Shallow Copy And Deep Copy
Dec 1, 2010
As I understand it a shallow copy is like a CLONE copy of an object where the values for each property are independent of one another whereas a DEEP copy is a copy that uses the same memory locations and therefore if you change a value in one it is also shown in the second item ( By Reference to the same memory locations ).So my main question is, when dealing with CLASSEs, STRUCTUREs etcetera containing REFERENCE types.is there anyway to quickly create a CLONE or shallow copy of an OBJECT or not ? The only way I can think of is to put the item into a one dimensional array and use the CLONE method for an array. [code]
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Oct 19, 2010
Shallow vs. Deep copies of objects. Why would anyone want a shallow copy of, say, a multidimensional array?! If I wanted something to act just like something else (and this is what shallow copies do), why would I create a second instance to do what the 1st instance does already? I think I understand the point of objects and that just copying the contents of one object to another does not make them independent, but it seems that the whole point of doing:
[Code]...
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Jan 31, 2010
Is there any way possible to deep copy a Control? Just want to know if its possible
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Jan 20, 2010
I have created a form with a tab control that I want to be able to make a copy of in such a way that all the child controls and their data are copied as well. I have tried this:
Dim NewPage as TabPage = tcViews.TabPages.Item(0)
tcViews.TabPages.Add(NewPage)
I end up with a reference to the first page. That is, if I change something in the old page, it changes in the new one as well. I believe this is because VB.NET treats assignments of classes as references, rather than values. Hence only the memory address of the original is copied, so essentially both refer to the same tab page in memory. I also tried serialization and deserialization.
The TabPage is apparently not serializable. And I heard about MemberwiseClone, but it isn't accessible, according to Visual Studio. There doesn't appear to be a Clone method available either. How do I make a new tab page that is totally independent of the original, but that has copies of the original page's controls and their property data, which can then be edited independently of the originals?
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Aug 15, 2006
If I have a generic.list(of ClassA), is there a simple way to create a deep copy of this list that will not affect the original copy? It seems to work if I have a generic list of Structures, but for some reason the copy constructor for lists of classes only copies pointers to the elements (or maybe a pointer to the whole list?). I would move to structures if it were not for the fact that I can't find a way to edit the members in the structs in the list. eg:list(0).a = 5 'Does not workIs there some way to get around this without declaring an instance of that structure, like this:dim str as StructA = list(0)str.a = 5I'd
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Aug 5, 2011
If I instantiate an object within a function in VB.NET and return it, does it return it be reference or by value. IE - should I be worried about performance if I write something like this:
Public Function ret_obj_func() As big_object
Dim ret_obj As New big_obj(<lots of stuff>)
Return ret_obj
End Function
If I call this function from somewhere else, will it instantiate the object in the ret_obj and then create a deep copy to pass back a copy to the caller, Or will it just pass back a reference?
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Feb 6, 2012
I am trying to make a deep copy by adding a clone property to my class.
[Code]...
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Apr 27, 2009
Essentially what I want to do is copy a WebBrowser object such that I can do the equivalent of "Open In New Tab" or "Open In New Window" actions, maintaining any posted data. I don't just want to navigate to the same URL as in the original WebBrowser object, rather I want to repeat the HttpWebRequest.
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Dec 28, 2009
I got a problem...after load crystal report viewer, I am unable to right click->Copy or ctrl+c and copy any text. I am using vb.net 2005, crystal Report 11...I am showing the report content on the Report Viewer..
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Apr 3, 2011
i am mukesh i want a form were i have a button now i want to copy what ever i still now changes made in a vb.net from to be stored inside the pendrive just by clicking on the button does it possible i have done a project which is a shops project now my client wants to do that project when he is in shop he will use it in laptop but when he moves to some other location he wants to carry that project in a pendrive since he is not so much educated o he needs only one key which he must press to copy the database from my source my documents to the pendrive does it possible
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May 27, 2011
I have a weird behavior when trying to copy a file with System.IO.File.Copy. The file never gets copied. More than that, the call doesn't generate an exeption!
I am using VB.NET, Framework 3.5. I'm trying to copy in C:Temp and I do have the privileges. Or at least I used to...
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Nov 8, 2011
The triangle that is. I copy it and it pastes 4. Want to copy it to my richtextbox
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Sep 22, 2009
When i copy a table into DataSet is it possible to copy its index's as well? right now i add kinda big table (250k + rows) into dataset and i need to query that DataSet table in my application, the problem is that in some quires it's getting slow.what is the right approch to solve this problem?
