Create A Base Class For Connecting The Database?
Jan 20, 2010i just like to know how create a base class for connecting the database.just the simple one.
what are the best practice in creating a base class connection.
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Create A New Class That Inherits From The Base Form Class And Define A New() Method With Parameters?
Oct 1, 2008I've been creating short test apps repeatedly to try to understand some of the concepts in VB.NET.For the most part it has been illuminating.I read Bucky's .NET knowlegebase tutorial on passing objects as parameters to newly created forms. He shows how to create a new class that inherits from the base form class and define a New() method with parameters Extending the concept I thought about doing the same thing with a form that was created at design-time (In this case Form2).
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Error - Base Class 'System.Windows.Forms.Panel' Specified For Class 'MenuButton' Cannot Be Different From The Base Class 'System.Windows.Forms.UserControl'
Mar 12, 2010When I do this
Public Class cInherits : Inherits Panel
I get this: Base class 'System.Windows.Forms.Panel' specified for class 'MenuButton' cannot be different from the base class 'System.Windows.Forms.UserControl' of one of its other partial types.
How do I inherit?
Create Log-In Page Connecting Access Database?
Dec 5, 2008I'm doing my work in VB express 2008. I'm trying to connect it to my access 2007 Database, so a user can log in with ther username and password, if they are using valid username/password.
I've connected my Access 2007 database using Data Source window: data->show data sources->add new data source.
Is this the correct way to connect database for my Log-In page? [code]...
Form Inheritance - Error1Base Class 'MenuStrip' Specified For Class 'Lesson2' Cannot Be Different From The Base Class
Apr 15, 2010I have put this code in the global form Inherits System.Windows.Forms.Form. And then in the form that will inherit this from the global Inherits MenuStrip. "MenuStrip" is what the global form is called. But keep getting this error: Error1Base class 'MenuStrip' specified for class 'Lesson2' cannot be different from the base class 'System.Windows.Forms.Form' of one of its other partial types.
View 5 RepliesConnecting To External Data Base?
Oct 23, 2011I have changed my Data Base location to external now I am getting an error. I know way, I need to fix it but do not know where
View 4 RepliesVS 2008 Connecting To SQL Data Base
Jun 16, 2011I am trying to familiarise my self with connecting to SQL and manipulating data and I seem to have fallen at the first hurdle I am trying to programmtically connect to a database and fill a data grid with a dataset.
The problem seems to be with the data provider my code is:
Dim strConnection As String = "Data Source=GARY-LAPTOPSQLEXPRESS;Initial Catalog=OriginalFileLocations;Integrated Security=True;Provider=SQLOLEDB"
Dim cnnOriginalFileLo As OleDbConnection = New OleDbConnection
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VS 2008 Connecting To SQL Data Base?
Mar 27, 2011I used to be able to program in VB6 and am now trying to learn .netI am trying to familiarise my self with connecting to SQL and manipulating data and I seem to have fallen at the first hurdleI am trying to programmtically connect to a database and fill a data grid with a dataset.
View 9 RepliesCall Method Base Class In Program Passing Sub Class Objects?
Apr 22, 2012Base class has one field to hold numeric balance value. With 2 methods that accept arguments for adding and subtracting the new input calculating new balance. Sub class has four fields dates, transaction, memo and amount.I have a deposit form, and withdraw form. Each time one transaction is entered it creates an object with sub class fields, then adds to the account collection. My problem is not understanding how to call the deposit/withdraw method and pass the current transaction amount back to the base class to alculate the new balance. Does anyone have any links to information/tutorials on how to perform something like this? As you can see with my code I have tried various different approaches without any success.
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.net - Suppress A Property Or Method From A Base-class In A Derived Class?
Apr 7, 2011Supose a base class
Public Class airplane
Private var_num_seats As Integer
Private var_num_engines As Integer
[code]....
Obviously, I don't wish that the class Glider has the method "start_engines" neither the property "num_engines". Otherwise, other child classes may have. How can I supress these property and method in child class, not just ignoring (if I can)?
