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  • Loading saved byte array to memory stream causes out of memory exception

    - by user2320861
    At some point in my program the user selects a bitmap to use as the background image of a Panel object. When the user does this, the program immediately draws the panel with the background image and everything works fine. When the user clicks "Save", the following code saves the bitmap to a DataTable object. MyDataSet.MyDataTableRow myDataRow = MyDataSet.MyDataTableRow.NewMyDataTableRow(); //has a byte[] column named BackgroundImageByteArray using (MemoryStream stream = new MemoryStream()) { this.Panel.BackgroundImage.Save(stream, ImageFormat.Bmp); myDataRow.BackgroundImageByteArray = stream.ToArray(); } Everything works fine, there is no out of memory exception with this stream, even though it contains all the image bytes. However, when the application launches and loads saved data, the following code throws an Out of Memory Exception: using (MemoryStream stream = new MemoryStream(myDataRow.BackGroundImageByteArray)) { this.Panel.BackgroundImage = Image.FromStream(stream); } The streams are the same length. I don't understand how one throws an out of memory exception and the other doesn't. How can I load this bitmap? P.S. I've also tried using (MemoryStream stream = new MemoryStream(myDataRow.BackgroundImageByteArray.Length)) { stream.Write(myDataRow.BackgroundImageByteArray, 0, myDataRow.BackgroundImageByteArray.Length); //throw OoM exception here. }

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  • Custom Controls Properties - C# , Forms - :(

    - by user353600
    Hi I m adding custom control to my flowlayoutpanel , its a sort of forex data , refresh every second , so on each timer tick , i m adding a control , changing controls button text , then adding it to flowlayout panel , i m doing it at each 100ms timer tick , it takeing tooo much CPU , here is my custom Control . public partial class UserControl1 : UserControl { public UserControl1() { InitializeComponent(); } private void UserControl1_Load(object sender, EventArgs e) { } public void displaydata(string name , string back3price , string back3 , string back2price , string back2 , string back1price , string back1 , string lay3price , string lay3 , string lay2price , string lay2 , string lay1price , string lay1 ) { lblrunnerName.Text = name.ToString(); btnback3.Text = back3.ToString() + "\n" + back3price.ToString(); btnback2.Text = back2.ToString() + "\n" + back2price.ToString(); btnback1.Text = back1.ToString() + "\n" + back1price.ToString(); btnlay1.Text = lay1.ToString() + "\n" + lay1price.ToString(); btnlay2.Text = lay2.ToString() + "\n" + lay2price.ToString(); btnlay3.Text = lay3.ToString() + "\n" + lay3price.ToString(); } and here is how i m adding control; private void timer1_Tick(object sender, EventArgs e) { localhost.marketData[] md; md = ser.getM1(); flowLayoutPanel1.Controls.Clear(); foreach (localhost.marketData item in md) { UserControl1 ur = new UserControl1(); ur.Name = item.runnerName + item.runnerID; ur.displaydata(item.runnerName, item.back3price, item.back3, item.back2price, item.back2, item.back1price, item.back1, item.lay3price, item.lay3, item.lay2price, item.lay2, item.lay1price, item.lay1); flowLayoutPanel1.SuspendLayout(); flowLayoutPanel1.Controls.Add(ur); flowLayoutPanel1.ResumeLayout(); } } now its happing on 10 times on each send , taking 60% of my Core2Duo cpu . is there any other way , i can just add contols first time , and then change the text of cutom controls buttons on runtime on each refresh or timer tick i m using c# .Net

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  • Grails - Removing an item from a hasMany association List on data bind?

    - by ecrane
    Grails offers the ability to automatically create and bind domain objects to a hasMany List, as described in the grails user guide. So, for example, if my domain object "Author" has a List of many "Book" objects, I could create and bind these using the following markup (from the user guide): <g:textField name="books[0].title" value="the Stand" /> <g:textField name="books[1].title" value="the Shining" /> <g:textField name="books[2].title" value="Red Madder" /> In this case, if any of the books specified don't already exist, Grails will create them and set their titles appropriately. If there are already books in the specified indices, their titles will be updated and they will be saved. My question is: is there some easy way to tell Grails to remove one of those books from the 'books' association on data bind? The most obvious way to do this would be to omit the form element that corresponds to the domain instance you want to delete; unfortunately, this does not work, as per the user guide: Then Grails will automatically create a new instance for you at the defined position. If you "skipped" a few elements in the middle ... Then Grails will automatically create instances in between. I realize that a specific solution could be engineered as part of a command object, or as part of a particular controller- however, the need for this functionality appears repeatedly throughout my application, across multiple domain objects and for associations of many different types of objects. A general solution, therefore, would be ideal. Does anyone know if there is something like this included in Grails?

