Search Results

Search found 20401 results on 817 pages for 'null coalescing operator'.

Page 383/817 | < Previous Page | 379 380 381 382 383 384 385 386 387 388 389 390  | Next Page >

• Track/Display Array Index As Part Of Cout (C++)

  - by John Smith

  Hi, I have a command line C++ program that lets you enter basic information about a person (ID number, name, age, etc.) and I want to output to a console in the following manner: ------------------------------------------------------------------- Index ID # First Name Last Name Age ------------------------------------------------------------------- 0 1234 John Smith 25 The person objects are stored in an array of Persons and I've overload the ostream (<<) operator to print out all of the fields like you see. The dashed lines and header come from a displayHdg() function. Anyhow, I have not been able to figure out how to get the proper index value for the array. Ideally, I'd like to generate the indices for each line, but all my attempts have failed. The array is looped through and each object printed in the main() function, and the ostream is overloaded in a person class, so I tried to use global variables as well as static variables, and all of those produce incorrect numbering (i.e. show 0, 1 the first time (for 2 objects), then change to 1, 2 on the next display). Any ideas?

  Read the article

• help with mysql triggers (checking values before insert)

  - by user332817

  hi I'm quite new to mysql and I'm trying to figure out how to use triggers. what I'm trying to do: I have 2 tables, max and sub_max, when I insert a new row to sub_max I want to check if the SUM of the values with the same foreign_key as the new row are less than the value in the max table. I think this sounds confusing so here are my tables: CREATE TABLE max( number INT , MaxAmount integer NOT NULL) CREATE TABLE sub_max( sub_number INT , sub_MaxAmount integer NOT NULL, number INT, FOREIGN KEY ( number ) REFERENCES max( number )) and here is my code for the trigger, I know the syntax is off but this is the best I could do from looking up tutorials. CREATE TRIGGER maxallowed after insert on submax FOR EACH ROW BEGIN DECLARE submax integer; DECLARE maxmax integer; submax = select sum(sub_MaxAmount) from sub_max where sub_number = new.sub_number; submax = submax + new. sub_MaxAmount; maxmax = select MaxAmount from max where number = new.number ; if max>maxmax rollback? END I wanted to know if I'm doing this remotely correctly. Thanks in advance.

  Read the article

• getting number from console!

  - by Johanna

  Hi this is my method that will be called if I want to get a number from user. but if the user also enter a right number just the "else" part will be run ,why? please help me tahnsk. public static int chooseTheTypeOfSorting() { System.out.println("Enter 0 for merge sorting OR enter 1 for bubble sorting"); int numberFromConsole = 0; try { InputStreamReader isr = new InputStreamReader(System.in); BufferedReader br = new BufferedReader(isr); String s = br.readLine(); DecimalFormat df = new DecimalFormat(); Number n = df.parse(s); numberFromConsole = n.intValue(); } catch (ParseException ex) { Logger.getLogger(DoublyLinkedList.class.getName()).log(Level.SEVERE, null, ex); } catch (IOException ex) { Logger.getLogger(DoublyLinkedList.class.getName()).log(Level.SEVERE, null, ex); } return numberFromConsole; } and in my main method: public static void main(String[] args) { int i = 0; i = getRandomNumber(10, 10000); int p = chooseTheTypeOfSorting(); DoublyLinkedList list = new DoublyLinkedList(); for (int j = 0; j < i; j++) { list.add(j, getRandomNumber(10, 10000)); if (p == 0) { //do something.... } if (p == 1) { //do something..... } else { System.out.println("write the correct number "); chooseTheTypeOfSorting(); }

