Why can't a sub implement an interface and handle event at the same time? The following gives my a syntax error:[code]I know I could handle this kind of logic with another method, but that is not the point. I just want to understand the reasoning behind this.
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I defined the following interface:
Interface INewFileDetector
...
roperty PollIntervalMsec As Integer
[code].....
I need to implement an event interface defined in a COM app so I can get events. I want to use System.Runtime.InteropServices.ComTypes.IConnectionPointContainer. In Adam Nathan's ".NET and COM", Adam shows some C# code that connects to an IE event set. There he does this:
[Code]...
I have a form for which the form load event only fires one time. When the program starts. It will not fire again until I end the program and restart. I have tried .show and .showdialog, but it acts the same. I have read about form load events loosing the handles, but my code looks exactly like it should.
Here is the load event code
PrivateSub frmBilling_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesMyBase.Load
LoadClients()
LoadTherapists()
LoadCPT() EndSub
Here is the code that calles the form.
PrivateSub BillingToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BillingToolStripMenuItem.ClickfrmBilling.Show()
frmbilling.show()
EndSub
I have a UserControl with a Panel (Panel1). The UserControl has a property Items (type ControlCollection) that returns the Controls collection of Panel1.Via a custom CollectionEditor, I tell the designer that it should add my custom controls called Item (inheriting Control). For the sake of example, the Item control is just a control with a random background color:[code]The custom CollectionEditor creates new Item controls using the DesignerHost service (and its CreateComponent method), so that they appear as actual components in Panel1, selectable during design-time just like any other control.It might be a little hard to see (because the colored Items are docked to the top), but I have selected the red item, which can also be seen from the Properties list.
As you can see in the code, I attach a Click event handler to each item as it is added to Panel1. When clicked, a MessageBox shows the color of the item. Obviously this is just for the sake of this example, but the point is that I need to be able to click an item and something then needs to happen.This works fine during run-time. I can click each item, and the MessageBox shows.The problem is that it does not work (quite obviously) during design-time. When I click it during design-time, it is simply selected (as any other control) and of course does not register any Click (nor MouseClick) events.But, I need the Click event to fire even when in design-time! Clicking an item corresponds to selecting it, and when selected (even in design-time), some other panel (not shown in this example) should be brought to the front so it gets visible. Now, I have created lots of things very similar to this (clicking an item during design-time), but there has always been one major difference: those items were not actual controls on the form. Instead, they were drawn manually on to their parent (and they only looked like separate controls). Obviously there was no design-time support for those 'items' (as they weren't controls), but I could handle clicking them quite easily: by handling the MouseClick event of the parent, I can check the location and see if it falls within an item. If so, that item was 'clicked' (artificially).This time, the items are actual controls, and this method does not work (the parent does not receive a MouseClick event either).So, does anyone know of any way to do this? The only way I can think of right now (although I have no idea how to implement it) is to somehow 'listen' to changes in the designer selection.
I am trying to implement an interface defined in IDL, in a vb.net class here is the idl
interface IEmissaryRoot : IDispatch {
id(0x68030000), propget]
out, retval] IActivityCol** );
[code]....
I'm trying to assign a datasource to a ComboBox control during runtime. When I do so, I get the attached message. [Code] I want to learn how to use an Interface. The error message is suggesting using an IList. How would I do this.
View 2 RepliesI have a situation where I am defining an interface and then using that directly eg:Dim x as IWhatever = new implementationOfIWhatever()Which is fine, butmplementationOfIWhatever also implements IDispoable so I want to be able to do x.Dispose or ideally Using x but get the error that that this is not declared or must implement IDispoable as IWhatever of course doesn't define Dispose or implement IDispoable
View 5 RepliesI am trying to implement an interface on an ASP.NET 3.5 web page that will let the user specify up to three conditions for insertion into a Linq to SQL query. It looks something like this:
[Code].....
how to assemble my query from the values in the various DDLs and TestBoxes.