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  • I want just the insert query for a temp table.

    - by John Stephen
    Hi..I am using C#.Net and Sql Server ( Windows Application ). I had created a temporary table. When a button is clicked, temporary table (#tmp_emp_details) is created. I am having another button called "insert Values" and also 5 textboxes. The values that are entered in the textbox are used and whenever com.ExecuteNonQuery(); line comes, it throws an error message Invalid object name '#tbl_emp_answer'.. Below is the set of code.. Please give me a solution. Code for insert (in insert value button): private void btninsertvalues_Click(object sender, EventArgs e) { username = txtusername.Text; examloginid = txtexamloginid.Text; question = txtquestion.Text; answer = txtanswer.Text; useranswer = txtanswer.Text; SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=tempdb;Integrated Security=True;"); SqlCommand com = new SqlCommand("Insert into #tbl_emp_answer values('"+username+"','"+examloginid+"','"+question+"','"+answer+"','"+useranswer+"')", con); con.Open(); com.ExecuteNonQuery(); con.Close(); }

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  • How is timezone handled in the lifecycle of an ADO.NET + SQL Server DateTime column?

    - by stimpy77
    Using SQL Server 2008. This is a really junior question and I could really use some elaborate information, but the information on Google seems to dance around the topic quite a bit and it would be nice if there was some detailed elaboration on how this works... Let's say I have a datetime column and in ADO.NET I set it to DateTime.UtcNow. 1) Does SQL Server store DateTime.UtcNow accordingly, or does it offset it again based on the timezone of where the server is installed, and then return it offset-reversed when queried? I think I know that the answer is "of course it stores it without offsetting it again" but want to be certain. So then I query for it and cast it from, say, an IDataReader column to a DateTime. As far as I know, System.DateTime has metadata that internally tracks whether it is a UTC DateTime or it is an offsetted DateTime, which may or may not cause .ToLocalTime() and .ToUniversalTime() to have different behavior depending on this state. So, 2) Does this casted System.DateTime object already know that it is a UTC DateTime instance, or does it assume that it has been offset? Now let's say I don't use UtcNow, I use DateTime.Now, when performing an ADO.NET INSERT or UPDATE. 3) Does ADO.NET pass the offset to SQL Server and does SQL Server store DateTime.Now with the offset metadata? So then I query for it and cast it from, say, an IDataReader column to a DateTime. 4) Does this casted System.DateTime object already know that it is an offset time, or does it assume that it is UTC?

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  • Returning pointers in a thread-safe way.

    - by Roddy
    Assume I have a thread-safe collection of Things (call it a ThingList), and I want to add the following function. Thing * ThingList::findByName(string name) { return &item[name]; // or something similar.. } But by doing this, I've delegated the responsibility for thread safety to the calling code, which would have to do something like this: try { list.lock(); // NEEDED FOR THREAD SAFETY Thing *foo = list.findByName("wibble"); foo->Bar = 123; list.unlock(); } catch (...) { list.unlock(); throw; } Obviously a RAII lock/unlock object would simplify/remove the try/catch/unlocks, but it's still easy for the caller to forget. There are a few alternatives I've looked at: Return Thing by value, instead of a pointer - fine unless you need to modify the Thing Add function ThingList::setItemBar(string name, int value) - fine, but these tend to proliferate Return a pointerlike object which locks the list on creation and unlocks it again on destruction. Not sure if this is good/bad practice... What's the right approach to dealing with this?

