Search Results

Search found 29498 results on 1180 pages for 'object destruction'.

Page 578/1180 | < Previous Page | 574 575 576 577 578 579 580 581 582 583 584 585  | Next Page >

  • creating new instance fails PHP

    - by as3isolib
    I am relatively new to PHP and having some decent success however I am running into this issue: If I try to create a new instance of the class GenericEntryVO, I get a 500 error with little to no helpful error information. However, if I use a generic object as the result, I get no errors. I'd like to be able to cast this object as a GenericEntryVO as I am using AMFPHP to communicate serialize data with a Flex client. I've read a few different ways to create constructors in PHP but the typical 'public function Foo()' for a class Foo was recommended for PHP 5.4.4 //in my EntryService.php class public function getEntryByID($id) { $link = mysqli_connect("localhost", "root", "root", "BabyTrackingAppDB"); if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); exit(); } $query = "SELECT * FROM Entries WHERE id = '$id' LIMIT 1"; if ($result = mysqli_query($link, $query)) { // $entry = new GenericEntryVO(); this is where the problem lies! while ($row = mysqli_fetch_row($result)) { $entry->id = $row[0]; $entry->entryType = $row[1]; $entry->title = $row[2]; $entry->description = $row[3]; $entry->value = $row[4]; $entry->created = $row[5]; $entry->updated = $row[6]; } } mysqli_free_result($result); mysqli_close($link); return $entry; } //my GenericEntryVO.php class <?php class GenericEntryVO { public function __construct() { } public $id; public $title; public $entryType; public $description; public $value; public $created; public $updated; // public $properties; } ?>

    Read the article

  • C# Automatic Properties - Still null after +=?

    - by Sam Schutte
    This seems like a bug to me... I accept that automatic properties, defined as such: public decimal? Total { get; set; } Will be null when they are first accessed. They haven't been initialized, so of course they are null. But, even after setting their value through +=, this decimal? still remains null. So after: Total += 8; Total is still null. How can this be correct? I understand that it's doing a (null + 8), but seems strange that it doesn't pick up that it means it should just be set to 8... Addendums: I made the "null + 8" point in my question - but notice that it works with strings. So, it does null + "hello" just fine, and returns "hello". Therefore, behind the scenes, it is initializing the string to a string object with the value of "hello". The behavior should be the same for the other types, IMO. It might be because a string can accept a null as a value, but still, a null string is not an initialized object, correct? Perhaps it's just because a string isn't a nullable...

    Read the article

  • How can I prevent infinite recursion when using events to bind UI elements to fields?

    - by Billy ONeal
    The following seems to be a relatively common pattern (to me, not to the community at large) to bind a string variable to the contents of a TextBox. class MyBackEndClass { public event EventHandler DataChanged; string _Data; public string Data { get { return _Data; } set { _Data = value; //Fire the DataChanged event } } } class SomeForm : // Form stuff { MyBackEndClass mbe; TextBox someTextBox; SomeForm() { someTextBox.TextChanged += HandleTextBox(); mbe.DataChanged += HandleData(); } void HandleTextBox(Object sender, EventArgs e) { mbe.Data = ((TextBox)sender).Text; } void HandleData(Object sender, EventArgs e) { someTextBox.Text = ((MyBackEndClass) sender).Data; } } The problem is that changing the TextBox fires the changes the data value in the backend, which causes the textbox to change, etc. That runs forever. Is there a better design pattern (other than resorting to a nasty boolean flag) that handles this case correctly? EDIT: To be clear, in the real design the backend class is used to synchronize changes between multiple forms. Therefore I can't just use the SomeTextBox.Text property directly. Billy3