I have an interface program written in VB .Net (VS2008xxx.dll). Is it possible to implement the Interface in a VB6 program (VB6xxx.exe)?
View 8 RepliesSay I want to know more about a class mshtml.htmlinputelement for example.Say I want to know. What is his parent classes? What interface the class implement? How do I do so through object browser?
View 1 Repliesis it possible to implement strategy pattern with different parameters in VB.net? For example I have the following code:
Public Interface InterfaceDataManipulation
Sub updateMyData()
End Interface
How to implemente updateMyData in the class that implements above interface class with different parameter,for example in class x :
Public Class X
Implements InterfaceDataManipulation
Public Sub updateMyData(ByVal x as String)[code]......
But the IDE raises an error "class x must implement updateMyData on interface InterfaceDataManipulation"
I am a C# programmer but I have to work with some VB.Net code and I came across a situation where I have two methods on an interface with the same name but different method parameters. When I attempt to implement this interface in a class, VB.Net requires explicitly declaring "Implements MethodName" after the method signature. Since both method names are identical, this is confusing the compiler. Is there a way to get around this sort of problem? I suspect this must be a common occurrence. Any thoughts?
N.B. This was more a case of the programmer not verifying that the interface in question had not changed from underneath him.
Do i have to implement the serial port in the interface again if i have put it in the behind code? Do have any links that can make me understand.
View 8 Repliesi may be misunderstanding this but on MSDN i believe it says that it is good practice to implement the Dispose destructor in every class you write. should i (do you) really implement the IDisposable interface with every class i write? also, is the proper syntax for implementing an interface to put the "Implements" keyword on the line after the "class" declaration? i put it on the same line as "class" and I got an error.when coding the method implemented by the interface, is it mandatory to follow this syntax, as an example: Public Sub Dispose() Implements System. IDisposable. Dispose.
View 3 RepliesWhat's the best way to implement the timed event / scheduled event? An application that incorporates the functionality of Windows Scheduled Tasks.
View 3 RepliesAll my data objects implement an interface IFillable
Public Interface IFillable
Sub Fill(ByVal Datareader As Data.IDataReader)
End Interface
In the objects themselves you will typically see something like
Public Class Supplier
Implements IFillable
[Code]...
Now here is the tricky bit. Given that all my property names WILL ALWAYS match my database column names what I want to do is using reflection generate the fill method at compile time and infer the types and column names for the datareader.I am assuming I will need to structure this functionality as some sort of a tool/vs plugin? What I am looking for is guidance on the best way to go about this.
PS: BTW: Obviously I could easily do this using reflection at runtime but I dont want to take the performance hit for it (Although theoretically if I could cache the values somehow (static class?) it might not be too bad).
How do I limit an Interface when defining it? What is the correct technical term for what I am describing?For example, I want MyInterface to only be implemented for objects that implement IList(Of T) and ICollection(Of T).
View 5 RepliesWe have a web service solution in VB .Net 2005 that we have started getting an error in. We provide an interface like the following:
Public Interface IBatchTrackerService
Function InsertBatchTracker(ByVal BatchTrackerObject As BatchTracker, ByRef errorNum As Integer, ByRef errorMsg As String) As Integer
End Interface
In our class we implement this interface with the following code.
Public Class BatchTrackerService
Implements IBatchTrackerService
[code]....
This code was working properly but has now started causing errors. The error we receive is:
Class 'BatchTrackerService' must implement 'Function InsertBatchTracker(BatchTrackerObject As BusinessObjects.BatchTracker, ByRef errorNum As Integer, ByRef errorMsg As String) As Integer' for interface 'IBatchTrackerService'.
The odd thing is that the project compiles correctly, but shows many of these errors after the compile is finished.We recently installed Panda as our virus protection which caused a different error that I found the solution here for.
Updated 4/21/2009 at 11:50 Both the interface and the implementation are within the same project in the solution.