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  • Unpredictable CCK field name in returned View data

    - by AK
    I'm using views_get_view_result to directly access the data in a view. I've stumbled upon this odd behavior where cck fields are prefixed with the first field name as a query optimization. Explained here. What's bizarre though is that fields are named differently depending on whether I retrieve that data as Anonymous or as Admin. I'm pretty sure all my permissions are set up, and the view itself has no restrictions. What is going on here? This is a big problem since I can't know how to retrieve a field. Here's a dump of the two view results. Notice that node_data_field_game_date_field_game_home_score_value != node_data_field_game_official_field_game_home_score_value. // View as Admin stdClass Object ( [nid] => 3191 [node_data_field_game_date_field_game_date_value] => 2010-03-27T00:00:00 [node_type] => game [node_vid] => 5039 [node_data_field_game_date_field_game_official_value] => 0 [node_node_data_field_game_home_team_title] => TeamA [node_node_data_field_game_home_team_nid] => 3396 [node_data_field_game_date_field_game_home_score_value] => 68 [node_node_data_field_game_visitor_team_title] => TeamB [node_node_data_field_game_visitor_team_nid] => 3442 [node_data_field_game_date_field_game_visitor_score_value] => 118 ) // View as Anonymous stdClass Object ( [nid] => 3191 [node_data_field_game_date_field_game_date_value] => 2010-03-27T00:00:00 [node_type] => game [node_vid] => 5039 [node_data_field_game_official_field_game_official_value] => 0 [node_node_data_field_game_home_team_title] => TeamA [node_node_data_field_game_home_team_nid] => 3396 [node_data_field_game_official_field_game_home_score_value] => 68 [node_node_data_field_game_visitor_team_title] => TeamB [node_node_data_field_game_visitor_team_nid] => 3442 [node_data_field_game_official_field_game_visitor_score_value] => 118 )

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  • Embed URL from variable in HTML file in Rails application

    - by TejasM
    hi, I have a doubt which might be silly for experience Rails developers. I am creating an application which is suppose to embed a video player with URL passed to it. So while displaying i.e in XXX.html.erb file i am writting below code. Now problem is @movie.trailer is my variable in ruby code which has URL value . I want the embedded video to load with URL given by this variable value. Any suggestion how am i suppose to place the value of Ruby variable(@movie.trailer) in part. <object width="425" height="344"> <param name="movie" value="<% @movie.trailer %>"> </param><param name="allowFullScreen" value="true"> </param><param name="allowscriptaccess" alue="always"> </param><embed src="<% @movie.trailer %>" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object> Note :- This code is working perfectly fine if i statically give value of URL. Please help

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  • if a JAR is placed on app servers's classpath how do we reference it from JSP

    - by Omnipresent
    On our application we are getting an error saying: PWC6117: File "/struts-tags" not found code in the file thats giving error is: <%@ taglib prefix="s" uri="/struts-tags" %> This file is in struts2-core.jar which is placed on the classpath of the app server (Sun 9.1). The code will work fine and not complain when the jar is actually in WEB-INF/lib of the application, compared to being on classpath of the appserver. But we can not change that. it has to be on appservers classpath. But how should we change our code so that this error goes away? I can create mapping in my web.xml so that tag uri's are change. but what should taglib-location be changed to? so that it references to app servers classpath? <taglib> <taglib-uri>/WEB-INF/struts-tags.tld</taglib-uri> <taglib-location>/WEB-INF/struts-tags.tld</taglib-location> </taglib>

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  • Compound Primary Key in Hibernate using Annotations

