ArrayList Versus Structures - 'array Of Records'
Jun 23, 2009Is an ArrayList the same thing as a Structure (i.e. 'array of records')? If they're not the same think, what't the difference?
View 3 Replies
ADVERTISEMENT
Structures Versus Classes?
Feb 3, 2011I've been programming a custom structure to use in my program for a while now and I am debating whether I should switch over to using a class instead. Reason being is because I've read from a few sources that structures should be kept for simple storage of primitive types. However, I am using my structure to store a few integers and a few custom classes of my own.I haven't noticed any slowdowns or performance issues but I do know that I have to update the actual variables in the structures since they are value types and not reference types.
View 5 RepliesCreate An Array Of An Array (or Arraylist Of An Arraylist) To Hold Strings?
Mar 20, 2012I want to create an array of an array (or arraylist of an arraylist) to hold strings.I want to fill an array1 with string values Then add this array to array2. - but only taking up 1 row in array2 e.g something like array2(index)=array1 Then clear array1 then loop through this again with different data, and add it to the array2.so will end up with something like
array2(0)... contains a collection of array1 data
array2(1)... contains a collection of different array1 data
.. and so on
i think i need to make new instances of array1 each loop, but not sure.I dont mind if it uses arrays, or arraylists, or lists, or structure of arrayslists?
DB/Reporting :: Create Some Records Using Structures?
Feb 24, 2012I am basically trying to create some records using Structures as you can see below, however the value of Index doesnt seem to be incrementing as I am assigning it to txtCustomerId.text each time form loads, however the value of the text box remains at 1000 all the time
Code:
Public Class Form1
Dim NumberOfCustomers As Integer
Dim Index As Integer
[Code].....
VS 2010 : Comparing SQL Records Versus Calendar?
May 2, 2011I have a program that backs-up remote locations to a centralized FTP server. Upon successful completion, a record is written to a SQL database with the following information:
GUID (uniqueidentifier)
StoreID (varchar(5))
DateStamp (sqldatetime)
ProgramAndVersion(varchar(50))
I am currently managing the program by running a report on who has written a record to the database. If the record is not written, I manually go in and backup the necessary files.The problem with this, is that it can take up to 30 minutes/day to do this task. While that's not a long time, it's getting somebody to be dedicated when I'm off and that has proven to be difficult.
I want the program to automatically search for missing records, but I'm not sure how to do this. I was thinking about bringing in the last 30 days with a SELECT statement and then comparing the information that I have in the SQL database versus a calendar control (or something). I need to make this process completely automated and not very intensive on the SQL server. I only have the following
2010
Sub FindMissingBackups(ByVal DaysToCheck As Integer, ByVal StoreNumber As String)
Dim TodaysDate As SqlDateTime = Now()
Dim PastDate As SqlDateTime = DateAdd(DateInterval.Day, -DaysToCheck, Now())
[code]....
Initialising An Array Of Structures
Nov 7, 2009I have a Structure, and I am having trouble initialising it. Specifically when I try to populate the Vector3 variables, it tells me that they are Nothing, so I need to make them New when the array of this structure is declared.[code]Structures cannot declare a non-shared 'Sub New' with no parameters.I have no parameter to supply, and this will be an array so I'm not even sure how I would supply it.The second option to fix the error is to make the Sub New shared, but then I get other errors: Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class.Does anyone know how I can resolve this. My end goal is to have an array of this structure type with the Vector3s ready to use.
View 6 RepliesNeed To Have An Array Of UDTs(Structures)
Feb 21, 2012I need to have an Array of UDTs(Structures). Elements have to be added (at end) and removed (from anywhere). The different values of the elements need to be changeable.
I know how to implement it as an oldstyle array, but wouldn't it be better to implement as a List ( of T)? and if yes is such a procedure possible?[code...]
Save An Array Of Structures In .NET?
May 31, 2011I have 2 Structures
Public Structure One
Public ItemOne As String
Public ItemTwo As Integer
End Structure
[Code]...
