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  • Problem with MessageContract, Generic return types and clientside naming

    - by Soeteman
    I'm building a web service which uses MessageContracts, because I want to add custom fields to my SOAP header. In a previous topic, I learned that a composite response has to be wrapped. For this purpose, I devised a generic ResponseWrapper class. [MessageContract(WrapperNamespace = "http://mynamespace.com", WrapperName="WrapperOf{0}")] public class ResponseWrapper<T> { [MessageBodyMember(Namespace = "http://mynamespace.com")] public T Response { get; set; } } I made a ServiceResult base class, defined as follows: [MessageContract(WrapperNamespace = "http://mynamespace.com")] public class ServiceResult { [MessageBodyMember] public bool Status { get; set; } [MessageBodyMember] public string Message { get; set; } [MessageBodyMember] public string Description { get; set; } } To be able to include the request context in the response, I use a derived class of ServiceResult, which uses generics: [MessageContract(WrapperNamespace = "http://mynamespace.com", WrapperName = "ServiceResultOf{0}")] public class ServiceResult<TRequest> : ServiceResult { [MessageBodyMember] public TRequest Request { get; set; } } This is used in the following way [OperationContract()] ResponseWrapper<ServiceResult<HCCertificateRequest>> OrderHealthCertificate(RequestContext<HCCertificateRequest> context); I expected my client code to be generated as ServiceResultOfHCCertificateRequest OrderHealthCertificate(RequestContextOfHCCertificateRequest context); Instead, I get the following: ServiceResultOfHCCertificateRequestzSOTD_SSj OrderHealthCertificate(CompType1 c1, CompType2 c2, HCCertificateRequest context); CompType1 and CompType2 are properties of the RequestContext class. The problem is that a hash is added to the end of ServiceResultOfHCCertificateRequestzSOTD_SSj. How do I need define my generic return types in order for the client type to be generated as expected (without the hash)?

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  • Axis2 Class Generation

    - by Jack
    I have an instance of a derived class (called Child) that I would like to send between the client and server of my web service. However, the method that might be returning this instance, is marked as returning an instance of the parent class (called Parent). For example: public class Service{public Parent createInstanceOfParentOrChildObject();} While Child is not a parameter anywhere in the service nor is it ever specifically named as a return type (only Parent is ever named), it is nonetheless generated and returned inside certain methods (and then cast to Parent). I generated the wsdl file using Axis2 1.4.1 java2wsdl and specifying that it include this class (using the -xc parameter). I did not use Axis2 1.5.1 because it was not honoring the -xc parameter though it looks like that bug is supposedly fixed in Axis2 1.6. I even did a quick check of the generated .wsdl file to ensure that it did indeed include a definition for Child (and, of course, Parent). However, when I used wsdl2java to generate the server-side (and client-side) code, Child was not generated. How can I get wsdl2java to generate Child? I realize that I could do this by hand but I don't want to have to do this for both the client and server. I was also hoping that I could make this as easy as possible for people to use my wsdl to generate their own clients.

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  • InvalidCastException in DataGridView

    - by Max Yaffe
    (Using VS 2010 Beta 2 - .Net 4.0 B2 Rel) I have a class, MyTable, derived from BindingList where S is a struct. S is made up of several other structs, for example: public class MyTable<S>:BindingList<S> where S: struct { ... } public struct MyStruct { public MyReal r1; public MyReal r2; public MyReal R1 {get{...} set{...}} public MyReal R2 {get{...} set{...}} ... } public struct MyReal { private Double d; private void InitFromString(string) {this.d = ...;} public MyReal(Double d) { this.d = d;} public MyReal(string val) { this.d = default(Double); InitFromString(val);} public override string ToString() { return this.real.ToString();} public static explicit operator MyReal(string s) { return new MyReal(s);} public static implicit operator String(MyReal r) { return r.ToString();} ... } OK, I use the MyTable as a binding source for a DataGridView. I can load the data grid easily using InitFromString on individual fields in MyStruct. The problem comes when I try to edit a value in a cell of the DataGridView. Going to the first row, first column, I change the value of the existing number. It gives an exception blizzard, the first line of which says: System.FormatException: Invalid cast from 'System.String' to 'MyReal' I've looked at the casting discussions and reference books but don't see any obvious problems. Any ideas?

