Search Results

Search found 9273 results on 371 pages for 'complex strings'.

Page 318/371 | < Previous Page | 314 315 316 317 318 319 320 321 322 323 324 325  | Next Page >

• Bind to a markup externsion property

  - by user314580

  Hi, I have written a markup extension which stores amongst others a help text. This help text is shown on the right side of the main window. This works fine. Now, I want to add a tooltip for every control. The content of the tooltip should be same as for the helptext extension. The XAML code: <ListView ctrl:ListViewLayoutManager.Enabled="true" x:Name="ListViewSources" ItemsSource="{Binding SourceItems}" ItemContainerStyle="{DynamicResource ListViewItemStyleAlternate}" Height="150" MinWidth="350" Helper:HelpExtension.IsControl="true" Helper:HelpExtension.HelpText="{x:Static strings:GUIResource.HelpProfilesSourcesDescriptionText}" > <ListView.ToolTip> <ToolTip Style="{DynamicResource Own_TooltipStyle}"></ToolTip> </ListView.ToolTip> And now the code of the style: If I run the program I get the binding error: System.Windows.Data Error: 39 : BindingExpression path error: 'Helper:HelpExtension' property not found on 'object' ''ListView' (Name='ListViewSources')'. BindingExpression:Path=Helper:HelpExtension.HelpText; DataItem='ListView' (Name='ListViewSources'); target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String') Does anybody know how I can bind the TextBlock to the content of Helper:HelpExternsion.HelpText? Thanks Dieter

  Read the article

• Batch insert mode with hibernate and oracle: seems to be dropping back to slow mode silently

  - by Chris

  I'm trying to get a batch insert working with Hibernate into Oracle, according to what i've read here: http://docs.jboss.org/hibernate/core/3.3/reference/en/html/batch.html , but with my benchmarking it doesn't seem any faster than before. Can anyone suggest a way to prove whether hibernate is using batch mode or not? I hear that there are numerous reasons why it may silently drop into normal mode (eg associations and generated ids) so is there some way to find out why it has gone non-batch? My hibernate.cfg.xml contains this line which i believe is all i need to enable batch mode: <property name="jdbc.batch_size">50</property> My insert code looks like this: List<LogEntry> entries = ..a list of 100 LogEntry data classes... Session sess = sessionFactory.getCurrentSession(); for(LogEntry e : entries) { sess.save(e); } sess.flush(); sess.clear(); My 'logentry' class has no associations, the only interesting field is the id: @Entity @Table(name="log_entries") public class LogEntry { @Id @GeneratedValue public Long id; ..other fields - strings and ints... However, since it is oracle, i believe the @GeneratedValue will use the sequence generator. And i believe that only the 'identity' generator will stop bulk inserts. So if anyone can explain why it isn't running in batch mode, or how i can find out for sure if it is or isn't in batch mode, or find out why hibernate is silently dropping back to slow mode, i'd be most grateful. Thanks

  Read the article

• Why new String(bytes, enc).getBytes(enc) does not return the original byte array?

  - by Bozho

  I made the following "simulation": byte[] b = new byte[256]; for (int i = 0; i < 256; i ++) { b[i] = (byte) (i - 128); } byte[] transformed = new String(b, "cp1251").getBytes("cp1251"); for (int i = 0; i < b.length; i ++) { if (b[i] != transformed[i]) { System.out.println("Wrong : " + i); } } For cp1251 this outputs only one wrong byte - at position 23. For KOI8-R - all fine. For cp1252 - 4 or 5 differences. What is the reason for this and how can this be overcome? I know it is wrong to represent byte arrays as strings in whatever encoding, but it is a requirement of the protocol of a payment provider, so I don't have a choice. Update: representing it in ISO-8859-1 works, and I'll use it for the byte[] part, and cp1251 for the textual part, so the question remains only out of curiousity

  Read the article

• Which is the correct design pattern for my PHP application?