Results In an Unhandled exception. Bad Record Length. and then If I close it and reopen it I get an 'Unable to read beyond end of stream' error. So what is the best way to save an array of structures? Binary Reader/Writer? and why does this way not work (Even if its derived from VB6)
Sort An Array Of Structures In .NET?
Nov 17, 2009I have an array of structures:
Structure stCar
Dim Name As String
[code].....
Using Fixed Array Within A Structures?
Apr 19, 2010I have a class file which contains a structure like this.
<StructLayout(LayoutKind.Explicit)> _
Public Structure SampleStructure
<FieldOffset(0)> Public field1 As Int16
[Code]......
Populating From Datagrid To An Array Of Structures
Mar 23, 2009how to go about getting data populated from a data grid view to an array of structures? I have a data grid view with 6 fields and 10 records that match elements in my array. I declared a list of songs based off of my structure Song.
[Code]....
Error When Assigning Elements To An Array Of Structures?
Mar 21, 2011I am getting an error when helping someone with their code. They are trying to create an array of Items, but gets an error at ItemStruc(counter).ItemName = Contents(0)
I am not sure why. >_>
Structure is as follows:
public structure Item
dim itemName as String
[Code].....
Read Text File Into Array Of Structures?
May 9, 2012�On load read data from units.txt into an array of structures;�Allow the user to choose a major and then add units to a study plan.Note your program must not allow the user to add units not in the major and a unit can only be added once to a study plan;�Save student first name & last name, student number, unit codes to a user selected file (e.g. fred.txt); �Allow the user to select a student file to load using a common dialog control ;�Display the units for that student.
The program must have the following features:�It must use a common dialog control for saving data;�The program must have at least one general procedure; �The program must demonstrate the use of an array (array of structures recommended).I've attached a copy of the text file needed to be loaded.
VS 2008 Bubble Sort Array Structures?
Apr 15, 2009I've learned about and understand HOW to do a bubble sort (theoretically), but I can't seem to wrap my head around how to use a bubble sort with array structures. I'm supposed to be able to sort the inputted student information (via textfile) using bubble sort and display the result in a listbox. Buttons for Sort by last name, sort by gpa, & sort by letter grade.
[Code]...
Can't Get Data From Text File To Load Into An Array Of Structures
Dec 22, 2009I am trying to get the data from the text file to load into an array of structures and then be displayed in a listbox on FormLoad with no luck, all I get is a blank listbox.
Code:
Public Class frmMemList
'Create a structure to which data from text file MEMBERPHONES.TXT will be read.
Structure MemberList
[code]....
Can't Get Data From Text File To Load Into Array Of Structures?
Dec 22, 2009I am really struggling lately for some reason. I do not know why, but I can not get simple programming code to work, usually due to simple mistakes. Anyway, enough about that.Here is my code, I am trying to get the data from the text file to load into an array of structures and then be displayed in a listbox on F
Public Class frmMemList
'Create a structure to which data from text file MEMBERPHONES.TXT will be read.
Structure MemberList
[code].....
Create And Initialize An Array Of Structures Of A Fixed Size?
Mar 6, 2012I am trying to create and initialize an array of structures of a fixed size. Each struct will be populated when a button is clicked. Here is an example of my struct:
public structure buttonStruct
dim x() as Boolean
dim y() as Boolean
[code]....
In my form_load function I am declaring the array of structs and:
Dim BtnStruct(15) As ButtonStruct
BtnStruct(0).Initialize()
[code]....
Whenever a specific button is clicked, I am trying to collect data and store it in the respective struct and so for example, if button 1 is clicked then I will store the data associated with button 1 into BtnStruct(0). The position of the button is stored in a public variable called BtnNum. If I attempt to store information in the struct inside another function as follows, I receive an error
BtnStruct(BtnNum).x(pos - 1) = temp "btnstruct is not declared. it may not be inaccessible due to its protection level"
Read Binary Data In An Array Of Objects Or Structures?