  Read the article

• ArrayList<String> NullPointerException

  - by Carlucho

  Am trying to solve a labyrinth by DFS, using adj List to represent the vertices and edges of the graph. In total there are 12 nodes (3 rows[A,B,C] * 4 cols[0,..,3]). My program starts by saving all the vertex labels (A0,..C3), so far so good, then checks the adjacent nodes, also no problems, if movement is possible, it proceeds to create the edge, here its where al goes wrong. adjList[i].add(vList[j].label); I used the debugger and found that vList[j].label is not null it contains a correct string (ie. "B1"). The only variables which show null are in adjList[i], which leads me to believe i have implemented it wrongly. this is how i did it. public class GraphList { private ArrayList<String>[] adjList; ... public GraphList(int vertexcount) { adjList = (ArrayList<String>[]) new ArrayList[vertexCount]; ... } ... public void addEdge(int i, int j) { adjList[i].add(vList[j].label); //NULLPOINTEREXCEPTION HERE } ... } I will really appreaciate if anyone can point me on the right track regrading to what its going wrong... Thanks!

  Read the article

• How to add objects to NSArray from a different class with ARC

  - by Space Dust

  I needed to convert my code to ARC. I have an NSArray that I use to draw a path. I fill the objects of NSArray values from a different class. Problem is after converting to ARC, NSArray returns always null I can not see what I am doing wrong. bug.h @interface Ladybug : CCSprite <CCTargetedTouchDelegate>{ CCArray *linePathPosition; } @property (nonatomic, strong) CCArray *linePathPosition; @end bug.m @synthesize linePathPosition; -(id) init { if( (self=[super init] )) { self.linePathPosition = [[CCArray alloc] init]; } return self; } -(void) updatePosition:(CGPoint) position { [self.linePathPosition addObject:[NSValue valueWithCGPoint:position]]; NSLog(@"line path %@",linePathPosition); } -(void) breakMoveLadyBug { [self.linePathPosition removeAllObjects]; } In main .m - (void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event { Ladybug *ladybug1 = (Ladybug *)[self getChildByTag:99]; CCMotionStreak* streak = (CCMotionStreak *)[self getChildByTag:999]; CGPoint touchLocation = [touch locationInView: [touch view]]; CGPoint curPosition = [[CCDirector sharedDirector] convertToGL:touchLocation]; if (ladybug1.isSelected) { streak.position = curPosition; [ladybug1 updatePosition:curPosition]; NSLog(@"Cur position %@",NSStringFromCGPoint(curPosition)); if (!ladybug1.isMoving) { [ladybug1 startMoveLadyBug]; } } } Log: Cur position {331, 110} line path (null) What am I doing wrong? What is the proper way to define and init NSArray with ARC?

  Read the article

• x509 certificate verification in C

  - by sid

  Hi All, I do have certificates in DER and PEM format, My goal is to retrieve the fields of Issuer and Subject And verify the Certificate with the CA public key and simultaneously verify CA certificate with the Root public key. I am able to retrieve all the details of issuer and subject But unable to verify the certificate. Please help. The API's used, x509 = d2i_X509_fp (fp, &x509); //READING DER Format x509 = PEM_read_X509 (fp, &x509, NULL, NULL); //READING PEM Format X509_NAME_oneline(X509_get_subject_name(x509), subject, sizeof (subject)); //to retrive the Subject X509_NAME_oneline(X509_get_issuer_name(x509), issuer, sizeof (issuer)); //to retrive the Issuer // to store the CA public key (in unsigned char *key)that will be used to verify the certificate (My case Always sha1WithRSAEncryption) RSA *x = X509_get_pubkey(x509)->pkey.rsa; bn = x->n; //extracts the bytes from public key & convert into unsigned char buffer buf_len = (size_t) BN_num_bytes (bn); stored_CA_pubKey = (unsigned char *)malloc (buf_len); i_n = BN_bn2bin (bn, (unsigned char *)stored_CA_pubKey); if (i_n != buf_len) LOG(ERROR," : key error\n"); if (key[0] & 0x80) LOG(DEBUG, "00\n"); stored_CA_pubKeyLen = EVP_PKEY_size(X509_get_pubkey(x509)); For Verification I went through different approaches but unable to verify a) i_x509_verify = X509_verify(cert_x509, ca_pubkey); b) /* verify the signature */ int iRet1, iRet2, iReason; iRet1 = EVP_VerifyInit(&md_ctx, EVP_sha1()); iRet2 = EVP_VerifyUpdate(&md_ctx, cert_code, cert_code_len); rv = EVP_VerifyFinal(&md_ctx, (const unsigned char *)stored_CA_pubKey, stored_CA_pubKeyLen, cert_pubkey); NOTE : cert_code & stored_CA_pubKey is unsigned char buffer. Thanks in Advance

