Search Results

Search found 41535 results on 1662 pages for 'method reference'.

Page 195/1662 | < Previous Page | 191 192 193 194 195 196 197 198 199 200 201 202  | Next Page >

  • Whether to put method code in a VB.Net data storage class, or put it in a separate class?

    - by Alan K
    TLDR summary: (a) Should I include (lengthy) method code in classes which may spawn multiple objects at runtime, (b) does doing so cause memory usage bloat, (c) if so should I "outsource" the code to a class that is loaded only once and have the class methods call that, or alternatively (d) does the code get loaded only once with the object definition anyway and I'm worrying about nothing? ........ I don't know whether there's a good answer to this but if there is I haven't found it yet by searching in the usual places. In my VB.Net (2010 if it matters) WinForms project I have about a dozen or so class objects in an object model. Some of these are pretty simple and do little more than act as data storage repositories. The ones further up the object model, however, have an increasing number of methods. There can be a significant number of higher level objects in use though the exact number will be runtime dependent so I can't be more precise than that. As I was writing the method code for one of the top level ones I noticed that it was starting to get quite lengthy. Memory optimisation is something of a lost art given how much memory the average PC has these days but I don't want to make my application a resource hog. So my questions for anyone who knows .Net way better than I do (of which there will be many) are: Is the code loaded into memory with each instance of the class that's created? Alternatively is it loaded only once with the definition of the class, and all derived objects just refer to that definition? (I'm not really sure how that could be possible given that, for example, event handlers can be assigned dynamically, but no harm asking.) If the answer to the first one is yes, would it be more efficient to write the code in a "utility" object which is loaded only once and called from the real class' methods? Any thoughts appreciated.

    Read the article

  • How to call a method in another class in Java?

    - by Puchatek
    Currently I have two classes. a classroom class and a School class. I would like to write a method in the School class to call public void setTeacherName(String newTeacherName) from the classroom class. public class classroom { private String classRoomName; private String teacherName; public void setClassRoomName(String newClassRoomName) { classRoomName = newClassRoomName; } public String returnClassRoomName() { return classRoomName; } public void setTeacherName(String newTeacherName) { teacherName = newTeacherName; } public String returnTeacherName() { return teacherName; } } import java.util.ArrayList; public class School { private ArrayList<classroom> classrooms; private String classRoomName; private String teacherName; public School() { classrooms = new ArrayList<classroom>(); } public void addClassRoom(classroom newClassRoom, String theClassRoomName) { classrooms.add(newClassRoom); classRoomName = theClassRoomName; } // how to write a method to add a teacher to the classroom by using the classroom parameter // and the teachers name }

    Read the article

  • How to speed-up a simple method? (possibily without changing interfaces or data structures)

    - by baol
    Hello. I have some data structures: all_unordered_mordered_m is a big vector containing all the strings I need (all different) ordered_m is a small vector containing the indexes of a subset of the strings (all different) in the former vector position_m maps the indexes of objects from the first vector to their position in the second one. The string_after(index, reverse) method returns the string referenced by ordered_m after all_unordered_m[index]. ordered_m is considered circular, and is explored in natural or reverse order depending on the second parameter. The code is something like the following: struct ordered_subset { // [...] std::vector<std::string>& all_unordered_m; // size = n >> 1 std::vector<size_t> ordered_m; // size << n std::map<size_t, size_t> position_m; // positions of strings in ordered_m const std::string& string_after(size_t index, bool reverse) const { size_t pos = position_m.find(index)->second; if(reverse) pos = (pos == 0 ? orderd_m.size() - 1 : pos - 1); else pos = (pos == ordered.size() - 1 ? 0 : pos + 1); return all_unordered_m[ordered_m[pos]]; } }; Given that: I do need all of the data-structures for other purposes; I cannot change them because I need to access the strings: by their id in the all_unordered_m; by their index inside the various ordered_m; I need to know the position of a string (identified by it's position in the first vector) inside ordered_m vector; I cannot change the string_after interface without changing most of the program. How can I speed up the string_after method that is called billions of times and is eating up about 10% of the execution time?

    Read the article

  • How do I pass references as method parameters across AppDomains?