Dec 27, 2011I need to create a collection of millions of objects, each object has 3 double and one integer fields.If I remember (after more than 20 years without using C) in C you would allocate enough memory using a struct and an array, and read all the file content in one shot.In VB I created a class with the 4 members, and this constructor:
Sub New(BR As IO.BinaryReader)
X = BR.ReadDouble
Y = BR.ReadDouble
[code]....
Writing And Reading Simple Structures From Files Into An Array
Dec 23, 2010I coded anything but I remember when using VB6 or Pascal/Delphi we used to define records/ structures with fixed length fields, then write those structures to a file knowing that they would always be the same length. You could then open a particular record within the file or simply find out how many records existed by reading the file length.From what I understand, it seems that such methods are depreciated in VB.NET and such structures are written as a stream.Does it now mean that we can define things like variable length strings and not need to worry about buffers or boundaries?Is it possible to read through such files and pick out individual records? Are there methods of determining how many records that exist in a file? What I'm looking to do is simply store multiple records of a structure in a file then retrieve them into an array so I can manipulate their order by sorting the array and search within the array. This is only a learning project so it is unlikely that the resultant array is going to be large, although if this is not generaly a good method of doing this then it might be interesting to fidn out what is. So far, I have read that they way to write a structure to a file is to "serialises" it and then write the bytes - is this correct?[code]
View 5 RepliesJagged 3 Dimension Array Versus Lists?
Oct 18, 2011i have used in vba 3 dimensional jagged arrays where i had up to 10000 rows. i am now transferring this to vb.net and learnt that it would be better to work with lists. the dimensions are such as (30, 10000, 30). how would i structure this by using lists?
View 8 RepliesLoop Versus Array - Retrieving Data?
Oct 7, 2009Can I know which is better when retrieving data?
View 3 RepliesVB 2010 - Array Versus Data Table?
Mar 22, 2011I am interested in the pros and cons of data tables and arrays in VB 2010. I programmed decades ago in FORTRAN and used arrays extensively.However, I frequently see data tables in code snippets and don't know when they should be used in lieu of an array.
View 4 RepliesArray Of Structures Method - Get The File Read And Printed Onto A List Box?
Apr 17, 2012These are the directions for the assignment.So far I am able to get the file read and printed onto a list box.The book we have for the class does not clearly talk about using the array of structure method with formatting an imported text file.After that I'm pretty much having a bit of trouble with everything else.I know I can figure most of it out but what I'm having a big amount of trouble with is the array of structures that he wants.I know that when I have the file imported that I need to save it temporarily and go through it and at every ":" put it in an array and save that spot and then keep scanning through the file. I know it is going to be a for loop using the index to count through but I'm not sure if how to start it.This is how the text file that he wants sorted out looks.
Ally Gators:Tim Tebow:240:280:250
Ally Gators:Albert Gator:150:175:222
Ally Gators:Joe Cool:195:220:217[code]...........
C And C++ - Function - Extend It So That It Also Returns A Usable Array Of Pointers To Some Structures
Feb 18, 2009Correct the problems with this function, and then extend it so that it also returns a usable array of pointers to some structures.
The extended version of this function should: Maintain the same "char *" return type which returns a pointer to a usable, for storing a C string, memory buffer.
In addition, also return a usable array of pointers to structures. This array of pointers is of variable and random length, which must be obtained using GetNumberOfSomeSeqsToGenerate(), which is called, ONLY, from within this new extended version of the function.
The type of these structures and the function that should be used to get these structures are defined as follows:
typedef struct {
char* name; /* '\0'-terminated C string */
int number;
} SomeSeq;
[CODE]...
Rebuild Array Versus Linked List Traversal?
Mar 11, 2010I have been working on a number of card games. Important, of course, is shuffling the deck.I have come up with a few different ways to do this. Currently I do not shuffle, but to deal a card, I lay out the deck in order, selecting a random number between 1 and the number of cards remaining and selecting that card. I then remove that card from the deck so that another card can be picked.There are two main ways to do this, and I am trying to figure out which one is optimal.The first is to have an array of cards. When one card is dealt, a new array is formed with that card missing. I kind of like keeping the array size exactly the size of the deck, but perhaps this is not efficient. So, the first array has length n and the new array after the card is dealt has length n-1. VB.Net makes it simple to change array sizes around like this.
