Search Results

Search found 33882 results on 1356 pages for 'command window'.

Page 269/1356 | < Previous Page | 265 266 267 268 269 270 271 272 273 274 275 276  | Next Page >

• Is DevCon.exe still the best way to restart/power cycle USB ports after resuming from hibernation in

  - by ProfessionalAmateur

  I have a USB broadband card on my Windows 7 laptop. It loathes resuming from hibernation properly. Back in the XP days I would issue a call devcon.exe from the command prompt and restart the selected ports (Saves you having to manually unplug and plug back in your USB devices). Ive been trying this is Windows 7, but the UAC keeps getting in the way. I'll start a command prompt. Issue the devcon command, but UAC asks me if I really want to do this, when I click yes it opens a different command prompt and launches the command. After the command completed this new prompt window closes faster than the speed of light and I cannot see the results. So Im thinking there has to be a better way to do this in the Vista/Win7 world...?

  Read the article

• Desktop application, dependency injection

  - by liori

  I am thinking of applying a real dependency injection library to my toy C#/GTK# desktop application. I chose NInject, but I think this is irrelevant to my question. There is a database object, a main window and several utility window classes. It's clear that I can inject the database into every window object, so here DI is useful. But does it make sense to inject utility window classes into other window classes? Example: I have classes such as: class MainWindow {…} class AddItemWindow {…} class AddAttachmentWindow {…} class BrowseItemsWindow {…} class QueryBuilderWindow {…} class QueryBrowserWindow {…} class PreferencesWindow {…} … Each of the utility classes can be opened from MainWindow. Some utility windows can also be opened from other utility windows. Generally, there might be a really complex graph of who can open whom. So each of those classes might need quite a lot of other window classes injected. I'm worried that such usage will go against the suggestion not to inject too many classes at once and become a code smell. Should I use some kind of a service locator object here?

  Read the article

• TCP video streaming: TCP throughput(rate) and RTT

  - by misteryes

  we know that a rough estimation of TCP rate is: WINDOW/RTT, where WINDOW is the min(CWIN, RWIN), CWIN is the congestion window size of the sender, while RWIN is the receiving window. nowadays, the encoding rate of videos may be 1000KB/s(8000kbit/s), if RTT is 500ms, it needs the window size to be 2000KB. But we know that usually the receiving window size is below 64KB, there is a big gap. so if RTT is too large, TCP streaming is not possible? Is my understanding right? thanks!

  Read the article

• WordPress - Open Link in New Windows Default

  - by ninjaboi21

  Hey SuperUsers, is it possible to make some sort of change or add a plugin that allows me to make every 'external' link open in a new window? Just an example: if my blog was called http//timmy.com/ and I wanted to link to http//tom.com/, it would open a new window instead of the same window, but I wanted to link from http//timmy.com/ to http//timmy.com/somewhere/ in the same window. So I want all external link from my website to another in a new window/tab, but I want every internal link, from my website to somewhere else on my website, to be in the same window/tab. Is this possible?

  Read the article

• bash terminal/console strange overlapping behavior

  - by UpKey

  I am using gnome-terminal in Ubuntu 11.10 and seem to get long lines overlapping in the terminal window. When I copy a long command line and paste it into the terminal, the text gets overlapped to the start of the line and often covers the user prompt. If I resize the terminal window, making it wider the overlapping gets undone and everything looks normal. In previous versions of Ubuntu, if a line was too long it would continue on the next line below. Another problem I have noticed that may be related, is when using the up arrow key to show previously typed commands, sometimes instead of the output command line being replaced by the previous command each time the key is pressed, the lines get partially merged. A portion of the old line remains, and the next command gets joined onto the end. This leftover part of a command is persistent and does not get replaced next time the key is pressed, although the insertion point or blinking cursor is at the end of the latest recalled command, and the leftover has no effect if I press enter. Is this problem a bug or some setting that needs fixing? Where do I look for the cause? keyboard? gnome-terminal? bash? Thank you for any help or suggestions offered

  Read the article

• sudoers - simple explanation requested

  - by Redsandro

  Everytime I want to be able to run something that requires me to be a sudoer too many times, I need to google for the formatting of /etc/sudoers to remind me again what exactly is the proper way to write it. Now I see different writing styles in my sudoers file, which is the consequence of different google results over the months. I've also noticed that the second example (below) seems to work in XFCE, but not in Cinnamon (Gnome 3). This could be totally unrelated, but nontheless I'd like to know once and for all, what is the correct grammar of the sudoer line, and what is the difference between the given examples? redsandro ALL=NOPASSWD:/path/to/command redsandro ALL=(ALL) NOPASSWD:/path/to/command redsandro ALL=(ALL:ALL) NOPASSWD:/path/to/command Also, what are all the ALL's for? One user, one command, yet I need to use the ALL keyword up to three times? Am I doing this wrong? Of course, omitting NOPASSWD: makes you enter your password before you are permitted to run the command, but one point of confusion is the usage of = and :, for the final command that is the subject of the line can be prepended by either =, :, , or ), confusing grammar for similar semantics.