  - by user1487141

  I've been struggling to find good way to implement my system which essentially matches the season and episode number of a show from a string, you can see the current working code here: https://github.com/huddy/tvfilename I'm currently rewriting this library and want a nicer way to implement how the the match happens, currently essentially the way it works is: There's a folder with classes in it (called handlers), every handler is a class that implements an interface to ensure a method called match(); exists, this match method uses the regex stored in a property of that handler class (of which there are many) to try and match a season and episode. The class loads all of these handlers by instantiating each one into a array stored in a property, when I want to try and match some strings the method iterates over these objects calling match(); and the first one that returns true is then returned in a result set with the season and episode it matched. I don't really like this way of doing it, it's kind of hacky to me, and I'm hoping a design pattern can help, my ultimate goal is to do this using best practices and I wondered which one I should use? The other problems that exist are: More than one handler could match a string, so they have to be in an order to prevent the more greedy ones matching first, not sure if this is solvable as some of the regex patterns have to be greedy, but possibly a score system, something that shows a percentage of how likely the match is correct, i'd have no idea how to actually implement this though. I'm not if instantiating all those handlers is a good way of doing it, speed is important, but using best practices and sticking to design patterns to create good, extensible and maintainable code is my ultimate priority. It's worth noting the handler classes sometimes do other things than just regex matching, they sometimes prep the string to be matched by removing common words etc. Cheers for any help Billy

  Read the article

• Effective communication in a component-based system

  - by Tesserex

  Yes, this is another question about my game engine, which is coming along very nicely, with much thanks to you guys. So, if you watched the video (or didn't), the objects in the game are composed of various components for things like position, sprites, movement, collision, sounds, health, etc. I have several message types defined for "tell" type communication between entities and components, but this only goes so far. There are plenty of times when I just need to ask for something, for example an entity's position. There are dozens of lines in my code that look like this: SomeComponent comp = (SomeComponent)entity.GetComponent(typeof(SomeComponent)); if (comp != null) comp.GetSomething(); I know this is very ugly, and I know that casting smells of improper OO design. But as complex as things are, there doesn't seem to be a better way. I could of course "hard-code" my component types and just have SomeComponent comp = entity.GetSomeComponent(); but that seems like a cop-out, and a bad one. I literally JUST REALIZED, while writing this, after having my code this way for months with no solution, that a generic will help me. SomeComponent comp = entity.GetComponent<SomeComponent>(); Amazing how that works. Anyway, this is still only a semantic improvement. My questions remain. Is this actually that bad? What's a better alternative?

  Read the article

• Is is possible to do an end-run around generics covariance in C# < 4 in this hypothetical situation?

  - by John Feminella

  Suppose I have a small inheritance hierarchy of Animals: public interface IAnimal { string Speak(); } public class Animal : IAnimal { public Animal() {} public string Speak() { return "[Animal] Growl!"; } } public class Ape : IAnimal { public string Speak() { return "[Ape] Rawrrrrrrr!"; } } public class Bat : IAnimal { public string Speak() { return "[Bat] Screeeeeee!"; } } Next, here's an interface offering a way to turn strings into IAnimals. public interface ITransmogrifier<T> where T : IAnimal { T Transmogrify(string s); } And finally, here's one strategy for doing that: public class Transmogrifier<T> : ITransmogrifier<T> where T : IAnimal, new() { public T Transmogrify(string s) { T t = default(T); if (typeof(T).Name == s) t = new T(); return t; } } Now, the question. Is it possible to replace the sections marked [1], [2], and [3] such that this program will compile and run correctly? If you can't do it without touching parts other than [1], [2], and [3], can you still get an IAnimal out of each instance of a Transmogrifier in a collection containing arbitrary implementations of an IAnimal? Can you even form such a collection to begin with? static void Main(string[] args) { var t = new Transmogrifier<Ape>(); Ape a = t.Transmogrify("Ape"); Console.WriteLine(a.Speak()); // Works! // But can we make an arbitrary collection of such animals? var list = new List<Transmogrifier< [1] >>() { // [2] }; // And how about we call Transmogrify() on each one? foreach (/* [3] */ transmogrifier in list) { IAnimal ia = transmogrifier.Transmogrify("Bat"); } } }

  Read the article

• Ajax and JSF 1.1 using hidden iframe with "proxy forms", what do you think about this development st