    - by Thiado de Arruda
    I have been trying to get the following code to work(everything is defined in the same assembly) : namespace SomeApp{ public class A : MarshalByRefObject { public byte[] GetSomeData() { // } } public class B : MarshalByRefObject { private A remoteObj; public void SetA(A remoteObj) { this.remoteObj = remoteObj; } } public class C { A someA = new A(); public void Init() { AppDomain domain = AppDomain.CreateDomain("ChildDomain"); string currentAssemblyPath = Assembly.GetExecutingAssembly().Location; B remoteB = domain.domain.CreateInstanceFromAndUnwrap(currentAssemblyPath,"SomeApp.B") as B; remoteB.SetA(someA); // this throws an ArgumentException "Object type cannot be converted to target type." } } } What I'm trying to do is pass a reference of an 'A' instance created in the first AppDomain to the child domain and have the child domain execute a method on the first domain. In some point on 'B' code I'm going to call 'remoteObj.GetSomeData()'. This has to be done because the 'byte[]' from 'GetSomeData' method must be 'calculated' on the first appdomain. What should I do to avoid the exception, or what can I do to achieve the same result?

    Read the article

  • If I cast an IQueryable as an IEnumerable then call a Linq extension method, which implementation gets called?

    - by James Morcom
    Considering the following code: IQueryable<T> queryable; // something to instantiate queryable var enumerable = (IEnumerable<T>) queryable; var filtered = enumerable.Where(i => i > 3); In the final line, which extension method gets called? Is it IEnumerable<T>.Where(...)? Or will IQueryable<T>.Where(...) be called because the actual implementation is still obviously a queryable? Presumably the ideal would be for the IQueryable version to be called, in the same way that normal polymorphism will always use the more specific override. In Visual Studio though when I right-click on the Where method and "Go to Definition" I'm taken to the IEnumerable version, which kind of makes sense from a visual point-of-view. My main concern is that if somewhere in my app I use Linq to NHibernate to get a Queryable, but I pass it around using an interface that uses the more general IEnumerable signature, I'll lose the wonders of deferred database execution!

    Read the article

  • Coding style in .NET: whether to refactor into new method or not?

    - by Dione
    Hi As you aware, in .NET code-behind style, we already use a lot of function to accommodate those _Click function, _SelectedIndexChanged function etc etc. In our team there are some developer that make a function in the middle of .NET function, for example: public void Button_Click(object sender, EventArgs e) {     some logic here..     some logic there..     DoSomething();     DoSomethingThere();     another logic here..     DoOtherSomething(); } private void DoSomething() { } private void DoSomethingThere() { } private void DoOtherSomething() { } public void DropDown_SelectedIndexChanged() { } public void OtherButton_Click() { } and the function listed above is only used once in that function and not used anywhere else in the page, or called from other part of the solution. They said it make the code more tidier by grouping them and extract them into additional sub-function. I can understand if the sub-function is use over and over again in the code, but if it is only use once, then I think it is not really a good idea to extract them into sub-function, as the code getting bigger and bigger, when you look into the page and trying to understand the logic or to debug by skimming through line by line, it will make you confused by jumping from main function to the sub-function then to main function and to sub-function again. I know this kind of grouping by method is better when you writing old ASP or Cold fusion style, but I am not sure if this kind of style is better for .NET or not. Question is: which is better when you developing .NET, is grouping similar logic into a sub-method better (although they only use once), or just put them together inside main function and add //explanation here on the start of the logic is better? Hope my question is clear enough. Thanks.

    Read the article

  • Java: How do I implement a method that takes 2 arrays and returns 2 arrays?

    - by HansDampf
    Okay, here is what I want to do: I want to implement a crossover method for arrays. It is supposed to take 2 arrays of same size and return two new arrays that are a kind of mix of the two input arrays. as in [a,a,a,a] [b,b,b,b] ------ [a,a,b,b] [b,b,a,a]. Now I wonder what would be the suggested way to do that in Java, since I cannot return more than one value. My ideas are: - returning a Collection(or array) containing both new arrays. I dont really like that one because it think would result in a harder to understand code. - avoiding the need to return two results by calling the method for each case but only getting one of the results each time. I dont like that one either, because there would be no natural order about which solution should be returned. This would need to be specified, though resulting in harder to understand code. Plus, this will work only for this basic case, but I will want to shuffle the array before the crossover and reverse that afterwards. I cannot do the shuffling isolated from the crossover since I wont want to actually do the operation, instead I want to use the information about the permutation while doing the crossover, which will be a more efficient way I think.