    - by Rich
    Hi, I have a table which uses two columns to represent its primary key, a transaction id and then the sequence number. I tried what was recommended http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#entity-mapping in section 2.2.3.2.2, but when I used the Hibernate session to commit this Entity object, it leaves out the TXN_ID field in the insert statement and only includes the BA_SEQ field! What's going wrong? Here's the related code excerpt: @Id @Column(name="TXN_ID") private long txn_id; public long getTxnId(){return txn_id;} public void setTxnId(long t){this.txn_id=t;} @Id @Column(name="BA_SEQ") private int seq; public int getSeq(){return seq;} public void setSeq(int s){this.seq=s;} And here are some log statements to show what exactly happens to fail: In createKeepTxnId of DAO base class: about to commit Transaction :: txn_id->90625 seq->0 ...<Snip>... Hibernate: insert into TBL (BA_ACCT_TXN_ID, BA_AUTH_SRVC_TXN_ID, BILL_SRVC_ID, BA_BILL_SRVC_TXN_ID, BA_CAUSE_TXN_ID, BA_CHANNEL, CUSTOMER_ID, BA_MERCHANT_FREETEXT, MERCHANT_ID, MERCHANT_PARENT_ID, MERCHANT_ROOT_ID, BA_MERCHANT_TXN_ID, BA_PRICE, BA_PRICE_CRNCY, BA_PROP_REQS, BA_PROP_VALS, BA_REFERENCE, RESERVED_1, RESERVED_2, RESERVED_3, SRVC_PROD_ID, BA_STATUS, BA_TAX_NAME, BA_TAX_RATE, BA_TIMESTAMP, BA_SEQ) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?) [WARN] util.JDBCExceptionReporter SQL Error: 1400, SQLState: 23000 [ERROR] util.JDBCExceptionReporter ORA-01400: cannot insert NULL into ("SCHEMA"."TBL"."TXN_ID") The important thing to note is I print out the entity object which has a txn_id set, and then the following insert into statement does not include TXN_ID in the listing and thus the NOT NULL table constraint rejects the query.

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  • Protecting critical sections based on a condition in C#

    - by NAADEV
    Hello, I'm dealing with a courious scenario. I'm using EntityFramework to save (insert/update) into a SQL database in a multithreaded environment. The problem is i need to access database to see whether a register with a particular key has been already created in order to set a field value (executing) or it's new to set a different value (pending). Those registers are identified by a unique guid. I've solved this problem by setting a lock since i do know entity will not be present in any other process, in other words, i will not have same guid in different processes and it seems to be working fine. It looks something like that: static readonly object LockableObject = new object(); static void SaveElement(Entity e) { lock(LockableObject) { Entity e2 = Repository.FindByKey(e); if (e2 != null) { Repository.Insert(e2); } else { Repository.Update(e2); } } } But this implies when i have a huge ammount of requests to be saved, they will be queued. I wonder if there is something like that (please, take it just as an idea): static void SaveElement(Entity e) { (using ThisWouldBeAClassToProtectBasedOnACondition protector = new ThisWouldBeAClassToProtectBasedOnACondition(e => e.UniqueId) { Entity e2 = Repository.FindByKey(e); if (e2 != null) { Repository.Insert(e2); } else { Repository.Update(e2); } } } The idea would be having a kind of protection that protected based on a condition so each entity e would have its own lock based on e.UniqueId property. Any idea?

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  • Trying to write priority queue in Java but getting "Exception in thread "main" java.lang.ClassCastEx

    - by Dan
    For my data structure class, I am trying to write a program that simulates a car wash and I want to give fancy cars a higher priority than regular ones using a priority queue. The problem I am having has something to do with Java not being able to type cast "Object" as an "ArrayQueue" (a simple FIFO implementation). What am I doing wrong and how can I fix it? public class PriorityQueue<E> { private ArrayQueue<E>[] queues; private int highest=0; private int manyItems=0; public PriorityQueue(int h) { highest=h; queues = (ArrayQueue[]) new Object[highest+1]; <----problem is here } public void add(E item, int priority) { queues[priority].add(item); manyItems++; } public boolean isEmpty( ) { return (manyItems == 0); } public E remove() { E answer=null; int counter=0; do { if(!queues[highest-counter].isEmpty()) { answer = queues[highest-counter].remove(); counter=highest+1; } else counter++; }while(highest-counter>=0); return answer; } }

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  • richfaces suggestionBox passing additional values to backing bean