Updated 4/22/2009 at 08:16 I tried removing the BusinessObjects identifier from in front of the BatchTracker type but I still get the same thing. This is just one example of what has happened throughout the entire solution. Every implementation in this BatchTrackerService is flagged as an error, plus there are several other services that have almost every implementation flagged as an error as well. But somehow the project builds successfully, and yes, it runs properly!As for BusinessObjects, it contains many of the classes we use as parameters and it is simply another project within this solution. We do not reference any external assemblies to provide these classes to BusinessObjects.
Updated 4/22/2009 at 08:24 The last thing I noticed was that any function/procedure that doesn't use a 'BusinessObjects' class as a parameter, but simply uses strings, integers, etc is not flagged as an error.
Updated 4/22/2009 at 09:50 I tried reverting back to a previous version and I was able to compile and the error count stayed at zero. I narrowed it down to a check-in of one of the project files where the reference to BusinessObjects was slightly changed. I reverted just this project file and everything compiles fine now.
Recently I needed to compare a suggested pattern for IDisposable and object finalization with the auto-generated one we which VS2005/VB.NET provide. We have used the auto-generated one a fair bit, but after looking it the two side by side I had a number of questions about the VB.NET implementation..
[Code]...
Overall I am confused by the supposed added value of having an extended code-path that executes when Dispose() is called explicitly(as opposed to having a common path that is executed regardless of whether or not Dispose() was called explicitly). how it does anything other than delay the actual release of managed resources if Dispose() isn't called directly. In essence it seems to only work to make the managed resources unreachable in the object graph, orphaning them until the 2nd GC run rather than freeing them at a point where they are known to be no longer needed.
I am new to .Net Programming and would like to know if Reflection is suitable for traversing an Object to discover Collections within an instance of a class. I am working with the Microsoft.SqlServer.Management.Smo Namespace.
The plan is to connect to a database, determine what collections exists, then for each of those collections, if the Collection exposes objects which implement the IScriptable Interface, generate a script for the object.How do i do the following (This is pseudo-code as I am seeking assistance with using reflection or some other method to do the following)
[Code]...
I would like to enumerate all objects in db with one function if possible
is it allowed to use more than one Sub to handle the same event ? For example , may I have 2 separate subs to handle the Load event of a form ? Will they fight each other ?I have tested it and it seems to work fine , nevertheless I thought I'd ask you . In case you wonder , there is no great deal , I just want to copy the same lines of code in more forms so I am doing it just in favor of the looking aspect .
View 5 RepliesI created an interface - TermsService.vb and defined the following method : Function GetTermsList() As List (Of Terms)
how do I modify my TermsDB class to implement the TermsService interface I've just created? Here is my code: Have I implemented it correctly?
Imports System.Data.SqlClient
Friend Class TermsDB
Implements TermsService
[Code].....
I'm having trouble porting some .NET2-era C# to .NET2-era VB.NET. Specifically, I am trying to define an interface that an ASP.NET user control will implement.(For background, I am trying to re-implement Phil Haack's Model-View-Presenter example from several years ago: http://haacked.com/archive/2006/08/09/ASP.NETSupervisingControllerModelViewPresenterFromSchematicToUnitTestsToCode.aspx)
The C# interface I'm working from defines properties and events (IsPostBack, Load) that are already implemented by the base control.However, VB.NET is forcing me to explicitly implement these properties/events in the user control (Public Property IsPostBack() As Boolean Implements IView.IsPostBack...). I'd like to just define these in the interface and not have to do anything special in the code-behind of the implementing user control.I'm assuming that I can do this in VB.NET, I just don't know how. I've spent all sorts of time googling/bing-ing, and haven't come up with the answer.
I have some VB code which makes use of a COM api and results in a certain dialog box popping up on the screen. My program is a console application, that needs to run in a batch file, but I haven't found any other way to do things other than finding a way to automatically manipulate the dialog box. Here is the api call (omitting setup code) that results in the dialog popping up:
[Code]...