  - by Steel Plume

  Hi, currently I am using yet 1.1 specs, so I am trying to make simple what is too complex for me :p, managing backing beans with conflicting navigation rules, external params breaking rules and so on... for example when I need a backing bean used by other "views" simply I call it using FacesContext inside other backing beans, but often it's too wired up to JSF navigation/initialization rules to be really usable, and of course more simple is more useful become the FacesContext. So with only a bit of cross browser Javascript (simply a form copy and a read-write on a "proxy" form), I create a sort of proxy form inside the main user page (totally disassociated from JSF navigation rules, but using JSF taglibs). Ajax gives me flexibility on the user interaction, but data is always managed by JSF. Pratically I demand all "fictious" user actions to an hidden "iframe" which build up all needed forms according JSF rules, then a javascript simply clone its form output and put it into the user view level (CSS for showing/hiding real command buttons and making pretty), the user plays around and when he click submit, a script copies all "proxied" form values into the real JSF form inside the "iframe" that invokes the real submit of the form, what it returns is obviously dependent by your choice. Now JSF is really a pleasure :-p My real interest is to know what are your alternative strategy for using pure Ajax and JSF 1.1 without adopting middle layer like ajax4jsf and others, all good choices but too much "plugins" than specs.

  Read the article

• Is using advanced constructs (function, new, function calls) in JSON safe?

  - by Vilx-

  JSON is a nice way to pass complex data from my server side code to client side JavaScript. For example, in PHP I can write: <script type="text/javascript> var MyComplexVariable = <?= BigFancyObjectGraph.GetJSON() ?>; DoMagic(MyComplexVariable); </script> This is pretty cool, but sometimes you want to pass more than basic date, like dates or even function definitions. There is a simple and straightforward way of doing it too, like: <script type="text/javascript> var MyComplexVariable = { 'SimpleProperty' : 42, 'FunctionProperty' : function() { return 6*7; }, 'DateProperty' : new Date(989539200000), 'ArbitraryProperty' : GetTheMeaningOfLifeUniverseAndEverything() }; DoMagic(MyComplexVariable); </script> And this works like a charm on all browsers I've seen so far. But according to JSON.org such syntax is invalid. On the other hand, I've seen this syntax being used in very many places, including some popular JavaScript frameworks. So... Can I expect any problems if I use "unsupported" JSON features like the above? Why is it wrong or not?

  Read the article

• workaround for ORA-03113: end-of-file on communication channel

  - by Jefferstone

  The call to TEST_FUNCTION below fails with "ORA-03113: end-of-file on communication channel". A workaround is presented in TEST_FUNCTION2. I boiled down the code as my actual function is far more complex. Tested on Oracle 11G. Anyone have any idea why the first function fails? CREATE OR REPLACE TYPE "EMPLOYEE" AS OBJECT ( employee_id NUMBER(38), hire_date DATE ); CREATE OR REPLACE TYPE "EMPLOYEE_TABLE" AS TABLE OF EMPLOYEE; CREATE OR REPLACE FUNCTION TEST_FUNCTION RETURN EMPLOYEE_TABLE IS table1 EMPLOYEE_TABLE; table2 EMPLOYEE_TABLE; return_table EMPLOYEE_TABLE; BEGIN SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) < 'm' ) AS EMPLOYEE_TABLE) INTO table1 FROM dual; SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) >= 'm' ) AS EMPLOYEE_TABLE) INTO table2 FROM dual; SELECT CAST(MULTISET ( SELECT employee_id, hire_date FROM TABLE(table1) UNION SELECT employee_id, hire_date FROM TABLE(table2) ) AS EMPLOYEE_TABLE) INTO return_table FROM dual; RETURN return_table; END TEST_FUNCTION; CREATE OR REPLACE FUNCTION TEST_FUNCTION2 RETURN EMPLOYEE_TABLE IS table1 EMPLOYEE_TABLE; table2 EMPLOYEE_TABLE; return_table EMPLOYEE_TABLE; BEGIN SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) < 'm' ) AS EMPLOYEE_TABLE) INTO table1 FROM dual; SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) >= 'm' ) AS EMPLOYEE_TABLE) INTO table2 FROM dual; WITH combined AS ( SELECT employee_id, hire_date FROM TABLE(table1) UNION SELECT employee_id, hire_date FROM TABLE(table2) ) SELECT CAST(MULTISET ( SELECT * FROM combined ) AS EMPLOYEE_TABLE) INTO return_table FROM dual; RETURN return_table; END TEST_FUNCTION2; SELECT * FROM TABLE (TEST_FUNCTION()); -- Throws exception ORA-03113. SELECT * FROM TABLE (TEST_FUNCTION2()); -- Works