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  • Keyword 'this'(Me) is not available calling the base constructor

    - by serhio
    In the inherited class I use the base constructor, but can't use class's members calling this base constructor. In this example I have a PicturedLabel that knows it's own color and has a image. A TypedLabel : PictureLabel knows it's type but uses the base color. The (base)image that uses TypedLabel should be colored with the (base)color, however, I can't obtain this color: Error: Keyword 'this' is not available in the current context A workaround? /// base class public class PicturedLabel : Label { PictureBox pb = new PictureBox(); public Color LabelColor; public PicturedLabel() { // initialised here in a specific way LabelColor = Color.Red; } public PicturedLabel(Image img) : base() { pb.Image = img; this.Controls.Add(pb); } } public enum LabelType { A, B } /// derived class public class TypedLabel : PicturedLabel { public TypedLabel(LabelType type) : base(GetImageFromType(type, this.LabelColor)) //Error: Keyword 'this' is not available in the current context { } public static Image GetImageFromType(LabelType type, Color c) { Image result = new Bitmap(10, 10); Rectangle rec = new Rectangle(0, 0, 10, 10); Pen pen = new Pen(c); Graphics g = Graphics.FromImage(result); switch (type) { case LabelType.A: g.DrawRectangle(pen, rec); break; case LabelType.B: g.DrawEllipse(pen, rec); break; } return result; } }

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  • How do you create a non-Thread-based Guice custom Scope?

    - by Russ
    It seems that all Guice's out-of-the-box Scope implementations are inherently Thread-based (or ignore Threads entirely): Scopes.SINGLETON and Scopes.NO_SCOPE ignore Threads and are the edge cases: global scope and no scope. ServletScopes.REQUEST and ServletScopes.SESSION ultimately depend on retrieving scoped objects from a ThreadLocal<Context>. The retrieved Context holds a reference to the HttpServletRequest that holds a reference to the scoped objects stored as named attributes (where name is derived from com.google.inject.Key). Class SimpleScope from the custom scope Guice wiki also provides a per-Thread implementation using a ThreadLocal<Map<Key<?>, Object>> member variable. With that preamble, my question is this: how does one go about creating a non-Thread-based Scope? It seems that something that I can use to look up a Map<Key<?>, Object> is missing, as the only things passed in to Scope.scope() are a Key<T> and a Provider<T>. Thanks in advance for your time.

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  • WCF Services (with RIA)

    - by netlogging
    I am new to WCF and WCF derived services. I am using VS 2010, silverlight 4, ria services 4. Recently I created plain WCF REST services (no RIA, no SOAP) with my endpoint (using wsHttpBinging): <endpoint address="" behaviorConfiguration="wsBehavior" binding="wsHttpBinding" bindingConfiguration="wsbinding" contract="WcfService1.IService1"/> <behaviors> <endpointBehaviors> <behavior name="wsBehavior"> <webHttp/> </behavior>......... I use this service from silverlight 4 client and everything works fine. THEN, i created new project using "silverlight Business application" template which used RIA service. Now the web.config uses DomainServices and when i add wsHttpBind endpoint I doesnot work. I know i am not doing this correctly and i cant find any help online so far. What I am trying to do is creat a RESTful WCF application with RIA (no SOAP) and that i can use from silverlight 4 client. For some reason i cannot get the service working.

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  • WPF Designer has bug with parsing generic control with overrided property

    - by Ivan Laktyunkin
    I've created a generic lookless control with virtual property: public abstract class TestControlBase<TValue> : Control { public static readonly DependencyProperty ValueProperty; static TestControlBase() { ValueProperty = DependencyProperty.Register("Value", typeof(TValue), typeof(TestControlBase<TValue>)); } protected TestControlBase() { Focusable = false; Value = default(TValue); } public virtual TValue Value { get { return (TValue)GetValue(ValueProperty); } set { SetValue(ValueProperty, value); } } } Then I've made a control derived from it and overrided Value property: public class TestControl : TestControlBase<int> { public override int Value { get { return base.Value; } set { base.Value = value; } } } So I use it in a Window XAML: <TestControls:TestControl /> When I open window in designer all is OK, but when I put mouse cursor to this line, or to this control in designer I receive exception: Exception has been thrown by the target of an invocation. at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) at System.RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler) Ambiguous match found. at System.RuntimeType.GetPropertyImpl(String name, BindingFlags bindingAttr, Binder binder, Type returnType, Type[] types, ParameterModifier[] modifiers) at System.Type.GetProperty(String name) at MS.Internal.ComponentModel.DependencyPropertyKind.get_IsDirect() at MS.Internal.ComponentModel.DependencyPropertyKind.get_IsAttached() at MS.Internal.ComponentModel.APCustomTypeDescriptor.GetProperties(Attribute[] attributes) at MS.Internal.ComponentModel.APCustomTypeDescriptor.GetProperties() at System.ComponentModel.TypeDescriptor.TypeDescriptionNode.DefaultExtendedTypeDescriptor.System.ComponentModel.ICustomTypeDescriptor.GetProperties() at System.ComponentModel.TypeDescriptor.GetPropertiesImpl(Object component, Attribute[] attributes, Boolean noCustomTypeDesc, Boolean noAttributes) at System.ComponentModel.TypeDescriptor.GetProperties(Object component) at MS.Internal.Model.ModelPropertyCollectionImpl.GetProperties(String propertyNameHint) at MS.Internal.Model.ModelPropertyCollectionImpl.<GetEnumerator>d__0.MoveNext() at MS.Internal.Designer.PropertyEditing.Model.ModelPropertyMerger.<GetFirstProperties>d__0.MoveNext() at MS.Internal.Designer.PropertyEditing.PropertyInspector.UpdateCategories(Selection selection) at MS.Internal.Designer.PropertyEditing.PropertyInspector.OnSelectionChangedIdle() Who know this problem? Please explain :) I have no ideas except that WPF Designer doesn't like generics. If I replace generics by Object all is OK.