    Read the article

  • Is this method a good aproach to get SQL values from C#?

    - by MadBoy
    I have this little method that i use to get stuff from SQL. I either call it with varSearch = "" or varSearch = "something". I would like to know if having method written this way is best or would it be better to split it into two methods (by overloading), or maybe i could somehow parametrize whole WHERE clausule? private void sqlPobierzKontrahentDaneKlienta(ListView varListView, string varSearch) { varListView.BeginUpdate(); varListView.Items.Clear(); string preparedCommand; if (varSearch == "") { preparedCommand = @" SELECT t1.[KlienciID], CASE WHEN t2.[PodmiotRodzaj] = 'Firma' THEN t2.[PodmiotFirmaNazwa] ELSE t2.[PodmiotOsobaNazwisko] + ' ' + t2.[PodmiotOsobaImie] END AS 'Nazwa' FROM [BazaZarzadzanie].[dbo].[Klienci] t1 INNER JOIN [BazaZarzadzanie].[dbo].[Podmioty] t2 ON t1.[PodmiotID] = t2.[PodmiotID] ORDER BY t1.[KlienciID]"; } else { preparedCommand = @" SELECT t1.[KlienciID], CASE WHEN t2.[PodmiotRodzaj] = 'Firma' THEN t2.[PodmiotFirmaNazwa] ELSE t2.[PodmiotOsobaNazwisko] + ' ' + t2.[PodmiotOsobaImie] END AS 'Nazwa' FROM [BazaZarzadzanie].[dbo].[Klienci] t1 INNER JOIN [BazaZarzadzanie].[dbo].[Podmioty] t2 ON t1.[PodmiotID] = t2.[PodmiotID] WHERE t2.[PodmiotOsobaNazwisko] LIKE @searchValue OR t2.[PodmiotFirmaNazwa] LIKE @searchValue OR t2.[PodmiotOsobaImie] LIKE @searchValue ORDER BY t1.[KlienciID]"; } using (var varConnection = Locale.sqlConnectOneTime(Locale.sqlDataConnectionDetails)) using (SqlCommand sqlQuery = new SqlCommand(preparedCommand, varConnection)) { sqlQuery.Parameters.AddWithValue("@searchValue", "%" + varSearch + "%"); using (SqlDataReader sqlQueryResult = sqlQuery.ExecuteReader()) if (sqlQueryResult != null) { while (sqlQueryResult.Read()) { string varKontrahenciID = sqlQueryResult["KlienciID"].ToString(); string varKontrahent = sqlQueryResult["Nazwa"].ToString(); ListViewItem item = new ListViewItem(varKontrahenciID, 0); item.SubItems.Add(varKontrahent); varListView.Items.AddRange(new[] {item}); } } } varListView.EndUpdate(); }

    Read the article

  • Should convert String to Int in java @ 1.5 or use other method?

    - by NiksBestJPro
    I'm writing a program in which I want to terminate program by pressing any key(whether character or numbers), so I did a conversion from string to int using Integer.parseInt(variable) method and compare choices if it is not desired choice it should terminate the program but it show an error Exception in thread "main" java.lang.NumberFormatException: for input string: "d". program code is as follows:- public class mainClass { public static void main(String[]ar) { double res=0; Scanner in = new Scanner(System.in); Tdata td1 = new Tdata(); //another class object System.out.println("*Temperature Conversion*"); System.out.println("------------------------------"); System.out.println("Press 1- C2F"); System.out.println("Press 2- F2C"); System.out.println("<- Press aNY kEY TO Exit -"); String choice = in.nextLine(); //==================================================================== int ch = Integer.parseInt(choice); System.out.println("String has converted: " +ch); //verifying if converted into int if(ch == 1 || ch == 2) { if(ch == 1) { td1.getVal(37.4); res = td1.C2F(); System.out.println("Resulted Temperature: "+res); } else if(ch == 2) { td1.getVal(104.2); res = td1.F2C(); System.out.println("Resulted Temperature: "+res); } else { System.out.println("mind your input plz"); } } else { System.out.println("<- You select to exit ->"); System.exit(0); } //========================================================================================= }//end of main }//end of public class Now I think that I should convert undesired input to its previous state ie. String state.. is it right way or should Try another predefined method available in api. -Thanks! Niks

    Read the article

  • How do you create a generic method in a class?

