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  • ReadFile doesn't work asynchronously on Win7 and Win2k8

    - by f0b0s
    According to MSDN ReadFile can read data 2 different ways: synchronously and asynchronously. I need the second one. The folowing code demonstrates usage with OVERLAPPED struct: #include <windows.h> #include <stdio.h> #include <time.h> void Read() { HANDLE hFile = CreateFileA("c:\\1.avi", GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL); if ( hFile == INVALID_HANDLE_VALUE ) { printf("Failed to open the file\n"); return; } int dataSize = 256 * 1024 * 1024; char* data = (char*)malloc(dataSize); memset(data, 0xFF, dataSize); OVERLAPPED overlapped; memset(&overlapped, 0, sizeof(overlapped)); printf("reading: %d\n", time(NULL)); BOOL result = ReadFile(hFile, data, dataSize, NULL, &overlapped); printf("sent: %d\n", time(NULL)); DWORD bytesRead; result = GetOverlappedResult(hFile, &overlapped, &bytesRead, TRUE); // wait until completion - returns immediately printf("done: %d\n", time(NULL)); CloseHandle(hFile); } int main() { Read(); } On Windows XP output is: reading: 1296651896 sent: 1296651896 done: 1296651899 It means that ReadFile didn't block and returned imediatly at the same second, whereas reading process continued for 3 seconds. It is normal async reading. But on windows 7 and windows 2008 I get following results: reading: 1296661205 sent: 1296661209 done: 1296661209. It is a behavior of sync reading. MSDN says that async ReadFile sometimes can behave as sync (when the file is compressed or encrypted for example). But the return value in this situation should be TRUE and GetLastError() == NO_ERROR. On Windows 7 I get FALSE and GetLastError() == ERROR_IO_PENDING. So WinApi tells me that it is an async call, but when I look at the test I see that it is not! I'm not the only one who found this "bug": read the comment on ReadFile MSDN page. So what's the solution? Does anybody know? It is been 14 months after Denis found this strange behavior.

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  • listview Header check-box

    - by Andy
    Hi , I'm having a windows form which contains listview control , where listView1.View = View.Details; and listView1.CheckBoxes = true; then added a column with HeaderName as "FileName". listView1.Columns.Add("File Name", 200, HorizontalAlignment.Left); Here I would like to have check box in the Header of listview , ie FileName. Can anyone help me with this. Thanks in advance. andy

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  • Best way to test for a variable's existence in PHP; isset() is clearly broken

    - by chazomaticus
    From the isset() docs: isset() will return FALSE if testing a variable that has been set to NULL. Basically, isset() doesn't check for whether the variable is set at all, but whether it's set to anything but NULL. Given that, what's the best way to actually check for the existence of a variable? I tried something like: if(isset($v) || @is_null($v)) (the @ is necessary to avoid the warning when $v is not set) but is_null() has a similar problem to isset(): it returns TRUE on unset variables! It also appears that: @($v === NULL) works exactly like @is_null($v), so that's out, too. How are we supposed to reliably check for the existence of a variable in PHP? Edit: there is clearly a difference in PHP between variables that are not set, and variables that are set to NULL: <?php $a = array('b' => NULL); var_dump($a); PHP shows that $a['b'] exists, and has a NULL value. If you add: var_dump(isset($a['b'])); var_dump(isset($a['c'])); you can see the ambiguity I'm talking about with the isset() function. Here's the output of all three of these var_dump()s: array(1) { ["b"]=> NULL } bool(false) bool(false) Further edit: two things. One, a use case. An array being turned into the data of an SQL UPDATE statement, where the array's keys are the table's columns, and the array's values are the values to be applied to each column. Any of the table's columns can hold a NULL value, signified by passing a NULL value in the array. You need a way to differentiate between an array key not existing, and an array's value being set to NULL; that's the difference between not updating the column's value and updating the column's value to NULL. Second, Zoredache's answer, array_key_exists() works correctly, for my above use case and for any global variables: <?php $a = NULL; var_dump(array_key_exists('a', $GLOBALS)); var_dump(array_key_exists('b', $GLOBALS)); outputs: bool(true) bool(false) Since that properly handles just about everywhere I can see there being any ambiguity between variables that don't exist and variables that are set to NULL, I'm calling array_key_exists() the official easiest way in PHP to truly check for the existence of a variable. (Only other case I can think of is for class properties, for which there's property_exists(), which, according to its docs, works similarly to array_key_exists() in that it properly distinguishes between not being set and being set to NULL.)

