Search Results

Search found 14111 results on 565 pages for 'virtual machines'.

Page 20/565 | < Previous Page | 16 17 18 19 20 21 22 23 24 25 26 27  | Next Page >

  • Virtual channel tutorial for terminal services.

    - by Scott Chamberlain
    I am writing a program that will need to communicate to a server through a TS connection. Virtual Channels seems to be exactly what I need but Microsoft's documentation leaves very much to be desired. Does anyone know of good tutorials or just some examples I could use to help me. Preferred language is C# but C++ examples are fine too.

    Read the article

  • Making(programming) virtual drives on windows XP

    - by Manux
    Ahoy, I'd like to mount a "virtual drive" myself on Windows XP, I guess using the windows API. What I thought about would be like a server interface, meaning explorer.exe would send "queries", like, list directory, or get file through a pipe or whatever... I know some programs do it, maybe not the way I think it is done, but what the heck, if you know anything, enlighten me please!

    Read the article

  • Writing a Virtual Printer in .NET

    - by David Osborn
    I'm looking to create a virtual printer that passes data to my .NET application. I want to then create an installer that installs both the printer and the .NET application. It would we really nice to be able to write it all in C#, but I have a feeling that this will require a printer driver to be written is unmanaged code. Does anyone know of a fairly clean tutorial or example of how to do this?

    Read the article

  • Preference values - static without tables using a model with virtual attributes

    - by Mike
    Im trying to eliminate two tables from my database. The tables are message_sort_options and per_page_options. These tables basically just have 5 records which are options a user can set as their preference in a preferences table. The preferences table has columns like sort_preferences and per_page_preference which both point to a record in the other two tables containing the options. How can i set up the models with virtual attributes and fixed values for the options - eliminating table lookups every time the preferences are looked up?

    Read the article

  • Virtual Cam - Cam Split .NET

    - by Fish
    I'm looking for a virtual webcam driver to use in a .NET project, this project will be GPL, and have no idea how many installations there will be The idea is that the application is using the webcam without locking the device. Found a couple of programs that do the job, but either in application and/or too expensive: * http://www.softservice.org/products_camsplitter.html (9.99$/installation) * splitcamera.com (program, no SDK available) All idea's are welcome

    Read the article

  • Booting from virtual machine VMWAre

    - by vikp
    Hi, I have a VMWare virtual machine (windows xp). I have just started it up through the VMWare player and it's extremely slow on my laptop (expected). Is it possible to boot from that image like in mac bootcamp so that it's not virtualised and soo slow? Thank you

    Read the article

  • Implementing a virtual file system in .NET

    - by Charlie Somerville
    A while back a found a great-looking framework that allowed .net developers to implement a virtual file system. I thought I had bookmarked it, but it seems I haven't. Does anyone know any frameworks for doing this? EDIT: Here's a hint... It had a catchy, short name and it's own domain. Sorry, that's all I can remember :p

    Read the article

  • Why methods in C# are not automatically virtual?

    - by Alon
    It would be much more less work to define which methods are NOT overideable instead of which are overideable because (at least for me), when you're designing a class, you don't care if its heirs will override your methods or not... So, why methods in C# are not automatically virtual? What is the common sense in this?

    Read the article

  • Template class + virtual function = must implement?

    - by sold
    This code: template <typename T> struct A { T t; void DoSomething() { t.SomeFunction(); } }; struct B { }; A<B> a; is easily compiled without any complaints, as long as I never call a.DoSomething(). However, if I define DoSomething as a virtual function, I will get a compile error saying that B doesn't declare SomeFunction. I can somewhat see why it happens (DoSomething should now have an entry in the vtable), but I can't help feeling that it's not really obligated. Plus it sucks. Is there any way to overcome this? EDIT 2: Okay. I hope this time it makes sence: Let's say I am doing intrusive ref count, so all entities must inherit from base class Object. How can I suuport primitive types too? I can define: template <typename T> class Primitive : public Object { T value; public: Primitive(const T &value=T()); operator T() const; Primitive<T> &operator =(const T &value); Primitive<T> &operator +=(const T &value); Primitive<T> &operator %=(const T &value); // And so on... }; so I can use Primitive<int>, Primitive<char>... But how about Primitive<float>? It seems like a problem, because floats don't have a %= operator. But actually, it isn't, since I'll never call operator %= on Primitive<float>. That's one of the deliberate features of templates. If, for some reason, I would define operator %= as virtual. Or, if i'll pre-export Primitive<float> from a dll to avoid link errors, the compiler will complain even if I never call operator %= on a Primitive<float>. If it would just have fill in a dummy value for operator %= in Primitive<float>'s vtable (that raises an exception?), everything would have been fine.

