Search Results

Search found 16054 results on 643 pages for 'reference architecture'.

Page 563/643 | < Previous Page | 559 560 561 562 563 564 565 566 567 568 569 570  | Next Page >

  • What rules govern the copying of variables in Javascript closures?

    - by int3
    I'd just like to check my understanding of variable copying in Javascript. From what I gather, variables are passed/assigned by reference unless you explicitly tell them to create a copy with the new operator. But I'm a little uncertain when it comes to using closures. Say I have the following code: var myArray = [1, 5, 10, 15, 20]; var fnlist = []; for (var i in myArray) { var data = myArray[i]; fnlist.push(function() { var x = data; console.log(x); }); } fnlist[2](); // returns 20 I gather that this is because fnlist[2] only looks up the value of data at the point where it is invoked. So I tried an alternative tack: var myArray = [1, 5, 10, 15, 20]; var fnlist = []; for (var i in myArray) { var data = myArray[i]; fnlist.push(function() { var x = data; return function() { console.log(x); } }()); } fnlist[2](); // returns 10 So now it returns the 'correct' value. Am I right to say that it works because a function resolves all variable references to their 'constant' values when it is invoked? Or is there a better way to explain it? Any explanations / links to explanations regarding this referencing / copying business would be appreciated as well. Thanks!

    Read the article

  • Exposing a C++ API to C#

    - by Siyfion
    So what I have is a C++ API contained within a *.dll and I want to use a C# application to call methods within the API. So far I have created a C++ / CLR project that includes the native C++ API and managed to create a "bridge" class that looks a bit like the following: ManagedBridge.h namespace ManagedAPIWrapper { public ref class Bridge { public: int bridge_test(void); int bridge_test2(api_struct* temp); } } ManagedBridge.cpp int Bridge::bridge_test(void) { return test(); } int Bridge::bridge_test2(api_struct* temp) { return test2(temp); } I also have a C# application that has a reference to the C++/CLR "Bridge.dll" and then uses the methods contained within. I have a number of problems with this: I can't figure out how to call bridge_test2 within the C# program, as it has no knowledge of what a api_struct actually is. I know that I need to marshal the object somewhere, but do I do it in the C# program or the C++/CLR bridge? This seems like a very long-winded way of exposing all of the methods in the API, is there not an easier way that I'm missing out? (That doesn't use P/Invoke!)

    Read the article

  • .NET memory leak?

    - by SA
    I have an MDI which has a child form. The child form has a DataGridView in it. I load huge amount of data in the datagrid view. When I close the child form the disposing method is called in which I dispose the datagridview this.dataGrid.Dispose(); this.dataGrid = null; When I close the form the memory doesn't go down. I use the .NET memory profiler to track the memory usage. I see that the memory usage goes high when I initially load the data grid (as expected) and then becomes constant when the loading is complete. When I close the form it still remains constant. However when I take a snapshot of the memory using the memory profiler, it goes down to what it was before loading the file. Taking memory snapshot causes it to forcefully run garbage collector. What is going on? Is there a memory leak? Or do I need to run the garbage collector forcefully? More information: When I am closing the form I no longer need the information. That is why I am not holding a reference to the data.

    Read the article

  • Javascript Regex: Testing string for intelligent query

    - by Shyam
    Hi, I have a string that holds user input. This string can contain various types of data, like: a six digit id a zipcode that contains out of 4 digits and two alphanumeric characters a name (characters only) As I am using this string to search through a database, the query type is determined on the type of search, which i want to handle serverside using JavaScript (yes, I am using JavaScript serverside). Searching on StackOverflow, brought me some interesting information, like the .test-method, which seems perfect for my needs. The test-method returns either true or false based on the evaluation on the string using a regex object. I am using this page as a reference: http://www.javascriptkit.com/jsref/regexp.shtml So I am trying to determine the zipcode, by using the following very noobish regex. var r = /[A-Za-z]{2,2}/ As far I can understand, this should limit the amount of occurrences of alphanumeric characters to a maximum of two. See beneath the output of my JavaScript console. > var r = /[A-Za-z]{2,2}/ > var x = "2233AL" > r.test(x) true > var x = "2233A" > r.test(x) false > var x = "2233ALL" > r.test(x) true /* i want this to be false */ > A little help would be really appreciated!

