Search Results

Search found 33344 results on 1334 pages for 'helper method'.

Page 443/1334 | < Previous Page | 439 440 441 442 443 444 445 446 447 448 449 450  | Next Page >

  • singleton pattern in java- lazy Intialization

    - by flash
    public static MySingleton getInstance() { if (_instance==null) { synchronized (MySingleton.class) { _instance = new MySingleton(); } } return _instance; } 1.is there a flaw with the above implementation of the getInstance method? 2.What is the difference between the two implementations.? public static synchronized MySingleton getInstance() { if (_instance==null) { _instance = new MySingleton(); } return _instance; } I have seen a lot of answers on the singleton pattern in stackoverflow but the question I have posted is to know mainly difference of 'synchronize' at method and block level in this particular case.

    Read the article

  • How to yield a single element from for loop in scala?

    - by Julio Faerman
    Much like this question: Functional code for looping with early exit Say the code is def findFirst[T](objects: List[T]):T = { for (obj <- objects) { if (expensiveFunc(obj) != null) return /*???*/ Some(obj) } None } How to yield a single element from a for loop like this in scala? I do not want to use find, as proposed in the original question, i am curious about if and how it could be implemented using the for loop. * UPDATE * First, thanks for all the comments, but i guess i was not clear in the question. I am shooting for something like this: val seven = for { x <- 1 to 10 if x == 7 } return x And that does not compile. The two errors are: - return outside method definition - method main has return statement; needs result type I know find() would be better in this case, i am just learning and exploring the language. And in a more complex case with several iterators, i think finding with for can actually be usefull. Thanks commenters, i'll start a bounty to make up for the bad posing of the question :)

    Read the article

  • Programmatically Setting the Version of a Window's Service on the ProjectInstaller

    - by user302004
    I have a Windows Service created in Visual Studio 2005 in C#. I have a setup project and a ProjectInstaller class. I also have code to programmatically get the version from the AssemblyFileVersionAttribute. I need to figure out where I set the version that I've obtained (and where this code should go). I tried placing it in the InitializeComponent method on ProjectInstaller.Designer.cs and then appending the version to serviceInstaller1.DisplayName and serviceInstaller1.ServiceName. This didn't work and you're not supposed to modify the contents of this method. Any ideas?

    Read the article

  • Upload files, form within form

    - by Alexd2
    Hello everyone and thanks in advance. I have a problem and I have 2 form into one another, the domestic form is to perform a file upload. As I can do to make when sending in internal form not run the main form. <form name="x" method="post" action="xxx.php"> .... <form action="" method="post" enctype="multipart/form-data" target="xxx"> <input type="file" /> <input type="submit" /> </form> <iframe id="xxx" src="process.php"> </iframe> .... <input type="submit" name="pro" value="Register user"/ > </form> Doing this does not work, as this within another form. Any help or possible solution.

    Read the article

  • QuickTime movie disappearing from Javascript when scrolled offscreen in Firefox?

    - by c-had
    I have a web page I'm creating that uses Javascript to control an embedded QuickTime player. I add the QuickTime movie to the page using the AC_QuickTime.js file from Apple (as described here - http://developer.apple.com/mac/library/documentation/QuickTime/Conceptual/QTScripting_HTML/QTScripting_HTML_Document/ScriptingHTML.html#//apple_ref/doc/uid/TP40001525-2-SW1 ). Everything seems to be working fine - I can call methods on the QuickTime movie and control its playback (as well as get the current timestamp). The problem is that in Firefox, when I scroll down such that the QuickTime player is no longer visible, I get the following error every time I try to call a method on the QuickTime movie: Error calling method on NPObject! This does not occur in Safari. Why is this happening, and is there any way to work around this?

    Read the article

  • Can I reproduce Scala's behavior for == ?

    - by JPP
    In Programming in Scala, I can read that the == operator behaves as if it was defined like this: final def == (that: Any): Boolean = if (null eq this) {null eq that} else {this equals that} But there must actually be compiler magic to avoid null pointer exceptions, right? Is there any way for me to replicate this behavior with pure Scala; i.e., have an operator/method return one thing if the receiver is null and another one if it isn't? What I mean is an actual implementation of null eq this. I suppose I can write a "pimp" and then define the method on the wrapper class, but is there a more direct way to do this?

