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Generics can be very useful. I believe the complier actually creates the classes based on the type so you end up with multiple versions of the same class - one for each (or each combination of types if using <T, V> etc). This I suppose could lead to bloat if there are lots of different Ts in your code, but there would have to be a lot! If you used object then there would only ever be one type of the class.
I'm not fond of auto properties as there is no oportunity for validation in the setter or event raising.
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Not sure what you mean, but if you mean that the following...
Public Class Something(Of T1, T2)
Public Function GetSomething(ByVal var As T1) As T2
End Function
End Class
Public Class Form1
Private _field As Something(Of SomeClass, SomeOtherClass)
Sub Me_Load(...) Handles Me.Load
_field = New Something(Of SomeClass, SomeOtherClass)
Dim var As SomeOtherClass = _field.GetSomething(New SomeClass)
End Sub
End Class
...creates a couple of versions of SomeClass and SomeOtherClass I think you are wrong.
Actually I think the only instances of SomeClass and SomeOtherClass are the Class I pass to the Function and the Class that it returns (var). And of course I have an instance of the Something(Of T1, T2) Class.
Correct me if I am wrong 
When there is no need for validation or event raising a non-auto property creates a lot of overhead 
It's an OO world.
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Naerling wrote: couple of versions of SomeClass and SomeOtherClass I
think you are wrong
I will need to check (maybe over the weekend) but I'm sure I remember reading this on MSDN or somewhere similar.
Naerling wrote: When there is no need for validation or event raising a non-auto property
creates a lot of overhead
Not true, the backing field is created invisibly for you in the IL, these are identical to all intents and purposes (C#):
public T SomeData
{
get; set;
}
private T someData
public T SomeData
{
get { return someData; }
set {someData = value; }
}
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With overhead I meant extra code to write and dirty your screen 
Thanks for pointing it out though.
DaveyM69 wrote: but I'm sure I remember reading this on MSDN or somewhere similar
I would like to read that too
It's an OO world.
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Thanks for the link. It shows even code gets instantiated!
Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum
Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.
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Thanks for the link!
I think I misunderstood your earlier post after reading this.
And it never actually occured to me that value and reference types would work differently (well Rob already explained it pretty well too).
This article clears some things up though.
It's an OO world.
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If I recall correctly, the behaviour is as follows:
When the run-time loads a generic class, it does create multiple versions, but not as many as you may think.
Consider...
Public Class Pair(Of T1, T2) ' I detest the generic syntax for VB, C#'s <T1, T2> is so much clearer
Public First As T1
Public Second As T2
End Class
For T1, the compiler must generate a version of each value type (derived from System.Value, such as Int16, Int32, ...) because the representation of the object varies - some value types may be larger than the size of an object reference.
However, where T1 is an Object type, the variation can be omitted, as the representation remains constant.
Similarly for T2.
So for Pair(int, char) is one type, Pair(int, Person) is one, but Pair(int, object) can share the representation of Pair(int, Person). Obviously Pair(object, int) is another axis of variation, but there tend to be reasonable bounds to the amount that occur in practise.
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I am trying to retrieve a value within a textbox that has a vlue already passed to it within a webpage. As you can see I am trying to extract the last name here(red fire truck:
<span id="CallerForm1_CallerInformation1_lblLNameLabel" class="clsFormLabelSide" style="font-size:XX-Small;z-index: 109; left: 273px; position: absolute;
top: 56px">(last)</span>
<input name="CallerForm1:CallerInformation1:txtLName" type="text" value="RedFireTruck" maxlength="50" id="CallerForm1_CallerInformation1_txtLName" style="width:168px;z-index: 105; left: 266px; position: absolute;
top: 72px" />
What I have been using is the chunk within the methos: Document Completed. Im trying to store its value in a variable so I can pass the var to the next screen or a different page. All I could come up with was this. keep in mind I am using a msgbox to see if anything has been saved or retrieved by so far I havent gotten any notifications:
Dim theElementCollection As HtmlElementCollection = wbCHCTrac.Document.GetElementsByTagName("input")
If wbCHCTrac.Url.ToString.Contains("client/upd_caller.aspx?") Then
For Each currentElement As HtmlElement In theElementCollection
Dim controlName As String = currentElement.GetAttribute("id").ToString
If controlName = "CallerForm1:CallerInformation1:txtLName" Then
MsgBox(currentElement.GetAttribute("Value").ToString)
End If
Next
End If
Any help would be appreciated =)
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I am probably stating the obvious, but I presume you have at some stage determined whether the DocumentCompleted handler is ven getting fired, and if so whether execution is ever going within the first If statement?
And am I missing something.. your html has ...
id="CallerForm1_CallerInformation1_txtLName"
but then you're looking for an id ""CallerForm1:CallerInformation1:txtLName" (colon, not underscore)
Dim controlName As String = currentElement.GetAttribute("id").ToString
If controlName = "CallerForm1:CallerInformation1:txtLName" Then
Shouldn't that be..
Dim controlName As String = currentElement.GetAttribute("id").ToString
If controlName = "CallerForm1_CallerInformation1_txtLName" Then
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Hi,
We are releasing a complete project development SDK for everyone. This SDK is being used commercialy in my
company for more than 6 years, so it is stable. We solved a big problem for consulting companies -
integrate everything and automate everything, including : code subversion (proprietary), tasks/bugs, project
management (branching the whole solution with one click), data access (proprietary), generating a install version,
having multiple web sites, interfaces... code reuse with modules export/import... a lot of features.