    Read the article

  • Virtual function - including some html

    - by Ockonal
    Hello, I have a php-file which includes another html-file: <? virtual("../top.html");?> The problem is that any code before this include compiles and runs well, after - nothing. There aren't any errors etc. After commenting this line, everything works. Code was written under local computer with ArchLinux + LAMP. Now I have ubuntu 10.04 with the same configuration. What could it be?

    Read the article

  • How to install Ubuntu over http in virtual manager?

    - by Bond
    Hi, I am having a situation where I can not use a CD or PxE boot or wubi to install.I need to necessarily do an http install of Ubuntu.I am basically trying to create a guest OS in a virtualization setup on Xen on a non VT hardware. On a non VT hardware the virt-manager does not allow to install from local ISO or PXE even the only option is via a URL on http:// Here is what I did: 1) Download ubuntu 10.04 32 bit ISO 2) Kept it in /var/www (apache2 is running) 3) renamed it to ubuntu.iso and when I reached a stage where installation begins I gave path hxxp://localhost/ubuntu.iso but I got an error any installable distribution not found. 4) After this I did mkdir /var/www/sk mount -t iso9660 /var/www/ubuntu.iso /var/www/sk -o loop and this time during the installation I gave path http://localhost/sk I was able to see the contents in browser http://localhost/sk which you will see in a normal CD. But beginning installation I got same error ValueError: Could not find an installable distribution at 'http://localhost/sk So I want to just confirm if http install is done only this way or some other way because the installation is not proceeding.

    Read the article

  • Communication between state machines with hidden transitions

    - by slartibartfast
    The question emerged for me in embedded programming but I think it can be applied to quite a number of general networking situations e.g. when a communication partner fails. Assume we have an application logic (a program) running on a computer and a gadget connected to that computer via e.g. a serial interface like RS232. The gadget has a red/green/blue LED and a button which disables the LED. The LEDs color can be driven by software commands over the serial interface and the state (red/green/blue/off) is read back and causes a reaction in the application logic. Asynchronous behaviour of the application logic with regard to the LED color down to a certain delay (depending on the execution cycle of the application) is tolerated. What we essentially have is a resource (the LED) which can not be reserved and handled atomically by software because the (organic) user can at any time press the button to interfere/break the software attempt to switch the LED color. Stripping this example from its physical outfit I dare to say that we have two communicating state machines A (application logic) and G (gadget) where G executes state changes unbeknownst to A (and also the other way round, but this is not significant in our example) and only A can be modified at a reasonable price. A needs to see the reaction and state of G in one piece of information which may be (slightly) outdated but not inconsistent with respect to the short time window when this information was generated on the side of G. What I am looking for is a concise method to handle such a situation in embedded software (i.e. no layer/framework like CORBA etc. available). A programming technique which is able to map the complete behaviour of both participants on classical interfaces of a classical programming language (C in this case). To complicate matters (or rather, to generalize), a simple high frequency communication cycle of A to G and back (IOW: A is rapidly polling G) is out of focus because of technical restrictions (delay of serial com, A not always active, etc.). What I currently see as a general solution is: the application logic A as one thread of execution an adapter object (proxy) PG (presenting G inside the computer), together with the serial driver as another thread a communication object between the two (A and PG) which is transactionally safe to exchange The two execution contexts (threads) on the computer may be multi-core or just interrupt driven or tasks in an RTOS. The com object contains the following data: suspected state (written by A): effectively a member of the power set of states in G (in our case: red, green, blue, off, red_or_green, red_or_blue, red_or_off...etc.) command data (written by A): test_if_off, switch_to_red, switch_to_green, switch_to_blue operation status (written by PG): operation_pending, success, wrong_state, link_broken new state (written by PG): red, green, blue, off The idea of the com object is that A writes whichever (set of) state it thinks G is in, together with a command. (Example: suspected state="red_or_green", command: "switch_to_blue") Notice that the commands issued by A will not work if the user has switched off the LED and A needs to know this. PG will pick up such a com object and try to send the command to G, receive its answer (or a timeout) and set the operation status and new state accordingly. A will take back the oject once it is no longer at operation_pending and can react to the outcome. The com object could be separated of course (into two objects, one for each direction) but I think it is convenient in nearly all instances to have the command close to the result. I would like to have major flaws pointed out or hear an entirely different view on such a situation.

    Read the article

  • What are the advantages and disadvantages of the various virtual machine image formats?

