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  • Reverse search in Hibernate Search

    - by Javi
    Hello, I'm using Hibernate Search (which uses Lucene) for searching some Data I have indexed in a directory. It works fine but I need to do a reverse search. By reverse search I mean that I have a list of queries stored in my database I need to check which one of these queries match with a Data object each time Data Object is created. I need it to alert the user when a Data Object matches with a Query he has created. So I need to index this single Data Object which has just been created and see which queries of my list has this object as a result. I've seen Lucene MemoryIndex Class to create an index in memory so I can do something like this example for every query in a list (though iterating in a Java list of queries would not be very efficient): //Iterating over my list<Query> MemoryIndex index = new MemoryIndex(); //Add all fields index.addField("myField", "myFieldData", analyzer); ... QueryParser parser = new QueryParser("myField", analyzer); float score = index.search(query); if (score > 0.0f) { System.out.println("it's a match"); } else { System.out.println("no match found"); } The problem here is that this Data Class has several Hibernate Search Annotations @Field,@IndexedEmbedded,... which indicated how fields should be indexed, so when I invoke index() method on the FullTextEntityManager instance it uses this information to index the object in the directory. Is there a similar way to index it in memory using this information? Is there a more efficient way of doing this reverse search? Thanks

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  • Unable to change background colour for JOptionPane

    - by Sunil Kumar Sahoo
    Hi I have created sample progeam which will give same look and feel of a confirm dialog and set the background colour as red. But I donot know what is the problem that my background colour of option is displayed as the default colour but not red. also i need same look and feel of confirm dialog across all platforms. Here is the code that I have written. please help me to solve the issue public class JOptionPaneBackground { public static void main(String[] args) throws Exception { // UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName()); UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); UIDefaults uiDefaults = UIManager.getLookAndFeelDefaults(); List<Object> keys = new ArrayList<Object>(uiDefaults.keySet()); Collections.sort(keys, new Comparator<Object>() { public int compare(Object o1, Object o2) { return (o1.toString()).compareTo(o2.toString()); } }); for (Object key : keys) { System.out.println(String.format("%-40s = %s", key, uiDefaults.get(key))); } UIManager.put("OptionPane.background", Color.red); UIManager.put("Panel.background", Color.red); JOptionPane.showConfirmDialog(null, "Hello World!"); } }

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  • Name for method that takes a string value and returns DBNull.Value || string

    - by David Murdoch
    I got tired of writing the following code: /* Commenting out irrelevant parts public string MiddleName; public void Save(){ SqlCommand = new SqlCommand(); // blah blah...boring INSERT statement with params etc go here. */ if(MiddleName==null){ myCmd.Parameters.Add("@MiddleName", DBNull.Value); } else{ myCmd.Parameters.Add("@MiddleName", MiddleName); } /* // more boring code to save to DB. }*/ So, I wrote this: public static object DBNullValueorStringIfNotNull(string value) { object o; if (value == null) { o = DBNull.Value; } else { o = value; } return o; } // which would be called like: myCmd.Parameters.Add("@MiddleName", DBNullValueorStringIfNotNull(MiddleName)); If this is a good way to go about doing this then what would you suggest as the method name? DBNullValueorStringIfNotNull is a bit verbose and confusing. I'm also open to ways to alleviate this problem entirely. I'd LOVE to do this: myCmd.Parameters.Add("@MiddleName", MiddleName==null ? DBNull.Value : MiddleName); but that won't work. I've got C# 3.5 and SQL Server 2005 at my disposal if it matters.