  Read the article

• What's the best way to communicate the purpose of a string parameter in a public API?

  - by Dave

  According to the guidance published in New Recommendations for Using Strings in Microsoft .NET 2.0, the data in a string may exhibit one of the following types of behavior: A non-linguistic identifier, where bytes match exactly. A non-linguistic identifier, where case is irrelevant, especially a piece of data stored in most Microsoft Windows system services. Culturally-agnostic data, which still is linguistically relevant. Data that requires local linguistic customs. Given that, I'd like to know the best way to communicate which behavior is expected of a string parameter in a public API. I wasn't able to find an answer in the Framework Design Guidelines. Consider the following methods: f(string this_is_a_linguistic_string) g(string this_is_a_symbolic_identifier_so_use_ordinal_compares) Is variable naming and XML documentation the best I can do? Could I use attributes in some way to mark the requirements of the string? Now consider the following case: h(Dictionary<string, object> dictionary) Note that the dictionary instance is created by the caller. How do I communicate that the callee expects the IEqualityComparer<string> object held by the dictionary to perform, for example, a case-insensitive ordinal comparison?

  Read the article

• Ruby integer to string key

  - by Gene

  A system I'm building needs to convert non-negative Ruby integers into shortest-possible UTF-8 string values. The only requirement on the strings is that their lexicographic order be identical to the natural order on integers. What's the best Ruby way to do this? We can assume the integers are 32 bits and the sign bit is 0. This is successful: (i >> 24).chr + ((i >> 16) & 0xff).chr + ((i >> 8) & 0xff).chr + (i & 0xff).chr But it appears to be 1) garbage-intense and 2) ugly. I've also looked at pack solutions, but these don't seem portable due to byte order. FWIW, the application is Redis hash field names. Building keys may be a performance bottleneck, but probably not. This question is mostly about the "Ruby way".

  Read the article

• How to marshal an object and its content (also objects)

  - by Waldo Spek

  I have a question for which I suspect the answer is a bit complex. At this moment I am programming a DLL (class library) in C#. This DLL uses a 3rd party library and therefore deals with 3rd party objects of which I do not have the source code. Now I am planning to create another DLL, which is going to be used in a later stadium in my application. This second DLL should use the 3rd party objects (with corresponding object states) created by the first DLL. Luckily the 3rd party objects extend the MarshalByRefObject class. I can marshal the objects using System.Runtime.Remoting.Marshal(...). I then serialize the objects using a BinaryFormatter and store the objects as a byte[] array. All goes well. I can deserialize and unmarshal in a the opposite way and end up with my original 3rd party objects...so it appears... Nevertheless, when calling methods on my 3rd party deserialized objects I get object internal exceptions. Normally these methods return other 3rd party objects, but (obviously - I guess) now these objects are missing because they weren't serialized. Now my global question: how would I go about marshalling/serializing all the objects which my 3rd party objects reference...and cascade down the "reference tree" to obtain a full and complete serialized object? Right now my guess is to preprocess: obtain all the objects and build my own custom object and serialize it. But I'm hoping there is some other way...