    Read the article

  • C++ ulong to class method pointer and back

    - by Simone Margaritelli
    Hi guys, I'm using a hash table (source code by Google Inc) to store some method pointers defined as: typedef Object *(Executor::*expression_delegate_t)( vframe_t *, Node * ); Where obviously "Executor" is the class. The function prototype to insert some value to the hash table is: hash_item_t *ht_insert( hash_table_t *ht, ulong key, ulong data ); So basically i'm doing the insert double casting the method pointer: ht_insert( table, ASSIGN, reinterpret_cast<ulong>( (void *)&Executor::onAssign ) ); Where table is defined as a 'hash_table_t *' inside the declaration of the Executor class, ASSIGN is an unsigned long value, and 'onAssign' is the method I have to map. Now, Executor::onAssign is stored as an unsigned long value, its address in memory I think, and I need to cast back the ulong to a method pointer. But this code: hash_item_t* item = ht_find( table, ASSIGN ); expression_delegate_t delegate = reinterpret_cast < expression_delegate_t > (item->data); Gives me the following compilation error : src/executor.cpp:45: error: invalid cast from type ‘ulong’ to type ‘Object* (Executor::*)(vframe_t*, Node*)’ I'm using GCC v4.4.3 on a x86 GNU/Linux machine. Any hints?

    Read the article

  • Button inside a repeater with dropdownlist

    - by TheAlbear
    I have a repeater with a literal, a dropdown list, and a button. <asp:Repeater ID="Repeater1" runat="server" OnItemDataBound="rep_ItemDataBound" onitemcommand="Repeater1_ItemCommand"> <ItemTemplate> <div class="buypanel"> <ul> <li>Choose finish <asp:DropDownList ID="ddlFinish" runat="server"></asp:DropDownList></li> <li>Qty <asp:Literal ID="ltQty" runat="server"></asp:Literal></li> <li><asp:Button ID="butBuy" runat="server" Text="Button" /></li> </ul> </div> </ItemTemplate> </asp:Repeater> I am binding all the information in the code behind like protected void rep_ItemDataBound(object sender, RepeaterItemEventArgs e) { if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem) { Products product = (Products) e.Item.DataItem; //Dropdownlist to be bound. //Set Buy Button var butBuy = (Button) e.Item.FindControl("butBuy"); butBuy.CommandName = "Buy"; butBuy.CommandArgument = product.Id.ToString(); } } and i have my itemcommand to pick up on the button click protected void Repeater1_ItemCommand(object source, RepeaterCommandEventArgs e) { if(e.CommandName == "Buy") { } } I am not sure how, with a given button click, to pickup the right information from the text box and dropdown list which is along side it?

    Read the article

  • Can I get away with this or is it just too crude and unpractical ?

    - by The_AlienCoder
    I spent the whole of last night searching for a free AspNet web chat control that I could simply drag into my website. Well the search was in vain as I could not find a control that matched my needs i.e List of users, 1 to 1 chat, Ability to kick out users.. In the end I decided to create my own control from scractch. Although it works well on my machine Im concerned that It maybe a little crude and unpractical on a shared hosting enviroment. Basically this is what I did : Created an sql database that stores the chat messages. Wrote the stored procedures and and included a statement that clears old messages Then the 'crude' part : Dragged an update panel and timer control on my page Dragged a Repeater databound to the chat messages table inside the update panel Dragged another update panel and inside it put a textbox and a button Configured the timer control to tick every 5 seconds. ..and then I made it all work like this In the timer tick event I 'refreshed' the messages display by invoking Databind() on my repeater i.e protected void Timer1_Tick(object sender, EventArgs e) { MyRepeater.DataBind(); } Then in my send button click event protected void btnSend_Click(object sender, EventArgs e) { MyDataLayer.InsertMessage(Message, Sender, CurrTime); } Well It works well on my machine and Ive got the other functionalities(users list, kick out user..) to work by simply creating more tables. But like I said it seems a little crude to me. so I need a proffesional opinion. Should I run with this or try another Approach ?

