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You can use the Screen class. See Screen.AllScreens, which is a static property that returns a Screen[] array.
Microsoft MVP, Visual C#
My Articles
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Thanks for the great hint. I appreciate it.
Regards,
Eric C. Tomlinson
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Hi,
I got a question like this:
Q : You create an assembly by using Visual Studio.Net. The assembly is responsible for writing and reading order entry information to and from an XML data file. The assembly also writes and reads values from the Windows registry while it is being comsumed.
The assembly will be distributed to client comoputers by using your company intranet. All client computers are configured to implement the default .NET security policy.
You need to implement security in the assembly. What should you do?
a. implement declarative security and execute the permission demand to allow access to the file system and windows registry.
b. implement declarative security and execute the minimum permission request to allow access to the file system and windows registry.
c. implement imperative security and execute the permission demand to allow access to the file system and windows registry.
d. implement imperative security and execute the minimum permission request to allow access to the file system and windows registry.
Which one is correct? and Why?
Thanks a lot!!
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alanshen209 wrote:
Which one is correct
b
alanshen209 wrote:
Why?
Declarative has bettter performance than imperative and it didn't want any custom security so we use this one. I think we have to use minimu permission cause it has to be used through intranet, so it need to use tighter security.
Mazy
"I think that only daring speculation can lead us further and not accumulation of facts." - Albert Einstein
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Hello there
My friends and I are going to make an PocketPC application with c#. But at the moment we do not know if we will need an device for testing pusposes.
We figured out that there is an emulator "shipped" with the sdk but is this emulator enough for testing pusposes?
Our application will have an server / client architecture were the pocket pc is the client and receives / send information via LAN.
At the moment this is a new expierence for us because we have never made an working c# / pocketpc application. we are used to java programming from school therefor the change to c# wasn't that hard , but we don't know the details from c# about pocketpc application development.
i hope i have hit the right forum for my question.
thanks in advance
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If you installed VS.NET 2003 with the default options, you already have the Smart Device Extensions and an Emulator. You can also get the emulator from the Windows Mobile for PocketPC 2003 SDK (there's ones for PocketPC 2002 as well, though that NetCF is beta and will never be released).
The emulator is just that - it emulates the hardware and has an actual PocketPC image installed on top of it. So long as the OEM didn't rebuild it with missing critical system packages, you should be fine. Note, then, that it's not really the OS that's being emulated, it's the hardware with the OS installed.
Microsoft MVP, Visual C#
My Articles
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i just recogniced that i have only visual studio.net , at the moment i am using the school licensed version... i'll get my professional 2003 in the next weeks.
But if you say it's all included with vs.net 2003 than our problems are solved and we are able to save a lot of money 
thanks for your fast answer.
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Save money? It's all free (well, except VS.NET 2003 unless your school can get it for you for free).
The PocketPC 2002 SDK and emulators can be downloaded for free, though you can also order them on CD for the price of shipping and handler. If you can manage to find the NetCF 1.0 beta (which worked within VS.NET 2002), you can use that to target the emulators for PocketPC 2002 as well.
Microsoft MVP, Visual C#
My Articles
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yes we are safing the money for an pocketpc , but the vs.net2003 we'll need to buy because we are going to sell the application. this project is some sort of learning for our future. we are doing this for fun while we make our military / socialwork service and later when we are on the university.
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Hi,
I am trying to develop a custom metadata editor for ArcCatalog(ArcGIS), using VB.NET. I am using a COM component into my application. i am using esriObjecLibrary 1.0 into my reference, and its a .dll project, using VisualStudio.NET 2003. this metadata editor will be a pluging into ArcCatalog.
after writing the code, when i compile the project it says "Unable to emit assembly: Referenced assembly 'Interop.StdType' does not have a strong name"..
I went to the DOS prompt and gave a strong name to the assembly and added the assembly file into my AssemblyInfo.vb file, but still its not working.
if any of you have worked on this and know much about it, i will appreciate ur help...if u have worked on similar problem using C#.NET that will be of much help...
Thanks
software Used:
Visual Studio.NET 2003
ArcGIS 8.2
VB.NET
Platform: win2k
abhishek
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Create a key pair using sn.exe -k KeyFile.snk. When you generate an interop assembly, use the /keyfile:<filepath> switch to both tlbimp.exe and aximp.exe (if importing an ActiveX control to derive from AxHost as well). If you're doing this from within VS.NET, go to the project configuration and in there is a place you can either entire a file path (relative to the project root) or a key container name. I typically install my key into my machine store using sn.exe -i KeyFile.snk MyContainerName (obvious use a container name you want).