    - by Martlark
    When using the rich faces suggestionBox how can you pass more than one id or value from the page with the text input to the suggestionBox backing bean. ie: to show a list of suggested cities within a selected state? Here is my autoComplete method. public List< Suburb > autocomplete(Object suggest) { String pref = (String) suggest; ArrayList< Suburb > result = new ArrayList< Suburb >(); Iterator< Suburb > iterator = getSuburbs().iterator(); while( iterator.hasNext() ) { Suburb elem = ((Suburb) iterator.next()); if( (elem.getName() != null && elem.getName().toLowerCase().indexOf( pref.toLowerCase() ) == 0) || "".equals( pref ) ) { result.add( elem ); } } return result; } As you can see there is one value passed from the page, Object suggest, which is the text of the h:inputText (in the faceLets m:textFormRow ) <m:textFormRow id="suburb" label="#{msgs.suburbPrompt}" property="#{bean[dto].addressDTO.suburb}" required="true" maxlength="100" size="30" /> <rich:suggestionbox height="200" width="200" usingSuggestObjects="true" suggestionAction="#{suburbsMBean.autocomplete}" var="suburb" for="suburb" fetchValue="#{suburb.name}" id="suggestion"> <h:column> <h:outputText value="#{suburb.name}" /> </h:column> </rich:suggestionbox> Earlier in the page you can select a state which I'd like to use to pare down the list of suburbs that the suggestion box displays.

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  • Get Nhibernate entity and complete it from a web service.

    - by Nour Sabouny
    Hi every one. let's say that i have an order system. each "Order" references a "Customer" Object. when i fill the orders list in Data Access Layer, the customer object should be brought from a Customer Web Service "WCF". so i didn't map the Customer property in the Order mapping class, Id(o => o.OrderID).GeneratedBy.Identity(); //References(o => o.Customer).Not.Nullable().Column("CustomerID"); HasMany(o => o.Details).KeyColumn("OrderID").Cascade.AllDeleteOrphan(); Map(c => c.CustomerID).Not.Nullable(); and asked the nhibernate session to get me the orders list. and tried to loop on every order in the list to fill it's customer property, doe's any body have a good idea for this ???? IList<Order> lst = Session.CreateCriteria<Order>().List<Order>(); foreach (Order order in lst) order.Customer = serviceProxy.GetCustomerByID(order.CustomerID);

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  • Incorrect component when querying immediately after insert using NHibernate

    - by Am
    I have the following mapping for my table in MySql: <class name="Tag, namespace" table="tags" > <id name="id" type="Int32" unsaved-value="0"> <generator class="native"></generator> </id> <property name="name" type="String" not-null="true"></property> <component name="record_dates" class="DateMetaData, namespace" > <property name="created_at" type="DateTime" not-null="true"></property> <property name="updated_at" type="DateTime" not-null="true"></property> </component> </class> As you see the record_dates property is defined as a component field of type DateMetaDate. Both created_at and updated_at fields in 'tags' table are updated via triggers. Thus I can insert a new record like such: var newTag = new Tag() { name = "some string here" } Int32 id = (Int32)Session.Save(tag); Session.Flush(); ITag t = Session.Get<Tag>(id); ViewData["xxx"] = t.name; // -----> not null ViewData["xxx"] = t.record_dates.created_at; // -----> is null However when querying the same record back immediately after it was inserted the record_dates field ends up null even though in the table those fields have got values. Can any one please point out why the Session.Get ignores getting everything back from the table? is it because it caches the newly created record for which the records_dates is null? If so how can it be told to ignore the cached version?

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  • CoreMidi _MIDINetworkNotificationContactsDidChange symbol not found

    - by Domestic Cat
    I'm getting the following error after a crash in an iPad app that uses CoreMIDI (The * are to blank out the app name): Dyld Error Message: Symbol not found: _MIDINetworkNotificationContactsDidChange Referenced from: /var/mobile/Applications/8F08B78E-929D-4C5A-9F02-08FD5743C17F/***.app/*** Expected in: /System/Library/Frameworks/CoreMIDI.framework/CoreMIDI in /var/mobile/Applications/8F08B78E-929D-4C5A-9F02-08FD5743C17F/***.app/*** Dyld Version: 179.4 When the app launches, I listen for MIDI Network Sessions using [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(sessionDidChange:) name:MIDINetworkNotificationSessionDidChange object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(sessionDidChange:) name:MIDINetworkNotificationContactsDidChange object:nil]; Which seems to be what is causing the crash. This is after I call session = [MIDINetworkSession defaultSession]; session.enabled = YES; session.connectionPolicy = MIDINetworkConnectionPolicy_Anyone; MIDIClientCreate(CFSTR("MidiManager"), midiNotifyProc, (void*)self, &midiClientRef); This kind of looks like CoreMIDI library has not been included in the build. Problem is, it IS included in the build as a required framework. (And the deployment target is set to 4.2). I can run the build fine on my iPad and have been testing extensively with other users' iPads also with no problems whatsoever. Also, this is an update to an existing app that has had several updates already with no problems. I just double checked my deployment build and the framework is definitely included, and I just installed that build onto my iPad (with a different provisioning profile from the store) and it works fine also. What could be happening? Could it be that Xcode just did a bad build for the one I sent to Apple, or am I missing something obvious? Could I change the MIDINetworkNotificationSessionDidChange notification symbol to a literal string (@"MIDINetworkNotificationSessionDidChange") to fix things for the mean time? Thanks for any help!