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  • What could I add to this code to allow the cell height to dynamically change as I edit the JTextArea

    - by Dr. Plaguey
    The derived classes I am using public class TextAreaRenderer extends JTextArea implements TableCellRenderer { public TextAreaRenderer() { setLineWrap(true); setWrapStyleWord(true); } public Component getTableCellRendererComponent(JTable jTable, Object obj, boolean isSelected, boolean hasFocus, int row, int column) { setText((String)obj); int height_wanted = (int)getPreferredSize().getHeight() + 10; if (height_wanted != rootJTable.getRowHeight(row)) rootJTable.setRowHeight(row, height_wanted); return this; } } class TextEditor extends AbstractCellEditor implements TableCellEditor { protected JTextArea ta; String txt; public TextEditor() { ta = new JTextArea(); } //Implement the one CellEditor method that AbstractCellEditor doesn't. public Object getCellEditorValue() { return ta.getText(); } // Implement the one method defined by TableCellEditor. public Component getTableCellEditorComponent(javax.swing.JTable table, Object value,boolean isSelected, int row, int column) { txt = value.toString(); ta.setText(txt); ta.setLineWrap(true); return new JScrollPane(ta); } public boolean isCellEditable(EventObject anEvent) { return true; } } Set column renderer and editor rootJTable.getColumnModel().getColumn(1).setCellRenderer(new TextAreaRenderer()); rootJTable.getColumnModel().getColumn(1).setCellEditor(new TextEditor());

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  • Normalizing chains of .Skip() and .Take() calls

    - by dtb
    I'm trying to normalize arbitrary chains of .Skip() and .Take() calls to a single .Skip() call followed by an optional single .Take() call. Here are some examples of expected results, but I'm not sure if these are correct: .Skip(5) => .Skip(5) .Take(7) => .Skip(0).Take(7) .Skip(5).Skip(7) => .Skip(12) .Skip(5).Take(7) => .Skip(5).Take(7) .Take(7).Skip(5) => .Skip(5).Take(2) .Take(5).Take(7) => .Skip(0).Take(5) .Skip(5).Skip(7).Skip(11) => .Skip(23) .Skip(5).Skip(7).Take(11) => .Skip(12).Take(11) .Skip(5).Take(7).Skip(3) => .Skip(8).Take(4) .Skip(5).Take(7).Take(3) => .Skip(5).Take(4) .Take(11).Skip(5).Skip(3) => .Skip(8).Take(3) .Take(11).Skip(5).Take(7) => .Skip(5).Take(6) .Take(11).Take(5).Skip(3) => .Skip(3).Take(2) .Take(11).Take(5).Take(3) => .Skip(0).Take(3) Can anyone confirm these are the correct results to be expected? Here is the basic algorithm that I derived from the examples: class Foo { private int skip; private int? take; public Foo Skip(int value) { if (value < 0) value = 0; this.skip += value; if (this.take.HasValue) this.take -= value; return this; } public Foo Take(int value) { if (value < 0) value = 0; if (!this.take.HasValue || value < this.take) this.take = value; return this; } } Any idea how I can confirm if this is the correct algorithm?