  Read the article

• PyGTK/Quickly Add string to ListStore

  - by AllRadioisDead

  I'm trying to build an application that will prompt the user for a string, and then add that string to a Scrolling Listview object using quickly and PyGTK. I've been following this tutorial: http://developer.ubuntu.com/resources/app-developer-cookbook/multimedia/creating-a-simple-media-player/ When I hit the add button, the prompt comes up properly and I'm able to enter the string. The column appears correctly but the list ends up being blank. What am I doing wrong? import gettext from gettext import gettext as _ gettext.textdomain('spiderweb') from gi.repository import Gtk # pylint: disable=E0611 import logging logger = logging.getLogger('spiderweb') from spiderweb_lib import Window from spiderweb.AboutSpiderwebDialog import AboutSpiderwebDialog from spiderweb.PreferencesSpiderwebDialog import PreferencesSpiderwebDialog from quickly import prompts from quickly.widgets.dictionary_grid import DictionaryGrid import os # See spiderweb_lib.Window.py for more details about how this class works class SpiderwebWindow(Window): __gtype_name__ = "SpiderwebWindow" def finish_initializing(self, builder): # pylint: disable=E1002 """Set up the main window""" super(SpiderwebWindow, self).finish_initializing(builder) self.AboutDialog = AboutSpiderwebDialog self.PreferencesDialog = PreferencesSpiderwebDialog # Code for other initialization actions should be added here. self.supported_web_formats = [".net",".html", ".com"] def on_addbutton_clicked(self, widget, data=None): #let the user choose a path with the directory chooser response, string = prompts.string("Enter a string", "Please enter string:", "Sample Text") #make certain the user said ok before working if response == Gtk.ResponseType.OK: #make a list of the supported media files media_files = Gtk.ListStore(str) #add a dictionary to the list of media files media_files.append({"String":string}) #remove any children in scrolled window for c in self.ui.scrolledwindow1.get_children(): self.ui.scrolledwindow1.remove(c) #create the grid with list of dictionaries #only show the File column media_grid = DictionaryGrid(media_files, keys=["File"]) #show the grid, and add it to the scrolled window media_grid.show_all() self.ui.scrolledwindow1.add(media_grid)

  Read the article

• emacs starting maximised

  - by Seamus

  I want a keyboard shortcut to open emacs in a maximised window. I tried emacs --fullscreen, but that is full screen rather than maximised window... That is, the emacs window covers ubuntu menu bars. emacs -fw gets a full width window and emacs -fh gets a full height window, but if you put both options, it only reads the second one. At the moment, I just have another keyboard shortcut for maximising a window. Is there a way to get emacs to start maximised? Ubuntu 9.10, emacs 22, if that makes a difference.

  Read the article

• Vertically resize two windows at same time?

  - by Guy

  I love the new feature in Windows 7 where I can grab the title bar and "slam" a window against the right edge of the computer and it will size that window to the right half of the screen. I can then grab another window and do the same against the left side of the screen. Once I've done that I often find that one of those windows needs a bit more horizontal space and the other can do with less. So I grab the edge in the middle of each window and resize that window so I can most efficiently use my screen space. Problem is that I have to do this twice, once for each window. Is there a way to grab the inside vertical edge of both windows at the same time so that I can make one wider and the other smaller at the same time?

  Read the article

• Basic SDL2 Code which "Stop working" when calling SDL_Quit() [migrated]

  - by Rivten

  So I got into SDL2 with C++ quite recently and I did this very simple code : int main(int argc, char** argv) { SDL_Event *event; bool done = false; if(SDL_Init(SDL_INIT_VIDEO) != 0) { std::cerr << "Problèmes pour initialiser la SDL : " << SDL_GetError() << std::endl; return 1; } SDL_Window *window = 0; window = SDL_CreateWindow("Mopion", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, WIDTH, HEIGHT, SDL_WINDOW_SHOWN); if(window == 0) { done = true; } while(!done) { while(SDL_PollEvent(event)) { switch(event->type) { case SDL_QUIT: done = true; break; case SDL_KEYUP: if(event->key.keysym.sym == SDLK_q) { done = true; } break; default: break; } } } SDL_DestroyWindow(window); SDL_Quit(); return 0; } While that code executes at first quite well, when I hit the "Q" key, the window closes but I got a Windows Error Window saying that "My program stopped working." which is not very convenient. Using the debugger, I found that everything is fine until SDL_Quit() is called. Anyone has any idea why this is going on ? Thanks a lot !