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  • Eclipselink: Create objects from JOIN query

    - by Raven
    Hi, I have a SQL query SELECT * FROM Thing AS a JOIN Thing_Property AS b ON a.id=b.Thing_ID JOIN Property AS c ON b.properties_ID = c.id JOIN Item AS d ON c.item_ID = d.id ORDER BY a.name, d.name and I Eclipselink to create my object model with it. Here is the model: @SuppressWarnings("serial") @Entity public class Thing implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; @OneToMany(cascade=CascadeType.ALL) @PrivateOwned private List<Property> properties = new ArrayList<Property>(); ... // getter and setter following here } public class Property implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; @OneToOne private Item item; private String value; ... // getter and setter following here } public class Item implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; .... // getter and setter following here } // Code end but I can not figure out, how to make Eclipselink create the model from that query. Can you help?

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  • Nhibernate: Stop it from joining to a table that is not needed

    - by Aaron
    I have two tables (tbArea, tbPost) that relate to the following classes. class Area { int ID string Name ... } class Post { int ID string Title Area Area ... } These two classes map up with Fluent Nhibernate. Below is the post mapping. public class PostMapping : ClassMap<Post> { public PostMapping() { Cache.NonStrictReadWrite(); this.Table("tbPost"); Id(x => x.ID) .Column("PostID") .GeneratedBy .Identity(); References(x => x.Area) .ForeignKey("AreaID") .Column("AreaID"); ... } } Any time I perform a query on the Post table "where AreaID = 1(any AreaId)", nhibernate will join to the area table. (What Nhibernate generates for a query) SELECT post fields , area fields (automatically added) FROM tbPost p LEFT JOIN tbArea a on p.areaid = a.areaid where p.areaid = 1 I have tried setting Area to LazyLoad, to Fetch.Select, ReadOnly, and any other setting on the reference and still it will always join to Area. I am trying to optimize the backend database queries, and since I don't need the area object loaded just filtered I would like to eliminate the unnecessary join to Area each time I Query post. What configurations do I need to change or mappings to get area to still be related to post in my objects, but not query it when I filter on AreaID?

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  • Unable to get values in ftl from value stack in custom Result Type

    - by Nagadev
    Hello, I am unable retrieve value from value stack in FTL file. Here is the code. Action class holds a property called 'name' private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } public String execute(){ setName("From value stack .. "); return SUCCESS; } FTL code: ${name} Custom result Type deExecute Method Configuration configuration = new Configuration(); String templatePath = "/ftl"; ServletContext context = ServletActionContext.getServletContext(); configuration.setServletContextForTemplateLoading(context, templatePath); configuration.setObjectWrapper(new DefaultObjectWrapper()); Template template = configuration.getTemplate("sample.ftl"); OutputStreamWriter out = new OutputStreamWriter(System.out); template.process(ActionContext.getContext().getValueStack(), out); I am passing the value Stack which contains recently executed Action as well. But FTL is throwing an exception Expression name is undefined on line 1, column 3 in sample.ftl I tried with passing session instead of value stack and I could get the value in FTL. Please suggest me a way to get values from Action class to FTL from value stack. Thanks inadvance.

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  • Working with complex objects in Prevayler commands

    - by alexantd
    The demos included in the Prevayler distribution show how to pass in a couple strings (or something simple like that) into a command constructor in order to create or update an object. The problem is that I have an object called MyObject that has a lot of fields. If I had to pass all of them into the CreateMyObject command manually, it would be a pain. So an alternative I thought of is to pass my business object itself into the command, but to hang onto a clone of it (keeping in mind that I can't store the BO directly in the command). Of course after executing this command, I would need to make sure to dispose of the original copy that I passed in. public class CreateMyObject implements TransactionWithQuery { private MyObject object; public CreateMyObject(MyObject business_obj) { this.object = (MyObject) business_obj.clone(); } public Object executeAndQuery(...) throws Exception { ... } } The Prevayler wiki says: Transactions can't carry direct object references (pointers) to business objects. This has become known as the baptism problem because it's a common beginner pitfall. Direct object references don't work because once a transaction has been serialized to the journal and then deserialized for execution its object references no longer refer to the intended objects - - any objects they may have referred to at first will have been copied by the serialization process! Therefore, a transaction must carry some kind of string or numeric identifiers for any objects it wants to refer to, and it must look up the objects when it is executed. I think by cloning the passed-in object I will be getting around the "direct object pointer" problem, but I still don't know whether or not this is a good idea...