    Read the article

  • Entity Framework Decorator Pattern

    - by Anthony Compton
    In my line of business we have Products. These products can be modified by a user by adding Modifications to them. Modifications can do things such as alter the price and alter properties of the Product. This, to me, seems to fit the Decorator pattern perfectly. Now, envision a database in which Products exist in one table and Modifications exist in another table and the database is hooked up to my app through the Entity Framework. How would I go about getting the Product objects and the Modification objects to implement the same interface so that I could use them interchangeably? For instance, the kind of things I would like to be able to do: Given a Modification object, call .GetNumThings(), which would then return the number of things in the original object, plus or minus the number of things added by the modification. This question may be stemming from a pretty serious lack of exposure to the nitty-gritty of EF (all of my experience so far has been pretty straight-forward LOB Silverlight apps), and if that's the case, please feel free to tell me to RTFM. Thanks in advance!

    Read the article

  • How do software events work internally?

    - by Duddle
    Hello! I am a student of Computer Science and have learned many of the basic concepts of what is going on "under the hood" while a computer program is running. But recently I realized that I do not understand how software events work efficiently. In hardware, this is easy: instead of the processor "busy waiting" to see if something happened, the component sends an interrupt request. But how does this work in, for example, a mouse-over event? My guess is as follows: if the mouse sends a signal ("moved"), the operating system calculates its new position p, then checks what program is being drawn on the screen, tells that program position p, then the program itself checks what object is at p, checks if any event handlers are associated with said object and finally fires them. That sounds terribly inefficient to me, since a tiny mouse movement equates to a lot of cpu context switches (which I learned are relatively expensive). And then there are dozens of background applications that may want to do stuff of their own as well. Where is my intuition failing me? I realize that even "slow" 500MHz processors do 500 million operations per second, but still it seems too much work for such a simple event. Thanks in advance!

    Read the article

  • Returning objects in php

    - by user220201
    I see similar questions asked but I seem to have problem with more basic stuff than were asked. How to declare a variable in php? My specific problem is I have a function that reads a DB table and returns the record (only one) as an object. class User{ public $uid; public $name; public $status; } function GetUserInfo($uid) { // Query DB $userObj = new User(); // convert the result into the User object. var_dump($userObj); return $userObj; } // In another file I call the above function. .... $newuser = GetUserInfo($uid); var_dump($newuser); What is the problem here, I cannot understand. Essentially the var_dump() in the function GetUserInfo() works fine. The var_dump() outside after the call to GetUserInfo() does not work. Thanks for any help. S

    Read the article

  • NUll exception in filling a querystring by mocing framework

    - by user564101
    There is a simple controller that a querystring is read in constructor of it. public class ProductController : Controller { parivate string productName; public ProductController() { productName = Request.QueryString["productname"]; } public ActionResult Index() { ViewData["Message"] = productName; return View(); } } Also I have a function in unit test that create an instance of this Controller and I fill the querystring by a Mock object like below. [TestClass] public class ProductControllerTest { [TestMethod] public void test() { // Arrange var querystring = new System.Collections.Specialized.NameValueCollection { { "productname", "sampleproduct"} }; var mock = new Mock<ControllerContext>(); mock.SetupGet(p => p.HttpContext.Request.QueryString).Returns(querystring); var controller = new ProductController(); controller.ControllerContext = mock.Object; // Act var result = controller.Index() as ViewResult; // Assert Assert.AreEqual("Index", result.ViewName); } } Unfortunately Request.QueryString["productname"] is null in constructor of ProductController when I run test unit. Is ther any way to fill a querystrin by a mocking and get it in constructor of a control?

    Read the article

  • Codeigniter PHP - loading a view at an anchor point

    - by James Billings
    I have a form at the bottom of a long page, if a user fills out the form but it doesn't validate the page is reloaded in the typical codeigniter fashion: $this->load->view('template',$data); however because the form is way down at the bottom of the page I need the page to load down there like you do with HTML anchors. Does anyone know how to do this in codeigniter? I can't use the codeigniter redirect(); function because it loses the object and the validation errors are gone. Other frameworks I've used like Yii you can call the redirect function like: $this->redirect(); which solves the problem because you keep the object. I've tried using: $this->index() within the controller which works fine as a redirect but the validation errors are in another method which is where the current page is loaded from: $this->item($labs) but when I use this it get stuck in a loop Any ideas? I've seen this question a lot on the net but no clear answers. I'm researching using codeigniter "flash data" but think it's a bit overkill. cheers.