  Read the article

• Member function overloading/template specialization issue

  - by Ferruccio

  I've been trying to call the overloaded table::scan_index(std::string, ...) member function without success. For the sake of clarity, I have stripped out all non-relevant code. I have a class called table which has an overloaded/templated member function named scan_index() in order to handle strings as a special case. class table : boost::noncopyable { public: template <typename T> void scan_index(T val, std::function<bool (uint recno, T val)> callback) { // code } void scan_index(std::string val, std::function<bool (uint recno, std::string val)> callback) { // code } }; Then there is a hitlist class which has a number of templated member functions which call table::scan_index(T, ...) class hitlist { public: template <typename T> void eq(uint fieldno, T value) { table* index_table = db.get_index_table(fieldno); // code index_table->scan_index<T>(value, [&](uint recno, T n)->bool { // code }); } }; And, finally, the code which kicks it all off: hitlist hl; // code hl.eq<std::string>(*fieldno, p1.to_string()); The problem is that instead of calling table::scan_index(std::string, ...), it calls the templated version. I have tried using both overloading (as shown above) and a specialized function template (below), but nothing seems to work. After staring at this code for a few hours, I feel like I'm missing something obvious. Any ideas? template <> void scan_index<std::string>(std::string val, std::function<bool (uint recno, std::string val)> callback) { // code }

  Read the article

• OpenGL ES and real world development

  - by Mark

  Hi Guys, I'm trying to learn OpenGL ES quickly (I know, I know, but these are the pressures that have been thrusted upon me) and I have been read around a fair bit, which lots of success at rendering basic models, some basic lighting and 'some' texturing success too. But this is CONSTANTLY the point at which all OpenGL ES tutorials end, they never say more of what a real life app may need. So I have a few questions that Im hoping arent too difficult. How do people get 3d models from their favorite 3d modeling tool into the iPhone/iPad application? I have seen a couple of blog posts where people have written some python scripts for tools like Blender which create .h files that you can use, is this what people seem to do everytime? Or do the "big" tooling suites (3DS, Maya, etc...) have exporting features? Say I have my model in a nice .h file, all the vertexes, texture points, etc.. are lined up, how to I make my model (say of a basic person) walk? Or to be more general, how do you animate "part" of a model (legs only, turn head, etc...)? Do they need to be a massive mash-up of many different tiny models, or can you pre-bake animations these days "into" models (somehow) Truely great 3D games for the iPhone are (im sure) unbelievably complex, but how do people (game dev firms) seem to manage that designer/developer workflow? Surely not all the animations, textures, etc... are done programatically. I hope these are not stupid questions, and in actual fact, my app that Im trying to investigate how to make is really quite simple, just a basic 3D model that I want to be able to pan/tilt around using touch. Has anyone ever done/seen anything like this that I might be able to read up on? Thanks for any help you can give, I appreciate all types of response big or small :) Cheers, Mark

  Read the article

• Is there a way to find out whether a class is a direct base of another class?

  - by user176168

  Hi I'm wondering whether there is a way to find out whether a class is a direct base of another class i.e. in boost type trait terms a is_direct_base_of function. As far as I can see boost doesn't see to support this kind of functionality which leads me to think that its impossible with the current C++ standard. The reason I want it is to do some validation checking on two macro's that are used for a reflection system to specify that one class is derived from another e.g. header.h: #define BASE A #define DERIVED B class A {}; class B : public A { #include <rtti.h> }; rtti.h: // I want to check that the two macro's are correct with a compile time assert Rtti<BASE, DERIVED> m_rtti; Although the macro's seem unnecessary in this simple example in my real world scenario rtti.h is a lot more complex. One possible avenue would be to compare the size of the this pointer with the size of a this pointer cast to the base type and some how trying to figure out whether its the size of the base class itself away or something (yeah your right I don't know how that would work either! lol)