.NET Class Inherits A Base Class And Implements An Interface (works In C#)?
Apr 9, 2010I am trying to create a class in VB.NET which inherits a base abstract class and also implements an interface. The interface declares a string property called Description. The base class contains a string property called Description. The main class inherits the base class and implements the interface. The existence of the Description property in the base class fulfills the interface requirements. This works fine in C# but causes issues in VB.NET.
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Can't Inherit Shared Properties From A Base Class In A Child Class?
Dec 29, 2010This 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".
View 1 RepliesDoes An Inherited Class Automatically Implement An Interface From Its Base Class
Jun 10, 2011Suppose I have piece of code like this:
Public Interface ISomething
....
End Interface
[code]....
Returning A Inherited Class As Base Class Type With Web Services?
Sep 25, 2009I suspect I am being very silly here but I have the following setup
Class MustInherit myBaseClass
'some stuff
End Class
Class myInheritedClassA
[code]....
Running this results in the following error
Unhandled Exception: System.InvalidOperationException:
There was an error generating the XML document. --->
System.InvalidOperationException:
[code]....
is there any way of 'Widening' the inherited class to the base class so this would work?
EDIT:regarding XmlInclude(typeof inheritedClass), currently this method could potentially return a number of types of inherited class (i.e myInheritedClassA and myInheritedClassB) is it case of simply having to add each of the inheritedTypes in this tag?
Access The Base Class Inside A Derived Class?
Oct 22, 2010How do I access the base class inside a derived class?
View 1 RepliesGet Base Class Object Reference Outside The Class's Definition?
Dec 10, 2010If we are within the derived class then ofcource we can use MyBase keyword to access base class's object reference . That's fine , how can we take that base class's object reference outside that derived class's definition.My following code will explain what i want . Actually that is giving error right now, but it is explaining my requirement .
Public Class Base
Public x As String
End Class
[code]....
Actually there is error in ReadOnly Property BaseReference's Getter . Error is "Error 1 'MyBase' must be followed by '.' and an identifier. " how can i get base class object reference in Main method ?
Base Class Collection With Sub Class Objects
Jul 19, 2010[code]The reason that this is a problem is that this is a collection of EventBase objects, but I'm trying to populate it with child classes instead. For example, I might have a JumpEvent class that inherits EventBase, and this is being put into the EventBaseCollection. That means that value.GetType() returns the type of JumpEvent, which as you might guess does not equal the type of EventBase.The goal of course is to simply loop through all of the various events without having to know anything about the sub-classes. Is there a way to determine the type of the base class so that the OnValidate call will work? Or is this just the wrong way to go about it altogether?
View 2 RepliesConvert From Base Class To Inherited Class?
Jun 2, 2009I understand that inherited classes can't be converted from base classes. But is there any way to write a conversion sub, so that the base class gets assigned to MyBase, then extra properties are added?[code]...
View 7 Replies"upgrade" An Object To An Inherited Class, And Keep All The Base Class's Property Values?
Jul 5, 2010bare with me during this silly example. :-) Let's say I have a class like this:
Public Class Animal
Public iLegs as int32 ' Number of legs
Public bWings as Boolean ' Wings? Yes/No
End Class
And another class that inherits the "Animal" class and adds one more property:
Public Class ScaryAnimal
Inherits Animal
Public iScariness as int32 ' 0-100, how scary is it?
End Class
Now, if I have an instance of "Animal" with some values in it, and I decide I want to cast it to a ScaryAnimal for some reason, how do I do that without having to create a new instance of "ScaryAnimal" and copy each property value?Basically I'm looking for a way to do this, without having to write the lines marked with '*** below:
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[02/03] Base Class Called PageBase And Then A Derived Class TestPage That Inherits From PageBase
Feb 4, 2009I have a base class called PageBase and then a derived class TestPage that inherits from PageBase. In PageBase I have overridden the OnInit() and when it is called and I inspect the value of 'Me', it is of the type of the derived class and not the base class. My question is how does inheritance really work? For instance, when instantiating TestPage does an instance of PageBase get created too?