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  • How to access generic property without knowing the closed generic type

    - by Martin Booka Weser
    I have a generic Type as follows public class TestGeneric<T> { public T Data { get; set; } public TestGeneric(T data) { this.Data = data; } } If i have now an object (which is coming from some external source) from which i know that it's type is of some closed TestGeneric<, but i don't know the TypeParameter T. Now I need to access the Data of my object. Problem is that i can't cast the object, since i don't know exactly to which closed TestGeneric. I use // thx to http://stackoverflow.com/questions/457676/c-reflection-check-if-a-class-is-derived-from-a-generic-class private static bool IsSubclassOfRawGeneric(Type rawGeneric, Type subclass) { while (subclass != typeof(object)) { var cur = subclass.IsGenericType ? subclass.GetGenericTypeDefinition() : subclass; if (rawGeneric == cur) { return true; } subclass = subclass.BaseType; } return false; } to make sure, my object is of the generic type. The code in question is as follows: public static void Main() { object myObject = new TestGeneric<string>("test"); // or from another source if (IsSubclassOfRawGeneric(typeof(TestGeneric<>), myObject.GetType())) { // the following gives an InvalidCastException // var data = ((TestGeneric<object>)myObject).Data; // if i try to access the property with reflection // i get an InvalidOperationException var dataProperty = typeof(TestGeneric<>).GetProperty("Data"); object data = dataProperty.GetValue(myObject, new object[] { }); } } I need the Data regardless of its type (well, if i could ask for its type using GetType() would be fine, but not necessary) since i just want to dump it in xml using ToString(). Any suggestions? Thanx.

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  • Generating code -- is there an easy way to get a proper string representation of nullable type?

    - by Cory Larson
    So I'm building an application that is going to do a ton of code generation with both C# and VB output (depending on project settings). I've got a CodeTemplateEngine, with two derived classes VBTemplateEngine and CSharpTemplateEngine. This question regards creating the property signatures based on columns in a database table. Using the IDataReader's GetSchemaTable method I gather the CLR type of the column, such as "System.Int32", and whether it IsNullable. However, I'd like to keep the code simple, and instead of having a property that looks like: public System.Int32? SomeIntegerColumn { get; set; } or public Nullable<System.Int32> SomeIntegerColumn { get; set; }, where the property type would be resolved with this function (from my VBTemplateEngine), public override string ResolveCLRType(bool? isNullable, string runtimeType) { Type type = TypeUtils.ResolveType(runtimeType); if (isNullable.HasValue && isNullable.Value == true && type.IsValueType) { return "System.Nullable(Of " + type.FullName + ")"; // or, for example... return type.FullName + "?"; } else { return type.FullName; } }, I would like to generate a simpler property. I hate the idea of building a Type string from nothing, and I would rather have something like: public int? SomeIntegerColumn { get; set; } Is there anything built-in anywhere, such as in the VBCodeProvider or CSharpCodeProvider classes that would somehow take care of this for me? Or is there a way to get a type alias of int? from a type string like System.Nullable'1[System.Int32]? Thanks!

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  • Entity Framework - Foreign key constraints not added for inherited entity

    - by Tri Q
    Hello, It appears to me that a strange phenomenon is occurring with inherited entities (TPT) in EF4. I have three entities. 1. Asset 2. Property 3. Activity Property is a derived-type of Asset. Property has many activities (many-to-many) When modeling this in my EDMX, everything seems fine until I try to insert a new Property into the database. If the property does not contain any Activity, it works, but all hell breaks loose when I add some new activities to the new Property. As it turns out after 2 days of crawling the web and fiddling around, I noticed that in the EF store (SSDL) some of the constraints between entities were not picked up during the update process. Property_Activity table which links properties and activities show only one constraint FK_Property_Activity_Activity but FK_Property_Activity_Property was missing. I knew this is an Entity Framework anomoly because when I switched the relationship in the database to: Asset <-- Asset_Activity <-- Activity After an update, all foreign key constraints are picked up and the save is successful, with or without activities in the new property. Is this intended or a bug in EF? How do I get around this problem? Should I abandon inheritance altogether?