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  • Abstract mapping with custom JiBX marshaller

    - by aweigold
    I have created a custom JiBX marshaller and verified it works. It works by doing something like the following: <binding xmlns:tns="http://foobar.com/foo" direction="output"> <namespace uri="http://foobar.com/foo" default="elements"/> <mapping class="java.util.HashMap" marshaller="com.foobar.Marshaller1"/> <mapping name="context" class="com.foobar.Context"> <structure field="configuration"/> </mapping> </binding> However I need to create multiple marshallers for different HashMaps. So I tried to reference it with abstract mapping like this: <binding xmlns:tns="http://foobar.com/foo" direction="output"> <namespace uri="http://foobar.com/foo" default="elements"/> <mapping abstract="true" type-name="configuration" class="java.util.HashMap" marshaller="com.foobar.Marshaller1"/> <mapping abstract="true" type-name="overrides" class="java.util.HashMap" marshaller="com.foobar.Marshaller2"/> <mapping name="context" class="com.foobar.Context"> <structure map-as="configuration" field="configuration"/> <structure map-as="overrides" field="overrides"/> </mapping> </binding> However when doing so, when I attempt to build the binding, I receive the following: Error during code generation for file "E:\project\src\main\jibx\foo.jibx" - this may be due to an error in your binding or classpath, or to an error in the JiBX code My guess is that either I'm missing something I need to implement to enable my custom marshaller for abstract mapping, or custom marshallers do not support abstract mapping. I have found the IAbstractMarshaller interface in the JiBX API (http://jibx.sourceforge.net/api/org/jibx/runtime/IAbstractMarshaller.html), however the documentation seems unclear to me on if this is what I need to implement, as well as how it works if so. I have not been able to find an implementation of this interface to work off of as an example. My question is, how do you do abstract mapping with custom marshallers (if it's possible)? If it is done via the IAbstractMarshaller interface, how does it work and/or how should I implement it?

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  • Getting a visitors Facebook page

    - by Mr Carl
    Hey guys, this is more of a question out of curiosity, but is it possible to get somebody's Facebook page after they have visited your site? Was thinking maybe a chain of lookup stuff could be used starting with an IP to eventually perhaps get a name and thus that person's Facebook page. I have also heard you can read somebody's web history, is this true?

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  • Ajax doesn't work on remote server .

    - by Nuha
    Hello . when I Implemented chatting Function , I use Ajax to send messages between file to another . so , it is working well on local host . but , when I upload it in to remote server it doesn't work. can U tell me ,why ? is an Ajax need Special configuration ? Ajax code : function Ajax_Send(GP,URL,PARAMETERS,RESPONSEFUNCTION){? var xmlhttp? try{xmlhttp=new ActiveXObject("Msxml2.XMLHTTP")}? catch(e){? try{xmlhttp=new ActiveXObject("Microsoft.XMLHTTP")}? catch(e){? try{xmlhttp=new XMLHttpRequest()}? catch(e){? alert("Your Browser Does Not Support AJAX")}}}? ? err=""? if (GP==undefined) err="GP "? if (URL==undefined) err +="URL "? if (PARAMETERS==undefined) err+="PARAMETERS"? if (err!=""){alert("Missing Identifier(s)\n\n"+err);return false;}? ? xmlhttp.onreadystatechange=function(){? if (xmlhttp.readyState == 4){? if (RESPONSEFUNCTION=="") return false;? eval(RESPONSEFUNCTION(xmlhttp.responseText))? }? }? ? if (GP=="GET"){? URL+="?"+PARAMETERS? xmlhttp.open("GET",URL,true)? xmlhttp.send(null)? }? ? if (GP="POST"){? PARAMETERS=encodeURI(PARAMETERS)? xmlhttp.open("POST",URL,true)? xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded")? xmlhttp.setRequestHeader("Content-length",PARAMETERS.length)? xmlhttp.setRequestHeader("Connection", "close")? xmlhttp.send(PARAMETERS)? }? }

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  • SimpleMembership updating the "isconfirmed" flag

    - by Vijay V
    My Users table (the one that I created) has the following columns: UserId,UserName,FirstName,LastName,DOB After I ran this command WebSecurity.InitializeDatabaseConnection("DefaultConnection", "Users", "UserId", "UserName", autoCreateTables: true); it created the required simple membership tables for me. How would I go about "UnConfirming" an user or setting the "IsConfirmed" flag to false in the webpages_Membership using the new SimpleMembership API? (Earlier, before going to simplemembership using the "Membership" class I could update an user using the api call : Membership.UpdateUser( user );)