  Read the article

• Pointing to vectors

  - by Matt Munson

  #include <iostream> #include <vector> using namespace std; int main () { vector <int> qwerty; qwerty.push_back(5); vector <int>* p = &qwerty; cout << p[0]; //error: no match for 'operator<<' in 'std::cout << * p' } I'm generally unclear on how to use pointers with vectors, so I'm pretty mystified as to why this is not working. To my mind, this should print 5 to screen.

  Read the article

• Codeigniter php activerecord orm limit and offset

  - by user2167174

  I am a bit stuck with this problem I have in phpactiverecord. What I am trying to do is a pagination so I need to limit and offset the query results. I am accessing all of the user posts like so: $user-post; How can I query this to limit and offset the results? Thanx in advance. Code: public function office() { if (!$this->session->userdata('username')) { redirect(base_url()); } $data = array(); $data['posts'] = []; $user = User::find('first', array('id' => $this->session->userdata('id'))); if ($user != null) { if ($user->post != null) { foreach ($user->post as $post) { $posts = array($post->name, $post->description, $post->date,'<a href="'.base_url().'Posts/edit/'.$post->id.'">Edit</a> <br /><a href="'.base_url().'Posts/delete/'.$post->id.'">Delete</a>'); array_push($data['posts'], $posts); } $this->table->set_heading('Name', 'Description', 'Date', '<a href="'.base_url().'Posts/create">+Add</a>'); $tmpl = array('table_open' => '<table class="table table-stripped table-bordered user-posts">'); $this->table->set_template($tmpl); $data['table'] = $this->table->generate($data['posts']); } $this->load->view('template/header.php'); $this->load->view('Users/office.php', $data); $this->load->view('template/footer.php'); } else { redirect(base_url()); } }

  Read the article

• Does std::multiset guarntee insertion order?

  - by Naveen

  I have a std::multiset which stores elements of class A. I have provided my own implementation of operator< for this class. My question is if I insert two equivalent objects into this multiset is their order guaranteed? For example, first I insert a object a1 into the set and then I insert an equivalent object a2 into this set. Can I expect the a1 to come before a2 when I iterate through the set? If no, is there any way to achieve this using multiset?

  Read the article

• Problem understanding treesort in Haskell

  - by Jerry

  I am trying to figure out how exactly does treesort from here work (I understand flatten, insert and foldr). I suppose what's being done in treesort is applying insert for each element on the list thus generating a tree and then flattening it. The only problem I can't overcome here is where the list (that is the argument of the function) is hiding (because it is not written anywhere as an argument except for the function type declaration). One more thing: since dot operator is function composition, why is it an error when I change: treesort = flatten . foldr insert Leaf to treesort = flatten( foldr insert Leaf )?

