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Using an IList implementation like the ArrayList isn't always the answer. An array is fixed. Items can't be added or removed. This is often necessary in cases like returning the fonts installed on the system, or returning the printers installed on the system. In these cases, though, the property is read only (only implements the get accessor). If it was a list, developers can easily modify it (without even instantiating a new one) which might corrupt the behavior of the object.
Microsoft MVP, Visual C#
My Articles
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Do it just like you wrote :
<br />
public string[] Property{ <br />
get{return sProperty;}<br />
set{sProperty = value;}<br />
}<br />
and access it like so
<br />
Object o = new Object();<br />
o.Property = new String[] {"foo", "bar"};<br />
Console.WriteLine("{0} {1}", o.Property[0], o.Property[1]);<br />
another trick is to use default properties[^]
write you property like this
<br />
public string this[int index] {<br />
get { return sProperty[index]; }<br />
set { sProperty[index] = value; }<br />
}<br />
and access like this
<br />
Object o = new Object();<br />
o.Property = new String[2];<br />
o[0] = "foo";<br />
o[1] = "bar";<br />
Console.WriteLine("{0} {1}", o[0], o[1]);
HTH
The smaller the mind the greater the conceit.
Aesop
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The cop (FxCop) says do not return array as properties...
Jonathan de Halleux.
www.dotnetwiki.org
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Funny, the Cop didnt seem to have a problem with the little snippet I compiled 
But if they're the rules fair enough.
Cheers for the info.
The smaller the mind the greater the conceit.
Aesop
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Thanx - this is exactly what I needed.
I only need it because I'm converting some VB code and it does it this way.
What is the FxCop mentioned?
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i have an application which has a 2 MB .exe. but when it runs it uses the 21 MB of the primary memory. Before initialization of the forms it already uses 13-14 MB (in release mode).after main form loaded it bocomes 21 MB. Because i use dynamic binding when using class i don not think that it is because all project loding at start up. i think it is because of .net framework loads itself before. have any idea how can we decrease this use amount?
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Of course the .NET Framework is loaded before your app! What do you think managed your managed code? This is a runtime, just like Java required a JRE, VB requires the VB Virtual Machine (VM), etc. The CLR will take a few megs but the assemblies that are loaded into your application will take as much space as required to execute the code. The CLR JIT's only what is linked as it executes code, so it all isn't JIT'd at once (JIT-on-demand). In fact, an unmanaged AppDomain is created that loads the CLR and creates a managed AppDomain, then your executable is loaded into that AppDomain along with any dependent assemblies. It has to be loaded first or your application doesn't run.
How can you reduce memory? For once, implement a clean design. Close handles, dispose disposable objects, dispose modal forms (when you call ShowDialog) when you're finished with them. Use structs (allocated on the stack instead of the heap) when you need information on a short-lived duration (like a System.Windows.Forms.Message is used only for the current message, so there's no need to allocate it on the heap). All the things that computers science (or experience) should teach you.
Microsoft MVP, Visual C#
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Is it possible that in future releases of Windows, the CLR would be started as system starts and manage all dotNET applications? It seems that currently every single dotNET app loads a copy of the CLR into memory even when they are executed concurrently
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The CLR would be started with various system components in "Longhorn", but that won't change your program's behavior. The CLR - the runtime for managed code - is loaded for each app. This - like all runtimes - helps protect the other programs using the runtime and the operating system as well from each other. If your program was to crash and tear down the CLR, I definitely don't want it taking down mine or crashing the OS. This can even be done without crashing - a call to Environment.Exit unloads the CLR and quits the application immediately, regardless of any running threads.
Microsoft MVP, Visual C#
My Articles
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I need to go to another form in my project. I need that the main form will close when I press a button to go to the second form. I can't use Application.Exit because than the second form closes too.
please help!!!!
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Can you temporarily hide the main form?
What a piece of work is man, how noble in reason, how infinite in faculties, in form and moving how express and admirable . . . and yet to me, what is this quintessence of dust? -- Hamlet, Act II, Scene ii.
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Every form you create acts just like a class would so you could just do.
MySecondForm form = new MySecondForm();
form.Show();
this.Dispose();
The 'this' keyword refers to the object you're form is derived from including all of the custom objects
and functions you have put in. You could also just say 'Dispose();' instead of 'this.Dispose();' but
for keeping clarity it's better to use the this keyword.
You could also say 'this.Hide();' but then it keeps that form in memory which when you're dealing
with multiple forms this could eat up your memory pretty quickly. I just take my forms out of
memory when I don't need them.
------------------
I'm naked under my clothes...
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this.Dispose(); doesn't work for me. it still closes the whole application. the this.Hide works and altought I'm making a small program a slow computer is gonna run it so if you can recommend me of somthimg else that will allow me to save in memory usage please find me somthing that doesn't just hides the window but thanks anyway.
Modyfied: I just realized I don't need to close the main form and that the this.Dispose works for my other forms. anyway thanks alot you've been a great help for me. see ya later
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You can't dispose the main form because that's what the message pump (which Application.Run starts) waits for. If you dispose the main form, you effectively let the message pump know that it can quit and your entry point returns. When the entry point returns, the CLR unloads your application (if there are no running background threads).
See Charlie's response for a good solution (no need to repeat it).
Also, you might consider a wizard-like interface, even if it has no "Back" or "Previous" button. You load one Form which adds and removes instances of container classes (like the Panel) onto its surface. This is how property sheets and wizards (which actually use the same interfaces and functions) work in Windows Explorer and other applications that use the shell-provided property sheet implementation.