    - by Seth Spearman
    Hello, I am really trying to follow the DRY principle. I have a sub that looks like this? Private Sub DoSupplyModel OutputLine("ITEM SUMMARIES") Dim ItemSumms As New SupplyModel.ItemSummaries(_currentSupplyModel, _excelRows) ItemSumms.FillRows() OutputLine("") OutputLine("NUMBERED INVENTORIES") Dim numInvs As New SupplyModel.NumberedInventories(_currentSupplyModel, _excelRows) numInvs.FillRows() OutputLine("") End Sub I would like to collapse these into a single method using generics. For the record, ItemSummaries and NumberedInventories are both derived from the same base class DataBuilderBase. I can't figure out the syntax that will allow me to do ItemSumms.FillRows and numInvs.FillRows in the method. FillRows is declared as Public Overridable Sub FillRows in the base class. Thanks in advance. EDIT Here is my end result Private Sub DoSupplyModels() DoSupplyModelType("ITEM SUMMARIES",New DataBlocks(_currentSupplyModel,_excelRows) DoSupplyModelType("DATA BLOCKS",New DataBlocks(_currentSupplyModel,_excelRows) End Sub Private Sub DoSupplyModelType(ByVal outputDescription As String, ByVal type As DataBuilderBase) OutputLine(outputDescription) type.FillRows() OutputLine("") End Sub But to answer my own question...I could have done this... Private Sub DoSupplyModels() DoSupplyModelType(Of Projections)("ITEM SUMMARIES") DoSupplyModelType(Of DataBlocks)("DATA BLOCKS") End Sub Private Sub DoSupplyModelType(Of T as DataBuilderBase)(ByVal outputDescription As String, ByVal type As T) OutputLine(outputDescription) dim type as New T(_currentSupplyModel,_excelRows) type.FillRows() OutputLine("") End Sub Is that right? Does the New T() work? Seth

    Read the article

  • C# Method not returning a unique value when it should be.

    - by Josh King
    I have two methods, generateNounPhrase() and generateVerbPhrase(). VerbPhrase will call on NounPhrase half the time and it's output the output should be something to the effect of: the empty lot re-animates this pyramid (bold indicating where generateNounPhrase() is logically called). The true output however is in the form of: the empty lot re-animates the empty lot At first I thought my randomIndex method wasn't working as I had intended, but if I run the two methods again I do get different noun phrases but they are not unique at the beginning and end of the sentence as they should be. Any idea what I am doing wrong in order to get one method to show the same result? private string generateNounPhrase() { string nounPhraseString = ""; nounPhraseString = nounMarkersStringList[randomIndex(0,nounMarkersStringList.Count-1)]; if (included(1, 4, 2) == true) { nounPhraseString += " " + adjectivesStringList[randomIndex(0, adjectivesStringList.Count - 1)]; } nounPhraseString += " " + nounsStringList[randomIndex(0, nounsStringList.Count - 1)]; return nounPhraseString; } private string generateVerbPhrase() { string verbPhraseString = ""; if (included(1, 4, 2) == true) { verbPhraseString = intransitiveVerbsStringList[randomIndex(0, intransitiveVerbsStringList.Count - 1)]; } else { verbPhraseString = transitiveVerbsStringList[randomIndex(0, transitiveVerbsStringList.Count - 1)] + " " + generateNounPhrase(); } return verbPhraseString; }