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  • Creating has_many :through records 2x times

    - by antiarchitect
    I have models class Question < ActiveRecord::Base WEIGHTS = %w(medium hard easy) belongs_to :test has_many :answers, :dependent => :destroy has_many :testing_questions end class Testing < ActiveRecord::Base belongs_to :student, :foreign_key => 'user_id' belongs_to :subtest has_many :testing_questions, :dependent => :destroy has_many :questions, :through => :testing_questions end So when I try to bind questions to testing on it's creation: >> questions = Question.all ... >> questions.count => 3 >> testing = Testing.create(:user_id => 3, :subtest_id => 1, :questions => questions) Testing Columns (0.9ms) SHOW FIELDS FROM `testings` SQL (0.1ms) BEGIN SQL (0.1ms) COMMIT SQL (0.1ms) BEGIN Testing Create (0.3ms) INSERT INTO `testings` (`created_at`, `updated_at`, `user_id`, `subtest_id`) VALUES('2010-05-18 00:53:05', '2010-05-18 00:53:05', 3, 1) TestingQuestion Columns (0.9ms) SHOW FIELDS FROM `testing_questions` TestingQuestion Create (0.3ms) INSERT INTO `testing_questions` (`question_id`, `created_at`, `updated_at`, `testing_id`) VALUES(1, '2010-05-18 00:53:05', '2010-05-18 00:53:05', 31) TestingQuestion Create (0.4ms) INSERT INTO `testing_questions` (`question_id`, `created_at`, `updated_at`, `testing_id`) VALUES(2, '2010-05-18 00:53:05', '2010-05-18 00:53:05', 31) TestingQuestion Create (0.3ms) INSERT INTO `testing_questions` (`question_id`, `created_at`, `updated_at`, `testing_id`) VALUES(3, '2010-05-18 00:53:05', '2010-05-18 00:53:05', 31) TestingQuestion Create (0.3ms) INSERT INTO `testing_questions` (`question_id`, `created_at`, `updated_at`, `testing_id`) VALUES(1, '2010-05-18 00:53:05', '2010-05-18 00:53:05', 31) TestingQuestion Create (0.3ms) INSERT INTO `testing_questions` (`question_id`, `created_at`, `updated_at`, `testing_id`) VALUES(2, '2010-05-18 00:53:05', '2010-05-18 00:53:05', 31) TestingQuestion Create (0.3ms) INSERT INTO `testing_questions` (`question_id`, `created_at`, `updated_at`, `testing_id`) VALUES(3, '2010-05-18 00:53:05', '2010-05-18 00:53:05', 31) SQL (90.2ms) COMMIT => #<Testing id: 31, subtest_id: 1, user_id: 3, created_at: "2010-05-18 00:53:05", updated_at: "2010-05-18 00:53:05"> There is 6 SQL queries and 6 records in testing_questions are created. Why?

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  • Detect how many times the users have click the button...

    - by Jerry
    Hello guys. Just want to know if there is a way to detect how many times a user has clicked a button by using Jquery. My main application has a button that can add input fields depend on the users. He/She can adds as many input fields as they need. When they submit the form, The add page will add the data to my database. My current idea is to create a hidden input field and set the value to zero. Every time a user clicks the button, jquery would update the attribute of the hidden input field value. Then the "add page" can detect the loop time. See the example below. I just want to know if there are better practices to do this. Thanks for the helps. main page <form method='post' action='add.php'> //omit <input type="hidden" id="add" name="add" value="0"/> <input type="button" id="addMatch" value="Add a match"/> //omit </form> jquery $(document).ready(function(){ var a =0; $("#addMatch").live('click', function(){ $('#table').append("<input name='match"+a+"Name' />") //the input field will append //as many as the user wants. a++; $('#add').attr('value', 'a'); //pass the a value to hidden input field return false; }); Add Page $a=$_POST['a']; // for($k=0;$k<$a;$k++){ //get all matchName input field $matchName=$_POST['match'.$k.'Name']; //insert the match $updateQuery=mysql_query("INSERT INTO game (team) values('$matchName')",$connection); if(!$updateQuery){ DIE('mysql Error:'+mysql_error()); }

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  • Apache/Rails/Passenger directory URLs that don't end in '/' fail to 404.