    - by Matt
    Xen and Virtualbox etc both support a range of different virtual machine image formats. These are: vmdk, vdi, qcow & qcow2, hdd & vhd. Without any bias toward a particular product, I'm wanting to know what are the advantages and disadvantages of the various formats both from a features perspective, robustness and speed? One piece of info I discovered in a forum post was this: "The major difference is that VDI uses relatively large blocks (1MB) when growing an image, and thus has less overhead for block pointers etc. but isn't ultimately space efficient in the sense that if a single byte is non-zero in such a 1MB block the entire space is used. VMDK in contrast uses 64K blocks, and thus has more management overhead and generally a bit less disk space consumption What offsets this is that VDI is more efficient when it comes to snapshots." You might be thinking, I want to know this because I want to know which format to choose? Not exactly, I'm developing some software which utilises these formats and want to support one or more of them. Simplicity, large disks and ease of development are my main drivers.

    Read the article

  • How does a virtual machine work?

    - by Martin
    I've been looking into how programming languages work, and some of them have a so-called virtual machines. I understand that this is some form of emulation of the programming language within another programming language, and that it works like how a compiled language would be executed, with a stack. Did I get that right? With the proviso that I did, what bamboozles me is that many non-compiled languages allow variables with "liberal" type systems. In Python for example, I can write this: x = "Hello world!" x = 2**1000 Strings and big integers are completely unrelated and occupy different amounts of space in memory, so how can this code even be represented in a stack-based environment? What exactly happens here? Is x pointed to a new place on the stack and the old string data left unreferenced? Do these languages not use a stack? If not, how do they represent variables internally?

    Read the article

  • How does object of sub-class record information about its super-class the in a Virtual Inheritance

    - by Summer_More_More_Tea
    Hi there: I encounter this problem when tackling with virtual inheritance. I remember that in a non-virtual inheritance hierarchy, object of sub-class hold an object of its direct super-class. What about virtual inheritance? In this situation, does object of sub-class hold an object of its super-class directly or just hold a pointer pointing to an object of its super-class? By the way, why the output of the following code is: sizeof(A): 8 sizeof(B): 20 sizeof(C): 32 Code: #include <iostream> using namespace std; class A{ char k[ 3 ]; public: virtual void a(){}; }; class B : public virtual A{ char j[ 3 ]; public: virtual void b(){}; }; class C : public virtual B{ char i[ 3 ]; public: virtual void c(){}; }; int main( int argc, char *argv[] ){ cout << "sizeof(A): " << sizeof( A ) << endl; cout << "sizeof(B): " << sizeof( B ) << endl; cout << "sizeof(C): " << sizeof( C ) << endl; return 0; } Thanks in advance. Kind regards.

    Read the article

  • Non Blocking Keyboard on WinCE accessing the virtual keyboard

    - by Jan H.
    Hello Guys, I am desperately looking for a solution that enables me to read keyboard events in a non blocking way. These Keyboard events are generated by a VIRTUAL KEYBOARD that comes with the WinCE device. I have a console application running in C++, where the user is asked to navigate via 'ESC', 'U' and other characters through the menu. I first tried to use fread and stdin and realised that it is blocking call and waits for a carriage return. Then I tried to hook up to the windows message WM_KEYUP, but I never recieve this windows message. Furthermore I tried to use QtGUI together with the event QKeyEvent, but I never recieve any event. I wonder if it is in general possible to recieve non-blocking keyboard events on a WinCE device. I would be glad if you have any suggestions! Cheers, Jan

    Read the article

  • vir-install virtual machine hang on Probbing EDD

    - by user2256235
    I'm using vir-stall virtual machine, and my command is virt-install --name=gust --vcpus=4 --ram=8192 --network bridge:br0 --cdrom=/opt/rhel-server-6.2-x86_64-dvd.iso --disk path=/opt/as1/as1.img,size=50 --accelerate After running the command, it hangs on probing EDD, - Press the <ENTER> key to begin the installation process. +----------------------------------------------------------+ | Welcome to Red Hat Enterprise Linux 6.2! | |----------------------------------------------------------| | Install or upgrade an existing system | | Install system with basic video driver | | Rescue installed system | | Boot from local drive | | Memory test | | | | | | | | | | | | | | | +----------------------------------------------------------+ Press [Tab] to edit options Automatic boot in 57 seconds... Loading vmlinuz...... Loading initrd.img...............................ready. Probing EDD (edd=off to disable)... ok ÿ Previously, I wait a long time, it seems no marching. After I press ctrl + ] and stop it. I find it was running using virsh list, but I cannot console it using virsh concole gust. Any problem and how should I do. Many Thanks

    Read the article

< Previous Page | 16 17 18 19 20 21 22 23 24 25 26 27  | Next Page >