    Read the article

  • Returning JSON or XML for Exceptions in Jersey

    - by Dominic
    My goal is to have an error bean returned on a 404 with a descriptive message when a object is not found, and return the same MIME type that was requested. I have a look up resource, which will return the specified object in XML or JSON based on the URI (I have setup the com.sun.jersey.config.property.resourceConfigClass servlet parameter so I dont need the Accept header. My JAXBContextResolver has the ErrorBean.class in its list of types, and the correct JAXBContext is returned for this class because I can see in the logs). eg: http://foobar.com/rest/locations/1.json @GET @Path("{id}") @Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML}) public Location getCustomer(@PathParam("id") int cId) { //look up location from datastore .... if (location == null) { throw new NotFoundException("Location" + cId + " is not found"); } } And my NotFoundException looks like this: public class NotFoundException extends WebApplicationException { public NotFoundException(String message) { super(Response.status(Response.Status.NOT_FOUND). entity(new ErrorBean( message, Response.Status.NOT_FOUND.getStatusCode() ) .build()); } } The ErrorBean is as follows: @XmlRootElement(name = "error") public class ErrorBean { private String errorMsg; private int errorCode; //no-arg constructor, property constructor, getter and setters ... } However, I'm always getting a 204 No Content response when I try this. I have hacked around, and if I return a string and specify the mime type this works fine: public NotFoundException(String message) { super(Response.status(Response.Status.NOT_FOUND). entity(message).type("text/plain").build()); } I have also tried returning an ErrorBean as a resource. This works fine: {"errorCode":404,"errorMsg":"Location 1 is not found!"}

    Read the article

  • how to fill missing values from a list

    - by Stephane
    I have an object containing a date and a count. public class Stat { public DateTime Stamp {get; set;} public int Count {get; set ;} } I have a Serie object that holds a list of thoses Stat plus some more info such as name and so on... public class Serie { public string Name { get; set; } public List<Stat> Data { get; set; } ... } Consider that I have a List of Serie but the series don't all contain the same Stamps. I need to fill in the missing stamps in all series with a default value. I thought of an extension method with signature like this (please provide better name if you find one :) ) : public static IEnumerable<Serie> Equalize(this IEnumerable<ChartSerie> series, int defaultCount) this question seems to treat the same problem, but when querying directly the DB. of course I could loop through the dates and create another list. But is there any more elegant way to achieve this? i.e.: Serie A: 01.05.2010 1 03.05.2010 3 Serie B: 01.05.2010 5 02.05.2010 6 I should get : Serie A : 01.05.2010 1 02.05.2010 0 03.05.2010 3 Serie B: 01.05.2010 5 02.05.2010 6 03.05.2010 0

    Read the article

  • Writing a generic function that can take a Writer as well as an OutputStream

    - by ebruchez
    I wrote a couple of functions that look like this: def myWrite(os: OutputStream) = {} def myWrite(w: Writer) = {} Now both are very similar and I thought I would try to write a single parametrized version of the function. I started with a type with the two methods that are common in the Java OutputStream and Writer: type Writable[T] = { def close() : Unit def write(cbuf: Array[T], off: Int, len: Int): Unit } One issue is that OutputStream writes Byte and Writer writes Char, so I parametrized the type with T. Then I write my function: def myWrite[T, A[T] <: Writable[T]](out: A[T]) = {} and try to use it: val w = new java.io.StringWriter() myWrite(w) Result: <console>:9: error: type mismatch; found : java.io.StringWriter required: ?A[ ?T ] Note that implicit conversions are not applicable because they are ambiguous: both method any2ArrowAssoc in object Predef of type [A](x: A)ArrowAssoc[A] and method any2Ensuring in object Predef of type [A](x: A)Ensuring[A] are possible conversion functions from java.io.StringWriter to ?A[ ?T ] myWrite(w) I tried a few other combinations of types and parameters, to no avail so far. My question is whether there is a way of achieving this at all, and if so how. (Note that the implementation of myWrite will need, internally, to know the type T that parametrizes the write() method, because it needs to create a buffer as in new ArrayT.)