  Read the article

• WPF - data binding trigger before content changed

  - by 0xDEAD BEEF

  How do i create trigger, which fires BEFORE binding changes value? How to do this for datatemplate? <ContentControl Content="{Binding Path=ActiveView}" Margin="0,95,0,0"> <ContentControl.Triggers> <--some triger to fire, when ActiveView is changing or has changed ?!?!? --> </ContentControl.Triggers> public Object ActiveView { get { return m_ActiveView; } set { if (PropertyChanging != null) PropertyChanging(this, new PropertyChangingEventArgs("ActiveView")); m_ActiveView = value; if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("ActiveView")); } } How to do this for DataTemplate? <DataTemplate DataType="{x:Type us:LOLClass1}"> <ContentControl> <ContentControl.RenderTransform> <ScaleTransform x:Name="shrinker" CenterX="0.0" CenterY="0.0" ScaleX="1.0" ScaleY="1.0"/> </ContentControl.RenderTransform> <us:UserControl1/> </ContentControl> <DataTemplate.Triggers> <-- SOME TRIGER BEFORE CONTENT CHANGES--> <BeginStoryboard> <Storyboard> <DoubleAnimation Storyboard.TargetName="shrinker" Storyboard.TargetProperty="ScaleX" From="1.0" To="0.8" Duration="0:0:0.3"/> <DoubleAnimation Storyboard.TargetName="shrinker" Storyboard.TargetProperty="ScaleY" From="1.0" To="0.8" Duration="0:0:0.3"/> </Storyboard> </BeginStoryboard> </-- SOME TRIGER BEFORE CONTENT CHANGES--> </DataTemplate.Triggers> </DataTemplate> How to get notification BEFORE binding is changed? (i want to capture changing Visual component to bitmap and create sliding view animation)

  Read the article

• c++ multithread

  - by chnet

  I use C++ to implement a thread class. My code shows in the following. I have a problem about how to access thread data. In the class Thread, I create a thread use pthread_create() function. then it calls EntryPoint() function to start thread created. In the Run function, I want to access the mask variable, it always shows segment fault. So, my question is whether the new created thread copy the data in original class? How to access the thread own data? class Thread { public: int mask; pthread_t thread; Thread( int ); void start(); static void * EntryPoint (void *); void Run(); }; Thread::Thread( int a) { mask =a; } void Thread::Run() { cout<<"thread begin to run" <<endl; cout << mask <<endl; // it always show segmentfault here } void * Thread::EntryPoint(void * pthis) { cout << "entry" <<endl; Thread *pt = (Thread *) pthis; pt->Run(); } void Thread::start() { pthread_create(&thread, NULL, EntryPoint, (void *)ThreadId ); pthread_join(thread, NULL); } int main() { int input_array[8]={3,1,2,5,6,8,7,4}; Thread t1(1); t1.start(); }

  Read the article

• c++ multithread

  - by chnet

  I use c++ to implement a thread class. The code is in the following. I initialize two objects, wish it will start two threads (I use pthread_self() to look the thread Id). But the result shows that there is only one thread beside the main thread. I am a bit confused... class Thread { public: int mask; pthread_t thread; Thread( int ); void start(); static void * EntryPoint (void *); void Run(); }; Thread::Thread( int a) { mask =a; } void Thread::Run() { cout<<"thread begin to run" <<endl; cout <<" Thread Id is: "<< pthread_self() << endl; // the same thread Id. } void * Thread::EntryPoint(void * pthis) { cout << "entry" <<endl; Thread *pt = (Thread *) pthis; pt->Run(); } void Thread::start() { pthread_create(&thread, NULL, EntryPoint, (void *)ThreadId ); pthread_join(thread, NULL); } int main() { int input_array[8]={3,1,2,5,6,8,7,4}; Thread t1(1); Thread t2(2); t1.start(); t2.start() }

  Read the article

• Should java try blocks be scoped as tightly as possible?