Here is my code;
Partial Public Class TestPage
Inherits PageBase
Public Sub New()
[code]...
What Is The Base Class Of .NET?
Oct 19, 2009What is the base class of .NET?
View 2 RepliesCode To Create A Class For A Database Table
Mar 7, 2009code for creating a class in vb.net for a database table that includes insert,delete,update function.
View 1 RepliesGenerics - Create A Common Database Class In .NET?
Jun 12, 2009We have 3 databases providers we use to connect to our databases: DB2, MS SQL, and Interbase. I would like to create a single generic database wrapper class that can be used to talk to all three just by passing in the correct connection string, username, password, and the provider desired.
I don't want to have to add references and import all three providers in the database class. Is this possible?I have done this before in Java using the Class.forName() function.
VB - Extending The XMLElement - Create An XML Database For A Class
Oct 11, 2010I have to create an XML database for a class I'm taking, but I'm running into some problems. I'm trying to pack my data directly into the DOM using some classes I created and derived from the XMLDocument class, I'm trying to do it this way so I can easily manipulate the entries while the document is in memory and save them back to a file without having to mess around too deeply with the XMLDocument class. I'm running into some problems however when I try to typecast the elements I get from calling
Code:
XMLDocument.DocumentElement.Item
I assume that this is happening due to my derived class not being pushed into the DOM when a file is loaded, because it works just fine if I enter the data manually in code.
Code:
Option Explicit On
[CODE].............
Other than writing my own XMLReader I have no idea how to accomplish this, does anyone have an idea how I could go around doing this(other than writing my own XMLReader).
.net :: AddressOf In Base Class?
Mar 16, 2011When referencing a method's address, should we take into account the overriding or not?
Class B
Inherits A
Overrides Sub Foo
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C# - Extending The Base Class?
Mar 5, 2010When you create a webpage in ASP.net, the codebase inherits System.Web.UI.Page Now when I extend the page object to check for SessionExpired for example, I create a new class and inherit from system.web.ui.page, and overwrite some functions. The problem then is that on each page, I have to replace system.web.ui.page with my custompage class. Is there a way to extend a class by adding methods or modifying its methods directly (e.g. add the sessionExpired check to System.Web.UI.Page) ?I'm using .NET 2.0
View 2 RepliesDifferent Versions Of Base Class
Sep 7, 2011Any best practices on how to deal with different versions of base classes.We have made significant changes to the base class but still have lots of code inheriting from the old base class. Could you recommend how we introduce new base class.We'd like all new code to use the new base class. But, we would like the option to have old code still inherit from old base class so we have time to switch and test old classes with new base class.
View 11 RepliesMust Declare A 'Sub New' Because Its Base Class
Jul 17, 2010I have a class library that have a lot of classes, in every class I have "Inherits LINQDataContext". And In my xx.designer.vb file I have...
Public Sub New()
MyBase.New(Global.My.MySettings.Default.DbConnectionString, mappingSource)
OnCreated()
End Sub
But I get a lot of "Class 'xxxxx' must declare a 'Sub New' because its base class 'LINQDataContext' has more than one accessible 'Sub New' that can be called with no arguments." errors
Use Derived Class Shared Variables In Shared Methods Of Base Class?
Jun 4, 2010I 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
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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...
VS 2008 Class To Create Database And Tables From XML File
Jun 27, 2011I need some expert help in achieving this task. I have an xml file which will be emailed to me everyday. I need to loop through the xml and create tables in a database based on the xml nodes and their attributes. looking at the following xml fragment for example: Code:
So based on the above xml, I would have to create a Shipment table as a Parent with fields like ShipmentIdentifier. Then I would have to create an Event table with the ShipmentID as a foreign key and fields like Source, Code. Basically a field for each node. Then if there are columns in the table that are new, I would have to modify the table and add the column. I only have to create tables where there are child nodes or where the nodes have attributes.