    Read the article

  • Issue with changing an attribute with jquery

    - by rshivers
    Hello, I'm having an issue with changing the attribute for an id and can't seem to figure out what I'm doing wrong. I guess it doesn't help that I'm new to this also. I have a function that tests to make sure that I am pulling the correct id from the row in my form that I have dynamically created. It goes something like this: myFunction() { var id = $(id).attr("id"); alert("This is my id " + id); } This works with no problem and when I click the button assigned to alert me of my id it will give give me the id of the dynamic row in my form. The issue is now when I try to change the id with this: changeId() { var newId = $(id).attr("id", "x"); alert("This is my new id " + newId); } What happens in this case is that it will alert saying "This is my new id [object Object]" instead of giving me the new id. Any suggestions? I'd really appreciate any help with this.

    Read the article

  • csharp get value datatemplate element

    - by To-me
    Hello, Here is my code <ListBox x:Name="myList" IsSynchronizedWithCurrentItem="True" SelectionChanged="editElement"> <ListBox.ItemTemplate> <DataTemplate x:Name="ElementItemTemplate"> <StackPanel Name="stackPanelElementItem" Orientation="Horizontal"> <Label Name="SelectedItemlabel" Content="{Binding}" /> <Button Name="buttonDelElement" Click="btnDelElement">Delete</Button> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox> private void btnDelElement(object sender, RoutedEventArgs e) { ListBoxItem lbi2 = (ListBoxItem)(lstCursus.ItemContainerGenerator.ContainerFromItem(myList.Items.CurrentItem)); String selectedItem = lbi2.Content.ToString(); MessageBox.Show("Selected Item " + selectedItem + " ."); private void editCursus(object sender, RoutedEventArgs e) { MessageBox.Show("Selected Item " + selectedItem + " ."); /* some code to edit selected item using linq */ } My issue, SelectionChange doesn't work anymore and when I click on buttonDelElement, Selected Item doesn't change immediately. Please, any ideas?

    Read the article

  • Jquery- Get the value of first td in table

    - by Jerry
    Hello. I am trying to get the value of first td in each tr when a users clicks "click". The result below will output aa ,ee or ii. I was thinking about using clesest('tr')..but it always output "Object object". Not sure what to do on this one. Thanks. My html is <table> <tr> <td>aa</td> <td>bb</td> <td>cc</td> <td>dd</td> <td><a href="#" class="hit">click</a></td> </tr> <tr> <td>ee</td> <td>ff</td> <td>gg</td> <td>hh</td> <td><a href="#" class="hit">click</a></td> </tr> <tr> <td>ii</td> <td>jj</td> <td>kk</td> <td>ll</td> <td><a href="#" class="hit">click</a></td> </tr> </table> Jquery $(".hit").click(function(){ var value=$(this).// not sure what to do here alert(value) ; });

    Read the article

  • Python Beautiful Soup .content Property

    - by Robert Birch
    What does BeautifulSoup's .content do? I am working through crummy.com's tutorial and I don't really understand what .content does. I have looked at the forums and I have not seen any answers. Looking at the code below.... from BeautifulSoup import BeautifulSoup import re doc = ['<html><head><title>Page title</title></head>', '<body><p id="firstpara" align="center">This is paragraph <b>one</b>.', '<p id="secondpara" align="blah">This is paragraph <b>two</b>.', '</html>'] soup = BeautifulSoup(''.join(doc)) print soup.contents[0].contents[0].contents[0].contents[0].name I would expect the last line of the code to print out 'body' instead of... File "pe_ratio.py", line 29, in <module> print soup.contents[0].contents[0].contents[0].contents[0].name File "C:\Python27\lib\BeautifulSoup.py", line 473, in __getattr__ raise AttributeError, "'%s' object has no attribute '%s'" % (self.__class__.__name__, attr) AttributeError: 'NavigableString' object has no attribute 'name' Is .content only concerned with html, head and title? If, so why is that? Thanks for the help in advance.