  Read the article

• Cocoa nextEventMatchingMask not receiving NSMouseMoved event

  - by Jonny

  Hello, I created a local event loop and showed up a borderless window (derived from NSPanel), I found in the event loop there's no NSMouseMoved event received, although I can receive Mouse button down/up events. What should I do to get the NSMouseMoved events? I found making the float window as key window can receive the NSMouseMoved events, but I don't want to change key window. And it appears this is possible, because I found after clicking the test App Icon in System Dock Bar, I can receive the mousemoved events, and the key window/mainwindow are unchanged. Here's the my test code: (Create a Cocoa App project names FloatWindowTest, and put a button to link it with the onClick: IBAction). Thanks in advance! -Jonny #import "FloatWindowTestAppDelegate.h" @interface FloatWindow : NSPanel @end @interface FloatWindowContentView : NSView @end @implementation FloatWindowTestAppDelegate @synthesize window; - (void)delayedAction:(id)sender { // What does this function do? // 1. create a float window // 2. create a local event loop // 3. print out the events got from nextEventMatchingMask. // 4. send it to float window. // What is the problem? // In local event loop, althrough the event mask has set NSMouseMovedMask // there's no mouse moved messages received. // FloatWindow* floatWindow = [[FloatWindow alloc] init]; NSEvent* event = [NSApp currentEvent]; NSPoint screenOrigin = [[self window] convertBaseToScreen:[event locationInWindow]]; [floatWindow setFrameTopLeftPoint:screenOrigin]; [floatWindow orderFront:nil]; //Making the float window as Key window will work, however //change active window is not anticipated. //[floatWindow makeKeyAndOrderFront:nil]; BOOL done = NO; while (!done) { NSAutoreleasePool* pool = [NSAutoreleasePool new]; NSUInteger eventMask = NSLeftMouseDownMask| NSLeftMouseUpMask| NSMouseMovedMask| NSMouseEnteredMask| NSMouseExitedMask| NSLeftMouseDraggedMask; NSEvent* event = [NSApp nextEventMatchingMask:eventMask untilDate:[NSDate distantFuture] inMode:NSDefaultRunLoopMode dequeue:YES]; //why I cannot get NSMouseMoved event?? NSLog(@"new event %@", [event description]); [floatWindow sendEvent:event]; [pool drain]; } [floatWindow release]; return; } -(IBAction)onClick:(id)sender { //Tried to postpone the local event loop //after return from button's mouse tracking loop. //but not fixes this problem. [[NSRunLoop currentRunLoop] performSelector:@selector(delayedAction:) target:self argument:nil order:0 modes:[NSArray arrayWithObject:NSDefaultRunLoopMode]]; } @end @implementation FloatWindow - (id)init { NSRect contentRect = NSMakeRect(200,300,200,300); self = [super initWithContentRect:contentRect styleMask:NSTitledWindowMask backing:NSBackingStoreBuffered defer:YES]; if (self) { [self setLevel:NSFloatingWindowLevel]; NSRect frameRect = [self frameRectForContentRect:contentRect]; NSView* view = [[[FloatWindowContentView alloc] initWithFrame:frameRect] autorelease]; [self setContentView:view]; [self setAcceptsMouseMovedEvents:YES]; [self setIgnoresMouseEvents:NO]; } return self; } - (BOOL)becomesKeyOnlyIfNeeded { return YES; } - (void)becomeMainWindow { NSLog(@"becomeMainWindow"); [super becomeMainWindow]; } - (void)becomeKeyWindow { NSLog(@"becomeKeyWindow"); [super becomeKeyWindow]; } @end @implementation FloatWindowContentView - (BOOL)acceptsFirstMouse:(NSEvent *)theEvent { return YES; } - (BOOL)acceptsFirstResponder { return YES; } - (id)initWithFrame:(NSRect)frameRect { self = [super initWithFrame:frameRect]; if (self) { NSTrackingArea* area; area = [[NSTrackingArea alloc] initWithRect:frameRect options:NSTrackingActiveAlways| NSTrackingMouseMoved| NSTrackingMouseEnteredAndExited owner:self userInfo:nil]; [self addTrackingArea:area]; [area release]; } return self; } - (void)drawRect:(NSRect)rect { [[NSColor redColor] set]; NSRectFill([self bounds]); } - (BOOL)becomeFirstResponder { NSLog(@"becomeFirstResponder"); return [super becomeFirstResponder]; } @end

  Read the article

• Problem using easy_install on Windows 7, 64 bit. (cannot find python.exe)