  - by isme

  I've been told that there is some overhead in using the Java try-catch mechanism. So, while it is necessary to put methods that throw checked exception within a try block to handle the possible exception, it is good practice performance-wise to limit the size of the try block to contain only those operations that could throw exceptions. I'm not so sure that this is a sensible conclusion. Consider the two implementations below of a function that processes a specified text file. Even if it is true that the first one incurs some unnecessary overhead, I find it much easier to follow. It is less clear where exactly the exceptions come from just from looking at statements, but the comments clearly show which statements are responsible. The second one is much longer and complicated than the first. In particular, the nice line-reading idiom of the first has to be mangled to fit the readLine call into a try block. What is the best practice for handling exceptions in a funcion where multiple exceptions could be thrown in its definition? This one contains all the processing code within the try block: void processFile(File f) { try { // construction of FileReader can throw FileNotFoundException BufferedReader in = new BufferedReader(new FileReader(f)); // call of readLine can throw IOException String line; while ((line = in.readLine()) != null) { process(line); } } catch (FileNotFoundException ex) { handle(ex); } catch (IOException ex) { handle(ex); } } This one contains only the methods that throw exceptions within try blocks: void processFile(File f) { FileReader reader; try { reader = new FileReader(f); } catch (FileNotFoundException ex) { handle(ex); return; } BufferedReader in = new BufferedReader(reader); String line; while (true) { try { line = in.readLine(); } catch (IOException ex) { handle(ex); break; } if (line == null) { break; } process(line); } }

  Read the article

• Expression.OrElse, dynamically creating a condition.

  - by Jim

  Hi, I am attempting to create a dynamic where clause using the standard expression API. var query = ( from p in Parties orderby p.PartyId orderby p.FullName select p ).AsQueryable(); Expression<Func<Party, bool>> @fn = (p) => SqlMethods.Like(p.FullName, "%smith%") || SqlMethods.Like(p.Person.FirstName, "%smith%"); Expression<Func<Party, bool>> @sn = (p) => SqlMethods.Like(p.Person.FirstName, words[0]); ParameterExpression pe = Expression.Parameter(typeof(Party), "p"); Expression orelse = Expression.OrElse( Expression.Lambda(@fn, pe), Expression.Lambda(@sn, pe) ); The expressions above will ultimately be added to a where clause. I need to add a bunch of 'likes'. How do I do this? I get InvalidOperationException on the operator OrElse I have also tried Expression.Or Thanks Regards Craig.

  Read the article

• Why notify listeners in a content provider query method?

  - by cbrulak

  Vegeolla has this blog post about content providers and the snippet below (at the bottom) with this line: cursor.setNotificationUri(getContext().getContentResolver(), uri); I'm curious as to why one would want to notify listeners about a query operation. Am I missing something? Thanks @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { // Uisng SQLiteQueryBuilder instead of query() method SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder(); // Check if the caller has requested a column which does not exists checkColumns(projection); // Set the table queryBuilder.setTables(TodoTable.TABLE_TODO); int uriType = sURIMatcher.match(uri); switch (uriType) { case TODOS: break; case TODO_ID: // Adding the ID to the original query queryBuilder.appendWhere(TodoTable.COLUMN_ID + "=" + uri.getLastPathSegment()); break; default: throw new IllegalArgumentException("Unknown URI: " + uri); } SQLiteDatabase db = database.getWritableDatabase(); Cursor cursor = queryBuilder.query(db, projection, selection, selectionArgs, null, null, sortOrder); // Make sure that potential listeners are getting notified cursor.setNotificationUri(getContext().getContentResolver(), uri); return cursor; }

  Read the article

• Validating Age field javascript beginner

  - by Marcelo

  Hi people, I'm trying to validate an age field in a form but I'm having some problem. First I tried to make sure that the field will not be send empty. I don't know javascript so I searched some scripts and adapted them to this: function isInteger (s) { var i; if (isEmpty(s)) if (isInteger.arguments.length == 1) return 0; else return (isInteger.arguments[1] == true); for (i = 0; i < s.length; i++) { var c = s.charAt(i); if (!isDigit(c)) return false; } return true; } function isEmpty(s) { return ((s == null) || (s.length == 0)) } function validate_required(field,alerttxt) { with (field) { if (value==null||value=="") { alert(alerttxt);return false; } else { return true; } } } function validate_form(thisform) { with (thisform) { if ((validate_required(age,"Age must be filled out!")==false) || isInteger(age,"Age must be and int number")==false)) {email.focus();return false;} } } //html part <form action="doador.php" onsubmit="return validate_form(this)" method="post"> It's working fine for empty fields, but if I type any letters or characters in age field, it'll be sent and saved a 0 in my database. Can any one help me ? Sorry for any mistake in English, and thanks in andvance for your help.