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  • Attaching methods to prototype from within constructor function

    - by Matthew Taylor
    Here is the textbook standard way of describing a 'class' or constructor function in JavaScript, straight from the Definitive Guide to JavaScript: function Rectangle(w,h) { this.width = w; this.height = h; } Rectangle.prototype.area = function() { return this.width * this.height; }; I don't like the dangling prototype manipulation here, so I was trying to think of a way to encapsulate the function definition for area inside the constructor. I came up with this, which I did not expect to work: function Rectangle(w,h) { this.width = w; this.height = h; this.constructor.prototype.area = function() { return this.width * this.height; }; } I didn't expect this to work because the this reference inside the area function should be pointing to the area function itself, so I wouldn't have access to width and height from this. But it turns out I do! var rect = new Rectangle(2,3); var area = rect.area(); // great scott! it is 6 Some further testing confirmed that the this reference inside the area function actually was a reference to the object under construction, not the area function itself. function Rectangle(w,h) { this.width = w; this.height = h; var me = this; this.constructor.prototype.whatever = function() { if (this === me) { alert ('this is not what you think');} }; } Turns out the alert pops up, and this is exactly the object under construction. So what is going on here? Why is this not the this I expect it to be?

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  • Is it possible to spoof or reuse VIEWSTATE or detect if it is protected from modification?

    - by Peter Jaric
    Question ASP and ASP.NET web applications use a value called VIEWSTATE in forms. From what I understand, this is used to persist some kind of state on the client between requests to the web server. I have never worked with ASP or ASP.NET and need some help with two questions (and some sub-questions): 1) Is it possible to programmatically spoof/construct a VIEWSTATE for a form? Clarification: can a program look at a form and from that construct the contents of the base64-encoded VIEWSTATE value? 1 a) Or can it always just be left out? 1 b) Can an old VIEWSTATE for a particular form be reused in a later invocation of the same form, or would it just be luck if that worked? 2) I gather from http://msdn.microsoft.com/en-us/library/ms972976.aspx#viewstate_topic12 that it is possible to turn on security so that the VIEWSTATE becomes secure from spoofing. Is it possible for a program to detect that a VIEWSTATE is safeguarded in such a way? 2 a) Is there a one-to-one mapping between the occurrence of EVENTVALIDATION values and secure VIEWSTATEs? Regarding 1) and 2), if yes, can I have a hint about how I would do that? For 2) I am thinking I could base64-decode the value and search for a string that always is found in unencrypted VIEWSTATEs. "First:"? Something else? Background I have made a small tool for detecting and exploiting so called CSRF vulnerabilities. I use it to quickly make proof of concepts of such vulnerabilities that I send to the affected site owners. Quite often I encounter these forms with a VIEWSTATE, and these I don't know if they are secure or not. Edit 1: Clarified question 1 somewhat. Edit 2: Added text in italics.

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  • Which class should store the lookup table?