  - by Rune

  Hi, I have just now installed Python 2.6 on my Windows 7 (64 bit) Lenovo t61p laptop. I have downloaded Sphinx and nose and apparently installed them correctly using python setup.py install (at least no errors were reported during the installation). Now I am trying to install pymongo using easy_install but I am not having much success. It seems that easy_install isn't working at all. I execute easy_install as administrator: C:\>easy_install Cannot find Python executable C:\Program Files\Python26\python.exe The path C:\Program Files\Python26\python.exe is correct. I have found this bug report on bugs.python.org which seems to be related, although its status is 'Resolved'. Do you have any ideas as to what may be wrong? Any pointers, hints or tips for diagnosing the problem further would be greatly appreciated. EDIT: This is the stacktrace I receive when trying to install pymongo: C:\Users\Rune Ibsen\Documents\Downloads\pymongo-1.4>python setup.py install running install running bdist_egg running egg_info writing pymongo.egg-info\PKG-INFO writing top-level names to pymongo.egg-info\top_level.txt writing dependency_links to pymongo.egg-info\dependency_links.txt reading manifest file 'pymongo.egg-info\SOURCES.txt' reading manifest template 'MANIFEST.in' writing manifest file 'pymongo.egg-info\SOURCES.txt' installing library code to build\bdist.win-amd64\egg running install_lib running build_py running build_ext building 'pymongo._cbson' extension Traceback (most recent call last): File "setup.py", line 166, in <module> "doc": doc}) File "C:\Program Files\Python26\lib\distutils\core.py", line 152, in setup dist.run_commands() File "C:\Program Files\Python26\lib\distutils\dist.py", line 975, in run_commands self.run_command(cmd) File "C:\Program Files\Python26\lib\distutils\dist.py", line 995, in run_command cmd_obj.run() File "C:\Program Files\Python26\lib\site-packages\setuptools-0.6c9-py2.6.egg\setuptools\command\install.py", line 76, in run File "C:\Program Files\Python26\lib\site-packages\setuptools-0.6c9-py2.6.egg\setuptools\command\install.py", line 96, in do_egg_install File "C:\Program Files\Python26\lib\distutils\cmd.py", line 333, in run_command self.distribution.run_command(command) File "C:\Program Files\Python26\lib\distutils\dist.py", line 995, in run_command cmd_obj.run() File "C:\Program Files\Python26\lib\site-packages\setuptools-0.6c9-py2.6.egg\setuptools\command\bdist_egg.py", line 174, in run File "C:\Program Files\Python26\lib\site-packages\setuptools-0.6c9-py2.6.egg\setuptools\command\bdist_egg.py", line 161, in call_command File "C:\Program Files\Python26\lib\distutils\cmd.py", line 333, in run_command self.distribution.run_command(command) File "C:\Program Files\Python26\lib\distutils\dist.py", line 995, in run_command cmd_obj.run() File "C:\Program Files\Python26\lib\site-packages\setuptools-0.6c9-py2.6.egg\setuptools\command\install_lib.py", line 20, in run File "C:\Program Files\Python26\lib\distutils\command\install_lib.py", line 113, in build self.run_command('build_ext') File "C:\Program Files\Python26\lib\distutils\cmd.py", line 333, in run_command self.distribution.run_command(command) File "C:\Program Files\Python26\lib\distutils\dist.py", line 995, in run_command cmd_obj.run() File "setup.py", line 107, in run build_ext.run(self) File "C:\Program Files\Python26\lib\distutils\command\build_ext.py", line 340, in run self.build_extensions() File "C:\Program Files\Python26\lib\distutils\command\build_ext.py", line 449, in build_extensions self.build_extension(ext) File "setup.py", line 117, in build_extension build_ext.build_extension(self, ext) File "C:\Program Files\Python26\lib\distutils\command\build_ext.py", line 499, in build_extension depends=ext.depends) File "C:\Program Files\Python26\lib\distutils\msvc9compiler.py", line 448, in compile self.initialize() File "C:\Program Files\Python26\lib\distutils\msvc9compiler.py", line 358, in initialize vc_env = query_vcvarsall(VERSION, plat_spec) File "C:\Program Files\Python26\lib\distutils\msvc9compiler.py", line 274, in query_vcvarsall raise ValueError(str(list(result.keys()))) ValueError: [u'path'] C:\Users\Rune Ibsen\Documents\Downloads\pymongo-1.4> PS.: I previously installed Python 3.1 but later installed 2.6 because I am not sure whether pymongo supports 3.1. PPS.: I have tried installing pymongo using the python setup.py install approach, but this resulted in a nasty-looking stack trace, so I thought I would try to let easy_install take care of it for me. PPPS.: I am completely new to Python, easy_install, eggs etc.

  Read the article

• Where should I create my DbCommand instances?

  - by Domenic

  I seemingly have two choices: Make my class implement IDisposable. Create my DbCommand instances as private readonly fields, and in the constructor, add the parameters that they use. Whenever I want to write to the database, bind to these parameters (reusing the same command instances), set the Connection and Transaction properties, then call ExecuteNonQuery. In the Dispose method, call Dispose on each of these fields. Each time I want to write to the database, write using(var cmd = new DbCommand("...", connection, transaction)) around the usage of the command, and add parameters and bind to them every time as well, before calling ExecuteNonQuery. I assume I don't need a new command for each query, just a new command for each time I open the database (right?). Both of these seem somewhat inelegant and possibly incorrect. For #1, it is annoying for my users that I this class is now IDisposable just because I have used a few DbCommands (which should be an implementation detail that they don't care about). I also am somewhat suspicious that keeping a DbCommand instance around might inadvertently lock the database or something? For #2, it feels like I'm doing a lot of work (in terms of .NET objects) each time I want to write to the database, especially with the parameter-adding. It seems like I create the same object every time, which just feels like bad practice. For reference, here is my current code, using #1: using System; using System.Net; using System.Data.SQLite; public class Class1 : IDisposable { private readonly SQLiteCommand updateCookie = new SQLiteCommand("UPDATE moz_cookies SET value = @value, expiry = @expiry, isSecure = @isSecure, isHttpOnly = @isHttpOnly WHERE name = @name AND host = @host AND path = @path"); public Class1() { this.updateCookie.Parameters.AddRange(new[] { new SQLiteParameter("@name"), new SQLiteParameter("@value"), new SQLiteParameter("@host"), new SQLiteParameter("@path"), new SQLiteParameter("@expiry"), new SQLiteParameter("@isSecure"), new SQLiteParameter("@isHttpOnly") }); } private static void BindDbCommandToMozillaCookie(DbCommand command, Cookie cookie) { long expiresSeconds = (long)cookie.Expires.TotalSeconds; command.Parameters["@name"].Value = cookie.Name; command.Parameters["@value"].Value = cookie.Value; command.Parameters["@host"].Value = cookie.Domain; command.Parameters["@path"].Value = cookie.Path; command.Parameters["@expiry"].Value = expiresSeconds; command.Parameters["@isSecure"].Value = cookie.Secure; command.Parameters["@isHttpOnly"].Value = cookie.HttpOnly; } public void WriteCurrentCookiesToMozillaBasedBrowserSqlite(string databaseFilename) { using (SQLiteConnection connection = new SQLiteConnection("Data Source=" + databaseFilename)) { connection.Open(); using (SQLiteTransaction transaction = connection.BeginTransaction()) { this.updateCookie.Connection = connection; this.updateCookie.Transaction = transaction; foreach (Cookie cookie in SomeOtherClass.GetCookieArray()) { Class1.BindDbCommandToMozillaCookie(this.updateCookie, cookie); this.updateCookie.ExecuteNonQuery(); } transaction.Commit(); } } } #region IDisposable implementation protected virtual void Dispose(bool disposing) { if (!this.disposed && disposing) { this.updateCookie.Dispose(); } this.disposed = true; } public void Dispose() { this.Dispose(true); GC.SuppressFinalize(this); } ~Class1() { this.Dispose(false); } private bool disposed; #endregion }

