How would I create my custom Role class based on that autogenerated class? I have read a few articles on the net but I am still lost. Can someone please show me how to do this, and what I must import(using visual basic). I want to add some validation to the string property where Role1 cannot be more than 50 characters.
Autogenerated class
[Code]...
Here are essential excerpts for the code creating the class and the page using it:
Imports System.Collections.ObjectModel
Public Class Test (Of T as xyz)
Inherits Collection (Of T)
[code].....
I am trying to jump from ASP Classic to asp.net. I have followed tutorials to get Entity Framework and LINQ to connect to my test database, but I am having difficulties figuring out ExecuteQuery(). I believe the problem is that I need an "entity class" for my database, but I can't figure out how to do it. Here is my simple code:
Dim db as New TestModel.TestEntity
Dim results AS IEnumerable(OF ???) = db.ExecuteQuery(Of ???)("Select * from Table1")
From the microsoft example site, they use an entity class called Customers, but I don't understand what that means.
This is also posted in the database development forum. As I think the same problem could apply to things other than connections, I am posting it here also. I have created a custom class. All methods in this class, I want to interact with a single connection object.
Imports MySql.Data.MySqlClient
Public Class clsRegTester
Private cn As New MySqlConnection
[code].....
my aim is to create a new instance box at the push of a button, the box has strings name and Id to be filled concatenating the auto generated ID i.e. 0 to 210 plus a string "Box" added by the user. I had problems earlier creating a structure within the class box, frankly I am not sure if the code below will work, as i try to run it in VB I get an error indicating that I am using the variables strBoxPositions() and strBoxNumbers() without assigning a value to it. The thing is the strBoxPositions() should automatically be filled by arrPosition() which will be created at the same time the new object box is created and the strNumbers() will be created with empty strings to be filled at latter stage by the used as and when necessary.
how could I initialise those arrays to get the program to run and perhaps ill be able to see if the code works or not, or just correct this code with a better way of code with comments, also if possible some indication on how could I update the strNumbers array inputing the strings one at a time on a text box field.
Public class form1
Public Class Box
Public intBoxID As Integer
[Code].....
When we can access the public methods via object then why is there need of inheritance.
View 2 RepliesI am trying to find way to design a report using my own custom class. I found links:
1.) How to work in Crystal Report with Object Data Source?
2.) Use .net object as data source in Crystal Report 2008
3.) Binding object with List<> to Crystal Report
4.) How to assign Custom class as datasource in crystal report
They were quite helpful, but I have been stuck in the first step while designing report as my custom class's property is not listed in field list of crystal report design view.[code]When I add my class objects to crystal report I do not get the usertype field from users class in field list.So how can I add usertype field to my field list? Or do I have to take another approach?The reason i wanted to use it as i am:
1.) Showing a form where user can type keyword
2.) program filters the records as per keyword using LINQ
3.) when user clicks the print button, I want to set the filtered records as datasource of my report
I want to build a MVC helper function for which I pass a Entity Framework object and have it build a select. Generally speaking I tried something like this:
Public Function RenderSelect(ByVal helper As HtmlHelper, ByVal sSelectName As String, ByVal aItmes As Array, Optional ByVal sTitleKeyName As String = "name", Optional ByVal sValueKeyName As String = "id") As String
' open select
[Code].....
However, it isn't working. It would be great to have a way to do this and pass the current entity object.
Dynamic Object Properties in a MVC Helper on a Entity Framework object
View 1 RepliesI want to create a custom class that has inside an array of another custom class (see my code below) but when the programm runs is crashes. Why? What is the right expression???? Plz help I'm a newbie in VB.net.....
Public Class ctrarray
Public nameclass As String
Public ctrlindex(glvar_spaces) As ctrlindexclass
End Class
[code]....
I am using the O/R Designer to create entity classes in VB 2010. I am observing different results for different database tables that I can't explain and more importantly, can't replicate the results that I want.Using server explorer, I have dragged a number of tables on the O/R designer surface, thereby creating the entity classes.
I have saved the project and can access the various entity classes in my project code. I first noticed a difference when changes made to object instances from some tables/entity classes appeared to persist while changes made to object instances from other tables/entity classes did not persist. These object instances are created, accessed, and changed using the exact same code patterns except for the object, class and table names.
I have been looking to see if there are any differences between the way in which the entity classes are treated, either in my code, in server explorer, or in the O/R Designer. I cannot find any. The properties of the entity classes indicate that all of the classes use the runtime methods for insert, delete and update. As far as I am aware, I have not knowingly made changes to these methods.