    Read the article

  • Icons in menu are smaller than they should be

    - by martinpelant
    Hello I have a little problem. All the icons in my apk are smaller than the same icons in other apps (Gmail etc.) This is how it looks like in my apk and this is the same icon in Gmail.apk. I have copied these icons directly from SDK to the specific folders for hdpi, mdpi and ldpi. Here is an example of a hdpi icon I use and my menu.xml <?xml version="1.0" encoding="utf-8"?> <menu xmlns:android="http://schemas.android.com/apk/res/android"> <item android:id="@+id/refresh" android:title="@string/refresh" android:icon="@drawable/ic_menu_refresh" /> <item android:id="@+id/add" android:title="@string/add" android:icon="@drawable/ic_menu_add" /> <item android:id="@+id/login" android:title="@string/account" android:icon="@drawable/ic_menu_login" /> </menu> Does anybody know how to make these icon have the same size as in other apk's? I have tried the asset studio with no effect. UPDATE: If I reference an icon directly from android (android:drawable) then it has normal size. However not all icons can be referenced.

    Read the article

  • Get textboxes in to a list! c#

    - by Chelsea_cole
    public class Account { public string Username { get { return Username; } set { Username = value; } } } public class ListAcc { static void Data() { List<Account> UserList = new List<Account>(); //example of adding user account Account acc = new Account(); acc.Username = textBox1.Text; //error UserList.Add(acc); } } there are a error from access to textBox1.Text? ( An object reference is required for the nonstatic field, method, or property)... Someone can help? but if the code is: private void textBox1_TextChanged(object sender, EventArgs e) { List<Account> UserList = new List<Account>(); //example of adding user account Account acc = new Account(); acc.Username = textBox1.Text; UserList.Add(acc); } it's work! someone can help me fix my error? Many thanks!

    Read the article

  • NHibernate Entity code conversion from #C to VB.Net

    - by CoderRoller
    Hello and thanks for your help in advance. I am starting on the NHibernate world and i am experimenting with the NHibernate CookBook recipes, i am trying to set a base entity class for my entities and this is the C# code for this. I would like to know whats the VB.NET version so i can implement it in my sample project. This is the C# code: public abstract class Entity<TId> { public virtual TId Id { get; protected set; } public override bool Equals(object obj) { return Equals(obj as Entity<TId>); } private static bool IsTransient(Entity<TId> obj) { return obj != null && Equals(obj.Id, default(TId)); } private Type GetUnproxiedType() { return GetType(); } public virtual bool Equals(Entity<TId> other) { if (other == null) return false; if (ReferenceEquals(this, other)) return true; if (!IsTransient(this) && !IsTransient(other) && Equals(Id, other.Id)) { var otherType = other.GetUnproxiedType(); var thisType = GetUnproxiedType(); return thisType.IsAssignableFrom(otherType) || otherType.IsAssignableFrom(thisType); } return false; } public override int GetHashCode() { if (Equals(Id, default(TId))) return base.GetHashCode(); return Id.GetHashCode(); } } I tried using an online converter but puts a Nothing reference in place of default(TId) that doesn't seem right to me that's why I request for help: Private Shared Function IsTransient(obj As Entity(Of TId)) As Boolean Return obj IsNot Nothing AndAlso Equals(obj.Id, Nothing) End Function I Would appreciate the insight you may give me on the subject.

    Read the article

  • Multiple ID's in database

    - by eric
    I have a database that contains a few tables such as person, staff, member, and supporter. The person table contains information about every staff, member, and supporter. The information it contains is name,address,email, and telephone. I also created an id that is the primary key. My issue is that I also have an primary key ID for staff, member, and supporter. For instance, in the person table is John with id 1. He is a supporter so in the supporter table is pID(for person id)to reference back to John with all his information and ID(for supporter ID). pID references to the person table and every person has an ID incremented by 1 starting at 1. supporter ID is for every supporter and also starts at 1 and is incremented by 1. Is it possible to have in the supporter table pID = 1 and supporter ID = 1? Another person may have a pID = 26 and supporter ID = 5. Or will supporter ID have to be different than the pID and be something like "sup"? So you would have pID = 1 and supporter ID = sup1 or pID = 26 and supporter ID = sup5

    Read the article

  • How do I repeat function over several row.