    - by Portamento
    I'm using Apache with passenger to run a rails app. In my rails app, I have some static content in subdirectories of the public directory. Each subdirectory has an index.html in it. So, inside the public directory, I have a subdir called 'b' and inside it, is an index.html. So it's like this: /public/b/index.html I have links to these pages, of the form: http://a.com/b If I do this in my regular non-rails web directory, Apache correctly rewrites this URL to be http://a.com/b/ which then, subsequently shows the index.html. It's only when accessing my rails app that it doesn't work. In fact, if I turn off passenger mod... so it just accesses my rails app like a regular document root, it works correctly also. What the heck do I need to do to get this to work properly with passenger? Again, it works fine in apache itself when passenger is not involved. I am running passenger 2.1.3. I have another server running passenger 2.0 that doesn't seem to have this problem, but I don't see anything different in the config other than the different versions of passenger itself. HELP! Been working on this for two days solid with no improvement!

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  • SSL signed certificates for internal use

    - by rogueprocess
    I have a distributed application consisting of many components that communicate over TCP (for examle JMS) and HTTP. All components run on internal hardware, with internal IP addresses, and are not accessible to the public. I want to make the communication secure using SSL. Does it make sense to purchase signed certificates from a well-known certificate authority? Or should I just use self-signed certs? My understanding of the advantage of trusted certs is that the authority is an entity that can be trusted by the general public - but that is only an issue when the general public needs to be sure that the entity at a particular domain is who they say they are. Therefore, in my case, where the same organization is responsible for the components at both ends of the communication, and everything in between, a publicly trusted authority would be pointless. In other words, if I generate and sign a certificate for my own server, I know that it's trustworthy. And no one from outside the organization will ever be asked to trust this certificate. That is my reasoning - am I correct, or is there some potential advantage to using certs from a known authority?

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  • Copying a subset of data to an empty database with the same schema

    - by user193655
    I would like to export part of a database full of data to an empty database. Both databases has the same schema. I want to maintain referential integrity. To simplify my cases it is like this: MainTable has the following fields: 1) MainID integer PK 2) Description varchar(50) 3) ForeignKey integer FK to MainID of SecondaryTable SecondaryTable has the following fields: 4) MainID integer PK (referenced by (3)) 5) AnotherDescription varchar(50) The goal I'm trying to accomplish is "export all records from MainTable using a WHERE condition", for example all records where MainID < 100. To do it manually I shuold first export all data from SecondaryTable contained in this select: select * from SecondaryTable ST outer join PrimaryTable PT on ST.MainID=PT.MainID then export the needed records from MainTable: select * from MainTable where MainID < 100. This is manual, ok. Of course my case is much much much omre complex, I have 200+ tables, so donig it manually is painful/impossible, I have many cascading FKs. Is there a way to force the copy of main table only "enforcing referntial integrity". so that my query is something like: select * from MainTable where MainID < 100 WITH "COPYING ALL FK sources" In this cases also the field (5) will be copied. ====================================================== Is there a syntax or a tool to do this? Table per table I'd like to insert conditions (like MainID <100 is only for MainTable, but I have also other tables).