    Read the article

  • Can't call an object method. PHP reports variable undefined

    - by user1285697
    This is the weirdest bug! It is probably something silly, but I have no idea how to fix it. If anyone could help, I would be most grateful! I have three files, one is called items.php, another is called tableFunctions.php, and the third is called mysql.php. I use two global objects called 'mysql' and 'tableFunctions'. They are stored in the files 'mysql.php', and 'tableFunctions.php', respectively. In each file, I create an instance of its object, assigning it to the global variable $_mysql, or $_table. like this: In the file mysql.php: global $_mysql; $_mysql = new mysql(); In the file tableFunctions.php: global $_table; $_table = new tableFunctions(); Here's how it is supposed to work: The items.php file includes the tableFunctions.php file... Which in turn, needs the mysql.php file, so it includes it too. In the items.php file, I call the method getTable(), which is contained in the object tableFunctions.(and in the variable $_table.) Like this: $t = $_table->getTable('items'); The getTable function calls the method, arrayFromResult(), which is contained within in the object mysql.(and in the variable $_mysql.) Like this: $result = $_mysql->arrayFromResult($r); That's where I get the error. PHP says that the variable '$_mysql' is undefined, but I defined it in the 'mysql.php' file.(see above) I also included mysql.php with the following code: include_once 'mysql.php'; I have no idea what is wrong! If anyone can help that would be much appreciated. The source files can be downloaded with the following link: https://www.dropbox.com/sh/bjj2gyjsybym89r/YLxqyNvQdn

    Read the article

  • How to access property in sub method after it runs?

    - by Warren
    I'm having a hard time working this one out but I think it should be pretty simple. Basically, I have this method which talks to a webservice and I need to return some data from the sub method, the "authCode". What am I doing wrong? How can I get the authCode out of the manager, or can I create a block or something to to ensure that the manager block runs first? Am I even using the right words - blocks, sub methods??? Please help :) - (NSString *)getAuthCodeEXAMPLE { __block NSString *returnString = @"nothing yet!"; NSURL *baseURL = [NSURL URLWithString:BaseURLString]; NSDictionary *parametersGetAuthCode = @{@"req": @"getauth"}; AFHTTPSessionManager *manager = [[AFHTTPSessionManager alloc] initWithBaseURL:baseURL]; manager.responseSerializer = [AFJSONResponseSerializer serializer]; [manager POST:APIscript parameters:parametersGetAuthCode success:^(NSURLSessionDataTask *task, id responseObject) { if ([task.response isKindOfClass:[NSHTTPURLResponse class]]) { NSHTTPURLResponse *r = (NSHTTPURLResponse *)task.response; if ([r statusCode] == 200) { self.returnedData = responseObject; NSString *authCode = [self.returnedData authcode]; NSLog(@"Authcode: %@", authCode); returnString = authCode; } } } failure:^(NSURLSessionDataTask *task, NSError *error) { UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Error" message:[error localizedDescription] delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil]; [alertView show]; }]; //this currently returns "nothing yet!" return returnString; }

    Read the article

  • C# Basic Multi-Threading Question: Call Method on Thread A from Thread B (Thread B started from Thre

    - by Nick
    What is the best way to accomplish this: The main thread (Thread A) creates two other threads (Thread B and Thread C). Threads B and C do heavy disk I/O and eventually need to pass in resources they created to Thread A to then call a method in an external DLL file which requires the thread that created it to be called correctly so only Thread A can call it. The only other time I ever used threads was in a Windows Forms application, and the invoke methods were just what I needed. This program does not use Windows Forms, and as such there are no Control.Invoke methods to use. I have noticed in my testing that if a variable is created in Thread A, I have no trouble accessing and modifying it from Thread B/C which seems very wrong to me. With Winforms, I was sure it threw errors for trying to access things created on other threads. I know it is unsafe to change things from multiple threads, but I really hoped .NET would forbid it altogether to ensure safe coding. Does .NET do this, and I am just missing the boat, or does it only do it with WinForm apps? Since it does seemingly allow this, do I do something like an OS would do, create a flag and monitor it from Thread A to see if it changes. If it does, then call the method. Doesnt the event handler essentially do this, so could an event be used somehow called on the main thread?

    Read the article

  • Explicit return from a Ruby method - implementation hiding, reuse and optimisations.

    - by Chris McCauley
    Hi, Rather than allowing a Ruby method to blindly return the last statement evaluated, is there any advantage to returning nil explicitly? In terms of implementation hiding and reuse, it seems dangerous to blindly allow the last expression evaluated to be returned - isn't there a danger that a user will rely on this only to get a nasty surprise when the implementation is modified? Surely returning nil would be better unless an explicit return value was given. Following on, is there an optimisation that Ruby can make when the return is a simple type rather than a reference to a more complex object? Chris

    Read the article

  • Explicit return form a Ruby method - implementation hiding, reuse and optimisations.