  Read the article

• Weird behavior of fork() and execvp() in C

  - by ron

  After some remarks from my previous post , I made the following modifications : int main() { char errorStr[BUFF3]; while (1) { int i , errorFile; char *line = malloc(BUFFER); char *origLine = line; fgets(line, 128, stdin); // get a line from stdin // get complete diagnostics on the given string lineData info = runDiagnostics(line); char command[20]; sscanf(line, "%20s ", command); line = strchr(line, ' '); // here I remove the command from the line , the command is stored in "commmand" above printf("The Command is: %s\n", command); int currentCount = 0; // number of elements in the line int *argumentsCount = &currentCount; // pointer to that // get the elements separated char** arguments = separateLineGetElements(line,argumentsCount); printf("\nOutput after separating the given line from the user\n"); for (i = 0; i < *argumentsCount; i++) { printf("Argument %i is: %s\n", i, arguments[i]); } // here we call a method that would execute the commands pid_t pid ; if (-1 == (pid = fork())) { sprintf(errorStr,"fork: %s\n",strerror(errno)); write(errorFile,errorStr,strlen(errorStr + 1)); perror("fork"); exit(1); } else if (pid == 0) // fork was successful { printf("\nIn son process\n"); // if (execvp(arguments[0],arguments) < 0) // for the moment I ignore this line if (execvp(command,arguments) < 0) // execute the command { perror("execvp"); printf("ERROR: execvp failed\n"); exit(1); } } else // parent { int status = 0; pid = wait(&status); printf("Process %d returned with status %d.", pid, status); } // print each element of the line for (i = 0; i < *argumentsCount; i++) { printf("Argument %i is: %s\n", i, arguments[i]); } // free all the elements from the memory for (i = 0; i < *argumentsCount; i++) { free(arguments[i]); } free(arguments); free(origLine); } return 0; } When I enter in the Console : ls out.txt I get : The Command is: ls execvp: No such file or directory In son process ERROR: execvp failed Process 4047 returned with status 256.Argument 0 is: > Argument 1 is: out.txt So I guess that the son process is active , but from some reason the execvp fails . Why ? Regards REMARK : The ls command is just an example . I need to make this works with any given command . EDIT 1 : User input : ls > qq.out Program output : The Command is: ls Output after separating the given line from the user Argument 0 is: > Argument 1 is: qq.out In son process >: cannot access qq.out: No such file or directory Process 4885 returned with status 512.Argument 0 is: > Argument 1 is: qq.out