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  • Generic property- specify the type at runtime

    - by Lirik
    I was reading a question on making a generic property, but I'm a little confused at by the last example from the first answer (I've included the relevant code below): You have to know the type at compile time. If you don't know the type at compile time then you must be storing it in an object, in which case you can add the following property to the Foo class: public object ConvertedValue { get { return Convert.ChangeType(Value, Type); } } That's seems strange: it's converting the value to the specified type, but it's returning it as an object when the value was stored as an object. Doesn't the returned object still require un-boxing? If it does, then why bother with the conversion of the type? I'm also trying to make a generic property whose type will be determined at run time: public class Foo { object Value {get;set;} Type ValType{get;set;} Foo(object value, Type type) { Value = value; ValType = type; } // I need a property that is actually // returned as the specified value type... public object ConvertedValue { get { return Convert.ChangeType(Value, ValType); } } } Is it possible to make a generic property? Does the return property still require unboxing after it's accessed?

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  • How do you send in the LayoutRoot into a RelayCommand via a EventToCommand?

    - by user298145
    Grid example with the trigger: <Grid x:Name="LayoutRoot" DataContext="{Binding ProjectGrid, Source={StaticResource Locator}}"> <i:Interaction.Triggers> <i:EventTrigger EventName="Loaded"> <GalaSoft_MvvmLight_Command:EventToCommand Command="{Binding LoadedCommand, Mode=OneWay}" PassEventArgsToCommand="True"/> </i:EventTrigger> </i:Interaction.Triggers> In my ViewModel I set the LoadedCommand like this: public RelayCommand<RoutedEventArgs> LoadedCommand {get;private set;} And in the ViewModel initializer I have this: public ProjectGridViewModel() { LoadedCommand = new RelayCommand<RoutedEventArgs>(e => { this.DoLoaded(e); } ); } Then, in my DoLoaded I'm trying to do this: Grid _projectGrid = null; public void DoLoaded(RoutedEventArgs e) { _projectGrid = e.OriginalSource as Grid; } You can see I'm trying to get rid of my Loaded="" in my Grid in my view, and do a RelayCommand instead. The issue is the OriginalSource brings back nothing. My loaded event is running nice this way, but I need to get the Grid in via the RoutedEventArgs it seems. I tried passing in the Grid in the EventCommand with CommandParameter="{Binding ElementName=LayoutRoot}", but this just crashes VS2010 when hitting F5 and running the project. Any ideas? Or a better way to do this? I had the Loaded event run in the views C# then call the ViewModel in the Views code-behind, but I'd like to do a nicer binding. Talking to the ViewMode in the Views code-behind feels like a hack.

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  • Linker error: wants C++ virtual base class destructor

    - by jdmuys
    Hi, I have a link error where the linker complains that my concrete class's destructor is calling its abstract superclass destructor, the code of which is missing. This is using GCC 4.2 on Mac OS X from XCode. I saw http://stackoverflow.com/questions/307352/g-undefined-reference-to-typeinfo but it's not quite the same thing. Here is the linker error message: Undefined symbols: "ConnectionPool::~ConnectionPool()", referenced from: AlwaysConnectedConnectionZPool::~AlwaysConnectedConnectionZPool()in RKConnector.o ld: symbol(s) not found collect2: ld returned 1 exit status Here is the abstract base class declaration: class ConnectionPool { public: static ConnectionPool* newPool(std::string h, short p, std::string u, std::string pw, std::string b); virtual ~ConnectionPool() =0; virtual int keepAlive() =0; virtual int disconnect() =0; virtual sql::Connection * getConnection(char *compression_scheme = NULL) =0; virtual void releaseConnection(sql::Connection * theConnection) =0; }; Here is the concrete class declaration: class AlwaysConnectedConnectionZPool: public ConnectionPool { protected: <snip data members> public: AlwaysConnectedConnectionZPool(std::string h, short p, std::string u, std::string pw, std::string b); virtual ~AlwaysConnectedConnectionZPool(); virtual int keepAlive(); // will make sure the connection doesn't time out. Call regularly virtual int disconnect(); // disconnects/destroys all connections. virtual sql::Connection * getConnection(char *compression_scheme = NULL); virtual void releaseConnection(sql::Connection * theConnection); }; Needless to say, all those members are implemented. Here is the destructor: AlwaysConnectedConnectionZPool::~AlwaysConnectedConnectionZPool() { printf("AlwaysConnectedConnectionZPool destructor call"); // nothing to destruct in fact } and also maybe the factory routine: ConnectionPool* ConnectionPool::newPool(std::string h, short p, std::string u, std::string pw, std::string b) { return new AlwaysConnectedConnectionZPool(h, p, u, pw, b); } I can fix this by artificially making my abstract base class concrete. But I'd rather do something better. Any idea? Thanks