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  • Deserializing a FileStream on Client using WCF

    - by Grandpappy
    I'm very new to WCF, so I apologize in advance if I misstate something. This is using .NET 4.0 RC1. Using WCF, I am trying to deserialize a response from the server. The base response has a Stream as its only MessageBodyMember. public abstract class StreamedResponse { [MessageBodyMember] public Stream Stream { get; set; } public StreamedResponse() { this.Stream = Stream.Null; } } The derived versions of this class are actually what's serialized, but they don't have a MessageBodyMember attribute (they have other base types such as int, string, etc listed as MessageHeader values). [MessageContract] public class ChildResponse : StreamedResponse { [DataMember] [MessageHeader] public Guid ID { get; set; } [DataMember] [MessageHeader] public string FileName { get; set; } [DataMember] [MessageHeader] public long FileSize { get; set; } public ChildResponse() : base() { } } The Stream is always a FileStream, in my specific case (but may not always be). At first, WCF said FileStream was not a known type, so I added it to the list of known types and now it serializes. It also appears, at first glance, to deserialize it on the client's side (it's the FileStream type). The problem is that it doesn't seem to be usable. All the CanRead, CanWrite, etc are false, and the Length, Position, etc properties throw exceptions when being used. Same with ReadByte(). What am I missing that would keep me from getting a valid FileStream?

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  • Strategies for serializing an object for auditing/logging purpose in .NET?

    - by Jiho Han
    Let's say I have an application that processes messages. Messages are just objects in this case that implements IMessage interface which is just a marker. In this app, if a message fails to process, then I want to log it, first of all for auditing and troubleshooting purposes. Secondly I might want to use it for re-processing. Ideally, I want the message to be serialized into a format that is human-readable. The first candidate is XML although there are others like JSON. If I were to serialize the messages as XML, I want to know whether the message object is XML-serializable. One way is to reflect on the type and to see if it has a parameter-less constructor and the other is to require IXmlSerializable interface. I'm not too happy with either of these approaches. There is a third option which is to try to serialize it and catch exceptions. This doesn't really help - I want to, in some way, stipulate that IMessage (or a derived type) should be xml-serializable. The reflection route has obvious disadvantages such as security, performance, etc. IXmlSerializable route locks down my messages to one format, when in the future, I might want to change the serialization format to be JSON. The other thing is even the simplest objects now must implement ReadXml and WriteXml methods. Is there a route that involves the least amount of work that lets me serialize an arbitrary object (as long as it implements the marker interface) into XML but not lock future messages into XML?

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  • Problem consuming Exchange Web Service 2010 with jax-ws metro

    - by Johan Karlberg
    I am trying to consume the Exchange 2010 Web Service interface using JAX-WS. I'm using JAX-WS 2.2 RI (Metro 2.0). 2.1 exhibited the same problem. I am running into trouble with Exchange, which returns "HTTP/1.1 415 Cannot process the message because the content type 'text/xml;charset=utf-8' was not the expected type 'text/xml; charset=utf-8'." as a reponse (2.1 quoted the charset value, otherwise same response). Apparently I need to dictate the exact Content-type header for Exchange to be happy. Is there a way for me to do this without forcing me to manually rebuild the dependency? I currently rely on published maven artifacts, and would like to continue doing this if at all possible. The consuming process is a regular J2SE app, with no containers in sight. I have control of the application and can add pretty much anything required to the applications scope, but can not add out-of-process items like proxy servers. The client classes were generated from local WSDL, but the charset specification is derived from constants declared in the jaxws RI implementation, not the generated code. The resulting HTTP transport is thus handled by the standard http/https client from Sun JRE5 or JRE6.

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  • Is it possible to make a persistent connection between a Python web service and a .Net WCF Client?

    - by Ad Hock
    I have a .Net 3.5 SOAP client written in C# using the WCF. It's expecting basicHTTPBinding and a persistent connection with HTTP/1.1. I'm trying to create a Python 2.6 application that will act as a web-service for the client. My problem is that the client keeps closing the connection and opening a new one for every command to the web service. How does the .Net WCF client know to stay open when connecting with a .Net Service? When I create a dummy .Net web service the client connects fine and the connection remains persistent. From what I can tell, when connected to a .Net server, there are no special HTTP headers being sent, that makes sense since HTTP/1.1 assumes a persistent connection unless otherwise specified (right?). However, with the python web service I accept/open a connection and eventually the client will send a TCP FIN and the connection will close (the client never sends a FIN or RST when connecting to a .Net service). The communication goes something like this: Incoming -- HTTP Header for SOAP Command #1 Outgoing -- HTTP Header with a Continue Incoming -- Body of Command #1 Outgoing -- ACK Command #1 (HTTP headers and body) Incoming -- HTTP Header for SOAP Command #2 Outgoing -- HTTP Header with a Continue Incoming -- TCP FIN <Connection closes> <New connection opens and SOAP command #2 (with full HTTP headers) is sent> I'm using a SocketServer.ThreadingTCPServer as the server and a BaseHTTPServer.BaseHTTPRequestHandler for any requests. The handler is actually a derived class of that with a do_POST method to handle the HTTP headers. I've looked at WireShark captures and I'm stumped. I've tried setting socket options to SO_KEEPALIVE and SO_REUSEADDR in the server but that didn't seem to change anything. What am I missing?