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  • Need help how to call c# function which return type is array in jquery

    - by Manoj Wadhwani
    $('#calendar').fullCalendar ( { editable: true, events: $.ajax ( { type: "POST", url: "Calender.aspx/GetCDCatalog", contentType: "application/json; charset=utf-8", data: "{}", dataType: "json" } ) } ) calender.aspx is page and getcddialog is function which return type is array which doest not bind calender. public CD[] GetCDCatalog() { XDocument docXML = XDocument.Load(Server.MapPath("mydata.xml")); var CDs = from cd in docXML.Descendants("Table") select new CD { title = cd.Element("title").Value, star = cd.Element("star").Value, endTime = cd.Element("endTime").Value, }; return CDs.ToArray<CD>(); }

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  • asp:upload postedfile lost during postback

    - by Neil
    I am using an asp:upload control to upload an image and am using the postedfile property to insert the path to the database. In my form I have a dropdown with autopostback=true where the user can select a topic to populate a checkbox list of categories. During that postback, the postedfile value is being lost and after a little research I have discovered that the posted file value is not maintained in viewstate for security reasons. Has anybody else found out how to get around this?

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  • Translate the vb6 code to vb.net or c# or java!

    - by user292084
    Translate the vb6 code to vb.net or c# or java, too difficult to me, thank you. Dim dom As New DOMDocument Dim http As XMLHTTP Dim strRet As String If not Dom.load(c:\voucher.xml)then msgbox “file not exist” http.Open "Post", "http://127.0.0.1/import.asp", True http.Send dom.xml

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  • jQuery Checkbox class attribute

    - by mike
    how do you access the class attribute of a in a jQuery selector statement? for example <asp:CheckBox runat="server" ID="cbTest" Text="Cb Test" FieldName="1st Test Check Box" class="toggleBox"/> this: $(':checkbox').toggleAttr("checked", true, false) accesses the checkbox and applies a custom function to the checked attribute but if i want to filter based on a certain class how do i access/filter based on that?

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  • google maps marker draggable doesn't work

    - by ArmenGrigoryan
    I try all methods but in my google map on the marker doesn't work events, I try enable events and write (clickable: true), but it did not help, in test server working good, but on phpfox marker not clickable, help me please correct it go to it http://iguansystems.com/phpfoxdev/index.php?do=/pages/24/quickstart/step2/ link login - [email protected], and pass- tryuser in center frontend right at "Primary Venue" have "Can't find venue? Add New" click on "Add New" and window with a map open

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  • How can I check a radio button on load, based on it's value?

    - by Noor
    I've got the value of a radio button (r1) and I'm trying to use: $("input:radio[val=r1]").attr('checked', true); to check it. The thing is that I've got three radio buttons in a div, when I check one, the value of the checked button gets stored. When I reload the page I want the page to check the radio button that was chosen last. Thanks!

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  • Flex Air HTMLLoader blank pop up window when flash content is loaded

    - by user128938
    I have a flex Air program that loads external content with the HTMLLoader. Now for some reason whenever I load a page that has any flash content a blank system window pops up outside of my program. It's completely blank, all white with min, max and close buttons. If I close it any flash content I loaded stops working. For the life of my I can't figure out what's happening and there's no messages in the console and no title for the window. Does anyone have any ideas? I appreciate any help you can give. Here's the code I'm using: private var webPage:HTMLLoader; private function registerEvents():void { this.addEventListener(gameLoadEvent.GAME_LOAD, gameLoad); //webPage = new HTMLLoader(); } //function called back from Game Command to load correct game private function gameLoad(event:Event):void { var gameEvent:gameLoadEvent = event as gameLoadEvent; loadgame(gameEvent.url, gameEvent.variables); } private function loadgame(url:String, variableString:String):void { DesktopModelLocator.getInstance().scaleX = 1; DesktopModelLocator.getInstance().scaleY = 1; //var url:String = "http://pro-us.sbt-corp.com/aspx/member/LaunchGame.aspx"; var request:URLRequest = new URLRequest(url); //var variables:URLVariables = new URLVariables("gameNum=17&as=as1&t=demo&package=a&btnQuit=0"); if(variableString != null && variableString != ""){ var variables:URLVariables = new URLVariables(variableString); variables.exampleSessionId = new Date().getTime(); variables.exampleUserLabel = "guest"; request.data = variables; } webPage = HTMLLoader.createRootWindow(true, null, true, null); webPage.height = systemManager.stage.nativeWindow.height - 66; webPage.width = systemManager.stage.nativeWindow.width; webPage.load(request); webPage.navigateInSystemBrowser = false; flexBrowser.addChild(webPage); } ]]> </mx:Script> <mx:HTML id="flexBrowser" width="1366" height="658" backgroundAlpha="0.45" creationComplete="registerEvents();" x="0" y="0"> </mx:HTML>