View 1 RepliesArray Or ArrayList Or Structure In An Array?
Nov 9, 2010After gathering the Machine names on the (sealed) LAn i am then getting the ip addresses, MAc address and Macine User name of each machine on the LAn..These details will need to be accessed seperately for use in the security testing and i am unsure how best to store the active data (though eventually in a database) Am i best to create a Multidimensinal arrayList or array(bearing in mind that all the data is convereted to "String" (arrays can only store one data type??) The data found on the live network is allways changing making an array a difficult choice? I have read some tutorials mentioning making a structure with the data and storing this in an arraylist but i dont know whether this will make accessing the individual data items (ip,MAc,HostName etc) a difficult procedure?
View 1 Replies.net - SetValue/GetValue Versus Directly Accessing Array Via Arguments?
Jun 4, 2012I have an array which originally was a Variant array in VB6. Example code in VB6:
ListBoxDrawings.List(X1, Y1) = myArray(X2, Y2)
myArray(A, B) = ListBoxDrawings.List(I, C)
After running it through ArtinSoft's VBUC, its values are handled using GetValue & SetValue.Example code in VB.NET: (ignore conversion to ListView)
ListViewDrawings.Items(X1).SubItems(Y1).Text = CStr(myArray.GetValue(X2, Y2))
myArray.SetValue(ListViewDrawings.Items(I).SubItems(C).Text, A, B)
Since VB.NET doesn't do Variants, I figured out that the array should be typed as a 2D String Array. It seems like there's no reason to use GetValue/SetValue, as the former returns an Object and the latter takes one. This means that I'd have to cast the returned object as a String (Cstr) if I wanted to assign it to a variable, which seems like a pointless extra step that might introduce errors. Also, since the method has lots of overloads, the code might not be as clear. Is there any advantage to using SetValue / GetValue, or should I just consider that an artifact of VBUC converting a Variant, and access the array directly like the original code did?
VB.NET without Get/Set methods:
ListViewDrawings.Items(X1).SubItems(Y1).Text = myArray(X2, Y2)
myArray(A, B) = ListViewDrawings.Items(I).SubItems(C).Text
For Each Array In ArrayList?
Jun 7, 2011Dim iArr As Array For Each iArr In m_alTabell 'ReDim myArr(16, 11) If i dim iArr(0,0) as string I could do this.ii = ii + 1 iArr(i, constanter.colNames.colValue) =m_objList.GroupItems.Item(ii).ListItems(i).Value'm_alTabell.RemoveAt(ii - 1)'m_alTabell.Add(iArr)
[Code]...
I have a problem with this code. m_alTabell constists of 10 twodimensional arrays. I have some data in them from the beginning. Now I want to add data in each iArr in a_alTabell. This works fine on the first one. But then the trouble starts. It just keeps overwriting the first iArr in m_alTabell. So if i could redim iArr it would solve the problem but i cant do that course it needs to be declared as Array and not "Dim iArr(0,0) as string" since that couses other problems.
Put Into An Array Or Arraylist?
Jun 18, 2012Here's my code
Dim allelementds As HtmlElementCollection = MbFacebookBrowser.Document.GetElementsByTagName("span")
For Each DD As HtmlElement In allelementds
If DD.OuterHtml.Contains("resource") Then
TlsResourceComboBox.Items.Add(DD.GetAttribute("InnerText"))
[code]....
As you can see im currently using a combobox as a type of a list which uses index to give certain labels their text I know that there are only 4 indexes when getting the inner text so how can put those 4 indexes into a sort of list without me using a Combobox?
[2005] Today.date Versus Now Versus DateTime.Now?
Jan 16, 2009just want to know what is the difference between these date values?Once some one told me that its difference is server date and client date but not sure which one he meant.Below is 3 type of date currently I'm using and don't know what is the difference between them.
DateTime.Now is from System.DateTime.Now
Now is from Microsoft.VisualBasic.DateAndTime
Today.date is also from System.DateTime