    - by Chris McCauley
    Hi, Rather than allowing a Ruby method to blindly return the last statement evaluated, is there any advantage to returning nil explicitly? In terms of implementation hiding and reuse, it seems dangerous to blindly allow the last expression evaluated to be returned - isn't there a danger that a user will rely on this only to get a nasty surprise when the implementation is modified? Surely returning nil would be better unless an explicit return value was given. Following on, is there an optimisation that Ruby can make when the return is a simple type rather than a reference to a more complex object? Chris

    Read the article

  • Java: confirm method Binary division and find remainder is correct?

    - by cadwag
    I am parsing binary files and have to implement a CRC algorithm to ensure the file is not corrupted. Problem is that I can't seem to get the binary math working when using larger numbers. The example I'm trying to get working: BigInteger G = new BigInteger("11001", 2); BigInteger M = new BigInteger("1110010000", 2); BigInteger R = M.remainder(G); I am expecting: R = "0101" But I am getting: R = "1100" I am assuming the remainder of 0101 is correct since it is given to me in this book I am using as a reference for the CRC algorithm (it's not based in Java), but I can't seem to get it working. I can get small binary calculations to work that I have solved by hand, but not the larger ones. I'll admit that I haven't worked the larger ones by hand yet, that is my next step, but I wanted to see if someone could point out a glaring flaw I have in my code. Can anyone confirm or deny that my methodology is correct? Thanks

    Read the article

  • Clone LINQ To SQL object Extension Method throws object dispose exception....

    - by gtas
    Hello all, I have this extension method for cloning my LINQ To SQL objects: public static T CloneObjectGraph<T>(this T obj) where T : class { var serializer = new DataContractSerializer(typeof(T), null, int.MaxValue, false, true, null); using (var ms = new System.IO.MemoryStream()) { serializer.WriteObject(ms, obj); ms.Position = 0; return (T)serializer.ReadObject(ms); } } But while i carry objects with not all references loaded, while qyuerying with DataLoadOptions, sometimes it throws the object disposed exception, but thing is I don't ask for references that is not loaded (null). e.g. I have Customer with many references and i just need to carry on memory the Address reference EntityRef< and i don't Load anything else. But while i clone the object this exception forces me to load all the EntitySet< references with the Customer object, which might be too much and slow down the application speed. Any suggestions?

    Read the article

  • How do you use Exslt.dyn (especially the 'evaluate' method) in Umbraco?

    - by jeffreypriebe
    I am trying to execute the string contained in an XSL variable. Umbraco has hooks for several Exslt pieces, but it seems the Exslt.dyn (Exslt.dynamic) is not one of them. How do you add it in? Acceptable methods (in order of preference: Writing your own XSLT extension (possibly using existing Umbraco code for Exslt Dynamic). Uploading the XSL from http://www.exslt.org/dyn/functions/evaluate/index.html into Umbraco. Modifying the Umbraco source to add it (possibly using existing Umbraco code for Exslt Dynamic). The reason I mention Exslt Dyanmic is because some Umbraco XSLT sources show a reference that I am assuming existing in some versions of Umbraco. I cannot find it in the source code, however. (Example: the XSL sources pasted in here: http://our.umbraco.org/projects/starter-kits/business-website-starter-pack/general-%28bugs,-feedback,-feature-requests%29/8085-Changing-the-first-day-to-fx-monday)

    Read the article

  • TFS 2010 - TF14040 The Folder may not be checked out.

    - by Patricker
    I have a .NET 4 website in VS2010 stored in a TFS 2010 team project. I need to add a reference to System.Data.Linq.dll to the website. I am referencing a LINQ DataContext that is defined in another project and I get build errors saying that I need the reference to System.Data.Linq. I go up to the "Add Reference" menu option and add it like I would any normal reference, and it even shows up in the Web.config and in the Properties pages for the website... BUT if I build I still get the same error. So I found a place in my code where I was referencing the LINQ count function and it told me it was invalid because I was missing a reference and it offered to add the reference automatically. I told it to add the reference automatically and it is at this point that I get the error mentioned in the subject: TF14040: The folder $/Folder/Subfolder may not be checked out. No items were checked out I've done some research online but I haven't been able to find much. I saw on a blog that making the folder not readonly fixed the issue for him, but it didn't seem to work for me unless I misunderstood something. I tried loading up the project from source control onto a fresh computer where that project had never been loaded before and I can reproduce the issue the same way. Help would be greatly appreciated.