  Read the article

• Java: Typecasting to Generics

  - by bguiz

  This method that uses method-level generics, that parses the values from a custom POJO, JXlistOfKeyValuePairs (which is exactly that). The only thing is that both the keys and values in JXlistOfKeyValuePairs are Strings. This method wants to taken in, in addition to the JXlistOfKeyValuePairs instance, a Class<T> that defines which data type to convert the values to (assume that only Boolean, Integer and Float are possible). It then outputs a HashMap with the specified type for the values in its entries. This is the code that I have got, and it is obviously broken. private <T extends Object> Map<String, T> fromListOfKeyValuePairs(JXlistOfKeyValuePairs jxval, Class<T> clasz) { Map<String, T> val = new HashMap<String, T>(); List<Entry> jxents = jxval.getEntry(); T value; String str; for (Entry jxent : jxents) { str = jxent.getValue(); value = null; if (clasz.isAssignableFrom(Boolean.class)) { value = (T)(Boolean.parseBoolean(str)); } else if (clasz.isAssignableFrom(Integer.class)) { value = (T)(Integer.parseInt(str)); } else if (clasz.isAssignableFrom(Float.class)) { value = (T)(Float.parseFloat(str)); } else { logger.warn("Unsupported value type encountered in key-value pairs, continuing anyway: " + clasz.getName()); } val.put(jxent.getKey(), value); } return val; } This is the bit that I want to solve: if (clasz.isAssignableFrom(Boolean.class)) { value = (T)(Boolean.parseBoolean(str)); } else if (clasz.isAssignableFrom(Integer.class)) { value = (T)(Integer.parseInt(str)); } I get: Inconvertible types required: T found: Boolean Also, if possible, I would like to be able to do this with more elegant code, avoiding Class#isAssignableFrom. Any suggestions? Sample method invocation: Map<String, Boolean> foo = fromListOfKeyValuePairs(bar, Boolean.class);

  Read the article

• HELP Retrieving the url parameter from a JSON store from a EXTJS ComboBox

  - by Newbie

  I am having a problem retrieving the parameters from the url section of a json store for a combobox in EXTJS from my code behind page in c#. The following is the code in the store: var ColorStore = new Ext.data.JsonStore( { autoLoad: true, url: '/proxies/ReturnJSON.aspx?view=rm_colour_view', root: 'Rows', fields: ['company', 'raw_mat_col_code', 'raw_mat_col_desc'] }); And the following code is in my code behind page: protected void Page_Load(object sender, EventArgs e) { string jSonString = ""; connectionClass.connClass func = new connectionClass.connClass(); DataTable dt = func.getDataTable("sELECT * from rm_colour_view"); //Response.Write(Request.QueryString["view"]); string w = Request.Params.Get("url"); string z = Request.Params.Get("view"); string x = Request.Params.Get("view="); string c = Request.Params.Get("?view"); string s = Request.QueryString.Get("view"); string d = Request.Params["?view="]; string f = Request.Form["ColorStore"]; jSonString = Serialize(dt); Response.Write(jSonString); } The string w has gives the following output: /proxies/ReturnJSON.aspx but all the others strings return null... How can rm_colour_view from the datastore then be retrived??? Any help would be appreciated! Thanks

  Read the article

• algorithm to find longest non-overlapping sequences

  - by msalvadores

  I am trying to find the best way to solve the following problem. By best way I mean less complex. As an input a list of tuples (start,length) such: [(0,5),(0,1),(1,9),(5,5),(5,7),(10,1)] Each element represets a sequence by its start and length, for example (5,7) is equivalent to the sequence (5,6,7,8,9,10,11) - a list of 7 elements starting with 5. One can assume that the tuples are sorted by the start element. The output should return a non-overlapping combination of tuples that represent the longest continuos sequences(s). This means that, a solution is a subset of ranges with no overlaps and no gaps and is the longest possible - there could be more than one though. For example for the given input the solution is: [(0,5),(5,7)] equivalent to (0,1,2,3,4,5,6,7,8,9,10,11) is it backtracking the best approach to solve this problem ? I'm interested in any different approaches that people could suggest. Also if anyone knows a formal reference of this problem or another one that is similar I'd like to get references. BTW - this is not homework. Edit Just to avoid some mistakes this is another example of expected behaviour for an input like [(0,1),(1,7),(3,20),(8,5)] the right answer is [(3,20)] equivalent to (3,4,5,..,22) with length 20. Some of the answers received would give [(0,1),(1,7),(8,5)] equivalent to (0,1,2,...,11,12) as right answer. But this last answer is not correct because is shorter than [(3,20)].

  Read the article

• C# Convert string to nullable type (int, double, etc...)

