How To Distinguish Between Copying Class Data And Pointer
Oct 2, 2009
How do I distinguish copying data and a pointer when using a class?E.g.
public class myparams var1 as integervar2 as intergerv3 as stringend classmyvar as new myparamsmyvar.var1=1myvar.var2=2myvar.v3 ="hh"othervar as new myparams
I want to copy all of myvar data into othervar in one go.. without doing
othervar.var1=myvar.var1 etcusing othervar=myvar"
Looks like its just copying the pointer of myvar into othervar? Can I copy all the class data in one go? VB2008 user
My program has decided to assign pointers instead of make copies of an object, and I'm not sure why. I have something like this:
Public Class Foo Private myFooData As New List(Of FooData) Public Sub New(ByVal newFooData As List(Of FooData))
[Code]....
Very simplified, but basically what I'm doing. So for some reason today when I change item in newFoo.FooValues, originalFoo.FooValues also changes, and mainFoo does not. I've tried assigning the entire objects as well and I get the same results.
When inheriting class or control e.g. ListView, TreeView, etc..., what is the best way to distinguish between built-in methods/property/events and mine?
Currently, i start my methods/property/events with "aa" in order to make them at the top of auto complete list.
Public Class Form1 Public Declare Function GetModuleHandle Lib "kernel32" Alias "GetModuleHandleA" (ByVal lpModuleName As String) As IntPtr Public Declare Function GetProcAddress Lib "kernel32" Alias "GetProcAddress" (ByVal hModule As IntPtr, ByVal lpProcName As String) As IntPtr
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim hmod As IntPtr = GetModuleHandle(Nothing) 'Work Dim addrs As IntPtr = GetProcAddress(hmod , "TestFunction") 'Not work, always NULL why??
I'm trying to copy the elements from a List(Of Frequency) where Frequency is a custom class I have made. Everything in the other places seems alright but the problem seems to be with the copying, where it still references the original table, so changing the values of one changes the original. I've tried the List.CopyTo() method and tried converting to and array with List.ToArray and then using Array.Copy but it seems they always change the original. I've also tried a for loop and create and New instance of the classes but that doesn't work either. What I'm using it for is to pass the List(Of Frequency) to a new Task to do multitasking(), if anyone can think of a better method to pass a List(Of Frequency), or an array to to a task and have it not change the original.
I have a copying error with my program. I am trying to copy the internet cache folder, and the error states that some files cannont be copied (read only maybe?) How can i make it copy, or just skip the uncopyable files?
I have some textboxes that I need to get data to on another tab, everything works beautifully until I get to one and that is where the client ID has to be filled oin to that textbox. I have a chkBox that will verify the data that is suppose to be put over intothe tabbed page and if I check it, it will put the data into the textbox. Yet if I leave it unchecked the data does not get copied.
Public Class Form1 Private Sub ClientsBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
I have three data files that I include with my project. They are all set to Build Action Content and Copy to Output Copy Always. I have a preferences form that allows the user to copy these files to a folder of their choosing. It works fine in the IDE. However, when deployed one file will copy but the next returns an error the the file cannot be found. In the following code block a deployed application will copy ABW11Data.sdf but cannot find 100610_40.dtb or 2118@005.dtb. They are in the deployment files and I can search and find them in the clickonce installation although they are not in the same place as the ABW11data.sdf.
If My.Application.IsNetworkDeployed = False Then My.Computer.FileSystem.CopyFile(My.Application.Info.DirectoryPath + "ABW11Data.sdf", TextBoxFolder.Text, True) My.Computer.FileSystem.CopyFile(My.Application.Info.DirectoryPath + "100610_40.dtb", .SelectedPath + "100610_40.dtb", True)
I'm trying to program that specific data will be copied to the clipboard so the user can paste it in, for example, Excel or Word. I already know that the following code can do this:Clipboard.setdataobject( " some text " )But that's where my problem just starts. It seems I can only copy the data to Excel and Word etc. as long as my application is running. As soon as I quit it, the clipboard is empty.
I'm writing an app to print a list of beers that are currently on tap at the restaurant where I work part-time. We have 29 taps and dozens of different beers. I have 2 tables in a database (one with the "master list" of all the beers and an "on tap" one with one entry per tap). Each database entry includes fields for name, brewer, location, style and ABV. So far I've made a GUI with 29 combo boxes (one for each tap) and 2 buttons (one that opens a dialog box to modify the "master list" and one to print the list). The idea was to make it as simple as possible since the people who use it aren't great with computers and are often in a hurry.
Each combo box drops down the whole master list of beers and I'd like for the selected beer to be written to the corresponding index in the "on tap" table. My idea is to then extract the data from the "on tap" table and print it. I haven't done any coding yet, really, just drag-and-drop.It's frustrating since I know how I'd do the back end in C or C++, but not in VB. The reverse is true for the GUI.
I'm planning to create an VB.net application for retrieving data from a database (MS Access) and store it to a web server (MySQL data base). I really have confusion in my mind. I'm planning to use task scheduler so that the program will automatically run. I'm planning to set the time every 5 minutes.How can I avoid the redundancy of data? For example, I'm planning to get the sales for 5 minutes, after 5 minutes I will do it again. I think there will be redundancy in that case.
this is in reference to my main post here update mdb with data from different tables in dataseti have two tables in a dataset called dsSource. dsSource.Tables(0) has the following columns: ,,,,,,,code,art,sizerng1,sizerng2,sizerng3,etc...... dsSource.Tables(1) has the following columns: ,,,,,,,code,art,size1,size2,size3,etc...... the conditions here are: 1) to look for "1" in columns sizerng1, sizerng2, etc. of dsSource.Tables(0) 2) match code and art on both tables finally if both conditions are valid then the size values in columns size1, size2, etc. will be assigned to columns in sizerng1, sizerng2, etc. my main concern here is i have to loop through all rows in both tables which takes a long time, so is there a better way to do this than the code i have below?.