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  • Insane Graphics.lineStyle behavior

    - by Simon
    Hi all, I'd like some help with a little project of mine. Background: i have a little hierarchy of Sprite derived classes (5 levels starting from the one, that is the root application class in Flex Builder). Width and Height properties are overriden so that my class always remembers it's requested size (not just bounding size around content) and also those properties explicitly set scaleX and scaleY to 1, so that no scaling would ever be involved. After storing those values, draw() method is called to redraw content. Drawing: Drawing is very straight forward. Only the deepest object (at 1-indexed level 5) draws something into this.graphics object like this: var gr:Graphics = this.graphics; gr.clear(); gr.lineStyle(0, this.borderColor, 1, true, LineScaleMode.NONE); gr.beginFill(0x0000CC); gr.drawRoundRectComplex(0, 0, this.width, this.height, 10, 10, 0, 0); gr.endFill(); Further on: There is also MouseEvent.MOUSE_WHEEL event attached to the parent of the object that draws. What handler does is simply resizes that drawing object. Problem: Screenshot When resizing sometimes that hairline border line with LineScaleMode.NONE set gains thickness (quite often even 10 px) + it quite often leaves a trail of itself (as seen in the picture above and below blue box (notice that box itself has one px black border)). When i set lineStile thickness to NaN or alpha to 0, that trail is no more happening. I've been coming back to this problem and dropping it for some other stuff for over a week now. Any ideas anyone? P.S. Grey background is that of Flash Player itself, not my own choise.. :D

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  • How to make this OO?

    - by John
    Hello, Sorry for the poor title,I'm new to OOP so I don't know what is the term for what I need to do. I have, say, 10 different Objects that inherit one Object.They have different amount and type of class members,but all of them have one property in common - Visible. type TObj1=class(TObject) private a:integer; ...(More members) Visible:Boolean; end; TObj2=class(TObject) private b:String; ...(More members) Visible:Boolean; end; ...(Other 8 objects) For each of them I have a variable. var Obj1:TObj1; Obj2:TObj2; Obj3:TObj3; ....(Other 7 objects) Rule 1: Only one object can be initialized at a time(others have to be freed) to be visible. For this rule I have a global variable var CurrentVisibleObj:TObject; //Because they all inherit TObject Finally there is a procedure that changes visibility. procedure ChangeObjVisibility(newObj:TObject); begin CurrentVisibleObj.Free; //Free the old object CurrentVisibleObj:=newObj; //assign the new object CurrentVisibleObj:= ??? //Create new object CurrentVisibleObj.Visible:=true; //Set visibility to new object end; There is my problem,I don't know how to initialize it,because the derived class is unknown. How do I do this? I simplified the explanation,in the project there are TFrames each having different controls and I have to set visible/not visible the same way(By leaving only one frame initialized). Sorry again for the title,I'm very new to OOP.

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  • Passing control references as ref parameters

    - by Enmanuel
    Hi everyone. Please help me out here because im getting kind of confused.. I have a form in a C# winforms project and a couple of methods that are suposed to perform some tasks for this particular form and all derived ones, so one of those helper methods can make the example.. this one should fill comboboxes with a dataset. Its working properly now but when i coded the method with this signature protected void FillComboBox(kComboBox target, IEntClass_DA entity) { target.DataSource = entity.GetList().Tables[0]; target.DisplayMember = "name"; target.ValueMember = "id"; } I saw that the displayMember and ValueMember in the comboboxes were not holding the values after the method call. I just thought I should use ref parameters so the asignments are not wasted in read-only reference variables. It was ok by then but later, making an exercise of passing the whole form as a parameter I was warned by the compiler with the notice that this could not be passed as a ref parameter because it is read-only. Fine then, I keep working and see that even without the ref keyword i can use the ref variable from the form, update some properties and see the changes. So whats happening here: passing a reference of the control to the helper method gives me ability to change its members even when not using the ref parameter?? Thanks.