  Read the article

• A Communication System for XAML Applications

  - by psheriff

  In any application, you want to keep the coupling between any two or more objects as loose as possible. Coupling happens when one class contains a property that is used in another class, or uses another class in one of its methods. If you have this situation, then this is called strong or tight coupling. One popular design pattern to help with keeping objects loosely coupled is called the Mediator design pattern. The basics of this pattern are very simple; avoid one object directly talking to another object, and instead use another class to mediate between the two. As with most of my blog posts, the purpose is to introduce you to a simple approach to using a message broker, not all of the fine details. IPDSAMessageBroker Interface As with most implementations of a design pattern, you typically start with an interface or an abstract base class. In this particular instance, an Interface will work just fine. The interface for our Message Broker class just contains a single method “SendMessage” and one event “MessageReceived”. public delegate void MessageReceivedEventHandler( object sender, PDSAMessageBrokerEventArgs e); public interface IPDSAMessageBroker{  void SendMessage(PDSAMessageBrokerMessage msg);   event MessageReceivedEventHandler MessageReceived;} PDSAMessageBrokerMessage Class As you can see in the interface, the SendMessage method requires a type of PDSAMessageBrokerMessage to be passed to it. This class simply has a MessageName which is a ‘string’ type and a MessageBody property which is of the type ‘object’ so you can pass whatever you want in the body. You might pass a string in the body, or a complete Customer object. The MessageName property will help the receiver of the message know what is in the MessageBody property. public class PDSAMessageBrokerMessage{  public PDSAMessageBrokerMessage()  {  }   public PDSAMessageBrokerMessage(string name, object body)  {    MessageName = name;    MessageBody = body;  }   public string MessageName { get; set; }   public object MessageBody { get; set; }} PDSAMessageBrokerEventArgs Class As our message broker class will be raising an event that others can respond to, it is a good idea to create your own event argument class. This class will inherit from the System.EventArgs class and add a couple of additional properties. The properties are the MessageName and Message. The MessageName property is simply a string value. The Message property is a type of a PDSAMessageBrokerMessage class. public class PDSAMessageBrokerEventArgs : EventArgs{  public PDSAMessageBrokerEventArgs()  {  }   public PDSAMessageBrokerEventArgs(string name,     PDSAMessageBrokerMessage msg)  {    MessageName = name;    Message = msg;  }   public string MessageName { get; set; }   public PDSAMessageBrokerMessage Message { get; set; }} PDSAMessageBroker Class Now that you have an interface class and a class to pass a message through an event, it is time to create your actual PDSAMessageBroker class. This class implements the SendMessage method and will also create the event handler for the delegate created in your Interface. public class PDSAMessageBroker : IPDSAMessageBroker{  public void SendMessage(PDSAMessageBrokerMessage msg)  {    PDSAMessageBrokerEventArgs args;     args = new PDSAMessageBrokerEventArgs(      msg.MessageName, msg);     RaiseMessageReceived(args);  }   public event MessageReceivedEventHandler MessageReceived;   protected void RaiseMessageReceived(    PDSAMessageBrokerEventArgs e)  {    if (null != MessageReceived)      MessageReceived(this, e);  }} The SendMessage method will take a PDSAMessageBrokerMessage object as an argument. It then creates an instance of a PDSAMessageBrokerEventArgs class, passing to the constructor two items: the MessageName from the PDSAMessageBrokerMessage object and also the object itself. It may seem a little redundant to pass in the message name when that same message name is part of the message, but it does make consuming the event and checking for the message name a little cleaner – as you will see in the next section. Create a Global Message Broker In your WPF application, create an instance of this message broker class in the App class located in the App.xaml file. Create a public property in the App class and create a new instance of that class in the OnStartUp event procedure as shown in the following code: public partial class App : Application{  public PDSAMessageBroker MessageBroker { get; set; }   protected override void OnStartup(StartupEventArgs e)  {    base.OnStartup(e);     MessageBroker = new PDSAMessageBroker();  }} Sending and Receiving Messages Let’s assume you have a user control that you load into a control on your main window and you want to send a message from that user control to the main window. You might have the main window display a message box, or put a string into a status bar as shown in Figure 1. Figure 1: The main window can receive and send messages The first thing you do in the main window is to hook up an event procedure to the MessageReceived event of the global message broker. This is done in the constructor of the main window: public MainWindow(){  InitializeComponent();   (Application.Current as App).MessageBroker.     MessageReceived += new MessageReceivedEventHandler(       MessageBroker_MessageReceived);} One piece of code you might not be familiar with is accessing a property defined in the App class of your XAML application. Within the App.Xaml file is a class named App that inherits from the Application object. You access the global instance of this App class by using Application.Current. You cast Application.Current to ‘App’ prior to accessing any of the public properties or methods you defined in the App class. Thus, the code (Application.Current as App).MessageBroker, allows you to get at the MessageBroker property defined in the App class. In the MessageReceived event procedure in the main window (shown below) you can now check to see if the MessageName property of the PDSAMessageBrokerEventArgs is equal to “StatusBar” and if it is, then display the message body into the status bar text block control. void MessageBroker_MessageReceived(object sender,   PDSAMessageBrokerEventArgs e){  switch (e.MessageName)  {    case "StatusBar":      tbStatus.Text = e.Message.MessageBody.ToString();      break;  }} In the Page 1 user control’s Loaded event procedure you will send the message “StatusBar” through the global message broker to any listener using the following code: private void UserControl_Loaded(object sender,  RoutedEventArgs e){  // Send Status Message  (Application.Current as App).MessageBroker.    SendMessage(new PDSAMessageBrokerMessage("StatusBar",      "This is Page 1"));} Since the main window is listening for the message ‘StatusBar’, it will display the value “This is Page 1” in the status bar at the bottom of the main window. Sending a Message to a User Control The previous example sent a message from the user control to the main window. You can also send messages from the main window to any listener as well. Remember that the global message broker is really just a broadcaster to anyone who has hooked into the MessageReceived event. In the constructor of the user control named ucPage1 you can hook into the global message broker’s MessageReceived event. You can then listen for any messages that are sent to this control by using a similar switch-case structure like that in the main window. public ucPage1(){  InitializeComponent();   // Hook to the Global Message Broker  (Application.Current as App).MessageBroker.    MessageReceived += new MessageReceivedEventHandler(      MessageBroker_MessageReceived);} void MessageBroker_MessageReceived(object sender,  PDSAMessageBrokerEventArgs e){  // Look for messages intended for Page 1  switch (e.MessageName)  {    case "ForPage1":      MessageBox.Show(e.Message.MessageBody.ToString());      break;  }} Once the ucPage1 user control has been loaded into the main window you can then send a message using the following code: private void btnSendToPage1_Click(object sender,  RoutedEventArgs e){  PDSAMessageBrokerMessage arg =     new PDSAMessageBrokerMessage();   arg.MessageName = "ForPage1";  arg.MessageBody = "Message For Page 1";   // Send a message to Page 1  (Application.Current as App).MessageBroker.SendMessage(arg);} Since the MessageName matches what is in the ucPage1 MessageReceived event procedure, ucPage1 can do anything in response to that event. It is important to note that when the message gets sent it is sent to all MessageReceived event procedures, not just the one that is looking for a message called “ForPage1”. If the user control ucPage1 is not loaded and this message is broadcast, but no other code is listening for it, then it is simply ignored. Remove Event Handler In each class where you add an event handler to the MessageReceived event you need to make sure to remove those event handlers when you are done. Failure to do so can cause a strong reference to the class and thus not allow that object to be garbage collected. In each of your user control’s make sure in the Unloaded event to remove the event handler. private void UserControl_Unloaded(object sender, RoutedEventArgs e){  if (_MessageBroker != null)    _MessageBroker.MessageReceived -=         _MessageBroker_MessageReceived;} Problems with Message Brokering As with most “global” classes or classes that hook up events to other classes, garbage collection is something you need to consider. Just the simple act of hooking up an event procedure to a global event handler creates a reference between your user control and the message broker in the App class. This means that even when your user control is removed from your UI, the class will still be in memory because of the reference to the message broker. This can cause messages to still being handled even though the UI is not being displayed. It is up to you to make sure you remove those event handlers as discussed in the previous section. If you don’t, then the garbage collector cannot release those objects. Instead of using events to send messages from one object to another you might consider registering your objects with a central message broker. This message broker now becomes a collection class into which you pass an object and what messages that object wishes to receive. You do end up with the same problem however. You have to un-register your objects; otherwise they still stay in memory. To alleviate this problem you can look into using the WeakReference class as a method to store your objects so they can be garbage collected if need be. Discussing Weak References is beyond the scope of this post, but you can look this up on the web. Summary In this blog post you learned how to create a simple message broker system that will allow you to send messages from one object to another without having to reference objects directly. This does reduce the coupling between objects in your application. You do need to remember to get rid of any event handlers prior to your objects going out of scope or you run the risk of having memory leaks and events being called even though you can no longer access the object that is responding to that event. NOTE: You can download the sample code for this article by visiting my website at http://www.pdsa.com/downloads. Select “Tips & Tricks”, then select “A Communication System for XAML Applications” from the drop down list.