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  • NHibernate Many to Many delete all my data in the table

    - by Daoming Yang
    I would love to thank @Stefan Steinegger and @David helped me out yesterday with many-to-many mapping. I have 3 tables which are "News", "Tags" and "News_Tags" with Many-To-Many relationship and the "News_Tags" is the link table. If I delete one of the news records, the following mappings will delete all my news records which have the same tags. One thing I need to notice, I only allowed unique tag stored in the "Tag" table. This mapping make sense for me, it will delete the tag and related News records, but how can I implement a tagging system with NHibernate? Can anyone give me some suggestion? Many thanks. Daoming. News Mapping: <class name="New" table="News" lazy="false"> <id name="NewID"> <generator class="identity" /> </id> <property name="Title" type="String"></property> <property name="Description" type="String"></property> <set name="TagsList" table="New_Tags" lazy="false" inverse="true" cascade="all"> <key column="NewID" /> <many-to-many class="Tag" column="TagID" /> </set> </class> Tag Mapping: <class name="Tag" table="Tags" lazy="false"> <id name="TagID"> <generator class="identity" /> </id> <property name="TagName" type="String"></property> <property name="DateCreated" type="DateTime"></property> <!--inverse="true" has been defined in the "News mapping"--> <set name="NewsList" table="New_Tags" lazy="false" cascade="all"> <key column="TagID" /> <many-to-many class="New" column="NewID" /> </set> </class>

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  • JPA Inheritance and Relations - Clarification question

    - by Michael
    Here the scenario: I have a unidirectional 1:N Relation from Person Entity to Address Entity. And a bidirectional 1:N Relation from User Entity to Vehicle Entity. Here is the Address class: @Entity public class Address implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.AUTO) privat Long int ... The Vehicles Class: @Entity public class Vehicle implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne private User owner; ... @PreRemove protected void preRemove() { //this.owner.removeVehicle(this); } public Vehicle(User owner) { this.owner = owner; ... The Person Class: @Entity @Inheritance(strategy = InheritanceType.JOINED) @DiscriminatorColumn(name="PERSON_TYP") public class Person implements Serializable { @Id protected String username; @OneToMany(cascade = CascadeType.ALL, orphanRemoval=true) @JoinTable(name = "USER_ADDRESS", joinColumns = @JoinColumn(name = "USERNAME"), inverseJoinColumns = @JoinColumn(name = "ADDRESS_ID")) protected List<Address> addresses; ... @PreRemove protected void prePersonRemove(){ this.addresses = null; } ... The User Class which is inherited from the Person class: @Entity @Table(name = "Users") @DiscriminatorValue("USER") public class User extends Person { @OneToMany(mappedBy = "owner", cascade = {CascadeType.PERSIST, CascadeType.REMOVE}) private List<Vehicle> vehicles; ... When I try to delete a User who has an address I have to use orphanremoval=true on the corresponding relation (see above) and the preRemove function where the address List is set to null. Otherwise (no orphanremoval and adress list not set to null) a foreign key contraint fails. When i try to delete a user who has an vehicle a concurrent Acces Exception is thrown when do not uncomment the "this.owner.removeVehicle(this);" in the preRemove Function of the vehicle. The thing i do not understand is that before i used this inheritance there was only a User class which had all relations: @Entity @Table(name = "Users") public class User implements Serializable { @Id protected String username; @OneToMany(mappedBy = "owner", cascade = {CascadeType.PERSIST, CascadeType.REMOVE}) private List<Vehicle> vehicles; @OneToMany(cascade = CascadeType.ALL) @JoinTable(name = "USER_ADDRESS", joinColumns = @JoinColumn(name = "USERNAME") inverseJoinColumns = @JoinColumn(name = "ADDRESS_ID")) ptivate List<Address> addresses; ... No orphanremoval, and the vehicle class has used the uncommented statement above in its preRemove function. And - I could delte a user who has an address and i could delte a user who has a vehicle. So why doesn't everything work without changes when i use inheritance? I use JPA 2.0, EclipseLink 2.0.2, MySQL 5.1.x and Netbeans 6.8