I would delete the interop assemblies you've already created and regenerate them as I've mentioned here. Also be sure you use a key pair (possibly the same one - it helps identify your assemblies, though it's not verifiable like X.509 certificates). A strong name requires that the assembly be signed, which you seem to already know. A strongly named assembly can only use strongly named assemblies.
Microsoft MVP, Visual C#
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A quick question about the oleDbDataAdapter. Is it a good idea to use these in threads to update a dataset? I notice that if I am running concurrent threads where each uses an adapter to fill a dataset, the first thread will work, and the second thread (different adapter and dataset, but same connection) will run, but nothing will be put into my dataset. Obviously the second thread cannot fill its dataset because the connection is open from the first thread. I understand why the adapter isn't filling my dataset, but I'm sort of shocked it would just skip the fill command without giving any indication that it did so. What is the int that the Fill function returns anyway? Can I use that number to determine if the function actually did its job? And if so, what would be the best way to go about using adapters in threads...right now I'm locking them down until the connection is free...is there a better way? Just curious, thanks a bunch! 
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When using the System.Data.OleDb classes, your options are limited because of the abstraction that OLE DB provides (basically the whole purpose of its existence). With the System.Data.SqlClient classes this really isn't a problem.
You might check if the OLE DB provider for whatever you're connecting to supports connection pooling or limitations that might help in this situation. The properties that you pass to your connection string are used by the OLE DB provider for your data source.
Other than that, locking against a shared resource (such as a static property of some class) or using a delegation approach to create and execute commands and / or adapters (and synchronizing them internally) are about your only options. It's the OLE DB provider for your data source here that is the problem.
Microsoft MVP, Visual C#
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I've been writing a desktop sharing engine for .NET (pcanywhere sort of deal) . . . and I rely on the region class heavily for accumulating change rectangles (which I pull from the region class using the GetRegionScans method). I recently ran into the memory leak bug located in the GDI+ GetRegionScans call (see http://www.bobpowell.net/getregionscansbug.htm [^]for more details). Has anybody found a reasonable alternative to this bug? If not, any ideas or documentation on region minimal spanning rectangle algorithms?
Thanks!
-Guy
Senior Research Scientist
http://www.perspectivelabs.com
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There must be a way?
I've written many "NT Service" programs with VB6 and most have some sort of user interface. They all have an icon in the tray to indicate 'I'm running'.
Now comes C#. I've written the service and installed it, but I'm having one hard time trying to figure out how to have some UI involved. I've triggered threads in the onStart() that toggle between a non-visible form which holds a notifyicon and a UI. Clicking on the icon shows a form, closing the form reloads the icon in the tray, perfect. However, after logging off then logging back on the icon moved to bit heaven, I'm assuming because there was nothing left to hold it and I don't know how to reload the form from within its called method.
In VB6, its as simple as using a timer to keep attempting to put the icon in the tray. If there's an error nobodys logged in, no place to put the icon, so try again in a few seconds. When there's no error, someone must have logged in.
I don't know how to see if a user has logged on to re-start the method I don't know how to write!
There's got to be a way to simply have a "service process", owned and operated by the 'system' display its own icon from its own process when it knows its running and have it be there after a user logs back on. I stress owned by the "system" because due permissions available on the target machine, the polling of service manager with normal user rights can not be done. These boxes are really locked down, so the administrator has to install the program and the system has to run it.
Can anyone please help?
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I have two separate combo boxes and I would like to create one function to populate them.
I would like to be able to pass a combobox control and use it.
I.E.
void LoadDD(<no sure=""> <ddname>)
{
string[] dirs = Directory.GetDirectories("\\Family");
foreach (string dir in dirs)
{
<ddname>.Items.Add(new ListItem(GetName(dir), dir));
}
}
Any ideas??
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You almost had it. If you want to tie the method to a particular control:
void LoadData(ComboBox box)
{
string[] dirs = Directory.GetDirectories("\\Family");
foreach(string dir in dirs)
{
box.Items.Add(new ListItem(GetName(dir), dir));
}
}
- Nick Parker
My Blog | My Articles
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I have an ArrayList. At some point I wish to copy all of it's items to a new ArrayList. I could probably loop through all objects in the ArrayList but isn't there a faster way (it seems to be a bit stupid method) ?