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  • Nested Class member function can't access function of enclosing class. Why?

    - by Rahul
    Please see the example code below: class A { private: class B { public: foobar(); }; public: foo(); bar(); }; Within class A & B implementation: A::foo() { //do something } A::bar() { //some code foo(); //more code } A::B::foobar() { //some code foo(); //<<compiler doesn't like this } The compiler flags the call to foo() within the method foobar(). Earlier, I had foo() as private member function of class A but changed to public assuming that B's function can't see it. Of course, it didn't help. I am trying to re-use the functionality provided by A's method. Why doesn't the compiler allow this function call? As I see it, they are part of same enclosing class (A). I thought the accessibility issue for nested class meebers for enclosing class in C++ standards was resolved. How can I achieve what I am trying to do without re-writing the same method (foo()) for B, which keeping B nested within A? I am using VC++ compiler ver-9 (Visual Studio 2008). Thank you for your help.

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  • Android, NetworkInfo.getTypeName(), NullpointerException

    - by moppel
    I have an activity which shows some List entries. When I click on a list item my app checks which connection type is available ("WIF" or "MOBILE"), through NetworkInfo.getTypeName(). As soon as I call this method I get a NullpointerException. Why? I tested this on the emulator, cause my phone is currently not available (it's broken...). I assume this is the problem? This is the only explanation that I have, if that's not the case I have no idea why this would be null. Here's some code snippet: public class VideoList extends ListActivity{ ... public void onCreate(Bundle bundle){ final ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); ... listview.setOnItemClickListener(new OnItemClickListener(){ public void onItemClick(AdapterView<?> parent, View view, int position, long id) { ... NetworkInfo ni = cm.getActiveNetworkInfo(); String connex = ni.getTypeName(); //Nullpointer exception here if(connex.equals("WIFI")doSomething(); } }); } }

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  • Call method immediately after object construction in LINQ query

    - by Steffen
    I've got some objects which implement this interface: public interface IRow { void Fill(DataRow dr); } Usually when I select something out of db, I go: public IEnumerable<IRow> SelectSomeRows { DataTable table = GetTableFromDatabase(); foreach (DataRow dr in table.Rows) { IRow row = new MySQLRow(); // Disregard the MySQLRow type, it's not important row.Fill(dr); yield return row; } } Now with .Net 4, I'd like to use AsParallel, and thus LINQ. I've done some testing on it, and it speeds up things alot (IRow.Fill uses Reflection, so it's hard on the CPU) Anyway my problem is, how do I go about creating a LINQ query, which calls Fills as part of the query, so it's properly parallelized? For testing performance I created a constructor which took the DataRow as argument, however I'd really love to avoid this if somehow possible. With the constructor in place, it's obviously simple enough: public IEnumerable<IRow> SelectSomeRowsParallel { DataTable table = GetTableFromDatabase(); return from DataRow dr in table.Rows.AsParallel() select new MySQLRow(dr); } However like I said, I'd really love to be able to just stuff my Fill method into the LINQ query, and thus not need the constructor overload.