  Read the article

• Pyglet OpenGL drawing anti-aliasing

  - by Jared Forsyth

  I've been looking around for a way to anti-alias lines in OpenGL, but none of them seem to work... here's some example code: import pyglet from pyglet.gl import * window = pyglet.window.Window(resizable=True) @window.event def on_draw(): window.clear() pyglet.gl.glColor4f(1.0,0,0,1.0) glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA) glEnable (GL_BLEND) glEnable (GL_LINE_SMOOTH); glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE) glLineWidth (3) pyglet.graphics.draw(2, pyglet.gl.GL_LINES, ('v2i', (10, 15, 300, 305)) ) pyglet.app.run() Can anyone see what I am doing wrong?

  Read the article

• refresh parent page from child's child page

  - by Nani

  Hi, Is it possible to refresh parent page from child's child page using javascript. I have a webform which opens a child window, a button on child window closes the present child window and opens a subchild window. Now a button on subchild should close the window and refresh the parent form. Please suggest me the way of doing it. Thank You.

  Read the article

• Does WPF refresh drawing similar to Windows Forms?

  - by Joan Venge

  So if I have a WPF window, would moving another window over the WPF window cause the WPF window to do thousands of redraws like Windows Forms? I am wondering the effects of using vectors in this case, as opposed to everything being bitmap-based like Window Forms.

  Read the article

• How can I get rid of specific error messages in the mac terminal?

  - by Julian Weimer

  For some reasons i always get the following whenever i log into my terminal: : command not found : command not found : command not found : command not found : command not found It's really a minor problem because everything is working fine, or at least everything what im using in the terminal. Still it would just look nicer without them. Any help? I'm running Mac OS 10.5.8 <= if this helps solving the problem

  Read the article

• Create multiple modal windows with javascript (+jQuery), what is the best practice to indentify wind

  - by Kirzilla

  Hello, When creating every instance of Window object I should bind close button of each window to closing this window. But how should I identify windows? Should I create unique id for each Window instance or maybe another way? What is the best way to create such identifiers, maybe some kind of singleton object with id parameter which should be incremented each time when window is created? Thank you.

  Read the article

• Why is the value of this string, in a bash script, being executing?