    Read the article

  • How to get the value of an XML element using Linq even when empty.

    - by Yeodave
    Please excuse my stupidity, I tend to find the traversing XML overly complicated. I am using ASP.NET in VB. I have an XML document which contains all the details of staff in my company... <staff> <staffName>Test Staff</staffName> <staffTitle>Slave</staffTitle> <staffDepartmentName>Finance</staffDepartmentName> <staffOffice>London</staffOffice> <staffEmail>[email protected]</staffEmail> <staffPhone>0207 123 456</staffPhone> <staffNotes>Working hours Mon to Thurs 9.15 - 5.15</staffNotes> <staffBio></staffBio> </staff> As you can see, some nodes do not always contain data for ever member of staff; only Directors have biographies. I access the values like this... For Each staff In ( _ From matches In myXMLFile.Descendants("staff").Descendants("staffName") _ Where matches.Nodes(0).ToString.ToLower.Contains(LCase(search)) _ Order By matches.Value _ Select matches) staffName = staff.Descendants("staffName").Nodes(0).ToString) staffTitle = staff.Descendants("staffTitle").Nodes(0).ToString) staffOffice = staff.Descendants("staffOffice").Nodes(0).ToString) staffEmail = staff.Descendants("staffEmail").Nodes(0).ToString) staffPhone = staff.Descendants("staffPhone").Nodes(0).ToString) staffNotes = staff.Descendants("staffNotes").Nodes(0).ToString) staffBio = staff.Descendants("staffBio").Nodes(0).ToString) ' Do something with that data... Next Once it gets to staffBio I get an error saying "Object reference not set to an instance of an object." obviously because that node does not exist. My question is how can I assign the value to a variable even when it is empty without having to do a conditional check before each assignment?

    Read the article

  • Rails nested association issue

    - by Ben Langfeld
    Ok, so I'm new to both Ruby and Rails and I'm trying to do what I believe is called a nested association (please correct me if this is the wrong terminology). I currently have a User model and a Domains model and I have many to many associations setup (using has_many :through) between the two, and this works fine. I now want to extend this to allow for a single role per domain per user (eg User1 is a member of Domain1 and has the role "Admin"). I have setup a Roles model with a single field (name:string) and have created three roles. I have also added a role_id column to the join table (memberships). I expected (and this is probably the issue) to be able to just use user1 = User.find(1) user1.domains.first => <some domain object> user1.domains.first.role => <some role object> but this returns a method not defined error. Can anyone tell me what I'm failing to grasp here? My model classes can be seen at http://gist.github.com/388200

    Read the article

  • Why use Intent.URI_INTENT_SCHEME

    - by hks
    while reading Android docs about Widgets I stumbled upon this piece of code whose purpose is to launch a service for retrieving a factory for StackView items. // Set up the intent that starts the StackViewService, which will // provide the views for this collection. Intent intent = new Intent(context, StackWidgetService.class); // Add the app widget ID to the intent extras. intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]); intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME))); // Instantiate the RemoteViews object for the App Widget layout. RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.widget_layout); // Set up the RemoteViews object to use a RemoteViews adapter. // This adapter connects // to a RemoteViewsService through the specified intent. // This is how you populate the data. rv.setRemoteAdapter(appWidgetIds[i], R.id.stack_view, intent); You can find it here I have a problem understanding why do you need to call intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME))); I understand that it gives URI a prefix intent://, but is it necessary here?

    Read the article

  • How to make 2 incompatible types, but with the same members, interchangeable?