    Read the article

  • Returning string in java using 3 parameters

    - by user2905118
    Need to write a method describePerson() that takes 3 parameters, a String giving a person’s name, a boolean indicating their gender (true for female, false for male), and an integer giving their age. The method should return a String formatted as in the following examples: Lark is female. She is 2 years old. Or Jay is male. He is 1 year old. I am not sure how to write it correctly (my code): int describePerson(String name, boolean gender, int age) { String words=""; if(gender==true) return (name + "is "+gender+". "+"She is"+age+ "years old.); else return (name + "is "+gender+". "+"She is"+age+ "years old.); } The outcome "year" and "years" is also differs, but i don't know how to make it correct..

    Read the article

  • Obj-C memory management for an NSView * instance variable

    - by massimoperi
    My custom view has a subview as an instance variable. Here is a sample interface: @interface MyCustomView : NSView { NSView *aSubview; } @end Then, in the .m file, I initialize aSubView and add it to the custom view. - (id)init { self = [super initWithFrame:CGRectMakeFrame(0.0, 0.0, 320.0, 480.0); if (self) { aSubview = [[NSView alloc] initWithFrame(0.0, 0.0, 100.0, 100.0); [self addSubview:aSubview]; } return self; } Where should I release aSubView? In the -dealloc method? - (void)dealloc { [aSubView release]; [super dealloc]; } Or directly after adding it to the custom view in the -init method? - (id)init { [...] [self addSubview:aSubview]; [aSubview release]; [...] } Which one is the best implementation?

    Read the article

  • Methods specific only to an instance? What are they called in Ruby?

    - by daremarkovic
    I know there are "instance methods", "class methods" but what are these types of methods called, for eg: s1 = "This is my STRING!" def s1.m1 downcase end p s1 # => "This is my STRING!" p s1.m1 # => "this is my string!" What type of method is the "m1" method called on the s1 "instance" of the "string" class? It's really weird because I didn't know this was possible at all if I try: s2 = "This is ANOTHER string" s2.m1 # => Won't work! Which kind of makes sense, but not sure why defining methods like m1 on instances on a class are useful at all.

    Read the article

  • User class - 'load' data

    - by John
    <?php class User { private $id; private $username; public function __construct($id = null) { $this->id = $id; if (!is_null($this->id)) { $this->load(); } } public function load() { } } ?> In the 'load' method I am going to load all the information from the current user (id) But I wonder how is the best way to load all info. I could grab all data and then just assign all private variables, but I assume there must be another "cheaper" way to get all the data so I can use as such $this-variable; And not have to ASSIGN every single data row, I select in the load method. How?

    Read the article

  • Drawing a waveform in C#

    - by user488792
    Hi! I want to be able to display a WaveForm in C#, along with some simple features such as zooming and selection. I already have the data as a short[] of amplitude values. However, I am an amateur when it comes to hardcoding GUI. I have already found a possible helper class WaveFormClass that may help me achieve this but as a backup, I want to learn how to manually do it. So may I ask for some methods and possibly some links that will help? Thanks!

    Read the article

  • question on revrse array

    - by davit-datuashvili
    we know algorithm how reverse array of n integers for (int i=0;i<n/2;i++){ swap(a[i],a[n-1-i]): } is this method better according the speed of algorithm or not because swap using xor is more fast then in other method here is code public class swap{ public static void main(String[]args){ int a[]=new int[]{2,4,5,7,8,11,13,12,14,24}; System.out.println(" array at the begining:"); for (int i=0;i<a.length;i++){ System.out.println(a[i]); } for (int j=0;j<a.length/2;j++){ a[j]^=a[a.length-1-j]; a[a.length-1-j]^=a[j]; a[j]^=a[a.length-1-j]; } System.out.println("reversed array:"); for (int j=0;j<a.length;j++){ System.out.println(a[j]); } } } //result array at the begining: 2 4 5 7 8 11 13 12 14 24 reversed array: 24 14 12 13 11 8 7 5 4 2

    Read the article

  • (Action<T>).Name does not return expected values

    - by Tomas Lycken
    I have the following method (used to generate friendly error messages in unit tests): protected string MethodName<TTestedType>(Action<TTestedType> call) { return string.Format("{0}.{1}", typeof(TTestedType).FullName, call.Method.Name); } But when I call it as follows, I don't get the expected results: var nm = MethodName<MyController>(ctrl => ctrl.Create()); After running this code, nm contains "<Create_CreateShowsView>b__8", and not (as expected) "Create". How should I change the code to obtain the expected result?

