Ok so my boss told me that I can't use DataSet's and dataadapter and such like this because it isnt good for scalability. So, I must change the way I have my 28,000 records binded to my form. The problem is, I'm only 3 months in with VB.NET and I don't know of any other way to accomplish what I need to do. I was reading somewhere that I can use a Class as my "Order" and I can bind the variables/properties to the form and with this, I can navigate through records while having controls on each important part of the "Order". Unfortunately, I don't know what I'm doing, this is as far as [code]Any guidance as to what I am to do from here in order to pull the data from my database and bind to the property, then to a text box/combo box, and a way that I can use my binding navigator to go through the many records.
I'm new in .NET programming.I have a class Form1 that includes Button1_Click event.Button1_Click creates a multiple Text Boxies at run time)Here is the class:
Public Class Form1 Dim shiftDown As Integer Dim counter As Integer
Is there a way to validate ALL properties in a class at once? I have a class with various validations added to property "Getter" to validate user inputs. (The problem is that all my validations only invoke if a user input something to the field that bind to the property. Any fields that user simply bypass will not get validated). Ideally I want to loop through each property and validate in a "Save()" method.
Is there any way to add new properties to a control? For example, I'm using an "OvalShape" from Microsoft's Powerpacks, these are designated as "Cells". I would like to add properties to the class itself (if I had a physical class to edit) for different processes such as "energy level", "family number", "mutation", etc. General variables that are either Boolean, Integers, or etc. If there isn't a way to edit the powerpack class itself, is there a way I can use the ovalshape power pack in my own class and add extra properties to it myself?
I am just learning about making classes and need to make one with 2 properties.Below is the beginning of a class for ingredients in a coffee machine.But I want sugar and water to also hold name (string) ='sugar' and number(integer) = 4 so its like thisIngredients.coffee.name or ingredients.coffee.number[code]
I'm trying to make a very simple audio tag editor. The idea is that the user can select as many audio files as he likes from a ListView, and a PropertyGrid will then display their tags + their values.When multiple files are selected, I want the property grid to display the values of the tags that all files have in common, and display empty values for tags that the files do not have in common.As an example, look at the properties list in your Visual Studio IDE when you select multiple controls (of the same type for this matter). Select a few Button controls, for example, and notice that the properties whose values are the same (often things like Font, ForeColor, etc) are displayed. Also notice that the values for properties that are not the same (Text, Name, etc) are empty.
I'm trying to figure out a way to sort the entries of a listbox... but in a different way instead of the obvious one (sorted property). First of all, I need to explain how the items are populated at first:
I define some global variables of a class as follows:
Private Class MyClass Private var1 as Decimal Private list1 as List(Of string)[code].....
But I found that after this form is closed, all above variables, var1, list1, list2 still exist in memory. I thought they should be collected by gc since the form is already disposed as I confirmed.
Add: I have monitored half an hour after the form is closed. But these variables are not collected by gc. I have an automatic update procedure on the form which uses above variables.Since the above variables still hold values, the automatic update procedure is always called which causes exception. (One quick fix is to check if form.isDisposed in update procedure. But I do not think this is elegeant. Besides, these variables occupy memory.)
How do I say, in an if then statement, If this image is currently displayed in a picturebox then a certain value is assigned or a certain event should happen?
This is another one of my "I think it's not possible but I need confirmation" questions.I have a base class for a bunch of child classes. Right now, this base class has a few common properties the children use, like Name. The base is an abstract class (MustInherit)Technically, this means that everytime a child class is instantiated, it lugs around, in memory, its own copy of Name. The thing is, Name is going to be a fixed value for all instances of a given child. I.e., Child1.Name will return "child_object1", and Child2.Name will return "child_object2".
I am fairly new to VB.NET so I research alot when I run into bugs. Problem is I cannot find a solution to this, or anything remotely dealing with it. I am developing software to connect to a remote mysql server, run a query, and come back with a dataset. I have run this query against the server through a mysql prompt and have received a result successfully. But when i try to run this query from my app, I get an object reference error.
Through debugging I have found that the @ character used for variables in sql strings, is causing the problem in my code, but i cannot find a way to pass this query to the server without visual studio throwing errors. Every answer to the use of variables that I have found, suggests specifically stipulating the variable values in my code, which I do not want to do.
I am finding it exceptionally difficult to pass an sql query result (string) into a variable.No matter what I try, I can't seem to get anything but boolean output from my reader function.I need to obtain staff "account type" from my staff table and then define that account type in a variable.
basically i was wondering if we could inherit shared variables but restrict its scope to only that of the class itself.
Class A Public Shared shared_variable as Boolean = true End Class
[code]....
when i do this A.shared_variable = False, B's shared_variable also becomes false. how do i stop this?i cannot remove the Shared keyword because shared_variable should be able to be accessed without an instance of the class?
Why use simple properties instead of fields in C#?
If I have a class, does it matter if I use a Variable instead of a Property? I mean, unless I need something to run during the get/set time period, does it really matter?
I have several classes that use a bunch of strings for directories, arguments, etc.
At the moment, they're all just declared globally within the class like so:
VB.NET Private str1 As String = "path" Private str2 As String = "path2" Private str3 As String = "arg"
To me, that looks awful and doesn't seem like the proper way of doing things. So, I was thinking, should I make a property for each string and then use a constructor to initialize them?