Just to explane why I need this: I'm translating an old Visual C++ MFC program into C# (with blessings of the original author). I ran into an object CArray that is an usual array but is capable of growing and shrinking dynamically. Anyway, at some point the thing copies itself into another CArray. There's no equivalent for that in C# as far as I know. Code:
oldArr.Copy(newArr);
oldArr.RemoveAll;
Regards, Desmond
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ArrayList oldArr = new ArrayList();
oldArr.AddRange( new string[] {"hello", "world!"} );
ArrayList newArr = new ArrayList(oldArr);
Console.WriteLine(newArr[0].ToString());
Additionally, you can use the .CopyTo method, using an array as a temporary buffer, or as a the destination array itself:
ArrayList list = new ArrayList();
list.AddRange( new string[] {"hello", "world"} );
string[] tempArr = new string[2];
list.CopyTo(tempArr);
ArrayList list2 = new ArrayList(tempArr);
MessageBox.Show(list2[0].ToString());
---------------------------
He who knows that enough is enough will always have enough.
-Lao Tsu
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Doesn't this make a swallow copy instead of a deep copy ?
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Yes, so long as what the ArrayList contains are reference types. If you want to perform a deep copy, you could do something like this:
private ArrayList Copy(ArrayList list)
{
if (list == null) throw new ArgumentNullException("list");
ArrayList copy = (ArrayList)list.Clone();
for (int i=0; i<copy.Count; i++)
if (copy[i] is ICloneable) copy[i] = ((ICloneable)copy[i]).Clone();
return copy;
}So long as the objects that the list contains are cloneable, you'll clones depending on the internal implement (perhaps deep or only partly deep).
Microsoft MVP, Visual C#
My Articles
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Or just call ArrayList.Clone.
Microsoft MVP, Visual C#
My Articles
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I am trying to draw RTF text in my custom UserControl without actually having a RichTextBox window. I have seen a couple articles on the web about creating a windowless RichTextBox by supplying it with a custom ITextHost interface (see http://www.codeguru.com/Cpp/controls/richedit/windowless/article.php/c5367).
The problem is, these examples are for c++ and I am wondering how one could go about doing this from C#. Is there a way to somehow import the ITextHost interface from the control? Does anybody have any clue to point me in the right direction? (and no, I am not above using unmanaged code to get this to work).
Or is there a better way to accomplish this?
Thanks in advance!
Michael
Developer, Author, Chef
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.NET is a natural progression from COM, and can easily interop with COM. Read Interoperating with Unmanaged Code[^] in the .NET Framework SDK for basic information on these concepts.
Also, be sure to read Windowless Rich Edit Controls[^] in the Platform SDK for details information, not just examples.
First, you should consider encapsulating both the CreateTextServices API as well as the implementation of ITextHost in a class to make it easy to use. You then need to declare the ITextHost and, optionally (though recommended), ITextServices interfaces in C#. An example of (part, since it's so long) of ITextHost host looks like this (methods must be in order since this interface inherits from IUnknown and methods must be in the proper VTBL order):
[Guid("c5bdd8d0-d26e-11ce-a89d-00aa006cadc5")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface ITextHost
{
IntPtr TxGetDC();
IntPtr TxReleaseDC(IntPtr hdc);
bool TxShowScrollBar(IntPtr fnBar, bool fShow);
}Be sure you know the conversion from unmanaged to managed data types. For example, many of the methods use INT, which is not necessarily 32 bits. It is system dependent, just like IntPtr. You can also use a Int64 (long) and use MarshalAs(UnmanagedType.SysInt) which would make it easier and should work well for many, many years (since 64-bit processors are just starting to hit main-stream on the x86 platform supported by current CLI implementations).
The CreateTextServices factory function would look like this:
[DllImport("riched20.dll")]
private static extern int CreateTextServices(
[MarshalAs(UnmanagedType.IUnknown)] object punkOuter,
ITextHost pITextHost,
[MarshalAs(UnmanagedType.IUnknown), Out] out object ppUnk);You could also use IntPtr instead of object and then use appropriate methods from the System.Runtime.InteropServices.Marshal class to get the information you need. Note that you do not need to implement IUnknown on your object. The CLR does this for you. Note that the out object is a pointer to a pointer that returns either a ITextService or ITextDocument implementation. If you re-declare these in managed code, you can simply cast the output object to these interfaces (or use the as operator). If the cast return null (or throws an exception), then then interface it not supported. The CLR performs the QueryInterface for you automatically.
When you start looking at all the structs, consts, and other interfaces you would need to implement for full support, I'm sure you'll see why there isn't a .NET implementation! It's much easier in C++ where you can include the headers that contain all these definitions for you and don't have to worry about marshaling (all that would be handled by the COM runtime).
If you decide to venture this way, be sure to have a good working knowledge of COM interoperability in .NET.
You might consider using a mixed-mode MC++ (Managed C++ assembly) that can include the necessary headers and aggregate the methods you need on a __gc class (since a managed class can't implement an unmanaged interface like ITextHost. You could easily use the resulting assembly from any other .NET language like C#. There's still be a lot fo to, but this will probably be a much easier approach.
Microsoft MVP, Visual C#
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