    - by ChrisBD
    I'll admit that I'm not an Excel guru so maybe someone here can help me. On my worksheet I have several blocks of data. I calculate the sum of all items within column D of that block. Within each block I am checking the value of the cell in column C and if it contains the letter "y" and the value in column D of that row is equal to zero I must exclude the total sum of column D. Currently I am doing this by multiplying the sum value by either 1 or 0 which is produced by running a test over the cell contents. Below is an example of what I am using to test rows 23 to row 25 inclusively for data in Column D. I am also performing the same on Column E and G, but the "y" character is always in column C, hence the absolut column reference. =IF(AND($C23="y",D23=0),0,1)*IF(AND($C24="y",D24=0),0,1)*IF(AND($C25="y",D25=0),0,1) There must be a more efficient way to do this. Ideally I would like to write a function that I can paste into a cell and then select the rows or cells over which I run the test. Can anyone point me in the right direction?

    Read the article

  • Using unions to simplify casts

    - by Steven Lu
    I realize that what I am trying to do isn't safe. But I am just doing some testing and image processing so my focus here is on speed. Right now this code gives me the corresponding bytes for a 32-bit pixel value type. struct Pixel { unsigned char b,g,r,a; }; I wanted to check if I have a pixel that is under a certain value (e.g. r, g, b <= 0x10). I figured I wanted to just conditional-test the bit-and of the bits of the pixel with 0x00E0E0E0 (I could have wrong endianness here) to get the dark pixels. Rather than using this ugly mess (*((uint32_t*)&pixel)) to get the 32-bit unsigned int value, i figured there should be a way for me to set it up so I can just use pixel.i, while keeping the ability to reference the green byte using pixel.g. Can I do this? This won't work: struct Pixel { unsigned char b,g,r,a; }; union Pixel_u { Pixel p; uint32_t bits; }; I would need to edit my existing code to say pixel.p.g to get the green color byte. Same happens if I do this: union Pixel { unsigned char c[4]; uint32_t bits; }; This would work too but I still need to change everything to index into c, which is a bit ugly but I can make it work with a macro if i really needed to.

    Read the article

  • Is there a point to have multiple VS projects for an ASP.NET MVC application?

    - by mare
    I'm developing MVC application where I currently have 3 projects in solution. Core (it is supposed to be for Repositories, Business Classes, Models, HttpModules, HttpFilters, Settings, etc.) Data access (Data provider, for instance SqlDataProvider for working with SQL Server datastore - implements Repository interfaces, XmlDataProvider - also implements Repository interfaces but for local XML files as datastore) ASP.NET MVC project (all the typical stuff, UI, controllers, content, scripts, resources and helpers). I have no Models in my ASP.NET MVC project. I've just run into a problem because of that coz I want to use the new DataAnnotation feature in MVC 2 on my Bussiness class, which are, as said in Core, however I have I want to be able to localize the error messages. This where my problem starts. I cannot use my Resources from MVC project in Core. The MVC project references Core and it cannot be vice-versa. My options as I see them are: 1) Move Resources out but this would require correcting a whole bunch of Views and Controllers where I reference them, 2) Make a complete restructure of my app What are your thoughts on this? Also, Should I just move everything business related into Models folder in MVC project?? Does it even make any sense to have it structured like that, because we can just make subfolders for everything under MVC project? The whole Core library is not intended to ever be used for anything else, so there actually no point of compiling it to a separate DLL. Suggestions appreciated.