  Read the article

• How to display a generic error page in Asp.Net MVC 2

  - by Picflight

  I have the following in my base controller: protected override void OnException(ExceptionContext filterContext) { if (filterContext == null) { throw new ArgumentNullException("filterContext"); } // If custom errors are disabled, we need to let the normal ASP.NET exception handler // execute so that the user can see useful debugging information. if (filterContext.ExceptionHandled || !filterContext.HttpContext.IsCustomErrorEnabled) { return; } Exception exception = filterContext.Exception; // If this is not an HTTP 500 (for example, if somebody throws an HTTP 404 from an action method), // ignore it. if (new HttpException(null, exception).GetHttpCode() != 500) { return; } // TODO: What is the namespace for ExceptionType? //if (!ExceptionType.IsInstanceOfType(exception)) //{ // return; //} // Send Email MailException(exception); // TODO: What does this line do? base.OnException(filterContext); filterContext.Result = new ViewResult { ViewName = "Error" }; filterContext.ExceptionHandled = true; filterContext.HttpContext.Response.Clear(); filterContext.HttpContext.Response.StatusCode = 500; } In my Shared folder, I have an Error.aspx View. Web.config <customErrors mode="On" /> I am still seeing the yellow screen when an exception occurs. What am I doing incorrectly?

  Read the article

• codegen:nullValue vs msprop:nullValue

  - by Ken

  Ok, I have datasets that I created way back in 1.1 framework to which we used codegen:nullValue within the XSD to handle null values. However if I open one of these datasets with vs 2005 (i.e. 2.0 framework) and add a column, it removes the codegen setting from the entire xsd but adds in msprop:nullValue However, unlike previous years, I noticed this time the proper property code was NOT over riden from returning the null value specified in codegen as it was doing in the past. Meaning the msprop appears to be creating the proper code behind the scenes (See example). Anyone know of any other differnces? Should I be concerned with deploying a new xsd, WITHOUT the codegen code but instead with the msprop xml? Example: Original creates _ Public Property ParentID() As Integer Get If Me.IsParentIDNull Then Return -1 Else Return CType(Me(Me.tableCompany.ParentIDColumn),Integer) End If End Get Set Me(Me.tableCompany.ParentIDColumn) = value End Set End Property New creates _ Public Property ParentID() As Integer Get If Me.IsParentIDNull Then Return -1 Else Return CType(Me(Me.tableCompany.ParentIDColumn),Integer) End If End Get Set Me(Me.tableCompany.ParentIDColumn) = value End Set End Property BUT is there anything else that might be occuring that I am NOT seeing thus MAKING me re-enter all the codegen settings? THANKS!

  Read the article

• Fiscal year, quarters, student table, and faculty table... How do I relate these?!

  - by yuudachi

  I have a student and faculty table. The primary key for student is studendID (SID) and faculty's primary key is facultyID, naturally. Student has an advisor column and a requested advisor column, which are foreign key to faculty. That's simple enough, right? However, now I have to throw in dates. I want to be able to view who their advisor was for a certain quarter (such as 2009 Winter) and who they had requested. The result will be a table like this: Year | Term | SID | Current | Requested ------------------------------------------------ 2009 | Winter | 860123456 | 1 | NULL 2009 | Winter | 860445566 | 3 | NULL 2009 | Winter | 860369147 | 5 | 1 And then if I feel like it, I could also go ahead and view a different year and a different term. I am not sure how these new table(s) will look like. Will there be a year table with three columns that are Fall, Spring and Winter? And what will the Fall, Spring, Winter table have? I am new to the art of tables, so this is baffling me... Also, I feel I should clarify how the site works so far now. Admin can approve student requests, and what happens is that the student's current advisor gets overwritten with their request. However, I think I should not do that anymore, right?