Microsoft MVP, Visual C#
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If you're using VS.NET, your application entry point probably looks like this:
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
This means that
1) this call will not return until Form1 has closed
2) the application will terminate immediately after Form1 is closed.
If you need to close Form1 have have the app keep plugging away, you can't rely on the VS.NET-generated code. Instead, you can write a class to handle showing the form(s) you need to show.
public class AppStarter{
public AppStarter(){
Form1 frm = new Form1();
frm.Show();
}
[STAThread]
public void Main(){
Application.Run(new AppStarter());
}
}
Now the application will run as long as the instance of AppStarter created in Main() is alive. You need to remember to call Application.Exit() when your last form closes or the app will never die, even if there's nothing on screen because the lifetime of the app is no longer directly related to the lifetime of the form.
Charlie
if(!curlies){ return; }
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Hey all,
I'm pretty new to .NET, and want to know how to use someone else's managed C++ code from my C# app. The C++ code is already compiled to DLLs, but doesn't appear to have been put in a namespace.
All I want is to create an object of the class, and call a few void methods
Any help is much appreciated, G
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Just reference it like you would if you were calling your c# code in a dll. Every .NET language compiles down to the same basic construct which is IL.
------------------
I'm naked under my clothes...
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Before I go and write my own converter - is there one available in .NET Framework? Is there a function to which I can give 0.003 inch and it converts it to milimeters (I don't need the code for this function - I need to know if in the .NET Framework there exists one already)?
Tomaz
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No. The System.Windows.Forms.SystemInformation encapsulates some of the GetDeviceCaps functionality, but not all - including things you'd need like LOGPIXELSX and LOGPIXELSY. It has some other useful things, though, if you want to check it out anyway.
Microsoft MVP, Visual C#
My Articles
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Hi, I was wondering if anyone had tried printing from a webservice without the use of forms. Im trying to create a webservice that when called from a remote browser, will print to the computers default printer. I have found many resources for printing but they all use forms. Any help/guidance is much apprieciated.
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Is what you're printing documents that are send to the web service, or are you printing data passed to the web service? In the former case, you must invoke the application associated with that object. In many cases, the major programs support a "/print" switch or "print" verb. You could do something like the following:
ProcessStartInfo info = new ProcessStartInfo();
info.FileName = "path to document";
info.UseShellExecute = true;
info.Verb = "print";
Process.Start(info); If you are printing data, you need a graphics handle in which to print. The .NET base class libraries allow you to instantiate a new PrintDocument and to attach handlers to its events like PrintPage, which pass a Graphics object in the PrintPageEventArgs. You can see the PrintDocument class documentation for an example. It is invoked from a Button on a form's Click event handler, but common sense would tell you that you don't need to invoke this from a control. Just instantiate the PrintDocument, attach your handlers, and do the painting on the PrintPageEventArgs.Graphics.
Note, it is likely that the username under which ASP.NET runs will require a Windows station, i.e. a Windows desktop session associated with it. Make sure that account under which ASP.NET runs ("ASPNET" by default) has the "Log in locally" privilege ("ASPNET" should by default).
Microsoft MVP, Visual C#
My Articles
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Heath,
Thanks for your reply. I am trying to print data that is passed into the webservice. I belive I have set up the handler correctly but its still not working. The code works in a regular C# project just fine but not in my webservice. When I browse to the webservice I just get an error "This page cannot be displayed HTTP 500 - Internal server error". It seems as if PrintPageEventArgs object that is passed into the print handler needs some setting up first, but i'm not sure how to do this. Here is my code if anyone cares to point and laugh. Again thanks for any help.
public class Service1 : System.Web.Services.WebService
{
public Service1()
{
//CODEGEN: This call is required by the ASP.NET Web Services Designer
InitializeComponent();
}
PrintDocument pd = new PrintDocument();
[WebMethod]
public string printIt()
{
pd.PrinterSettings.PrinterName = @"\\printers\printer / HP";
pd.PrintPage += new PrintPageEventHandler(this.printItHandler);
PrintPageEventArgs ea;
if (pd.PrinterSettings.IsValid)
{
pd.Print();
return "printing worked";
}
return "Printing failed";
}
private void printItHandler(Object sender ,
PrintPageEventArgs e)
{
String textToPrint = "Printing is fun!!";
Font printFont = new Font("Courier New", 12);
int leftMargin = e.MarginBounds.Left;
int topMargin = e.MarginBounds.Top;
e.Graphics.DrawString(textToPrint, printFont,
Brushes.Black, leftMargin, topMargin);
}
}
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HTTP status code 500 could be just about anything. That's like just saying, "There's an error". If this is an ASP.NET application, check the trace.axd "file" from your web application's root if logging is enabled from your web application's Web.config file. This should give more information.
I'm not even totally sure if this will work, although I'm fairly positive this will not work if the user doesn't have local login privileges since a Windows station (i.e., support for window and graphic handles) would have to be available (so far as docs read).
If you need more information about how to set up printing, then read the .NET Framework SDK documentation for the related classes, such as PrintDocument, PrinterSettings, etc. That's why it's there.
Microsoft MVP, Visual C#
My Articles
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Heath,
Thanks for the reply. I'll definatly give the trace.axd a look. As far as login privaledges go, Im testing on the same machine as I am developing on so that should'nt be an issue. Also, everything I have so far IS from the SDK documentation and has not helped. If I wanted to use forms with button event listeners I am sure that info would be of great use. Like I said, this code works fine in a standard C# project. Thanks again.
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