    Read the article

  • Can't operator == be applied to generic types in C#?

    - by Hosam Aly
    According to the documentation of the == operator in MSDN, For predefined value types, the equality operator (==) returns true if the values of its operands are equal, false otherwise. For reference types other than string, == returns true if its two operands refer to the same object. For the string type, == compares the values of the strings. User-defined value types can overload the == operator (see operator). So can user-defined reference types, although by default == behaves as described above for both predefined and user-defined reference types. So why does this code snippet fail to compile? void Compare<T>(T x, T y) { return x == y; } I get the error Operator '==' cannot be applied to operands of type 'T' and 'T'. I wonder why, since as far as I understand the == operator is predefined for all types? Edit: Thanks everybody. I didn't notice at first that the statement was about reference types only. I also thought that bit-by-bit comparison is provided for all value types, which I now know is not correct. But, in case I'm using a reference type, would the the == operator use the predefined reference comparison, or would it use the overloaded version of the operator if a type defined one? Edit 2: Through trial and error, we learned that the == operator will use the predefined reference comparison when using an unrestricted generic type. Actually, the compiler will use the best method it can find for the restricted type argument, but will look no further. For example, the code below will always print true, even when Test.test<B>(new B(), new B()) is called: class A { public static bool operator==(A x, A y) { return true; } } class B : A { public static bool operator==(B x, B y) { return false; } } class Test { void test<T>(T a, T b) where T : A { Console.WriteLine(a == b); } }

    Read the article

  • FLTK in Cygwin using Eclipse (Linking errors)

    - by qpingu
    I have this assignment due that requires the usage of FLTK. The code is given to us and it should compile straight off of the bat, but I am having linking errors and do not know which other libraries I need to include. I currently have "opengl32", "fltk_gl", "glu32", and "fltk" included (-l), each of which seem to reduce the number of errors. I compiled FLTK using make with no specified options. Including all of the produced library files doesn't fix the problem, and I'm convinced that it's just some Windows specific problem. Compile log: **** Build of configuration Debug for project CG5 **** make all Building target: CG5.exe Invoking: Cygwin C++ Linker g++ -o"CG5.exe" ./src/draw_routines.o ./src/gl_window.o ./src/my_shapes.o ./src/shape.o ./src/shapes_ui.o ./src/tesselation.o -lopengl32 -lfltk_z -lfltk_gl -lglu32 -lfltk /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../libfltk_gl.a(Fl_Gl_Window.o):Fl_Gl_Window.cxx:(.text+0x197): undefined reference to `_SelectPalette@12' /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../libfltk_gl.a(Fl_Gl_Window.o):Fl_Gl_Window.cxx:(.text+0x1a7): undefined reference to `_RealizePalette@4' /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../libfltk_gl.a(Fl_Gl_Window.o):Fl_Gl_Window.cxx:(.text+0x1fe): undefined reference to `_glDrawBuffer@4' /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../libfltk_gl.a(Fl_Gl_Window.o):Fl_Gl_Window.cxx:(.text+0x20d): undefined reference to `_glReadBuffer@4' /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../libfltk_gl.a(Fl_Gl_Window.o):Fl_Gl_Window.cxx:(.text+0x23a): undefined reference to `_glGetIntegerv@8' /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../libfltk_gl.a(Fl_Gl_Window.o):Fl_Gl_Window.cxx:(.text+0x2c3): undefined reference to `_glOrtho@48' /usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../libfltk_gl.a(Fl_Gl_Window.o):Fl_Gl_Window.cxx:(.text+0x2f3): undefined reference to `_SwapBuffers@4' ...and lots more Thanks a ton for the help. EDIT: These first few lines are obviously OpenGL related, although I'm still not sure what additional libraries need to be included.