  Read the article

• Apply CSS Style on all elements except with a SPECIFIC ID

  - by Rajesh Paul

  CSS Code(what I need) <style> div[id!='div1']// I actually needed an inequality operator for NOT EQUAL TO { font-size:40px; } </style> HTML code <body> <div>abc</div> <div>def</div> <div id='div1'>ghi</div> </body> The CSS didn't work as I intended. I actually wanted to define the style for all <div>-elements except the one with id='div1'. How can I do that?

  Read the article

• Java try finally variations

  - by Petr Gladkikh

  This question nags me for a while but I did not found complete answer to it yet (e.g. this one is for C# http://stackoverflow.com/questions/463029/initializing-disposable-resources-outside-or-inside-try-finally). Consider two following Java code fragments: Closeable in = new FileInputStream("data.txt"); try { doSomething(in); } finally { in.close(); } and second variation Closeable in = null; try { in = new FileInputStream("data.txt"); doSomething(in); } finally { if (null != in) in.close(); } The part that worries me is that the thread might be somewhat interrupted between the moment resource is acquired (e.g. file is opened) but resulting value is not assigned to respective local variable. Is there any other scenarios the thread might be interrupted in the point above other than: InterruptedException (e.g. via Thread#interrupt()) or OutOfMemoryError exception is thrown JVM exits (e.g. via kill, System.exit()) Hardware fail (or bug in JVM for complete list :) I have read that second approach is somewhat more "idiomatic" but IMO in the scenario above there's no difference and in all other scenarios they are equal. So the question: What are the differences between the two? Which should I prefer if I do concerned about freeing resources (especially in heavily multi-threading applications)? Why? I would appreciate if anyone points me to parts of Java/JVM specs that support the answers.

  Read the article

• Get a button in itemscontrol and add eventhandler to its click event

  - by rockdale

  I have a custom control shows a customer info with an itemscontrol shows this customer's invoices. within the itemscontrol, I have button, in my code behind I want to wire the button's click event to my host window, but do now know how. //public event RoutedEventHandler ViewDetailClick; public static readonly RoutedEvent ButtonViewClickEvent = EventManager.RegisterRoutedEvent( "ButtonViewClick", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(custitem)); public event RoutedEventHandler ButtonViewClick { add { AddHandler(ButtonViewClickEvent, value); } remove {RemoveHandler(ButtonViewClickEvent, value);} } public override void OnApplyTemplate() { base.OnApplyTemplate(); this.lstInv = GetTemplateChild("lstInv") as ItemsControl; lstInv.ItemContainerGenerator.StatusChanged += new EventHandler(ItemContainerGenerator_StatusChanged); } private void ItemContainerGenerator_StatusChanged(object sender, EventArgs e) { if (lstInv.ItemContainerGenerator.Status == System.Windows.Controls.Primitives.GeneratorStatus.ContainersGenerated) { lstInv.ItemContainerGenerator.StatusChanged -= ItemContainerGenerator_StatusChanged; for (int i = 0; i < this.lstInv.Items.Count; i++) { ContentPresenter c = lstInv.ItemContainerGenerator.ContainerFromItem(lstInv.Items[i]) as ContentPresenter; DataTemplate dt = c.ContentTemplate; Grid grd = dt.LoadContent() as Grid; Button btnView = grd.FindName("btnView") as Button; if (btnView != null) { btnView.Click += new RoutedEventHandler(ButtonView_Click); //btnView.Click+= delegate(object senderObj, RoutedEventArgs eArg) //{ // if (this.ViewDetailClick != null) // { // this.ViewDetailClick(this, eArg); // } //}; } } private void ButtonView_Click(object sender, RoutedEventArgs e) { MessageBox.Show("clicked"); //e.RoutedEvent = ButtonViewClickEvent; //e.Source = sender; //RaiseEvent(e); } I succeed getting the btnView, then attach the click event, but the click event never get fired. Thanks in advance -rockdale