Would that make a difference at all? Is that the proper way of doing things?Also, some strings are used in a ton of different places and they're basically just being copied from one class and pasted into another. So, do you think I should do what I suggested above, but with a class whose sole purpose is to house those strings so that the code isn't duplicated a million times everywhere? Would that be the most efficient way of doing things?
I have a class in which some of the fields are also classes.I can put values in the "normal" properties, but in the others when o try to assign values it gives the: "Object reference not set to an instance of an object"But the code compiles fine.
dados_Defenicao = New ServiceReference1.draftClaimEntryDefinition dados_Defenicao.arCode = "123" dados_Defenicao.claimMarket.warrantyType = "w" - Here it gives the error
I have a class in which some of the fields are also classes.
I can put values in the "normal" properties, but in the others when o try to assign values it gives the: "Object reference not set to an instance of an object"
But the code compiles fine.
dados_Defenicao = New ServiceReference1.draftClaimEntryDefinition dados_Defenicao.arCode = "123" dados_Defenicao.claimMarket.warrantyType = "w" - Here it gives the error
I am programmer from some time only, I have certain doubts in fundamentals, could you please clarify on the following:Case 1:
[Code]...
Does case 1 and case 2 yield same result, I mean is a private value necessarily in there?, can we use property itself to use its own value in its Set and get statements?
I have a bunch of private variables I've typed out and I want to put all of my corresponding Public ReadOnly Properties in a bunch below them.Is there some way of copying ten lines of
Private _myVar As String
and pasting in ten sets of
Public Readonly Property MyVar As String Get Return _myVar[code]....
I'm currently copying the whole bunch of variable declarations, Find+Replacing Private _ into Public ReadOnly Property then going line-by-line expanding the definitions and writing return statements.how to avoid all this nonsense in the future, as I'm developing on a virtual terminal server, and the input lag on my little copy/paste/type operations on the code is driving me up the wall.
What i have going on, is i have a MySQL connector as a resource on my application, and im basically trying to connect to my MySQL server, to either a) register a new account, or b) check that the account exists and they are premium, and login, Now what i have run into problems with is: My MySQL Database Name has a _ in it which VB is not allowing for some strange reason.
The code i am using is below
Imports MySql.Data.MySqlClient
Public Class Form1
Function UpdateRecord(ByVal query As String) As Integer
[CODE]...
How i can allow the _ into the application, because the only databases that don't have a _ in the user or dbname are a) Paid ones which i DO NOT have the money for or self hosted ones, i cannot leave my computer on 24/7
In the form design I set up a TableLayoutPanel, 20x20 cells and in cell (1,1) a PictureBox (called Target) containing the image of a small target. The properties box for Target shows some very promising properties, Column and Row - and if you overwrite the values in the properties box, the PictureBox obligingly shifts to the corresponding cell position in th design. However in VB it is not possible to refer to Me.Target.Row or .Column - neither appears during coding in the menu of properties, and deliberately coding either of them produces an error like
Error 1 'row' is not a member of 'System.Windows.Forms.PictureBox'.
1. Why does the properties box show properties that cannot be altered programmatically?
2. How can my program move Target around in the TableLayoutPanel?
I wrote a function that copies the properties of one class to another so make a copy of an object.So something like
MyObject myObject = myOtherObject.MyCustomCopy(myObject) where myObject and myOtherObject are of the same type. I do it by bascually doing myObject.prop1 = myOtherObject.prop1
[code]....
I am pretty sure in the past I used a .NET object that automaticaly did this, by reflection I guess, but can't remember it ... or an I imagining that such a method exists?
So, how can I set (if it's possible) the localization for these labels? I've this kind of assignment in modules and not in the form. It's possible to set a resources file also for modules?
I am using vb.net with phpMyAdmin MySql database. While running the piece of code below, the program hangs in the for loop before the variables are assigned values from the data table(dt)...
'Check for appraisal period----------------------------------------------------------------------- Dim sqlCheckDate As String = "SELECT * FROM tblappraisalsetting where appSetID=(select max(appSetID) from tblappraisalsetting);"
I am trying to add shared members in derived classes and use that values in base classes...
I have base
class DBLayer public shared function GetDetail(byval UIN as integer) dim StrSql = string.format("select * from {0} where uin = {1}", tablename, uin) end function end class
[Code]..
currently there is error using the tablename variable of derived class in base class but i want to use it i dun know other techniques if other solutions are better then u can post it or u can say how can i make it work? confused...
as you might guess from the variable names I'm making a game (but this problem isn't game related!) which involves multiple "bullets" moving along straight trajectories. This is my attempt at changing my code for firing one bullet into one for firing many bullets at once. It works perfectly except for one thing.The class I made (BulletClass) to contain all the things needed to move the bullet isn't setting all of its properties correctly. I apologise for the walls of code however I wasn't entirely sure whether I should chop bits out. I wanted to colour code my code so that you could scroll through and see the subs where things have gone wrong, but apparently I can't even code a new thread. Let alone a video game. Instead I'll just list them, you can search for them if you like or just scroll through at your leisure.
[Code]...
In a nutshell: the properties TargetPosY, TargetPosX, ShipPosX and ShipPoseY are not working properly. As a result the calculations involving them are skewed and the bullets always travel directly downward.
What's the proper way to declare variables in a class? I've been doing something like:
'in a class public shared teststring As String = "first" 'on a code behind
[Code]....
with shared variables loading a second window or reloading the page (without clicking the button) renders the hello world string. so how do I declare variables in a class but make it per instance?