    Read the article

  • Subtype polymorphism and arrays

    - by user133466
    Computer[] labComputers = new Computer[10]; with public class Computer { ... void toString(){ // print computer specs } } public class Notebook extends Computer{ ... void toString(){ // print computer specs + laptop color } } each subscripted variable labComputers[i] can reference either a Computer object or a Notebook object because Notebook is a subclass of Computer. For the method call labComputers[i].toString(), polymorphism ensures that the correct toString method is called. I wonder what if we do Notebook[] labComputers = new Notebook[10]; what kind or error would I get if I reference with Computer object and a Notebook object

    Read the article

  • Restrict confirm message on page reload with f5

    - by Max
    In my JSP page I am using post method while submitting the page. So once I go from Page 1 to page 2. In Page 2, If I press F5 I am getting alert as "To display this page, Firefox must send information that will repeat any action (such as a search or order confirmation) that was performed earlier." I knew this question is a bit sarcastic but please give me an Idea. I can't change my method from POST to GET because I need to send large amount of data. Thanks in advance... Edited: In my Page1.JSP I call onClick function in that function I call action as "/page2servlet.do". Now, In Java side I use Spring Framework. With MVC Object I return to page2.jsp. So where do the response.sendRedirect Fit.

    Read the article

  • android : Dynamically changing the content of tab

    - by Jomia
    I want to change the content of a tab? when tha tab is created i set the content of the tab by setContent() method. But if I click again, I want to change the content that means change to another activity. I used setOnTabChangedListener() method, but I am not sure about how to set the content to another intent? Resources res = getResources(); TabHost tabHost=getTabHost(); tabHost.addTab(tabHost.newTabSpec("tab1").setIndicator("HOME").setContent(new Intent(getBaseContext(),homeGroup.class))); tabHost.addTab(tabHost.newTabSpec("tab2").setIndicator("ABOUT US").setContent(new Intent(getBaseContext(),aboutusGroup.class))); tabHost.setCurrentTab(0); tabHost.setOnTabChangedListener(new OnTabChangeListener() { @Override public void onTabChanged(String tabId) { //here i want to set the content of each tab to another intent // for 'tab1', change to home.class // for 'tab2', change to aboutus.class //how to set these? } }); Please help me.. Thank you..

    Read the article

  • Android SurfaceView/Canvas flickering after trying to clear it

    - by Mark D
    So I am trying to clear the Canvas using canvas.drawColor(Color.BLACK) but if I just call this once, the display flickers and displays the old drawing which should have been covered up by the drawColor. Here is the important bits of my code - public void update() { //This method is called by a Thread Canvas canvas = holder.lockCanvas(null); if (canvas != null) { onDraw(canvas); } holder.unlockCanvasAndPost(canvas); } @Override protected void onDraw(Canvas canvas) { if (toClear) { canvas.drawColor(Color.BLACK); //if this is not set to change back to false, it does not flicker toClear = false; } //Draw some objects that are moving around } public void clearScreen() { //This method is called when the user pressed a button toClear = true; } After Googling around a litte, I heard about double buffering but came to the understanding that lockCanvas() and unlockCanvasAndPost() should handle this for me. What is going wrong here?

    Read the article

  • control.focus() after selectedIndexChanged

    - by kyle
    I need to focus on a textbox after an item has been selected from a dropdownlist. I've tried control.focus() and setfocus(). The last thing I've tried was Set_Focus(dtbEffectiveDate.ClientID) inside the SelectedIndexChanged method with the folowing method. Protected Sub Set_Focus(ByVal ControlName As String) Dim strScript As String strScript = "<script language=javascript> window.setTimeout(""" + ControlName + ".focus();"",0); </script>" RegisterStartupScript("focus", strScript) End Sub I'm out of answers so any help would be awesome.

    Read the article

  • Just how much do I want to make virtual?

    - by Alex
    I am writing an abstract superclass where literally every method is going to be overridden. There is some default functionality I could implement, but most of the time it's enough to leave the implementation to the subclass writer. Since just about every method is going to be overwritten, how much should I make virtual and how much should I just leave as regular methods? In the current incarnation, everything is virtual, but I still haven't let this loose to anyone to use, so the design is flexible. What advantages/disadvantages are there to virtual functions? Links to good reading material about this would be appreciated.