  - by Nathan Koop

  I am attempting to do some data conversion. Unfortunately, much of the data is in strings, where it should be int's or double, etc... So what I've got is something like: double? amount = Convert.ToDouble(strAmount); The problem with this approach is if strAmount is empty, if it's empty I want it to amount to be null, so when I add it into the database the column will be null. So I ended up writing this: double? amount = null; if(strAmount.Trim().Length>0) { amount = Convert.ToDouble(strAmount); } Now this works fine, but I now have five lines of code instead of one. This makes things a little more difficult to read, especially when I have a large amount of columns to convert. I thought I'd use an extension to the string class and generic's to pass in the type, this is because it could be a double, or an int, or a long. So I tried this: public static class GenericExtension { public static Nullable<T> ConvertToNullable<T>(this string s, T type) where T: struct { if (s.Trim().Length > 0) { return (Nullable<T>)s; } return null; } } But I get the error: Cannot convert type 'string' to 'T?' Is there a way around this? I am not very familiar with creating methods using generics.

  Read the article

• Thread mutex behaviour

  - by Alberteddu

  Hi there, I'm learning C. I'm writing an application with multiple threads; I know that when a variable is shared between two or more threads, it is better to lock/unlock using a mutex to avoid deadlock and inconsistency of variables. This is very clear when I want to change or view one variable. int i = 0; /** Global */ static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; /** Thread 1. */ pthread_mutex_lock(&mutex); i++; pthread_mutex_unlock(&mutex); /** Thread 2. */ pthread_mutex_lock(&mutex); i++; pthread_mutex_unlock(&mutex); This is correct, I think. The variable i, at the end of the executions, contains the integer 2. Anyway, there are some situations in which I don't know exactly where to put the two function calls. For example, suppose you have a function obtain(), which returns a global variable. I need to call that function from within the two threads. I have also two other threads that call the function set(), defined with a few arguments; this function will set the same global variable. The two functions are necessary when you need to do something before getting/setting the var. /** (0) */ /** Thread 1, or 2, or 3... */ if(obtain() == something) { if(obtain() == somethingElse) { // Do this, sometimes obtain() and sometimes set(random number) (1) } else { // Do that, just obtain(). (2) } } else { // Do this and do that (3) // If # of thread * 3 > 10, then set(3*10) For example. (4) } /** (5) */ Where I have to lock, and where I have to unlock? The situation can be, I think, even more complex. I will appreciate an exhaustive answer. Thank you in advance. —Alberto

  Read the article

• HashMap Memory Leak because of Dynamic Array

  - by Jake M

  I am attempting to create my own HashMap to understand how they work. I am using an array of Linked Lists to store the values(strings) in my hashmap. I am creating the array like this: Node** list; Instead of this: Node* list[nSize]; This is so the array can be any size at runtime. But I think I am getting a memory leak because of how I am doing this. I dont know where the error is but when I run the following simple code the .exe crashes. Why is my application crashing and how can I fix it? Note: I am aware that using a vector would be much better than an array but this is just for learning and I want to challenge myself to create the hashmap using a 'Dynamic' Array. PS: is that the correct term(Dynamic Array) for the kind of array I am using? struct Node { // to implement }; class HashMap { public: HashMap(int dynSize) { *list = new Node[dynSize]; size = dynSize; for (int i=0; i<size; i++) list[i] = NULL; cout << "END\n"; } ~HashMap() { for (int i=0; i<size; i++) delete list[i]; } private: Node** list; // I could use a vector here but I am experimenting with a pointer to an array(pointer), also its more elegant int size; }; int main() { // When I run this application it crashes. Where is my memory leak? HashMap h(5); system("PAUSE"); return 0; }

  Read the article

• Confusion in MIPS code

  - by Haya Hallian

  While going through the MIPS code I got some confusion. Code is shown as follows .data key: .ascii "key: " # "key: \n" char: .asciiz " \n" .text .globl main main: jal getchar la $a0, char # $a0 contains address of char variable (" \n") sb $v0, ($a0) # replace " " in char with v0, which is read_character (X) la $a0, key # now a0 will contain, address of "key: " "X\n" What I dont understand is that how load address instruction works. First a0 contained address of char variable. In next line we are storing value of v0 in that location. there is no offset with ($a0), is that assumed to be 0 like in 0($a0)? Why only the " " empty space is replaced with v0, and why not the "\n" get replaced? or It may also have been the case that both the empty space and \n character get replced by v0. Secondly when we load the address of key in a0, the previous address should be overwritten. a0 should have contained the address of key only, but from comment it seems that the two strings are concatenated. How does that happen.