The ONLY difference that I find is in the file NameofClass.designer.vb. This is an automatically generated document. The partial class of those objects that appear to persist changes contains different code from that of other partial classes where changes to objects do not persist.In the declarations section of this partial class, the following lines appear:
<Global.System.Data.Linq.Mapping.TableAttribute(Name:="dbo.OrderofBattle")> _
Partial Public Class OrderofBattle
Implements System.ComponentModel.INotifyPropertyChanging, System.ComponentModel.INotifyPropertyChanged
[code]....
If I am right then I want to enable persistence in my other classes by causing this additional code to be generated for them. But how? why the code for this one class hase been generated differently than for all the others (actually it is this way for 2 out of about 15 classes). What setting or or selection do I have to make to enable this code to be created for my other entity classes during the automated process?
I'm pretty new to the EDM, so bear with me. I have a windows form that has a DataGridView on it that's bound from the EDM I created. I figured out how to update my changes fine, but it's when the user creates a new row that I'm having a problem.I tried numerous ways and many google searches, but came up with nothing so far.
[Code]...
Error (occurs when calling _Context.SaveChanges()): Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.
I have extended an Entity Framework 4 entity class with a calculated property in a partial class. This member is not available on the client to which the entities are exposed via WCF RIA Services.when using C# appears to be changing the extension of the partial class file from .cs to .shared.cs. I tried this with my VB.Net solution (.vb to .shared.vb) and got a long list of errors. I believe what happened is that the partial class lost its association with the entity on the client - it inherited from object rather than EntityObject.
My best guess is that this is related to the way that VB.Net handles namespaces.Each project has a 'Root Namespace' which is prepended to anything that is defined within a code file. C# has a 'Default Namespace'which is the namespace into which new types are placed by default - via a namespace statement within the file.The partial class is probably having the client namespace prepended to it which puts it into a different namespace than the entity with which it is associated on the server.Is there any means of extending an entity in such a way that those extensions are available on the client via WCF RIA Services and VB.Net?
I have a database table called Job. I have mapped this table using LINQ to SQL so that I have a class called Job.
What I want to do is add some methods to the Job class. The Job class is defined in the LINQ to SQL classes .dbml file. So, in order to add methods, or anything else to the Job class what should I do?
Should I create a partial class named Job and define the methods in there? Will that then get mixed in properly? Not sure how to proceed on this one.
I have a database table called Job. I have mapped this table using LINQ to SQL so that I have a class called Job.What I want to do is add some methods to the Job class. The Job class is defined in the LINQ to SQL classes .dbml file. So, in order to add methods, or anything else to the Job class what should I do?Should I create a partial class named Job and define the methods in there? Will that then get mixed in properly? Not sure how to proceed on this one.
View 2 RepliesI have a database table called Job. I have mapped this table using LINQ to SQL so that I have a class called Job.What I want to do is add some methods to the Job class. The Job class is defined in the LINQ to SQL classes .dbml file. So, in order to add methods, or anything else to the Job class what should I do?Should I create a partial class named Job and define the methods in there? Will that then get mixed in properly? Not sure how to proceed on this one.
View 1 RepliesI have to begin saying that I'm working with Visual Basic. The problem is that I have a Entity Framework object and I want to indicate that this object implements a interface, for example:
Public Interface ICatalog
Property created_at() As Date
Property id() As Long
End Interface
Those properties are allready in the object. In c# I've done this just by declaring a partial class of the object and indicates that implements that interface, but in basic is not working, I supouse that is because of the language sintaxis used to declare that a property is implementing some property of the interface, for example:Public Property created_at() As Date Implements ICatalog.created_at
I'm getting an Entity Framework object collection from my Products table called oProducts. I am looping through the collection and setting the Quantity field from a separate function. Before I write out a display of the objects in HTML, I want to sort them by the Quantity. So, I am using LINQ to create a new collection and try to order from the object collection that I just modified. The modified values are definitely in the object collection and output properly, but the sort ordering isn't working on the modified field.
Dim oProducts = From p in ctx.Products _
Where p.Active = True _
Select p
[Code]....
I'm writing a solution where the data entities are passed to clients using datasets through a WCF service, with nHibernate as ORM. My predecessor has written some translator classes, converting datasets to entities and vice versa. In most cases he's declared the return object as a parameter for the object.
For example:
Public Shared Function CreateEntity(ByVal ds As DataSetObject, ByVal entity As EntityObject) As EntityObject
Dim row As ds.EntityObjectRow = ds.EntityObject(0)
entity.Id = row.Id
[code]....
He's not with the company anymore, so I can't ask him why he's done it this way. Hence my question here. Is there some performance gain, or traceablity thing with nHibernate by using the first implementation rather than the latter?