    - by Quigrim
    Yesterday 2 of the guys on our team came to me with an uncommon problem. We are using a third-party component in one of our winforms applications. All the code has already been written against it. They then wanted to incorporate another third-party component, by the same vender, into our application. To their delight they found that the second component had the exact same public members as the first. But to their dismay, the 2 components have completely separate inheritance hierarchies, and implement no common interfaces. Makes you wonder... Well, makes me wonder. An example of the problem: public class ThirdPartyClass1 { public string Name { get { return "ThirdPartyClass1"; } } public void DoThirdPartyStuff () { Console.WriteLine ("ThirdPartyClass1 is doing its thing."); } } public class ThirdPartyClass2 { public string Name { get { return "ThirdPartyClass2"; } } public void DoThirdPartyStuff () { Console.WriteLine ("ThirdPartyClass2 is doing its thing."); } } Gladly they felt copying and pasting the code they wrote for the first component was not the correct answer. So they were thinking of assigning the component instant into an object reference and then modifying the code to do conditional casts after checking what type it was. But that is arguably even uglier than the copy and paste approach. So they then asked me if I can write some reflection code to access the properties and call the methods off the two different object types since we know what they are, and they are exactly the same. But my first thought was that there goes the elegance. I figure there has to be a better, graceful solution to this problem.

    Read the article

  • Windows Form UserControl design time properties

    - by Raffaeu
    I am struggling with a UserControl. I have a UserControl that represent a Pager and it has a Presenter object property exposed in this way: [Browsable(false)] [DesignSerializationAttribute(DesignSerializationAttribute.Hidden)] public object Presenter { get; set; } The code itself works as I can drag and drop a control into a Windows From without having Visual Studio initializing this property. Now, because in the Load event of this control I call a method of the Presenter that at run-time is null ... I have introduced this additional code: public override void OnLoad(...) { if (this.DesignMode) { base.OnLoad(e); return; } presenter.OnViewReady(); } Now, every time I open a Window that contains this UserControl, Visual Studio modifies the Windows designer code. So, as soon as I open it, VS ask me if I want to save it ... and of course, if I add a control to the Window, it doesn't keep the changes ... As soon as I remove the UserControl Pager the problem disappears ... How should I tackle that in the proper way? I just don't want that the presenter property is initialized at design time as it is injected at runtime ...

    Read the article

  • C++: Static variable inside a constructor, are there any drawbacks or side effects?

    - by doc
    What I want to do: run some prerequisite code whenever instance of the class is going to be used inside a program. This code will check for requiremts etc. and should be run only once. I found that this can be achieved using another object as static variable inside a constructor. Here's an example for a better picture: class Prerequisites { public: Prerequisites() { std::cout << "checking requirements of C, "; std::cout << "registering C in dictionary, etc." << std::endl; } }; class C { public: C() { static Prerequisites prerequisites; std::cout << "normal initialization of C object" << std::endl; } }; What bothers me is that I haven't seen similar use of static variables so far. Are there any drawbacks or side-effects or am I missing something? Or maybe there is a better solution? Any suggestions are welcome.

    Read the article

  • Question about singleton property

    - by Jack
    I'm reading the java tutorial for enums located here and have a question: http://java.sun.com/j2se/1.5.0/docs/guide/language/enums.html#Card The part i'm confused about is as follows: "The Card class, above, contains a static factory that returns a deck, but there is no way to get an individual card from its rank and suit. Merely exposing the constructor would destroy the singleton property (that only a single instance of each card is allowed to exist). Here is how to write a static factory that preserves the singleton property, using a nested EnumMap: " Now as I understand, changing the original private "Card" constructor to public would allow us to instantiate an unlimited number of copies of a "Card" object with a given suit+rank. The solution as proposed was to create an EnumMap which would store four Maps (one for each suit), which themselves contained 13 Card objects with the rank as their keys. And so now if you wanted to retrieve a specific Card object from the deck, you would just call the "valueOf" method. My question now is, what's the prevent you with calling the valueOf method as many times as you like? Wouldn't that lead to the same problem as making the original private constructor public? Thanks.

    Read the article

< Previous Page | 574 575 576 577 578 579 580 581 582 583 584 585  | Next Page >