  - by Ross

  Hello Why is this script executing the string in the if statement: #!/bin/bash FILES="*" STRING='' for f in $FILES do if ["$STRING" = ""] then echo first STRING='hello' else STRING="$STRING hello" fi done echo $STRING when run it with sh script.sh outputs: first lesscd.sh: line 7: [hello: command not found lesscd.sh: line 7: [hello hello: command not found lesscd.sh: line 7: [hello hello hello: command not found lesscd.sh: line 7: [hello hello hello hello: command not found lesscd.sh: line 7: [hello hello hello hello hello: command not found hello hello hello hello hello hello p.s. first attempt at a shell script thanks

  Read the article

• How to assign Application Icon that will display in Task bar?

  - by viky

  I am working on a Wpf desktop application, whenever i run my application it shows me a window and associated tab in the task bar(Normal windows feature). My problem is that the tab is using window's icon for unknown file-type, I tried with Icon property of Window, Icon gets assigned but still problem is when I run application, task bar Tab initially displays window's icon for unknown file-type and when window-load completes it changes to the Icon assigned. I want Icon there from beginning. Any help?

  Read the article

• Why is the value if this string executing in a bash script?

  - by Ross

  Hello Why is this script executing the string in the if statement: #!/bin/bash FILES="*" STRING='' for f in $FILES do if ["$STRING" = ""] then echo first STRING='hello' else STRING="$STRING hello" fi done echo $STRING when run it with sh script.sh outputs: first lesscd.sh: line 7: [hello: command not found lesscd.sh: line 7: [hello hello: command not found lesscd.sh: line 7: [hello hello hello: command not found lesscd.sh: line 7: [hello hello hello hello: command not found lesscd.sh: line 7: [hello hello hello hello hello: command not found hello hello hello hello hello hello p.s. first attempt at a shell script thanks

  Read the article

• UNIX pipes on C block on read

  - by Toni Cárdenas

  I'm struggling to implement a shell with pipelines for class. typedef struct { char** cmd; int in[2]; int out[2]; } cmdio; cmdio cmds[MAX_PIPE + 1]; Commands in the pipeline are read and stored in cmds. cmdio[i].in is the pair of file descriptors of the input pipe returned by pipe(). For the first command, which reads from terminal input, it is just {fileno(stdin), -1}. cmdin[i].outis similar for the output pipe/terminal output. cmdio[i].in is the same as cmd[i-1].out. For example: $ ls -l | sort | wc CMD: ls -l IN: 0 -1 OUT: 3 4 CMD: sort IN: 3 4 OUT: 5 6 CMD: wc IN: 5 6 OUT: -1 1 We pass each command to process_command, which does a number of things: for (cmdi = 0; cmds[cmdi].cmd != NULL; cmdi++) { process_command(&cmds[cmdi]); } Now, inside process_command: if (!(pid_fork = fork())) { dup2(cmd->in[0], fileno(stdin)); dup2(cmd->out[1], fileno(stdout)); if (cmd->in[1] >= 0) { if (close(cmd->in[1])) { perror(NULL); } } if (cmd->out[0] >= 0) { if (close(cmd->out[0])) { perror(NULL); } } execvp(cmd->cmd[0], cmd->cmd); exit(-1); } The problem is that reading from the pipe blocks forever: COMMAND $ ls | wc Created pipe, in: 5 out: 6 Foreground pid: 9042, command: ls, Exited, info: 0 [blocked running read() within wc] If, instead of exchanging the process with execvp, I just do this: if (!(pid_fork = fork())) { dup2(cmd->in[0], fileno(stdin)); dup2(cmd->out[1], fileno(stdout)); if (cmd->in[1] >= 0) { if (close(cmd->in[1])) { perror(NULL); } } if (cmd->out[0] >= 0) { if (close(cmd->out[0])) { perror(NULL); } } char buf[6]; read(fileno(stdin), buf, 5); buf[5] = '\0'; printf("%s\n", buf); exit(0); } It happens to work: COMMAND $ cmd1 | cmd2 | cmd3 | cmd4 | cmd5 Pipe creada, in: 11 out: 12 Pipe creada, in: 13 out: 14 Pipe creada, in: 15 out: 16 Pipe creada, in: 17 out: 18 hola! Foreground pid: 9251, command: cmd1, Exited, info: 0 Foreground pid: 9252, command: cmd2, Exited, info: 0 Foreground pid: 9253, command: cmd3, Exited, info: 0 Foreground pid: 9254, command: cmd4, Exited, info: 0 hola! Foreground pid: 9255, command: cmd5, Exited, info: 0 What could be the problem?

  Read the article

• jQuery resize width on firefox

  - by LM35DT

  I'm doing some experiments with jquery n widths for a liquid column and I'm not sure why it isn't working on firefox. It works fine on IE6,7,8 Chrome, Opera(sluggish). I found some articles about firefox not recognizing the .resize attribute but no explanation/solution =\ $(document).ready(function(){ $(midCol).width((window,$(window).width()) - 470) $(window).resize(function(){$(midCol).width((window,$(window).width()) - 470) }) });

  Read the article

< Previous Page | 265 266 267 268 269 270 271 272 273 274 275 276  | Next Page >