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  • Selecting the contents of an ASP.NET TextBox in an UpdatePanel after a partial page postback

    - by Scott Mitchell
    I am having problems selecting the text within a TextBox in an UpdatePanel. Consider a very simple page that contains a single UpdatePanel. Within that UpdatePanel there are two Web controls: A DropDownList with three statically-defined list items, whose AutoPostBack property is set to True, and A TextBox Web control The DropDownList has a server-side event handler for its SelectedIndexChanged event, and in that event handler there's two lines of code: TextBox1.Text = "Whatever"; ScriptManager.RegisterStartupScript(this, this.GetType(), "Select-" + TextBox1.ClientID, string.Format("document.getElementById('{0}').select();", TextBox1.ClientID), true); The idea is that whenever a user chooses and item from the DropDownList there is a partial page postback, at which point the TextBox's Text property is set and selected (via the injected JavaScript). Unfortunately, this doesn't work as-is. (I have also tried putting the script in the pageLoad function with no luck, as in: ScriptManager.RegisterStartupScript(..., "function pageLoad() { ... my script ... }");) What happens is the code runs, but something else on the page receives focus at the conclusion of the partial page postback, causing the TextBox's text to be unselected. I can "fix" this by using JavaScript's setTimeout to delay the execution of my JavaScript code. For instance, if I update the emitted JavaScript to the following: setTimeout("document.getElementById('{0}').select();", 111); It "works." I put works in quotes because it works for this simple page on my computer. In a more complex page on a slower computer with more markup getting passed between the client and server on the partial page postback, I have to up the timeout to over a second to get it to work. I would hope that there is a more foolproof way to achieve this. Rather than saying, "Delay for X milliseconds," it would be ideal to say, "Run this when you're not going to steal the focus." What's perplexing is that the .Focus() method works beautifully. That is, if I scrap my JavaScript and replace it with a call to TextBox1.Focus(); then the TextBox receives focus (although the text is not selected). I've examined the contents of MicrosoftAjaxWebForms.js and see that the focus is set after the registered scripts run, but I'm my JavaScript skills are not strong enough to decode what all is happening here and why the selected text is unselected between the time it is selected and the end of the partial page postback. I've also tried using Firebug's JavaScript debugger and see that when my script runs the TextBox's text is selected. As I continue to step through it the text remains selected, but then after stepping off the last line of script (apparently) it all of the sudden gets unselected. Any ideas? I am pulling my hair out. Thanks in advance...

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  • Mootools 1.2.4 delegation not working in IE8...?

    - by michael
    Hey there everybody-- So I have a listbox next to a form. When the user clicks an option in the select box, I make a request for the related data, returned in a JSON object, which gets put into the form elements. When the form is saved, the request goes thru and the listbox is rebuilt with the updated data. Since it's being rebuilt I'm trying to use delegation on the listbox's parent div for the onchange code. The trouble I'm having is with IE8 (big shock) not firing the delegated event. I have the following HTML: <div id="listwrapper" class="span-10 append-1 last"> <select id="list" name="list" size="20"> <option value="86">Adrian Franklin</option> <option value="16">Adrian McCorvey</option> <option value="196">Virginia Thomas</option> </select> </div> and the following script to go with it: window.addEvent('domready', function() { var jsonreq = new Request.JSON(); $('listwrapper').addEvent('change:relay(select)', function(e) { alert('this doesn't fire in IE8'); e.stop(); var status= $('statuswrapper').empty().addClass('ajax-loading'); jsonreq.options.url = 'de_getformdata.php'; jsonreq.options.method = 'post'; jsonreq.options.data = {'getlist':'<?php echo $getlist ?>','pkey':$('list').value}; jsonreq.onSuccess = function(rObj, rTxt) { status.removeClass('ajax-loading'); for (key in rObj) { status.set('html','You are currently editing '+rObj['cname']); if ($chk($(key))) $(key).value = rObj[key]; } $('lalsoaccomp-yes').set('checked',(($('naccompkey').value > 0)?'true':'false')); $('lalsoaccomp-no').set('checked',(($('naccompkey').value > 0)?'false':'true')); } jsonreq.send(); }); }); (I took out a bit of unrelated stuff). So this all works as expected in firefox, but IE8 refuses to fire the delegated change event on the select element. If I attach the change function directly to the select, then it works just fine. Am I missing something? Does IE8 just not like the :relay? Sidenote: I'm very new to mootools and javascripting, etc, so if there's something that can be improved code-wise, please let me know too.. Thanks!

