using a Binding Source to Bind my Collection to a ListBox? I can bind the class to the binding source, but im not sure how to let it know what type of list it is, or how to display the correct item.
I'm trying to get the listbox to display the ItemNames. Here's my class and collection class.
<System.Serializable()> Public Class SurveyItem Private itemNm As String Property ItemName() As String
I am trying to create new variables inside a class after creating its object at runtime. The problem is that I don't know the variable names or the value beforehand so I have to create the new variables at runtime.
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This is a more elaborate explanation of my code. If you observe that in the Eval function I have tried to evaluate Fval(abc). Now the object array abc is not declared in the Test class because it existence is not known beforehand. What I want to do is create an object array abc of length 2 and populate it with some values and when Fval(abc) is called then then the value of index 1 should be the return value of Eval fucntion.
I've bound a collection with public properties that are of type double to a datagridview control. If, in the datagrid, the user enters a value that is a string I get an error thrown, and I can't seem to find the method to handle it.
The only way I've been able to fix this is to make all public items in my bound collection of type string, and in the get/set make the private variables double.
This is a huge pain; is there any way to do this in a more elegant fashion?
2nd question is there a way to make the default header text something other than the public property name? (I know I can manually change this in the code later, I was wondering if there was a way to automatically have it something else)
(below is example code; I've changed the P property to reflect that change I had to make)
Public Class clsPIDElement Private _P As Double Private _I As Double
I was wondering if its possible to bind a datagrid column to a list (Of T) thats stored within an observable collection!
Here's my current code:
Dim _BindWithThis As New List(Of BindWithThis) Me.DataContext = _BindWithThis For i = 0 To 3
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This currently displays four rows of "(Collection)". Is it possible to step into one of these "Collection" rows and display the data? I know that this is possible to do with a list box by binding with a specific element in the collection:
I have a GUI which allows the user to select a report to view/edit. When the user selects a report, it shows the Items in the report. The Item has many properties - most of which are binding properly. One of the properties is Owner, and this is bound to a ComboBoxColumn.
Report
Items
Owner
I have done something very similar to this a few times and had no problems when I set the DataPropertyName, DataSource, ValueMember, and DisplayMember. The only difference is that this time instead of the Item type having an OwnderID it actually has an instance of the Owner object.giving the items bound in the list a self-referencing property that allows them to return themselves for the purposes of setting the ValueMember.However, When I bind it this way:
I get a lot of errors like: Unable to cast object of type 'System.String' to type 'Owner'.
and:
The following exception occurred in the DataGridView:
System.ArgumentException: DataGridViewComboBoxCell value is not valid.To replace this default dialog please handle the DataError event.I was able to get around some of these errors by binding it like this:
and also by making the ToString function on the Owner display the OwnerName property. This seems pretty hacky though - and I think I'm misunderstanding something fundamental as it still does not function properly.
My problem is similar to the one described in this article, but I'm trying to use a different grid(DevExpress.xtraGrid) and therefore the answer (if it even works) does not apply for me: Binding Collection to DataGrid without showing all columns
Briefly, I'm binding the grid to the collection of custom objects - cMessage - to grid's datasource, but I don't want all the propertieties of the cMessage to be shown in the grid. Is there any way to hide some properties from the binding, while leaving them acessible from outside (ie.leave them as public or friend)?
I'm looking for a tutorial on how to Adding a list(of Class) or Collection as another Class's Property.What I am after is something like the Columns Collection for the DatagridView control.I would like to add Items in the graphics screen. Where the item list is displayed in the left panel and the selected Item properties are displayed in the right panel.
My problem is similar to the one described in this article, but I'm trying to use a different grid (DevExpress.xtraGrid) and therefore the answer (if it even works) does not apply for me: [URL]
Briefly, I'm binding the grid to the collection of custom objects - cMessage - to grid's datasource, but I don't want all the propertieties of the cMessage to be shown in the grid. Is there any way to hide some properties from the binding, while leaving them acessible from outside (ie.leave them as public or friend)?
I need to bind a textblock.text property to a single element in an observable collection, or array element, and have the text update using the INotifyPropertyChanged or INotifyCollectionChanged, whichever is best.
Most examples describe ways to bind listboxes or other list views to entire collections, but my application needs to update several textblocks on a screen depending on notification of a change in one or more elements of an array.
Is it possible to bind a single textblock to a single array element? Is it possible to get notification of the proper type that will update one or more of the textblocks if any assigned element changes?
I have a user control with its own context menu, however I need to add additional items to that menu.
The approach I took was to have a dependency property called ContextMenuItems:
Public Shared ReadOnly ContextMenuItemsProperty As DependencyProperty = DependencyProperty.Register("ContextMenuItems", GetType(ObservableCollection(Of MenuItem)), GetType(SmartDataControl), New FrameworkPropertyMetadata(New
I am not too sure about the syntax , since I am still very new to VB..
So this is what I have in a class
Code:Public Class DocumentDelivery Implements IDisposable Public Shared RenderList As New List(Of Byte()())
Public Function Initialize(ByRef env As et.User.SystemCommon.Environment, ByRef errs As et.Exec.Utilities.ErrorCollection) As Boolean
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I didn't write the existing class, I am just making changes to it. I am not sure why there is no constructor. However, Intialize() is called every time a the class is created.Right now, I set the default capacity of the RenderList, (the class variable) to 1 in Initialize method.
Is there a way to set the capacity outside of the initialize method? what is the syntax?
[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?