  Read the article

• Aligning messageformat on printing a JTable.

  - by DanielFH

  I'm using this for the moment to print out my table, and it works. But I'm not really happy with the layout of the messageformatting, I would like to have both pagenumber and date in the footer, and date format aligned to the left side of the table, and page to the right. How can I do that? Been reading some stuff about overriding the PrintTable method, but seems to get pretty complex from what I've read. Hope you can help me with this issue, thank you. :) import javax.print.attribute.HashPrintRequestAttributeSet; import javax.print.attribute.PrintRequestAttributeSet; import javax.print.attribute.standard.OrientationRequested; import javax.swing.JTable; import dk.beesys.rims.ui.WindowInventory; public class Print { private static Print INSTANCE; public static Print getInstance() { if (INSTANCE == null) { INSTANCE = new Print(); } return INSTANCE; } private Print(){ } public void printList(java.awt.event.ActionEvent ignore) { String strDate = MessageFormat.format("{0,date,short} {0,time,short}", new Date()); MessageFormat header = new MessageFormat("- {0} -"); MessageFormat footer = new MessageFormat("Printed: " + strDate); PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet(); aset.add(OrientationRequested.LANDSCAPE); try { WindowInventory.getInstance().getTable().print(JTable.PrintMode.FIT_WIDTH, header, footer, true, aset, true); } catch (java.awt.print.PrinterException e) { System.err.format("Cannot print %s%n", e.getMessage()); } }

  Read the article

• iphone viewWillAppear not firing

  - by chzk

  I've read numerous posts about people having problems with viewWillAppear when you do not create your view heirarchy JUST right. My problem is I can't figure out what that means. If I create a RootViewController and call addSubView on that controller, I would expect the added view(s) to be wired up for viewWillAppear events. Does anyone have an example of a complex programmatic view heirarchy that successfully recieves viewWillAppear events at every level? Apple Docs state: Warning: If the view belonging to a view controller is added to a view hierarchy directly, the view controller will not receive this message. If you insert or add a view to the view hierarchy, and it has a view controller, you should send the associated view controller this message directly. Failing to send the view controller this message will prevent any associated animation from being displayed. The problem is that they don't describe how to do this. What the hell does "directly" mean. How do you "indirectly" add a view. I am fairly new to Cocoa and iPhone so it would be nice if there were useful examples from Apple besides the basic Hello World crap. Any help is greatly appreciated...

  Read the article

• Domain Authentication from .NET Client over VPN

  - by Holy Christ

  I am writing a ClickOnce WPF app that will sometimes be used over VPN. The app uses resources available only to domain authenticated users. Some of the things include accessing SSRS Reports, accessing LDAP to lookup user information, hitting web services, etc. When a user logs in from a machine that is not authenticated on the domain, I need to somehow get his credentials, authenticate him on the domain, and store his credentials. What is the recommended approach for authenticating domain users over VPN? How can I securely store the credentials? I've found several articles but, not much posted recently and a lot of the solutions seem kinda hacky, or aren't very secure (ie - storing strings clear text in memory). It would be cool if I could use the ActiveDicrtoryMembershipProvider, but that seems to be geared for use in web apps. EDIT: The above is kind of a workaround. The user must enter their domain credentials to authenticate on the VPN. It would be ideal to access the credentials the user has already entered to login to the VPN instead of the WindowsIdentity.GetCurrent() (which returns the user logged into the computer). Any ideas on how that could work? We use Juniper Networks to connect to the VPN. Thanks!

  Read the article

< Previous Page | 314 315 316 317 318 319 320 321 322 323 324 325  | Next Page >