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  • How to upgrade internal php version of Zend Studio / Eclipse

    - by Moak
    I was following this tutorial when typing up this code: public function search($term){ $filter = function($tag) use ($term){ if(stristr($tag,$term)) return true; return false; }; return array_filter($this->_tags,$filter); } I get following errors in Zend Studio 8 syntax error, unexpected '{' syntax error, unexpected 'function' syntax error, unexpected 'use' However the code works fine on my Xampp with php 5.3.1 - How can I find the version of PHP in Zend Studio, and how can I upgrade it?

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  • java double buffering problem

    - by russell
    Whats wrong with my applet code which does not render double buffering correctly.I am trying and trying.But failed to get a solution.Plz Plz someone tell me whats wrong with my code. import java.applet.* ; import java.awt.* ; import java.awt.event.* ; public class Ball extends Applet implements Runnable { // Initialisierung der Variablen int x_pos = 10; // x - Position des Balles int y_pos = 100; // y - Position des Balles int radius = 20; // Radius des Balles Image buffer=null; //Graphics graphic=null; int w,h; public void init() { Dimension d=getSize(); w=d.width; h=d.height; buffer=createImage(w,h); //graphic=buffer.getGraphics(); setBackground (Color.black); } public void start () { // Schaffen eines neuen Threads, in dem das Spiel l?uft Thread th = new Thread (this); // Starten des Threads th.start (); } public void stop() { } public void destroy() { } public void run () { // Erniedrigen der ThreadPriority um zeichnen zu erleichtern Thread.currentThread().setPriority(Thread.MIN_PRIORITY); // Solange true ist l?uft der Thread weiter while (true) { // Ver?ndern der x- Koordinate repaint(); x_pos++; y_pos++; //x2--; //y2--; // Neuzeichnen des Applets if(x_pos>410) x_pos=20; if(y_pos>410) y_pos=20; try { Thread.sleep (30); } catch (InterruptedException ex) { // do nothing } Thread.currentThread().setPriority(Thread.MAX_PRIORITY); } } public void paint (Graphics g) { Graphics screen=null; screen=g; g=buffer.getGraphics(); g.setColor(Color.red); g.fillOval(x_pos - radius, y_pos - radius, 2 * radius, 2 * radius); g.setColor(Color.green); screen.drawImage(buffer,0,0,this); } public void update(Graphics g) { paint(g); } } what change should i make.When offscreen image is drawn the previous image also remain in screen.How to erase the previous image from the screen??

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  • Basic shared memory program in C

    - by nicopuri
    Hi, I want to make a basic chat application in C using Shared memory. I am working in Linux. The application consist in writing the client and the server can read, and if the server write the client can read the message. I tried to do this, but I can't achieve the communication between client and server. The code is the following: Server.c int main(int argc, char **argv) { char *msg; static char buf[SIZE]; int n; msg = getmem(); memset(msg, 0, SIZE); initmutex(); while ( true ) { if( (n = read(0, buf, sizeof buf)) 0 ) { enter(); sprintf(msg, "%.*s", n, buf); printf("Servidor escribe: %s", msg); leave(); }else{ enter(); if ( strcmp(buf, msg) ) { printf("Servidor lee: %s", msg); strcpy(buf, msg); } leave(); sleep(1); } } return 0; } Client.c int main(int argc, char **argv) { char *msg; static char buf[SIZE-1]; int n; msg = getmem(); initmutex(); while(true) { if ( (n = read(0, buf, sizeof buf)) 0 ) { enter(); sprintf(msg, "%.*s", n, buf); printf("Cliente escribe: %s", msg); leave(); }else{ enter(); if ( strcmp(buf, msg) ) { printf("Cliente lee: %s", msg); strcpy(buf, msg); } leave(); sleep(1); } } printf("Cliente termina\n"); return 0; } The shared memory module is the folowing: #include "common.h" void fatal(char *s) { perror(s); exit(1); } char * getmem(void) { int fd; char *mem; if ( (fd = shm_open("/message", O_RDWR|O_CREAT, 0666)) == -1 ) fatal("sh_open"); ftruncate(fd, SIZE); if ( !(mem = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) ) fatal("mmap"); close(fd); return mem; } static sem_t *sd; void initmutex(void) { if ( !(sd = sem_open("/mutex", O_RDWR|O_CREAT, 0666, 1)) ) fatal("sem_open"); } void enter(void) { sem_wait(sd); } void leave(void) { sem_post(sd); }

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