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  • MYSQL fetch 10 posts, each w/ vote count, sorted by vote count, limited by where clause on posts

    - by nibblebot
    I want to fetch a set of Posts w/ vote count listed, sorted by vote count (e.g.) Post 1 - Post Body blah blah - Votes: 500 Post 2 - Post Body blah blah - Votes: 400 Post 3 - Post Body blah blah - Votes: 300 Post 4 - Post Body blah blah - Votes: 200 I have 2 tables: Posts - columns - id, body, is_hidden Votes - columns - id, post_id, vote_type_id Here is the query I've tried: SELECT p.*, v.yes_count FROM posts p LEFT JOIN (SELECT post_id, vote_type_id, COUNT(1) AS yes_count FROM votes WHERE (vote_type_id = 1) GROUP BY post_id ORDER BY yes_count DESC LIMIT 0, 10) v ON v.post_id = p.id WHERE (p.is_hidden = 0) ORDER BY yes_count DESC LIMIT 0, 10 Correctness: The above query almost works. The subselect is including votes for posts that have is_hidden = 1, so when I left join it to posts, if a hidden post is in the top 10 (ranked by votes), I can end up with records with NULL on the yes_count field. Performance: I have ~50k posts and ~500k votes. On my dev machine, the above query is running in .4sec. I'd like to stay at or below this execution time. Indexes: I have an index on the Votes table that covers the fields: vote_type_id and post_id EXPLAIN id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY p ALL NULL NULL NULL NULL 45985 Using where; Using temporary; Using filesort 1 PRIMARY <derived2> ALL NULL NULL NULL NULL 10 2 DERIVED votes ref VotingPost VotingPost 4 319881 Using where; Using index; Using temporary; Using filesort

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  • Why does this Object wonk out & get deleted ?

    - by brainydexter
    Stepping through the debugger, the BBox object is okay at the entry of the function, but as soon as it enters the function, the vfptr object points to 0xccccc. I don't get it. What is causing this ? Why is there a virtual table reference in there when the object is not derived from other class. (Though, it resides in GameObject from which my Player class inherits and I retrieve the BBox from within player. But, why does the BBox have the reference ? Shouldn't it be player who should be maintained in that reference ?) For 1; some code for reference: A. I retrieve the bounding box from player. This returns a bounding box as expected. I then send its address to GetGridCells. const BoundingBox& l_Bbox = l_pPlayer-GetBoundingBox(); boost::unordered_set < Cell*, CellPHash & l_GridCells = GetGridCells ( &l_Bbox ); B. This is where a_pBoundingBox goes crazy and gets that garbage value. boost::unordered_set< Cell*, CellPHash CollisionMgr::GetGridCells(const BoundingBox *a_pBoundingBox) { I think the following code is also pertinent, so I'm sticking this in here anyways: const BoundingBox& Player::GetBoundingBox(void) { return BoundingBox( &GetBoundingSphere() ); } const BoundingSphere& Player::GetBoundingSphere(void) { BoundingSphere& l_BSphere = m_pGeomMesh-m_BoundingSphere; l_BSphere.m_Center = GetPosition(); return l_BSphere; } // BoundingBox Constructor BoundingBox(const BoundingSphere* a_pBoundingSphere); Can anyone please give me some idea as to why this is happening? Also, if you want me to post more code, please do let me know. Thanks!

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  • Encryption puzzle / How to create a ProxyStub for a Remote Assistance ticket

    - by Jon Clegg
    I am trying to create a ticket for Remote Assistance. Part of that requires creating a PassStub parameter. As of the documenation: http://msdn.microsoft.com/en-us/library/cc240115(PROT.10).aspx PassStub: The encrypted novice computer's password string. When the Remote Assistance Connection String is sent as a file over e-mail, to provide additional security, a password is used.<16 In part 16 they detail how to create as PassStub. In Windows XP and Windows Server 2003, when a password is used, it is encrypted using PROV_RSA_FULL predefined Cryptographic provider with MD5 hashing and CALG_RC4, the RC4 stream encryption algorithm. As PassStub looks like this in the file: PassStub="LK#6Lh*gCmNDpj" If you want to generate one yourself run msra.exe in Vista or run the Remote Assistance tool in WinXP. The documentation says this stub is the result of the function CryptEncrypt with the key derived from the password and encrypted with the session id (Those are also in the ticket file). The problem is that CryptEncrypt produces a binary output way larger then the 15 byte PassStub. Also the PassStub isn't encoding in any way I've seen before. Some interesting things about the PassStub encoding. After doing statistical analysis the 3rd char is always a one of: !#$&()+-=@^. Only symbols seen everywhere are: *_ . Otherwise the valid characters are 0-9 a-z A-Z. There are a total of 75 valid characters and they are always 15 bytes. Running msra.exe with the same password always generates a different PassStub, indicating that it is not a direct hash but includes the rasessionid as they say. Some other ideas I've had is that it is not the direct result of CryptEncrypt, but a result of the rasessionid in the MD5 hash. In MS-RA (http://msdn.microsoft.com/en-us/library/cc240013(PROT.10).aspx). The "PassStub Novice" is simply hex encoded, and looks to be the right length. The problem is I have no idea how to go from any hash to way the ProxyStub looks like.

