'save changes' button. What happens is that the "Update successful" message is displayed twice.
I think this is because every time the user checks a checkbox an instance of UpdatePanel is created. If a I select five different people using the checkboxes and then hit 'save changes' I get five "Update successful" messages.
I am not sure how to overcome this. It feels like each time a checkbox is clicked I need to check if an instance of UpdatePanel exists and then destroy it. I tried using UpdatePanel = Nothing and also investigated IDisposable and GC.Collect() but with no luck.
[code]....
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 TabControl object on my form with many tabs created in code (TabPages) and my problem is that the same objects that are in the initial TabPage needs to be in the other TabPages created in code, I have this done in code when the user clicks the 'New Tab' menu option, however the same code is used for any new tabs created. The problem created here is that I have an event against one of the objects that appear in the other TabPages, but because the same code is used to create any new tab pages, the event will only work on the newest tab page, if that makes sense? By the way these objects that appear on the other TabPages are properties at the top so events can be handled against them in the respective subroutine.
[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]...
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?
I 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 can usually find the answers to most of my questions via the Google Gods, but not this time.I have a form that has a TabPageControl and on that page a collection of labels and text boxes via a usercontrol.
On the form I have a button that allows the user to create a new tabpage, when the code adds a new page, it automatically adds the UserControl collection. I can't get my head around how to access the objects on the newly created tabpage.
What I need to be able todo is take the index of the tabpage that has focus and translate that against the UerContol name, but I havn't a clue how to do it!
[Code]...
I am adding a grid of buttons to a form at run-time, and all of then use the same Handler.My question is : Is there any way I canadd the TextBox at run-time ?I know how to but without it on the form, the IDE isn't very happy about the "MyClick" Sub - TextBox1 is not declared......
' some logic here to make nice rows and Columns of buttons
' with different .Text and .Name
Me.Controls.Add(btn)
[code]....
I wish to develop a program using DAO to access an .mdb database in a data navigational way and avoiding SQL. I have defined workspace, database and recordsets with a "DAO." prefix and referenced the Microsoft DAO Compatibility Library. When debugging, my statement setting the reference for the defined database name to the physical database, causes the following error - "Object reference not set to an instance of an object." It seems that the "New" keyword should be used to create an object instance but a statement such as "Public Db as New DAO.Database" is not allowed because DAO.Database is an interface not a class.
How do I create an instance of the object in this situation?
I have an application that dynamically creates winforms.
Dim NewS As New Form
Dim NewT as new Timer
NewT.Interval = 5000
[Code].....
I am trying to make a pretty complicated, layered program.I have my main form which creates an instance of another form (addValue and myAddValue). From myAddValue I then want to access a few other classes to do various verification and other bits of code.Here though I have a problem.With the form ContactDetails, it just can't seem to read myAddValue.txtName or the others.If I try and read AddValue normally it says about it not being able to access a non-shared member (Expected that this doesn't work, it was just an attempt at something different)How do I read myAddValue from a class which isn't the one that created and isn't the one that it is an instance of?
View 3 RepliesAny best method of managing multiple SQL connections .net (VB). My application connects to four instances of SQL Server (2000, 2005, 2008, 2008R2) restoring databases, modifying data and taking backups. In addition to managing databases the app also has its own DB (on the 2008 instance) for storing various data. I'm using two methods to connect to the instances, SMO (For backups, restoring and retrieving information about the databases, size etc) and SqlClient for querying each database for many tasks such as updating fields and executing sql scripts.I have multiple forms for performing various tasks so there are many places I'm opening / closing connections.
Would it be best to maintain a persistent global connection to each instance from the application? (Two in total, one for SMO and the other for SqlClient) or open close a connection for each task I'm performing?) I'm not using LINK as I need the tasks to be as fast as possible. The connection string will differ on each connection (Based on Instance and Database being connected to) how would I manage this? A string in the config file for the applications database would make sense, as that would be static but the databases being worked on will vary with each connection. Currently I'm creating a connection for each instance within the main form:
Dim 2000Connection = New SqlConnection("Data Source=" & SQLServerName & _
"SQL2000;Initial Catalog=Master;User ID=sa;Password=P@ssw0rd;Pooling=True;")
Dim 2005Connection = New SqlConnection("Data Source=" & SQLServerName & _
"SQL2005;Initial Catalog=Master;User ID=sa;Password=P@ssw0rd;Pooling=True;")
Dim 2008Connection = New SqlConnection("Data Source=" & SQLServerName & _
"SQL2008;Initial Catalog=Master;User ID=sa;Password=P@ssw0rd;Pooling=True;")
[Code] .....
Is bindingsource.count only used to give the total items in a list? I'm trying to prepare data for a pie chart, and need to count the instances of different items in a column (If there's a way that the Chart will do this itself, I've not been able to find it, it seems to need linked items and values). The bindingsource is already filtered and would prefer not to combine filters.Would it be best to loop through the rows of the column and count them 'manually' or is there a quicker way of doing this?Put it in a datagridview? Is it possible to use Aggregate Count on a bindingsource?
View 4 Repliesi need to count the no of instances of a word in a string using vb.net i can do the usual way as my problem is a little different for eg i need to count the no of occurrences of -> in tree_ptr->sub.another->valu=3;
View 9 RepliesThe below Code is written inside the Timer Tick event. It works fine as long as the Time and Date are not same. When the Time and Date are same it only displays 1 message. How can I show multiple message for the same date and Time ? I think this can be done If I create different instances for a form. But I don't know how many same time and Date will be there in the database. So I can't do that.
Dim frm As New frmMessage
Dim nowDate As String = String.Format("{0:M/d/yyyy}", DateTime.Now)
Dim nowTime As String = String.Format("{0:h:mm tt}", DateTime.Now)
[Code]....
when i create a class ( ie ahuman ), i declare a object (ahuman) , i give it properties and with the properties i also can set the property ahuman , by creating the property ahuman (new) and set its variables, and declare its variables by declaring properties like weight, lenght, female or not.the problem for me is that i have multiple forms multiple class files , i cant oversee how to get track of all the new instances of classes.it is much easier to use pulbic shared properties to use a method in another class.
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