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  • Setting spinners onResume doesn't work

    - by DixieFlatline
    Hello! I want to save text from 2 edittexts(et1,et2) and selection from 3 spinners(spinnerm,spinner and spinner2) onPause and setting them back onResume. Text from edittexts is saved correctly, only spinner selection don't work as desired. My code: public void onResume(){ super.onResume(); Log.d("REZUM","notr smo"); SharedPreferences seti = getSharedPreferences( "pavzica", MODE_PRIVATE); spinnerm.setSelection(seti.getInt("m", 0)); spinner.setSelection(seti.getInt("k", 0)); spinner2.setSelection(seti.getInt("p", 0)); et1.setText(seti.getString("zade", "")); et2.setText(seti.getString("Vseb", "")); } public void onPause() { shraniPolja(); super.onPause(); } public void shraniPolja() { SharedPreferences seti = getSharedPreferences( "pavzica", MODE_PRIVATE); SharedPreferences.Editor edito = seti.edit(); edito.putString("zade", et1.getText().toString()); edito.putString("Vseb", et2.getText().toString()); edito.putInt("m", spinnerm.getSelectedItemPosition()); edito.putInt("k", spinner.getSelectedItemPosition()); edito.putInt("p", spinner2.getSelectedItemPosition()); edito.putBoolean("b", true); edito.commit(); } What am i doing wrong?

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  • Constructor and Destructors in C++ [Not a question] [closed]

    - by Jack
    I am using gcc. Please tell me if I am wrong - Lets say I have two classes A & B class A { public: A(){cout<<"A constructor"<<endl;} ~A(){cout<<"A destructor"<<endl;} }; class B:public A { public: B(){cout<<"B constructor"<<endl;} ~B(){cout<<"B destructor"<<endl;} }; 1) The first line in B's constructor should be a call to A's constructor ( I assume compiler automatically inserts it). Also the last line in B's destructor will be a call to A's destructor (compiler does it again). Why was it built this way? 2) When I say A * a = new B(); compiler creates a new B object and checks to see if A is a base class of B and if it is it allows 'a' to point to the newly created object. I guess that is why we don't need any virtual constructors. ( with help from @Tyler McHenry , @Konrad Rudolph) 3) When I write delete a compiler sees that a is an object of type A so it calls A's destructor leading to a problem which is solved by making A's destructor virtual. As user - Little Bobby Tables pointed out to me all destructors have the same name destroy() in memory so we can implement virtual destructors and now the call is made to B's destructor and all is well in C++ land. Please comment.

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  • Asp MVC - "The Id field is required" validation message on Create; Id not set to [Required]

    - by burnt_hand
    This is happening when I try to create the entity using a Create style action in Asp.Net MVC 2. The POCO has the following properties: public int Id {get;set;} [Required] public string Message {get; set} On the creation of the entity, the Id is set automatically, so there is no need for it on the Create action. The ModelState says that "The Id field is required", but I haven't set that to be so. Is there something automatic going on here? EDIT - Reason Revealed The reason for the issue is answered by Brad Wilson via Paul Speranza in one of the comments below where he says (cheers Paul): You're providing a value for ID, you just didn't know you were. It's in the route data of the default route ("{controller}/{action}/{id}"), and its default value is the empty string, which isn't valid for an int. Use the [Bind] attribute on your action parameter to exclude ID. My default route was: new { controller = "Customer", action = "Edit", id = " " } // Parameter defaults EDIT - Update Model technique I actually changed the way I did this again by using TryUpdateModel and the exclude parameter array asscoiated with that. [HttpPost] public ActionResult Add(Venue collection) { Venue venue = new Venue(); if (TryUpdateModel(venue, null, null, new[] { "Id" })) { _service.Add(venue); return RedirectToAction("Index", "Manage"); } return View(collection); }

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  • C# how to calculate hashcode from an object reference.