    Read the article

  • Loading a view routed by a URL parameter (e.g., /users/:id) in MEAN stack

    - by Matt Rowles
    I am having difficulties with trying to load a user by their id, for some reason my http.get call isn't hitting my controller. I get the following error in the browser console: TypeError: undefined is not a function at new <anonymous> (http://localhost:9000/scripts/controllers/users.js:10:8) Update I've fixed my code up as per comments below, but now my code just enters an infinite loop in the angular users controllers (see code below). I am using the Angular Express Generator for reference Backend - nodejs, express, mongo routes.js: // not sure if this is required, but have used it before? app.param('username', users.show); app.route('/api/users/:username') .get(users.show); controller.js: // This never gets hit exports.show = function (req, res, next, username) { User.findOne({ username: username }) .exec(function (err, user) { req.user = user; res.json(req.user || null); }); }; Frontend - angular app.js: $routeProvider .when('/users/:username', { templateUrl: function( params ){ return 'users/view/' + params.username; }, controller: 'UsersCtrl' }) services/user.js: angular.module('app') .factory('User', function ($resource) { return $resource('/api/users/:username', { username: '@username' }, { update: { method: 'PUT', params: {} }, get: { method: 'GET', params: { username:'username' } } }); }); controllers/users.js: angular.module('app') .controller('UsersCtrl', ['$scope', '$http', '$routeParams', '$route', 'User', function ($scope, $http, $routeParams, $route, User) { // this returns the error above $http.get( '/api/users/' + $routeParams.username ) .success(function( user ) { $scope.user = user; }) .error(function( err) { console.log( err ); }); }]); If it helps, I'm using this setup

    Read the article

  • fluent nhibernate - storing and retrieving three classes in/from one table

    - by Will I Am
    Noob question. I have this situation where I have these objects: class Address { string Street; string City; ... } class User { string UserID; Address BillingAddress; Address MailingAddress; ... } What is the proper way of storing this data using (fluent) nHibernate? I could use a separate Address table and create a reference, but they are 1:1 relationships so I don't really want to incur the overhead of a join. Ideally I would store this as a single flat record. So, my question is, what is the proper way of storing an instance of class 'User' in such a way that it stores its contents and also the two addresses as a single record? My knowledge is failing me on how I can store this information in such a way that the two Address records get different column names (e.g. BillingAddress_Street and MailingAddress_Street, for example), and also how to read a record back into a User instance.

    Read the article

  • Static selection and Ruby on Rails objects

    - by Dave
    Hi all- I have a simple problem, but am having trouble wrapping my head around it. I have an video object that should have one or more "genres". This list of genres should be prepopulated and then the user should just select one or more using autocomplete or some such. Here is the question: Is it worth creating a table with genres for the static selection? Or should it just be included in the presentation layer? If there is a static table, how do we name it correctly. I envision something like this class Video < ActiveRecord::Base has_many :genres ... end class Genre < ... belongs_to :video ... end But then we get a table called genre, that basically maps all the selected genres to their parent videos. There would need to be some static table to reference the static genres. Is this the best way to do it? Sorry if this was rambl-y a little stream of conciousness. Thanks!

    Read the article

  • UPDATE Table SET Field

    - by davlyo
    This is my Very first Post! Bear with me. I have an Update Statement that I am trying to understand how SQL Server handles it. UPDATE a SET a.vField3 = b.vField3 FROM tableName a INNER JOIN tableName b ON a.vField1 = b.vField1 AND b.nField2 = a.nField2 – 1 This is my query in its simplest form. vField1 is a Varchar nField2 is an int (autonumber) vField3 is a Varchar I have left the WHERE clause out so understand there is logic that otherwise makes this a nessessity. Say vField1 is a Customer Number and that Customer has 3 records The value in nField2 is 1, 2, and 3 consecutively. vField3 is a Status When the Update comes to a.nField2 = 1 there is no a.nField2 -1 so it continues When the Update comes to a.nField2 = 2, b.nField2 = 1 When the Update comes to a.nField2 = 3, b.nField2 = 2 So when the Update is on a.nField2 = 2, alias b reflects what is on the line prior (b.nField2 = 1) And it SETs the Varchar Value of a.vField3 = b.vField3 When the Update is on a.nField2 = 3, alias b reflects what is on the line prior (b.nField2 = 2) And it (should) SET the Varchar Value of a.vField3 = b.vField3 When the process is complete –the Second of three records looks as expected –hence the value in vField3 of the second record reflects the value in vField3 from the First record However, vField3 of the Third record does not reflect the value in vField3 from the Second record. I think this demonstrates that SQL Server may be producing a transaction of some sort and then an update. Question: How can I get the DB to Update after each transaction so I can reference the values generated by each transaction?