Here is the site with information / downloads / samples and forums:
http://sycraf.com/default.aspx
The main goal of this release is that people can create open software with this platform - you can export and
import any project done with the SDK... similar with source forge, but more .NET oriented.
If you need any online help, use the skype button in the support page.
Thanks for reading.
-Rod
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Not the place for advertising.
I know the language. I've read a book. - _Madmatt
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This is not an add, its a free tool.
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Doesn't matter, this forum is for people to ask questions, and receive answers, about issues involving .NET Framework. You have neither asked a question nor provided an answer to one. Instead, you have posted an advertisement, regardless if the tool is free or not. You have been a member here for over five years and this is the first thing you choose to post?
I know the language. I've read a book. - _Madmatt
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I agree with Mark, if you want to promote your software then post an article about it, and let people decide for themselves on its value.
I must get a clever new signature for 2011.
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Ok, i will write an article about the tool.
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Sounds dreadful. 
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How do I transfer file (SSH) in vb.net (VS 2005)?
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Your question is pretty vague, but maybe this article[^] will get you started. The project is now hosted on sourceforge[^]. Also, there is sharpssh2[^].
As far as VB.net goes, you can just add a reference to SharpSSH and call the code from your VB app. Further, there isn't any native support for SSH in .net AFAIK. I hope this helps.
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This is my first post here so Hi everyone!, in the beginning i want to say sorry for my bad English (this isn't my mother tongue).
So i have problem when using wrapper (EMGU) for openCV CvExtractMSER method, i cannot receive any result from it.
Here is an example of code that i used:
Image<Gray, byte> img = new Image<Bgr, byte>(filePath).Convert<Gray,Byte>();
Emgu.CV.Features2D.MSERDetector param = new Emgu.CV.Features2D.MSERDetector(1, 10, 100, 0.05f, 0.2f, 200, 1.01, 0.03, 3);
MemStorage storage = new MemStorage();
Image<Gray, Byte> mask = new Image<Gray, Byte>(img.Width, img.Height, new Gray(1));
Seq<Point>[] regions= img.ExtractMSER(mask, ref param, storage);
regions length is always zero (is empty)..
I tested before MSER parameters and testimage in C implementation https://code.ros.org/trac/opencv/browser/trunk/opencv/samples/c/mser_sample.cpp?rev=2633 and everything works fine, here not, why?
I can mention that I measured execution time of line
Seq<Point>[] regions= img.ExtractMSER(mask, ref param, storage);
and it's around 40ms (similar to C implementation) so something is calculated inside method..;)
Thanks in advance..
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hello
i have in my application 2 windows, mainwindow and window2, in window2 there is a bool variable and its false per default, after clicking a button in windows 2 it becomes true and another function in the mainwindow start and should change a buttoncontent in the mainwindow if the variable of windows is true..
the problem is the mainwindow class doesnt get the changing of the variable of window2 and still thinks its false and also the content isnt changing
here is the code of the mainwindow:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
public Window2 window2instance2 { get; set; }
public void ChangeButton1Content()
{
if (window2instance2.key)
{
Button1.Content = "I Changed";
}
}
private void Openwindows2_Click(object sender, RoutedEventArgs e)
{
Window2 window2instance = new Window2();
window2instance.MainWindowInstance = this;
window2instance.Show();
}
}
and this is the codebehind of window2:
public partial class Window2 : Window
{
public Window2()
{
InitializeComponent();
}
public bool key = false;
public MainWindow MainWindowInstance { get; set; }
public void window2button_Click(object sender, RoutedEventArgs e)
{
MainWindow mainwindow = new MainWindow();
mainwindow.window2instance2 = this;
key = true;
MainWindowInstance.ChangeButton1Content();
this.Close();
}
}
this was my last try and compiler is telling me at " if (window2instance2.key)" that Object reference not set to an instance of an object.
any tipps how can i resolve that?
thanks and cheers
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Well, in the MainWindow class, you define a property for Window2 that you don't assign to. In the code for Openwindows2_Click, you create a local variable version of Window2, and instantiate that. So, you can't get to Window2 outside of this method because it's not in scope. You do a similar thing in Window2 attempting to reference MainWindow.
So, the first fix is to stop using the method level variable, and use the property. The second thing I'd look at is using a delegate, rather than relying on the second form directly calling a method on the first form. To do this, create a delegate in Window2 which your MainWindow class subscribes to, and then call this delegate from Window2, which will notify MainWindow that there's something to do. If this seems familiar to you, it's because this is how events work in .NET.
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Thanks for the replay pete
yes i know how delegates and stuff work in wpf but actually i m a little bit confused
can u please show me with an example code how it will work? that will be easily for me to understand
thanks very much
jack
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This[^] might help you get a better understanding.
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MainWindow mainwindow = new MainWindow(); is creating a new instance of MainWindow. It is not the MainWindow that created Window2.
try:
public partial class Window2 : Window
{
public MainWindow mainWindow;
public bool key = false;
public Window2(MainWindow mainWindow )
{
InitializeComponent();
this.mainWindow = mainWindow;
}
public void window2button_Click(object sender, RoutedEventArgs e)
{
mainWindow.ChangeButton1Content();
this.Close();
}
public void Dispose()
{
mainWindow = null;
}
}
[Edit] Sorry there is one other thing
private void Openwindows2_Click(object sender, RoutedEventArgs e)
{
if (this.window2instance2 == null) this.window2instance2 = new Window2(this);
this.window2instance.Show();
}
"You get that on the big jobs."
modified on Monday, March 14, 2011 6:34 PM
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