    - by Wayne
    Folks, here's a thorny problem for you! A part of the TickZoom system must collect instances of every type of object into a Dictionary< type. It is imperative that their equality and hash code be based on the instance of the object which means reference equality instead of value equality. The challenge is that some of the objects in the system have overridden Equals() and GetHashCode() for use as value equality and their internal values will change over time. That means that their Equals and GetHashCode are useless. How to solve this generically rather than intrusively? So far, We created a struct to wrap each object called ObjectHandle for hashing into the Dictionary. As you see below we implemented Equals() but the problem of how to calculate a hash code remains. public struct ObjectHandle : IEquatable<ObjectHandle>{ public object Object; public bool Equals(ObjectHandle other) { return object.ReferenceEquals(this.Object,other.Object); } } See? There is the method object.ReferenceEquals() which will compare reference equality without regard for any overridden Equals() implementation in the object. Now, how to calculate a matching GetHashCode() by only considering the reference without concern for any overridden GetHashCode() method? Ahh, I hope this give you an interesting puzzle. We're stuck over here. Sincerely, Wayne

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  • Animating translation and scaling of view in Android

    - by hgpc
    I have to animate a view from state A to B with changes to its scale, position and scrolling. I know everything about state A (widthA, heightA, topA, leftA, scrollXA, scrollYA) and state B (widthB, heightB, topB, leftB, scrollXB, scrollYB). So far I wrote the following code: AnimationSet animation = new AnimationSet(true); int toXDelta; // What goes here? int toYDelta; // What goes here? TranslateAnimation translateAnimation = new TranslateAnimation(1, toXDelta, 1, toYDelta); translateAnimation.setDuration(duration); animation.addAnimation(translateAnimation); float scale = (float) widthB / (float) widthA; ScaleAnimation scaleAnimation = new ScaleAnimation(1, scale, 1, scale); scaleAnimation.setDuration(duration); animation.addAnimation(scaleAnimation); animation.setAnimationListener(new AnimationListener() { @Override public void onAnimationEnd(Animation arg0) { view.clearAnimation(); // Change view to state B } @Override public void onAnimationRepeat(Animation arg0) {} @Override public void onAnimationStart(Animation arg0) {} }); view.startAnimation(animation); Is this the right way to do this? If so, how should I calculate the values of toXDelta and toYDelta? I'm having trouble finding the exact formula. Thanks!

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  • Modelbinding using Interfaces in ASP.NET MVC 2

    - by Thomas
    I have the following View Data: public class ShoppingCartViewData { public IList<IShoppingCartItem> Cart { get; set; } } I populate the viewdata in my controller: viewData.Cart = CurrentSession.CartItems; return View(viewData); And send the data to the view and display it using: <% for (int i = 0; i < Model.Cart.Count; i++ ) { %> <%= Html.TextBoxFor(m => m.Cart[i].Quantity)%> <%= Html.HiddenFor(m => m.Cart[i].Id) %> <% } %> I want to be able to catch the viewdata on the post. When I try: [HttpPost] public ActionResult UpdateCart(ShoppingCartViewData viewData) { ... } When I run this I get a: System.MissingMethodException: Cannot create an instance of an interface. Can anyone shed some light on this. What would I have to do to get this to work? Many Thanks

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  • CSS: Possible to define styles mid way through an html document?

    - by Dr. Zim
    In ASP.NET MVC, there are these snippets of html called view templates which appear when their matching data appears on the screen. For example, if you have a customer order and it has a vendor address, the vendor address view template shows up populated with data. Unfortunately, these don't have access to "MasterPages" nor are aware of their CSS surroundings. Instead of loading these up with style tags, is there any way to create partial CSS files that could work for that particular html snippet, a sort of in-line CSS style section? It would be really nice to plop this down just before we render the partial view: <style type="text/css"> input { margin: .2em .2em; overflow: hidden; width: 18.8em; height: 1.6em; border: 1px solid black;} </style> to have the 15 or so input fields in that particular Html snippet be formatted the same. These are swapped out, so the positions of the input fields change. This may also imply a CSS reset on each partial view.

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