    Read the article

  • Help with simple javascript loop

    - by Gabriel
    Hello, I have a simple javascript that I'd like to loop for multiple elements. Here's my code: <script type='text/javascript'> for(i = 1; i < 100; i++) { $('#link'+i).click(function() { $('#container').removeClass(); $('#container').addClass('templateid'+i); }); } </script> What I'd like to achieve is the same addClass function for multiple id's (e.g. link2, link3, link4), with the corresponding class (e.g. template2, template3, template4). Any help would be hugely appreciated! For reference, an individual call like this one, does work, so I don't see why the loop above doesn't function the same: <script type='text/javascript'> $('#link2').click(function() { $('#container').removeClass(); $('#container').addClass('templateid2'); }); </script>

    Read the article

  • In C# should I reuse a function / property parameter to compute cleaner temporary value or create a

    - by Hamish Grubijan
    The example below may not be problematic as is, but it should be enough to illustrate a point. Imagine that there is a lot more work than trimming going on. public string Thingy { set { // I guess we can throw a null reference exception here on null. value = value.Trim(); // Well, imagine that there is so much processing to do this.thingy = value; // That this.thingy = value.Trim() would not fit on one line ... So, if the assignment has to take two lines, then I either have to abusereuse the parameter, or create a temporary variable. I am not a big fan of temporary variables. On the other hand, I am not a fan of convoluted code. I did not include an example where a function is involved, but I am sure you can imagine it. One concern I have is if a function accepted a string and the parameter was "abused", and then someone changed the signature to ref in both places - this ought to mess things up, but ... who would knowingly make such a change if it already worked without a ref? Seems like it is their responsibility in this case. If I mess with the value of value, am I doing something non-trivial under the hood? If you think that both approaches are acceptable, then which do you prefer and why? Thanks.

    Read the article

  • Javascript object properties access functions in parent constructor?

    - by Bob Spryn
    So I'm using this pretty standard jquery plugin pattern whereby you can grab an api after applying the jquery function to a specific instance. This API is essentially a javascript object with a bunch of methods and data. So I wanted to essentially create some private internal methods for the object only to manipulate data etc, which just doesn't need to be available as part of the API. So I tried this: // API returned with new $.TranslationUI(options, container) $.TranslationUI = function (options, container) { // private function? function monkey(){ console.log("blah blah blah"); } // extend the default settings with the options object passed this.settings = $.extend({},$.TranslationUI.defaultSettings,options); // set a reference for the container dom element this.container = container; // call the init function this.init(); }; The problem I'm running into is that init can't call that function "monkey". I'm not understanding the explanation behind why it can't. Is it because init is a prototype method?($.TranslationUI's prototype is extended with a bunch of methods including init elsewhere in the code) $.extend($.TranslationUI, { prototype: { init : function(){ // doesn't work monkey(); // editing flag this.editing = false; // init event delegates here for // languagepicker $(this.settings.languageSelector, this.container).bind("click", {self: this}, this.selectLanguage); } } }); Any explanations would be helpful. Would love other thoughts on creating private methods with this model too. These particular functions don't HAVE to be in prototype, and I don't NEED private methods protected from being used externally, but I want to know how should I have that requirement in the future.

    Read the article

  • Database PK-FK design for future-effective-date entries?

    - by Scott Balmos
    Ultimately I'm going to convert this into a Hibernate/JPA design. But I wanted to start out from purely a database perspective. We have various tables containing data that is future-effective-dated. Take an employee table with the following pseudo-definition: employee id INT AUTO_INCREMENT ... data fields ... effectiveFrom DATE effectiveTo DATE employee_reviews id INT AUTO_INCREMENT employee_id INT FK employee.id Very simplistic. But let's say Employee A has id = 1, effectiveFrom = 1/1/2011, effectiveTo = 1/1/2099. That employee is going to be changing jobs in the future, which would in theory create a new row, id = 2 with effectiveFrom = 7/1/2011, effectiveTo = 1/1/2099, and id = 1's effectiveTo updated to 6/30/2011. But now, my program would have to go through any table that has a FK relationship to employee every night, and update those FK to reference the newly-effective employee entry. I have seen various postings in both pure SQL and Hibernate forums that I should have a separate employee_versions table, which is where I would have all effective-dated data stored, resulting in the updated pseudo-definition below: employee id INT AUTO_INCREMENT employee_versions id INT AUTO_INCREMENT employee_id INT FK employee.id ... data fields ... effectiveFrom DATE effectiveTo DATE employee_reviews id INT AUTO_INCREMENT employee_id INT FK employee.id Then to get any actual data, one would have to actually select from employee_versions with the proper employee_id and date range. This feels rather unnatural to have this secondary "versions" table for each versioned entity. Anyone have any opinions, suggestions from your own prior work, etc? Like I said, I'm taking this purely from a general SQL design standpoint first before layering in Hibernate on top. Thanks!