  Read the article

• c#3.5 Deserialization error - object reference not set

  - by BBR

  I am trying to deserialize an xml string in c#3.5, the code below does work in c# 4.0. When I try to run in the code in c#3.5 I get an Object reference not set to an instance of an object exception when the code tries in initialize the XmlSerializer. Any help would be appreciated. string xml = "<boolean xmlns=\"http://schemas.microsoft.com/2003/10/serialization/\">false</boolean>"; var xSerializer = new XmlSerializer(typeof(bool), null, null, new XmlRootAttribute("boolean"), "http://schemas.microsoft.com/2003/10/serialization/"); using (var sr = new StringReader(xml)) using (var xr = XmlReader.Create(sr)) { var y = xSerializer.Deserialize(xr); } System.NullReferenceException was unhandled Message="Object reference not set to an instance of an object." Source="System.Xml" StackTrace: at System.Xml.Serialization.XmlSerializer..ctor(Type type, XmlAttributeOverrides overrides, Type[] extraTypes, XmlRootAttribute root, String defaultNamespace, String location, Evidence evidence) at System.Xml.Serialization.XmlSerializer..ctor(Type type, XmlAttributeOverrides overrides, Type[] extraTypes, XmlRootAttribute root, String defaultNamespace) .... at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException:

  Read the article

• "Order By" in LINQ-to-SQL Causes performance issues

  - by panamack

  I've set out to write a method in my C# application which can return an ordered subset of names from a table containing about 2000 names starting at the 100th name and returning the next 20 names. I'm doing this so I can populate a WPF DataGrid in my UI and do some custom paging. I've been using LINQ to SQL but hit a snag with this long executing query so I'm examining the SQL the LINQ query is using (Query B below). Query A runs well: SELECT TOP (20) [t0].[subject_id] AS [Subject_id], [t0].[session_id] AS [Session_id], [t0].[name] AS [Name] FROM [Subjects] AS [t0] WHERE (NOT (EXISTS( SELECT NULL AS [EMPTY] FROM ( SELECT TOP (100) [t1].[subject_id] FROM [Subjects] AS [t1] WHERE [t1].[session_id] = 1 ORDER BY [t1].[name] ) AS [t2] WHERE [t0].[subject_id] = [t2].[subject_id] ))) AND ([t0].[session_id] = 1) Query B takes 40 seconds: SELECT TOP (20) [t0].[subject_id] AS [Subject_id], [t0].[session_id] AS [Session_id], [t0].[name] AS [Name] FROM [Subjects] AS [t0] WHERE (NOT (EXISTS( SELECT NULL AS [EMPTY] FROM ( SELECT TOP (100) [t1].[subject_id] FROM [Subjects] AS [t1] WHERE [t1].[session_id] = 1 ORDER BY [t1].[name] ) AS [t2] WHERE [t0].[subject_id] = [t2].[subject_id] ))) AND ([t0].[session_id] = 1) ORDER BY [t0].[name] When I add the ORDER BY [t0].[name] to the outer query it slows down the query. How can I improve the second query? This was my LINQ stuff Nick int sessionId = 1; int start = 100; int count = 20; // Query subjects with the shoot's session id var subjects = cldb.Subjects.Where<Subject>(s => s.Session_id == sessionId); // Filter as per params var orderedSubjects = subjects .OrderBy<Subject, string>( s => s.Col_zero ); var filteredSubjects = orderedSubjects .Skip<Subject>(start) .Take<Subject>(count);

  Read the article

< Previous Page | 379 380 381 382 383 384 385 386 387 388 389 390  | Next Page >