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  • How to reliably replace a library-defined error handler with my own?

    - by sharptooth
    On certain error cases ATL invokes AtlThrow() which is implemented as ATL::AtlThrowImpl() which in turn throws CAtlException. The latter is not very good - CAtlException is not even derived from std::exception and also we use our own exceptions hierarchy and now we will have to catch CAtlException separately here and there which is lots of extra code and error-prone. Looks like it is possible to replace ATL::AtlThrowImpl() with my own handler - define _ATL_CUSTOM_THROW and define AtlThrow() to be the custom handler before including atlbase.h - and ATL will call the custom handler. Not so easy. Some of ATL code is not in sources - it comes compiled as a library - either static or dynamic. We use the static - atls.lib. And... it is compiled in such way that it has ATL::ThrowImpl() inside and some code calling it. I used a static analysis tool - it clearly shows that there're paths on which the old default handler is called. To ensure I even tried to "reimplement" ATL::AtlThrowImpl() in my code. Now the linker says it sees two declarations of ATL::AtlThrowImpl() which I suppose confirms that there's another implementation that can be called by some code. How can I handle this? How do I replace the default handler completely and ensure that the default handler is never called?

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  • Generate a set of strings with maximum edit distance

    - by Kevin Jacobs
    Problem 1: I'd like to generate a set of n strings of fixed length m from alphabet s such that the minimum Levenshtein distance (edit distance) between any two strings is greater than some constant c. Obviously, I can use randomization methods (e.g., a genetic algorithm), but was hoping that this may be a well-studied problem in computer science or mathematics with some informative literature and an efficient algorithm or three. Problem 2: Same as above except that adjacent characters cannot repeat; the i'th character in each string may not be equal to the i+1'th character. E.g., 'CAT', 'AGA' and 'TAG' are allowed, 'GAA', 'AAT', and 'AAA' are not. Background: The basis for this problem is bioinformatic and involves designing unique DNA tags that can be attached to biologically derived DNA fragments and then sequenced using a fancy second generation sequencer. The goal is to be able to recognize each tag, allowing for random insertion, deletion, and substitution errors. The specific DNA sequencing technology has a relatively low error rate per base (~1%), but is less precise when a single base is repeated 2 or more times (motivating the additional constraints imposed in problem 2).

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  • Encryption puzzle / How to create a PassStub for a Remote Assistance ticket

    - by Jon Clegg
    I am trying to create a ticket for Remote Assistance. Part of that requires creating a PassStub parameter. As of the documentation: http://msdn.microsoft.com/en-us/library/cc240115(PROT.10).aspx PassStub: The encrypted novice computer's password string. When the Remote Assistance Connection String is sent as a file over e-mail, to provide additional security, a password is used.<16 In part 16 they detail how to create as PassStub. In Windows XP and Windows Server 2003, when a password is used, it is encrypted using PROV_RSA_FULL predefined Cryptographic provider with MD5 hashing and CALG_RC4, the RC4 stream encryption algorithm. As PassStub looks like this in the file: PassStub="LK#6Lh*gCmNDpj" If you want to generate one yourself run msra.exe in Vista or run the Remote Assistance tool in WinXP. The documentation says this stub is the result of the function CryptEncrypt with the key derived from the password and encrypted with the session id (Those are also in the ticket file). The problem is that CryptEncrypt produces a binary output way larger then the 15 byte PassStub. Also the PassStub isn't encoding in any way I've seen before. Some interesting things about the PassStub encoding. After doing statistical analysis the 3rd char is always a one of: !#$&()+-=@^. Only symbols seen everywhere are: *_ . Otherwise the valid characters are 0-9 a-z A-Z. There are a total of 75 valid characters and they are always 15 bytes. Running msra.exe with the same password always generates a different PassStub, indicating that it is not a direct hash but includes the rasessionid as they say. Some other ideas I've had is that it is not the direct result of CryptEncrypt, but a result of the rasessionid in the MD5 hash. In MS-RA (http://msdn.microsoft.com/en-us/library/cc240013(PROT.10).aspx). The "PassStub Novice" is simply hex encoded, and looks to be the right length. The problem is I have no idea how to go from any hash to way the PassStub looks like.

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