    Read the article

  • How to know the type of an object in a list?

    - by nacho4d
    Hi, I want to know the type of object (or type) I have in my list so I wrote this: void **list; //list of references list = new void * [2]; Foo foo = Foo(); const char *not_table [] = {"tf", "ft", 0 }; list[0] = &foo; list[1] = not_table; if (dynamic_cast<LogicProcessor*>(list[0])) { //ERROR here ;( printf("Foo was found\n"); } if (dynamic_cast<char*> (list[0])) { //ERROR here ;( printf("char was found\n"); } but I get : error: cannot dynamic_cast '* list' (of type 'void*') to type 'class Foo*' (source is not a pointer to class) error: cannot dynamic_cast '* list' (of type 'void*') to type 'char*' (target is not pointer or reference to class) Why is this? what I am doing wrong here? Is dynamic_cast what I should use here? Thanks in advance EDIT: I know above code is much like plain C and surely sucks from the C++ point of view but is just I have the following situation and I was trying something before really implementing it: I have two arrays of length n but both arrays will never have an object at the same index. Hence, or I have array1[i]!=NULL or array2[i]!=NULL. This is obviously a waste of memory so I thought everything would be solved if I could have both kind of objects in a single array of length n. I am looking something like Cocoa's (Objective-C) NSArray where you don't care about the type of the object to be put in. Not knowing the type of the object is not a problem since you can use other method to get the class of a certain later. Is there something like it in c++ (preferably not third party C++ libraries) ? Thanks in advance ;)

    Read the article

  • Get element id on hover (or mouseover)

    - by Peter C
    Still getting to grips with jQuery and I am pleased to have got as far as I have, especially help from the posts in this forum. However, now got to a working function that does what I want, that is to create a radio group that looks like a button. It pulls data via json and loops through creating the radio buttons. I want to get the id of the radio buttons generated so that I can then parse through to the next step of the app but I can't get it to work. function FillDiv(groups, side) { var cnt = 1; var newClass = ''; var newType = ''; if (side == '#ck-button-left') { newClass = 'leftClass'; newType = 'radio' } else { newClass = 'rightClass'; newType = 'checkbox' } $.each(groups, function (index, groups) { $(side) .append( $(document.createElement('label')).attr({ id: cnt + 'lbl' }) ); $('#' + cnt + 'lbl') .append( $(document.createElement('input')).attr({ id: groups.GroupCode, type: newType, name: 'testGroup', class: newClass }) ); $('#' + groups.GroupCode).after ( $(document.createElement('span')).text(groups.GroupName).attr('class', 'leftSpan') ); $('#' + cnt + 'lbl').after($(document.createElement('br'))); cnt = cnt + 1; }); } Looking through various searched, it should work with something like... $('#leftSpan').mouseover(function () { $('#lblOutput').html(this.id); }); or, as I suspect, it is something to do with the nesting of the label/input that I need to reference the parent or child. Any pointers would be appreciated.

    Read the article

  • Combining two exe files

    - by Sophia
    Here's some background to my problem: I have a project in Visual C++ 2006 and a project in in Visual C++ 2010 Express. Both compiles to form an exe file each. I cannot convert my 2006 project to 2010 because I get a lot of "unable to load project" errors. I also cannot port my 2010 project code to 2006 (I always get errors no matter what I try, something to do with libraries). My final solution requires me to only have ONE executable. Is there anything I can do to achieve that? I've done some quick search on Google and found there to be exe joiners, but I've also heard that those things are often used to make malware. For reference, I am working with "dummy" clients, and therefore want to simplify things on their end as much as possible. Thus, having them executing one exe is better than having them execute two. Also, I do not wish for their antivirus to go haywire because I used some program to join two exe together. What do? Edit: The two project files do different things. For example, the project in VS2006 one sets up a server, and the project in VS2010 one grabs info on the user's OS. The code for the "server", I think, has a lot of dependencies and for some reason cannot convert to Visual c++ 2010. The code for "grabbing" requires some newer libraries and compiling options, and would not work if I port to 2006.