    Read the article

  • Entity Framework: An object with the same key already exists in the objectstatemanager

    - by NealR
    I see that this question has been asked a lot, however I haven't found anything yet that solves the problem I'm having. Obviously i'm using the Entity Framework to perform an update to a record. Once the updates are complete, however, whenever I try to save I get the following error message: An object with the same key already exists in the objectstatemanager At first I was passing in a collection object from the view that contained a copy of the the ZipCodeTerritory model object zipToUpdate. I changed the code by pulling this object out and just sending in the relevant fields instead. However, I'm still getting the same error. What's also weird is the first time I run this code, it works fine. Any attempt after that I get the error. Controller Here is the code from the method calling the edit function public static string DescriptionOnly(ZipCodeIndex updateZip) { if (!string.IsNullOrWhiteSpace(updateZip.newEffectiveDate) || !string.IsNullOrWhiteSpace(updateZip.newEndDate)) { return "Neither effective or end date can be present if updating Territory Code only; "; } _updated = 0; foreach (var zipCode in updateZip.displayForPaging.Where(x => x.Update)) { ProcessAllChanges(zipCode, updateZip.newTerritory, updateZip.newStateCode, updateZip.newDescription, updateZip.newChannelCode); } _msg += _updated + " record(s) updated; "; return _msg; } And here is the method that actually does the updating. private static void ProcessAllChanges(ZipCodeTerritory zipToUpdate, string newTerritory, string newStateCode, string newDescription, string newChannelCode) { try { if (!string.IsNullOrWhiteSpace(newTerritory)) zipToUpdate.IndDistrnId = newTerritory; if (!string.IsNullOrWhiteSpace(newStateCode)) zipToUpdate.StateCode = newStateCode; if (!string.IsNullOrWhiteSpace(newDescription)) zipToUpdate.DrmTerrDesc = newDescription; if (!string.IsNullOrWhiteSpace(newChannelCode)) zipToUpdate.ChannelCode = newChannelCode; if (zipToUpdate.EndDate == DateTime.MinValue) zipToUpdate.EndDate = DateTime.MaxValue; _db.Entry(zipToUpdate).State = EntityState.Modified; _db.SaveChanges(); _updated++; } catch (DbEntityValidationException dbEx) { _msg += "Error during update; "; EventLog.WriteEntry("Monet", "Error during ProcessAllChanges: " + zipToUpdate.ToString() + " |EX| " + dbEx.Message); } catch (Exception ex) { _msg += "Error during update; "; EventLog.WriteEntry("Monet", "Error during ProcessAllChanges: " + zipToUpdate.ToString() + " |MESSAGE| " + ex.Message); } } EDIT The ZipCodeIndex object contains a list of ZipCodeTerritory model objects. These aren't being pulled from a linq query, but instead simply passed back to the controller from the view. Here is the signature of the controller method that starts the process: [HttpPost] public ActionResult Update(ZipCodeIndex updateZip, string button)

    Read the article

  • Rendering HTML in rails without actually displaying it

    - by Kevin Whitaker
    Hello all, My current project requires me to assemble a .zip file containing HTML and text-only templates for a user to download, for importing into an email marketing program. I've inherited this project, and currently the code uses a "fake" model (that is a model that does not directly correlate to a database table), in which it stores the entire template in a string, using dynamic variables to populate certain areas. The "fake" model then has a method for creating a zip file. It seems to me that there has to be a better way to do this. I was wondering if there was a way to move the template into a .erb/haml file, and then write a method that would populate the file in preparation for being zipped up? Basically, is there a way to render an HTML and text file, without actually having to display them? Thanks for any help.

    Read the article

  • How to programatically access web sites that are blocked by my work?

    - by Gilbo
    I'm interested in creating a web application that will let me view sites that my work won't let me go to. I have a server where I can host it that I have access to from my work. I've had some success by using the method described in this article. Unfortunately any images and css (basically any html that has a "SRC" attribute) are still being blocked. Can anyone think of a better method to view work filtered sites? I don't want to change any proxy server settings on my machine.

    Read the article

  • Exception handling pattern

    - by treefrog
    It is a common pattern I see where the error codes associated with an exception are stored as Static final ints. when the exception is created to be thrown, it is constructed with one of these codes along with an error message. This results in the method that is going to catch it having to look at the code and then decide on a course of action. The alternative seems to be- declare a class for EVERY exception error case Is there a middle ground ? what is the recommended method ?

    Read the article

  • Is there any difference in the implementation of these three validation methods?

    - by dontWatchMyProfile
    Core Data is calling these methods in certain situations: - (BOOL)validateForInsert:(NSError **)outError; - (BOOL)validateForUpdate:(NSError **)outError; - (BOOL)validateForDelete:(NSError **)outError; I wonder if they're doing anything different, or if they're essentially doing the exact same things. As far as I know, these methods call the -validateValue:forKey:error: method once for every property. The only difference I can imagine is in the .validateForDelete: method. I see no reason why to validate an object when it shall be deleted, except for applying delete rules, probably only in the case of the DENY rule.

    Read the article

< Previous Page | 439 440 441 442 443 444 445 446 447 448 449 450  | Next Page >