I seem to have problem with passing a collection/sorted list/ list of strings from one class to another.I am using property procedure to pass it, however nothing is sent to another class. There isn't any error messages either.[code]
Is it posible to add Data Bindings to a variable so that the app. is able to count the caracters in in a field.Some thing like this below.I know this code dont work, I need something similar? [code]
I have a project in WPF 4 and VB.net 2010. I want to bind the volume property of a mediaelement to a variable in another module. Mind you, the variable is in the correct data type, so no conversion is necessary
Create a class named Service. Inside the Service class, declare a class variable named Started. The datatype of this variable is Boolean.Public Class Service Dim started as Boolean End Class Create a class named Server. Inside the Server class, declare a dynamic array that can contain elements of the type Service.(Note: For convenience, both the array and the variable Started can be accessible from a client program that creates an instance of Server and Service respectively)
Create a constructor for the Service class. When the constructor is executed, it will set the value of the class variable Started to True. Create two new classes: WebServer and DatabaseEngine. Both of these classes inherit from the class Service. Inside the Service class, declare a Sub procedure (method) named Terminate. This method should display the following text Service stopping in a message box when executed.This method can be overridden in classes that inherit from Service class.
Inside both the WebServer and DatabaseEngine class, override the method Terminate inherited from their base class Service. Both methods should first call the base class Terminate method. The messages Web server stopping and Database engine stopping should also be displayed in a message box when the Terminate method for the WebServer and DatabaseEngine are called respectively. These messages should only be displayed if the Started variable inherited from their base class is not equal to False.
Inside the Server class, declare a method named Shutdown. This method does not return any value. When executed, it will call the Terminate method for each of the Service instances (if any) in the arrServices array. You should call the Terminate method within a For Each loop that loops through the elements of the arrServices array.
In the Sub Main method, create an instance of the class Server. Set the size of the arrServices array in your Server instance to contain 2 elements. Create first a WebServer instance and then a DatabaseEngine instance into this array. Call the Shutdown method from your Server instance.
I want to created a nested class that can only be visible to and instantiated from the parent class.But I also want to be able to use an instance of the nested class through a public variable of the parent class.I tried making the nested class private, or making the nested class' constructor private, but it won't compile.Is it possible to do this in .NET?
OK So I know WHY I am having the error I am getting. I don't know HOW to fix it. Basically, if the user doesn't have a certain permission, I need to join another table. But .NET is so picky I can't just make two different queries in an IF statement and then use it outside of the if statement. I can think of some ugly work arounds for this, but I would rather not. I am fairly new to .NET I know just enough to be dangerous.
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because of this: Dim l As IEnumerable(Of Company) its not just IEnumerable of a Company, its got the source in it. I have to explicitly select source to use it in my datagrid. Can I make Dim l something that will make it stop complaining?
I have procedure (Import) that calls a for a new instance of frmImportData. I also have a class name clsBatch that has a data table property called prpParametersTable.For some reason, I get an error (indicated below with ERROR>>>) when trying to assign prpParameterTable to cv_dtImport2. The error states "Object reference not set to an instance of an object.". Why does this error not happen when I assign dtBP to cv_dtImport1? Both cv_dtImport1 and cv_dtImport2 are equal to Nothing and in my Import procedure dtBP = prpParametersTable.
Public Sub Import(ByVal clsB As clsBatch) Try Me.cv_clsB = clsB
I have three class files, accounts.vb and transactions.vb in addition to my form.vb. I am unable to retrieve a member variable from on class from inside the other. When the combobox index changes, the program loads the correct account (checking or saving) from two different sequential files. I don't think I have the calcBalance procedure in the correct class file. And that is what I am having trouble with. Accessing it to display it. [Code]
Class Human End Class and another class which refers to the human class
Class ASD Private somevar as new Human End Class
Ok now i've got a problem, i wish to rename my class Human, to Man. i've got to change Human to Man 2 times, which is OK but the problem is that in the real case, its not just 2 times, its like 500 times or more.
Well its something like a PHP on Javascript.
the following shows the solution of what i'm trying to do, but its in another language PHP/Javascript:
note: in php $ sign declares a variable, echo writes the variable out
I have a MainPage - mainpage.xaml Inside the MainPage I have a frame that hosts other pages. The first page that is auto loaded is the LogIn - LogIn.xaml
The user enters their email to login (no password required, just email to identify, its an internal app so passwords are not required or even wanted by users).
On MainPage.xaml the header should have a "Hello " TexBlock (name: ui_txbUserName). The LogIn page has a method which on submit gets the UserID (for other reasons and saves it) and the User Name.
I want to change the ui_txbUserName when the person logs in and update if he/she logs out of one account into another. I have looked at INotifyPropertyChanged and Dependency Properties and im just not sure how to go about doing this!
I have a MainPage - mainpage.xamlInside the MainPage I have a frame that hosts other pages. The first page that is auto loaded is the LogIn - LogIn.xamlThe user enters their email to login (no password required, just email to identify, its an internal app so passwords are not required or even wanted by users).On MainPage.xaml the header should have a "Hello " TexBlock (name: ui_txbUserName). The LogIn page has a method which on submit gets the UserID (for other reasons and saves it) and the User Name.I want to change the ui_txbUserName when the person logs in and update if he/she logs out of UsingOfficerID - its a global variable set when a person logs in, its used all over the place in the application.
The following code creates a Collection where every Item is assigned a value equal to the last item added. At the end of adding for example seven items all the entries are identical to the last one added, although each has the correct key
The parameter passed to the function - aCOA() - is a comma delimited string of three strings.
The code is as follows Public Function myCOA(ByVal aCOA() As String) Dim thisCOA As New Collection Dim keyCOA As String
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Is this a bug in the code or in the Collection Class. I have traced the operation of the code and all seems OK until the second entry is added at which time the first entry Item get the same value as the second entry Item and so on.