I am working on a Windows application written in VB with Visual Studio 2005. I have a number of fields where the user needs to enter currency amounts. I am using a MaskedTextBox with the following currency mask. msktxtAssessedVal.Mask = "$ #######.99"
The problem that I am having is that when the users type in the value, the cursor always starts at the leftmost position and appears to force as many digits as the mask. The typical data values can vary anywhere between 9,999,999.99 and 20,000.00. If the users do NOT have a value that has 7 digits left of the decimal point, they need to move the cursor to the correct position before they start typing in the value. These users are used to quickly typing in their data, then tabbing to the next field so the current behavior is not acceptable. We previously used a ComponentOne MaskedTextbox, however, their controls now are no longer free and the boss will not pay!!!
Does anyone know if there is a way for the maskedtextbox or any text control to detect where the user types the decimal and format the data accordningly?
My tile-based map editor project. So far, it works really awesome. Here, look at a picture: [URL] And the screenshot is outdated: Now I got the Pencil, Rectangle and FloodFill tools too!, the tilesets are from that popular (well, not so popular) game engine called RPGMaker.
Currently, this is how the map is structured:
One ArrayList represents the X coordinates.
One ArrayList in each X represents the Y coordinates.
One ArrayList in each X,Y represents the tile.
The tile is an ArrayList containing three elements:
The Image name (Tileset01 in the screenshot), the X coordinate in the image, and the Y coordinate in the image. Those coordinates are from the TILESET01 image, not map.
Getting the idea?
How do you locate a tile in the map when it is clicked?
First I get the cursor's position on the map picturebox, then convert it to a multiple of 32 (the tiles are 32x32, yes), divide the position X and Y by 32. The results are the indexes I need to get to the tile I clicked.
That method works just fine for me.
When the map picturebox invalidates and needs painting... When that happens, I iterate through each X and Y arrayList. When I get the arrayList that represents the tile, I use it to draw on the map.
For example:
Iterating X arrayList.... step 8......
Iterating Y arrayList..... step 3.......
Found arrayList with three elemetns: ("Tileset01",32,96)
Draw image on the map picturebox, source is "Tileset01" on rectangle (32,96,32,32)... draw it on map picturebox's point (8 * 32) and (3 * 32)
And so on.
Now you understand how I am working with my map editor, how I am locating clicked tiles, and how I am drawing it. Everything goes fine, except for one problem: At some point, the user might want to make a 500x500 map.
That means, an arrayList with 500 elements representing the X tiles. Then an arrayList with 500 elements for each X tile, representing the Y tiles. Then an arrayList in each X,Y pair.
Then multiply that result by 5, because there will be 5 drawing layers. How am I supposed to handle such huge maps?! My app explodes when I set the map dimensions to 500x500! 500x500 is the max setting allowed in my app. I also know that 500x500 map editors are possible, because I have seen others before. With great performance.
Thought I'd see if Stack overflow is quicker than me testing something while I get a thousand interruptions from other work :)
I'm updating an old VB net application and trying to refactor some of the logic as I go. The app looks for data from a single date across a few tables and writes that view to a file.
Writing the query in SQL I'd get the equivalent of
SELECT * FROM table
WHERE CAST(FLOOR(CAST(table.date AS float))AS datetime) = '15-Jul-2010'
Ideally I'd use
SELECT * FROM table WHERE date=@input
and add a date object as a parameter to a System.Data.SqlClient.SqlCommand instance
Are those two comparable? Will I get the results I expect?
How can we implement event bubbling in vb.net.
View 2 RepliesI am trying to implement a service object class for the POS for .NET library using VB9. Specifically, the BillDispenser class. I define my class and inherit from Microsoft.PointOfService.BillDispenser. As normal, it creates stubs for all the MustOverride (abstract) properties and methods that I need to override (I love that), EXCEPT for the events. Apparently thare two events defined as abstract (MustOverride) in the POSCommon base class, but VB doesn't generate stubs for them.[code]...
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