    Read the article

  • Getting value from pointer

    - by Eric
    Hi, I'm having problem getting the value from a pointer. I have the following code in C++: void* Nodo::readArray(VarHash& var, string varName, int posicion, float& d) { //some code before... void* res; float num = bit.getFloatFromArray(arregloTemp); //THIS FUNCTION RETURN A FLOAT AND IT'S OK cout << "NUMBER " << num << endl; d = num; res = &num; return res } int main() { float d = 0.0; void* res = n.readArray(v, "c", 0, d); //THE VALUES OF THE ARRAY ARE: {65.5, 66.5}; float* car3 = (float*)res; cout << "RESULT_READARRAY " << *car3 << endl; cout << "FLOAT REFERENCE: " << d << endl; } The result of running this code is the following: NUMBER 65.5 RESULT_READARRAY -1.2001 //INCORRECT IT SHOULD BE LIKE NUMBER FLOAT REFERENCE: 65.5 //CORRECT NUMBER 66.5 RESULT_READARRAY -1.2001 //INCORRECT IT SHOULD BE LIKE NUMBER FLOAT REFERENCE: 66.5 //CORRECT For some reason, when I get the value of the pointer returned by the function called readArray is incorrect. I'm passing a float variable(d) as a reference in the same function just to verify that the value is ok, and as you can see, THE FLOAT REFERENCE matches the NUMBER. If I declare the variable num(read array) as a static float, the first RESULT_READARRAY will be 65.5, that is correct, however, the next value will be the same instead of 66.5. Let me show you the result of running the code using static float variable: NUMBER 65.5 RESULT_READARRAY 65.5 //PERFECT FLOAT REFERENCE: 65.5 //¨PERFECT NUMBER 65.5 //THIS IS INCORRECT, IT SHOULD BE 66.5 RESULT_READARRAY 65.5 FLOAT REFERENCE: 65.5 Do you know how can I get the correct value returned by the function called readArray()?

    Read the article

  • Self referencing userdata and garbage collection

    - by drtwox
    Because my userdata objects reference themselves, I need to delete and nil a variable for the garbage collector to work. Lua code: obj = object:new() -- -- Some time later obj:delete() -- Removes the self reference obj = nil -- Ready for collection C Code: typedef struct { int self; // Reference to the object // Other members and function references removed } Object; // Called from Lua to create a new object static int object_new( lua_State *L ) { Object *obj = lua_newuserdata( L, sizeof( Object ) ); // Create the 'self' reference, userdata is on the stack top obj->self = luaL_ref( L, LUA_REGISTRYINDEX ); // Put the userdata back on the stack before returning lua_rawgeti( L, LUA_REGISTRYINDEX, obj->self ); // The object pointer is also stored outside of Lua for processing in C return 1; } // Called by Lua to delete an object static int object_delete( lua_State *L ) { Object *obj = lua_touserdata( L, 1 ); // Remove the objects self reference luaL_unref( L, LUA_REGISTRYINDEX, obj->self ); return 0; } Is there some way I can set the object to nil in Lua, and have the delete() method called automatically? Alternatively, can the delete method nil all variables that reference the object? Can the self reference be made 'weak'?

    Read the article

  • XSLT, process elements one by one

    - by qui
    Hi I am quite weak at XSLT so this might seem obvious. Here is some sample XML <term> <name>cholecystocolonic fistula</name> <definition>blah blah</definition> <reference>cholecystocolostomy</reference> </term> And here is the XSLT I wrote a while ago to process it <xsl:template name="term"> { "dictitle": "<xsl:value-of select="name" disable-output-escaping="yes" />", "html": "<xsl:value-of select="definition" disable-output-escaping="yes"/>", "referece": "<xsl:value-of select="reference" disable-output-escaping="yes"/> } </xsl:template> Basically I am creating JSON from the XML. The requirements have now changed so that now the XML can have more than one definition tag and reference tag. They can appear in any order, i.e definition, reference, reference, definition, reference. How can I update the XSLT to accommodate this? Probably worth mentioning that because my XSLT processor is using .NET I can only use XSLT 1.0 commands. Many thanks!

    Read the article

< Previous Page | 191 192 193 194 195 196 197 198 199 200 201 202  | Next Page >