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Mar 18, 2009
I have a backup class it copys every thing but the unmovable files witch in return when i test the dive that i just backed up all files to will not boot up missing win system32 config files??how would i add permission to my code??? or how do i over ride cant copy file because a nother process is useing it?
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Aug 5, 2010
I have a program that uses IO.File.Copy to copy files from point a to point b. Its slow, which is fine because there rather large files. I was wondering if there is way to get an estimate time to copy a particular file(s).
Example: File a will take 1 hour to copy, File B will take 30 minutes to copy. Estimate Total Time: 1 hour 30 minutes.
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Oct 30, 2009
how does this function works. How does it copy the frame? HDC BiBlt???
ublic Function copyFrame(ByVal src As PictureBox, ByVal rect As RectangleF) As Bitmap
If isRunning Then
Dim srcPic As Graphics = src.CreateGraphics[code].....
the above function is called from the below command which is in a timer event. mycam is a class including the copy frame function.
bm2 = myCam.copyFrame(PictureBox1, New RectangleF(0, 0, PictureBox1.Width, PictureBox1.Height))
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Mar 25, 2012
Using Windows form (Vb.net & Datagridview) Checkbox is using in datagridview row. I want to copy the selected row to new row. For Example
[URL]
The above code is working for if checkbox checked then it is taking the current row value. But i want to add new row, to copy all the current row values. How to do it.
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Feb 4, 2011
.net 3.5, VS 2010... this is for an asp.net website.I have an class called Agency. there is a second class called Agency_Queries. Agency_Queries inhertis the Agency class. I'm trying to create a function that will copy the like properties in Agency to Agency_Queries. I figured out how to do that.. but when i try to make it more generic so that i can pass in my class name and lists i'm doing something wrong.So if there is an list(of Agency) that needs to be copied to list(of Agency_Queries) i've got something like the following.
Dim AgencyS As List(Of Agency) = Nothing
Dim Oc As New Agency_Controller
AgencyS = Oc.GetAgencyData(0)
[code]....
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Aug 20, 2009
I am new to vb.net.I need to automate the selection of a pdf file on the desktop, and then copying it a specific folder and then renaming it.
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Jul 28, 2009
I am using webDAV and .Net 2.0 to gather information on an email account on a server unning Exchange Server 2003. I have access to the uri which looks like this:I attempted to copy the file like so:
Dim uri As New Uri(uriNode.InnerText)
If uri.IsFile() Then
Dim fn As String = Path.GetFileName(uri.LocalPath)
[code].....
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May 6, 2009
During the backup we sometimes get an error. IOExxception was unhandled[cod]e...
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Jan 22, 2011
i am trying to copy a dll from one location to another. i have a combobox from which i select a option then i want the program to copy my dll to another location acoording to the option i have selected. But Vb doesn't seem to copy it.it stays the same. for experiment i tried to copy a image. it worked perfectly.
does that mean i can't copy it.
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Apr 27, 2012
i want to copy a tabapage (and its contents) to created new tabpage
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Feb 23, 2011
Copy all images by FTP?
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Dec 15, 2011
Dim FilestoCopy As String
Dim NewCopies As String
FilestoCopy = "C:UsersDocuments*.txt"
NewCopies = "D:NewDocuments"
[code]....
I was wondering how to switch this to copy all .txt file from FilestoCopy to NewCopies
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May 14, 2009
I have a .Net web application that I want to take a copy of and create a new application that can be worked on independently of the first - i.e. I want to branch the codebase.
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Sep 16, 2009
copy data from one csv file to another csv file.
Basically I need to copy a column of numbers from one csv file to a second column position of another csv file.
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Dec 8, 2010
How can i copy image from one picturebox to another?
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Feb 9, 2010
pplication that uses SQL Server Express 2005.In my application (via VB.Net 2008) i have an object of type: Code:SqlClient.SqlConnection that i use to connect to my SQL database fileI want to have a backup process that will do simple copy of the SQL file to other location, efore i use the code
Code:
IO.File.Copy(mCurrentDB, mDestPath, True)
i close the connection like this:
[code].....
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Jun 21, 2010
I made SMALL PROJECT IN VB.NET ( USING TABLE, GRIDS) ON MY FRIENDS LAPTOP NOW I M UNABLE TO USE IT ON MY LAPTOP...FORMS ARE NOT WORKING ON MY LAPTOP..M NEW IN VB.NET
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