    - by max
    The world contains agents at different locations, with only a single agent at any location. Each agent knows where he's at, but I also need to quickly check if there's an agent at a given location. Hence, I also maintain a map from locations to agents. I have a problem deciding where this map belongs to: class World, class Agent (as a class attribute) or elsewhere. In the following I put the lookup table, agent_locations, in class World. But now agents have to call world.update_agent_location every time they move. This is very annoying; what if I decide later to track other things about the agents, apart from their locations - would I need to add calls back to the world object all across the Agent code? class World: def __init__(self, n_agents): # ... self.agents = {} self.agent_locations = {} for id in range(n_agents): x, y = self.find_location() agent = Agent(self,x,y) self.agents.append(agent) self.agent_locations[x,y] = agent def update_agent_location(self, agent, x, y): del self.agent_locations[agent.x, agent.y] self.agent_locations[x, y] = agent def update(self): # next step in the simulation for agent in self.agents: agent.update() # next step for this agent # ... class Agent: def __init__(self, world, x, y): self.world = world self.x, self.y = x, y def move(self, x1, y1): self.world.update_agent_location(self, x1, y1) self.x, self.y = x1, y1 def update(): # find a good location that is not occupied and move there for x, y in self.valid_locations(): if not self.location_is_good(x, y): continue if self.world.agent_locations[x, y]: # location occupied continue self.move(x, y) I can instead put agent_locations in class Agent as a class attribute. But that only works when I have a single World object. If I later decide to instantiate multiple World objects, the lookup tables would need to be world-specific. I am sure there's a better solution... EDIT: I added a few lines to the code to show how agent_locations is used. Note that it's only used from inside Agent objects, but I don't know if that would remain the case forever.

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  • Strange behaviour of CheckBox and TwoWay bound property

    - by walkor
    Hello, everyone. I fell in the following situation: I have a main UserControl with a DataGrid (which contains List). I need to show different panels depending on properties of the selected row(object). So i've created 2 controls and included them into this main control. Main control has 2 public properties - public List<ComplexObject> SourceList { get; set; } and public ComplexObject CurrentObject { get; set; } Pseudo-code: <UserControl x:Name="Main"> <DataGrid ItemsSource="{Binding SourceList}" SelectedItem="{Binding CurrentObject, Mode=TwoWay}"/> <Controls:RightPanelFirst Visibility="condition2"/> <Controls:RightPanelSecond Visibility="condition2"/> </UserControl> RightPanelFirst and RightPanelSecond have the following xaml: <UserControl> <... content here...> <CheckBox IsChecked="{Binding CurrentObject.ComplexProperty.SimpleProperty1, Mode=TwoWay}"> <CheckBox IsChecked="{Binding CurrentObject.ComplexProperty.SimpleProperty2, Mode=TwoWay}" x:Name="cbSecond"> <TextBox IsEnabled="{Binding IsChecked, ElementName=cbSecond}"/> </UserControl> So, my actual steps: Check both checkboxes (object values are set to true) Make other actions in code behind which modify CurrentObject. Then i want UI to reflect the changes, so I call NotifyPropertyChanged("CurrentObject"); SimpleProperty1 remains the same, but SimpleProperty2 resets to false I have no idea why this happens, can anyone help me please? Silverlight drives me mad.

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  • Fun with casting and inheritance

    - by Vaccano
    NOTE: This question is written in a C# like pseudo code, but I am really going to ask which languages have a solution. Please don't get hung up on syntax. Say I have two classes: class AngleLabel: CustomLabel { public bool Bold; // code to allow the label to be on an angle } class Label: CustomLabel { public bool Bold; // Code for a normal label // Maybe has code not in an AngleLabel (align for example). } They both decend from this class: class CustomLabel: Control { protected bool Bold; } The bold field is exposed as public in the descended classes. No interfaces are available on the classes. Now, I have a method that I want to beable to pass in a CustomLabel and set the Bold property. Can this be done without having to 1) find out what the real class of the object is and 2) cast to that object and then 3) make seperate code for each variable of each label type to set bold. Kind of like this: public void SetBold(customLabel: CustomLabel) { AngleLabel angleLabel; NormalLabel normalLabel; if (angleLabel is AngleLabel ) { angleLabel= customLabel as AngleLabel angleLabel.Bold = true; } if (label is Label) { normalLabel = customLabel as Label normalLabel .Bold = true; } } It would be nice to maybe make one cast and and then set bold on one variable. What I was musing about was to make a fourth class that just exposes the bold variable and cast my custom label to that class. Would that work? If so, which languages would it work for? (This example is drawn from an old version of Delphi (Delphi 5)). I don't know if it would work for that language, (I still need to try it out) but I am curious if it would work for C++, C# or Java. If not, any ideas on what would work? (Remember no interfaces are provided and I can not modify the classes.) Any one have a guess?