I am utilizing a centralized class object that needs to call another class object. The program itself will do something like the following
sFieldValue = CentralObject.ObjectHandler(1, TestFunction, "FunctionVar,FunctionVar2,FunctionVar3")
In the central object I have a function
Public
Function ObjectHandler(ByVal ObjectType
As
Integer,
[code]....
I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj
Inherits baseObj
Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
I've got a class that closely resembles one of my entities (I use the class for JSON de/serialization because the entity fails conversion to JSON, one of the known gotchyas of JSON + MVC).Once I deserilize a JSON string into my object, is there a way to automatically update the associated Entity model instance. The property names are the same.
'myDeserialized is the deserialized JSON object coming over the wire
Dim entityInstance As DLL.Person = db.getPersonById(myDeserialized.id)
myDeserialized.update(entityInstance)
[code].....
The code below works for the class that I hard coded "XCCustomers" in my RetrieveIDandName method where I use CType. However, I would like to be able to pass in various classes and property names to get the integer and string LIST returned. For example, in my code below, I would like to also pass in "XCEmployees" to my RetrieveIDandName method. I feel so close... I was hoping someone knew how to use CType where I can pass in the class name as a string variable.
Note, all the other examples I have seen and tried fail because we are using Option Strict On which disallows late binding. That is why I need to use CType.I also studied the "Activator.CreateInstance" code examples to try to get the class reference instance by string name but I was unable to get CType to work with that.When I use obj.GetType.Name or obj.GetType.FullName in place of the "XCCustomers" in CType(obj, XCCustomers)(i)I get the error "Type 'obj.GetType.Name' is not defined" or "Type 'obj.GetType.FullName' is not defined"
'+++++++++++++++++++++++++++++++
Imports DataLaasXC.Business
Imports DataLaasXC.Utilities
[code]....
I have the following query:
Dim queryStudent = (From p In dbContext.Residents _
Where p.people_code_id = people_id _
Where p.year = year _
[code].....
I have the following code:
Private Sub setDropdowns()
Using licensingModel As New licensingEntities
[code]....
My problem is that i dont know how to define the parameter type for the sub. Because they are different types of objectSets being passed each time, I thought IObjectSet(Of EntityObject) would work, but it gives me the following error:
Unable to cast object of type 'System.Data.Objects.ObjectSet1[licensingModel.tblLookup_Country]' to
type
'System.Data.Objects.IObjectSet1[System.Data.Objects.DataClasses.EntityObject]'‌
I have created a custom user control (JCUserControl), and I am using it in the Main Window. And my Main Window has no codebehind. I have this in the JCUserControl codebehind:
Private Sub ImmediateRadioButton_Checked(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles ImmediateRadioButton.Checked
SomeTextBox.IsEnabled = False
End Sub
When I run it, it fails with the NullReferenceException. If I comment out the SomeTextBox.IsEnabled = false, it runs without any problems.
Edit: Found out that I could just check if the radio buttons are loaded before doing whatever I want to do.
Private Sub ImmediateRadioButton_Checked(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles ImmediateRadioButton.Checked
If ImmediateRadioButton.IsLoaded Then
SomeTextBox.IsEnabled = False
End If
End Sub
I'm making a custom class that mocks the System.Drawing.Rectangle class because the Rectangle class doesn't have a name property. I need a name property because I am adding all of my rectangles to a collection and I need a little more info stored than just their locale and size. So I changed the _onPaint event but nothing is working out when I run the program?
Public Class Rectanglar : Inherits UserControl
Public BackgroundColor As Color = Color.Blue
Public Sub New(ByVal name As String, ByVal XY As Point, ByVal Widthy As Integer, ByVal Heighty As Integer)
[code].....
We have a huge windows application with poor exception handling. The application throw object reference error from lot of places and the system error message is showing to users as it is using message boxes.
I am looking for a simple solution which can be used to replace this message to something user friendly for the entire application
I'm trying to create a pivot table by opening an Excel file from my drive.But I'm receiving the error saying "Object reference not set to an instance of an object".[code]
View 1 RepliesI'm having this problem with my code and cannot seem to get past it although it was working fine before. The error is "An error occurred creating the form. See Exception.InnerException for details. The error is: Object reference not set to an instance of an object." The code is:
CODE:
I am trying to get information to be pulled out of a database and show in text boxes on another form (frmviewsdets). The error occurs when it gets to the line frmviewsdets.txtsnumber.Text = rdr("StudentNumber") and even when a breakpoint is applied there it just moves on to the next and so on.
I have tried to show frmviewsdets before I pull the data out of the database beut I get the same message.