'***put the sizes from weights to traps file row1 = 0 For Each dr As DataRow In dsSource.Tables(0).Rows
I have a barcode scanner connected to a PC that working with a c# program.now i want to distinguish between the scanner and the keyboard which one is sending data to my program.
somebody said this to me in another topic(but i can't do this yet): basically you can configure the scanner to send some characters that basically tell the computer "hi, it's me". When you see those characters in your input stream, you know the information is coming from the barcode scanner, not from something the user typed on the keyboard. Did you check the manual that came with your barcode scanner? It should have more information about this.
I want my to create an explorer like application. What control should i use to show the contents of a directory.I tried listview and listbox. Unfortunately i was unable to add items in a listview using the function getdirectories("D:")I managed to do so with listbox control. But how can i distinguish whether the selected entry is a file or a directory. Code snippet is given below :
Private Sub ListBox1_DoubleClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.DoubleClick <strong>sel = ListBox1.SelectedItem</strong> ListBox1.Items.Clear()
[code]....
I want that if thesel is file, then it'll be open in its default application,i.e. using system.process.start(sel.filetype).Else if sel is a directory then the directory will open.
I need to copy data using Vb.net if possible from one excel spreadworbook to another and place the data into the correct columns in the existing excel spreadsheet. The column titles of the spreadsheets match up, I have several templates I need to place data into and the order of the columns is different in each template so I need a way of searching for a column header in the template and then copying the data into that column.
Put a Datagridview on a form, fill it with data. dgv1.enabled = True and dgv1.enabled = False are almost the same look to the eye unlike other controls (textbox,combo, listview, etc ...) where there back color changed to light grey and you can distinguish if that control is enabled or disabled but not for Datagridview.
I'm using GetDriveType function to determine the drive type.the function works fine, but not with external HDD it returns 3 or "fixed" which confuses me!! is there any way to distinguish between internal (local) fixed HDD and external (USB) HDD?
I am just learning Visual Basic and I am following along in a book called "Build a Program Now!".I have an application that is calling a database in SQL and there are instructions for copying the .mdf and .ldf files from the bin folder to the project folder that should allow any changes made in the running application to be reflected in the rows of the database.I have copied the files as per the instructions, but the changes are not showing in the database.
The scenario is I would like to be able reference two similar 3rd party assemblies (e.g. assem1 and assem2) which both define a type with the same fully qualified name (e.g. Example.MyType). Is there any way to distinguish between these and refernce them seperately? I believe the answer is no but confirmation or correction would be handy. Edit: Answered for C# 2.0 and higher below but need an answer in VB.Net 1.1
title is a bit vague. Is there any way I can tell if it's the user or the code that's altered a combobox? I want certain things to happen when a combobox is updated, but I don't want them to happen when the code is altering the combobox at runtime, only when the user selects something out of them. Unfortunately, if I use the 'Selectedindexchanged' option that triggers when I change the contents in code too. I've tried disabled the combobox while I update it, but that doesn't seem to work. Any way to detect user input only? My combobox is drop-down only by the way, so it's only if they select an option - they can't type anything.
When inheriting class or control e.g. ListView, TreeView, etc..., what is the best way to distinguish between built-in methods/property/events and mine?Currently, i start my methods/property/events with "aa" in order to make them at the top of auto complete list.
how would you identify the shape of text like inside a scanned document containing text and graphics?In a perfect world,users would never enter data in the wrong form,files they choose to open would always exist and code would never have bugs.[URL]
I'm designing a small GUI Windows program that allow staff at a cinema to reserve seats for customers. There will be a total of 60 seats in the cinema. I have two classes in my program:-
1.) MainForm.vb - used for I/O actions and user interaction
2.) SeatManager.vb - used to hold and handle the background methods and functions that make the program work
Here is the code for my MainForm.vb class thusfar:-
Public Class MainForm Private Const m_totalNumberOfSeats As Integer = 60 Private m_seatManager As SeatManager
[Code]....
Basically, when the program opens, the lstReservations list in the MainForm class will be populated with a total of 60 (m_totalNumberOfSeats) entries to represent 60 seats. Each of these seats will contain the index number from the array m_nameList; this index number (+1) will represent the seat number and then in the lstReservations list, after the seat number, I'd like it to contain the respective entry from the m_nameList array. As all entries will be held in RAM, when the GUI is opened, all m_nameList array entries will be empty. As the user uses the program, they can highlight a row in the lstReservations list and then use the GUI textboxes to enter the customer's name which will then be populated into the respective array entry.
how to, when the GUI opens, ensure that the lstReservations list takes all of the blank entries from the m_nameList array and from there, I can highlight a row to carry out further methods on?
I created a VBA project in Excel. I would like to figure out how to transfer the data back in forth to make a more presentable and user-friendly program in VB Studio.Basically, I need my form in VB to input data to into an excel �workbook.data�, where the calculations are preformed. Then I need to copy the finished excel data cells �workbook.results� and paste them into an end result form in VB. I have tried looking at threads and cannot come up with a solution. There is no data saved each time the program runs, so I don't have a database.