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  • What features are heavily used in C# 2.0, but is not available in VBNET 2.0, and how to workaround?

    - by Will Marcouiller
    I don't want a war between VBNET and C# developpers, neither is my goal to open a C# VS VBNET confrontation. I would like you all to list a feature that is heavily used in C#, but is not available in VBNET 2.0, and how would you work around to achieve a similar behaviour or purpose? For example: C# Accepts void (return) lambda expressions. Here's an example with FNH mapping: Component(x => x.Address, m => { m.Map(x => x.Number); m.Map(x => x.Street); m.Map(x => x.PostCode); }); This is impossible to do before VBNET 4.0 (supposed to be doable in VBNET 4.0) VBNET Must write a helping method (Sub), and provide the AddressOf this method in order to workaround. Private Sub Helper(ByVal m As MType) m.Map(Function(x) x.Number) m.Map(Function(x) x.Street) m.Map(Function(x) x.PostCode) End Sub ... Component(Function(x) x.Address, AddressOf Helper) Now I know, it is not VBNET 2.0, but this is an example. VBNET 3.0 and 3.5 can used too. Please just mention what version of VBNET this refers to.

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  • ASP.NET MVC - hiding id in URL?

    - by mcfroob
    I'm building a basic blog application just now, for viewing data I'm just using the default route, i.e. - routes.MapRoute ( "Default", // Route name "{controller}/{action}/{id}", new { controller = "Blog", action = "Index", id = UrlParameter.Optional } ); So that when you go to mysite.com/View/12 it displays the blog with id 12. I want to modify the URLs so that they look as follows: mysite.com/View/2010/06/01/this-is-the-title. I could have a URL mapping like - routes.MapRoute( "View", "View/{year}/{month}/{day}/{title}", new { controller = "Blog", action = "View" } ); But then I'm not passing the ID into the Controller action so I would have to search on the date and title which doesn't feel right. On the other hand, if I pass the ID in it will show up in the URL which isn't what I'm aiming for either. Is there any way to redirect to the URL I want in the controller action after passing only the ID in as a paramter, or to pass the ID into the a Map Route but hide it in the URL? Thanks for your help!

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  • Entity Framework POCO objects

    - by Dan
    I'm struggling with understanding Entity Framework and POCO objects. Here's what I'm trying to achieve. 1) Separate the DAL from the Business Layer by having my business layer use an interface to my DAL. Maybe use Unity to create my context. 2) Use Entity Framework inside my DAL. I have a Domain model with objects that reside in my business layer. I also have a database full of tables that doesn't really represent my domain model. I setup Entity Framework and generated POCO objects by using the ADO.NET POCO Generator extension. This gave me an object for each table in my database. Now I want to be able to say context.GetAll<User>(); and have it return a list of my User objects. The User object is in my business layer. Is that possible? Does that make sense or am I totally off and should start over? I'm guessing I need to use the repository pattern to achieve this, but I'm not sure. Can anyone help?

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  • Fading in and fading out for a form

    - by karthik
    hi i have a requirement in which my form is transparent,if my mouse enters into it the form should became visible,if my mouse leaves out of the form it becomes transparent, i have three different controls placed in my form , each controls mouse leave and mouse enter is the same that of the form . if my mouse enters into the form and enters into a control form_mouseleaveevent and control_mouseenterd gets fired so iam not able to achieve it,how to overcome this. below is the piece of code for this: private void TransToOpac() { if (!isTransparent) return; if (TtoOON == false ) { TtoOON = true; for (i = this.Opacity; i <= 1; i = i + 0.02) { this.Opacity = i; Thread.Sleep(50); } isTransparent = false; TtoOON = false; } } private void OpacToTrans() { if (isTransparent) return; if (OtoTON == false ) { OtoTON = true; for (i = this.Opacity; i >= 0.5; i = i - 0.02) { this.Opacity = i; Thread.Sleep(50); } isTransparent = true; OtoTON = false; } } private void OnMouseEntered(object sender, EventArgs e) { TransToOpac(); } private void OnMouseLeft(object sender, EventArgs e) { OpacToTrans(); }

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