    Read the article

  • Sharing class member data between sub components

    - by Tim Gradwell
    I have an aggregate 'main' class which contains some data which I wish to share. The main class also has other class members. I want to share the data with these other class members. What is the correct / neatest way to do this? The specific example I have is as follows. The main class is a .net Form. I have some controls (actually controls within controls) on the main form which need access to the shared data. Main Form - DataX - DataY - Control1 -- Subcontrol1 - Control2 -- SubControl2 SubControls 1 and 2 both wish to access DataX and DataY. The trouble is, I feel like better practice (to reduce coupling), would be that either subcontrols should not know about Main Form, or Main Form should not know about subcontrols - probably the former. For subcontrols not to know about Main Form, would probably mean Main Form passing references to both Controls 1 and 2, which in turn would pass the references on to SubControls 1 and 2. Lots of lines of code which just forward the references. If I later added DataZ and DataW, and Controls 3 and 4 and SubControls 3 and 4, I'd have to add lots more reference forwarding code. It seems simpler to me to give SubControls 1 and 2 member references to Main Form. That way, any sub control could just ask for MainForm.DataX or MainForm.DataY and if I ever added new data, I could just access it directly from the sub controls with no hassle. But it still involves setting the 'MainForm' member references every time I add a new Control or Subcontrol. And it gives me a gut feeling of 'wrong'. As you might be able to tell I'm not happy with either of my solutions. Is there a better way? Thanks

    Read the article

  • Vectors or Java arrays for Tetris?

    - by StackedCrooked
    I'm trying to create a Tetris-like game with Clojure and I'm having some trouble deciding the data structure for the playing field. I want to define the playing field as a mutable grid. The individual blocks are also grids, but don't need to be mutable. My first attempt was to define a grid as a vector of vectors. For example an S-block looks like this: :s-block { :grids [ [ [ 0 1 1 ] [ 1 1 0 ] ] [ [ 1 0 ] [ 1 1 ] [ 0 1 ] ] ] } But that turns out to be rather tricky for simple things like iterating and painting (see the code below). For making the grid mutable my initial idea was to make each row a reference. But then I couldn't really figure out how to change the value of a specific cell in a row. One option would have been to create each individual cell a ref instead of each row. But that feels like an unclean approach. I'm considering using Java arrays now. Clojure's aget and aset functions will probably turn out to be much simpler. However before digging myself in a deeper mess I want to ask ideas/insights. How would you recommend implementing a mutable 2d grid? Feel free to share alternative approaches as well. Source code current state: Tetris.clj (rev452)

    Read the article

  • Can I make a derived class inherit a derived member from its base class in Java?

    - by Eric
    I have code that looks like this: public class A { public void doStuff() { System.out.print("Stuff successfully done"); } } public class B extends A { public void doStuff() { System.out.print("Stuff successfully done, but in a different way"); } public void doMoreStuff() { System.out.print("More advanced stuff successully done"); } } public class AWrapper { public A member; public AWrapper(A member) { this.member = member; } public void doStuffWithMember() { a.doStuff(); } } public class BWrapper extends AWrapper { public B member; public BWrapper(B member) { super(member); //Pointer to member stored in two places: this.member = member; //Not great if one changes, but the other does not } public void doStuffWithMember() { member.doMoreStuff(); } } However, there is a problem with this code. I'm storing a reference to the member in two places, but if one changes and the other does not, there could be trouble. I know that in Java, an inherited method can narrow down its return type (and perhaps arguments, but I'm not certain) to a derived class. Is the same true of fields?

    Read the article

< Previous Page | 559 560 561 562 563 564 565 566 567 568 569 570  | Next Page >