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  • Web Control added in .master control type not found in child page

    - by turtle
    I have a Web Site project, and within it I have a user Web Control defined in an ascx file. The control is added to the Site.Master, and it shows up correctly on the page and everything is fine. I need to override some of the control's fields on one of the pages that derive from Site.Master. // In OnLoad: MyControlName control = (MyControlName) Page.Master.GetBaseMasterPage().FindControl("controlID")); The issue is that MyControlName doesn't register as a valid Type on the child page. If I add a second instance of the control to the child page directly, the above works as needed, but if the control isn't placed directly on the page, and instead is only defined in the master page, the type is undefined. The control is not in a namespace, and is defined within the project, so I don't know why it is having such an issue location the appropriate type. If I put a breakpoint in the OnLoad, the type listed for the control is ASP.my_control_name_ascx, but using that does not work either. Why can't the child class reference the correct type? Can I fix this? Thanks!

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  • calculating the index of an array C#

    - by Kerry G
    I want to display a list of the answers a student entered incorrectly. How do I identify the index of these questions? I am hoping to change the contents of a textbox to a list of the questions answered incorrectly, which would require calculating the index of each incorrect question. using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace WindowsFormsApplication5 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } //return a pass/fail //return number of correct answers //return number of incorrect answers //return index figures of incorrect values public void examResults () { string[] correctAnswers = {B,D,A,A,C,A,B,A,C,D,B,C,D,A,D,C,C,B,D,A}; string[] studentResults = File.ReadAllLines("studentResults.txt"); var c = correctAnswers.Where((x, i) => x.Equals(studentResults[i])).Count(); if ( c <= 14) passFailBox.Text = "Student has failed the exam"; else passFailBox.Text = "Student has passed the exam"; numberCorrectBox.Text = "Student has answered" + c + "answers correctly"; int f; f= 21-c; numberIncorrectBox.Text = "Student has answered" + f + "answers incorrectly"; } } }

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  • How can I make VS2010 insert using statements in the order dictated by StyleCop rules.

    - by Hamish Grubijan
    The related default StyleCop rules are: Place using statements inside namespace. Sort using statements alphabetically. But ... System using come first (still trying to figure out if that means just using System; or using System[.*];). So, my use case: I find a bug and decide that I need to at least add an intelligible Assert to make debugging less painful for the next guy. So I start typing Debug.Assert( and intellisense marks it in Red. I hover mouse over Debug and between using System.Diagnostics; and System.Diagnostics.Debug I choose the former. This inserts using System.Diagnostics; after all other using statements. It would be nice if VS2010 did not assist me in writing code that won't build due to warnings as errors. How can I make VS2010 smarter? Is there some sort of setting, or does this require a full-fledged add-in of some sort?

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  • CURL C API: callback was not called

    - by Pierre
    Hi all, The code below is a test for the CURL C API . The problem is that the callback function write_callback is never called. Why ? /** compilation: g++ source.cpp -lcurl */ #include <assert.h> #include <iostream> #include <cstdlib> #include <cstring> #include <cassert> #include <curl/curl.h> using namespace std; static size_t write_callback(void *ptr, size_t size, size_t nmemb, void *userp) { std::cerr << "CALLBACK WAS CALLED" << endl; exit(-1); return size*nmemb; } static void test_curl() { int any_data=1; CURLM* multi_handle=NULL; CURL* handle_curl = ::curl_easy_init(); assert(handle_curl!=NULL); ::curl_easy_setopt(handle_curl, CURLOPT_URL, "http://en.wikipedia.org/wiki/Main_Page"); ::curl_easy_setopt(handle_curl, CURLOPT_WRITEDATA, &any_data); ::curl_easy_setopt(handle_curl, CURLOPT_VERBOSE, 1); ::curl_easy_setopt(handle_curl, CURLOPT_WRITEFUNCTION, write_callback); ::curl_easy_setopt(handle_curl, CURLOPT_USERAGENT, "libcurl-agent/1.0"); multi_handle = ::curl_multi_init(); assert(multi_handle!=NULL); ::curl_multi_add_handle(multi_handle, handle_curl); int still_running=0; /* lets start the fetch */ while(::curl_multi_perform(multi_handle, &still_running) == CURLM_CALL_MULTI_PERFORM ); std::cerr << "End of curl_multi_perform."<< endl; //cleanup should go here ::exit(EXIT_SUCCESS); } int main(int argc,char** argv) { test_curl(); return 0; } Many thanks Pierre

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  • The youtube API sometimes throws error: Call to a member function children() on a non-object

    - by Anna Lica
    When i launch the php script, sometime works fine, but many other times it retrieve me this errror Fatal error: Call to a member function children() on a non-object in /membri/americanhorizon/ytvideo/rilevametadatadaurlyoutube.php on line 21 This is the first part of the code // set feed URL $feedURL = 'http://gdata.youtube.com/feeds/api/videos/dZec2Lbr_r8'; // read feed into SimpleXML object $entry = simplexml_load_file($feedURL); $video = parseVideoEntry($entry); function parseVideoEntry($entry) { $obj= new stdClass; // get nodes in media: namespace for media information $media = $entry->children('http://search.yahoo.com/mrss/'); //<----this is the doomed line 21 UPDATE: solution adopted for ($i=0 ; $i< count($fileArray); $i++) { // set feed URL $feedURL = 'http://gdata.youtube.com/feeds/api/videos/'.$fileArray[$i]; // read feed into SimpleXML object $entry = simplexml_load_file($feedURL); if ( is_object($entry)) { $video = parseVideoEntry($entry); echo ($video->description."|".$video->length); echo "<br>"; } else { $i--; } } In this mode i force the script to re-check the file that caused the error

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  • Database Programming in C#, returning output from Stored Proc

    - by jpavlov
    I am working at gaining an understanding at how to interface stored procedures with applications. My example is simple, but it doesn't display my columns and rows in the command prompt, instead it display System.Data.SqlClient.SqlDataReader. How do I display the rows from my stored procudure? ----Stored Proc-- ALTER PROCEDURE dbo.SelectID AS SELECT * FROM tb_User; ----- Below is the code: using System; using System.Data.SqlClient; using System.IO; namespace ExecuteStoredProc { class Program { static void Main(string[] args) { SqlConnection cnnUserMan; SqlCommand cmmUser; //SqlDataReader drdUser; //Instantiate and open the connection cnnUserMan = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=c:\\Program Files\\Microsoft SQL Server\\MSSQL10.SQLEXPRESS\\MSSQL\\DATA\\UserDB.mdf; Integrated Security=True;Connect Timeout=30;User Instance=True"); cnnUserMan.Open(); //Instantiate and initialize command cmmUser = new SqlCommand("SelectID", cnnUserMan); cmmUser.CommandType = System.Data.CommandType.StoredProcedure; //drdUser = cmmUser.ExecuteReader(); Console.WriteLine(cmmUser.ExecuteReader()); Console.ReadLine(); } } } Thanks.

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  • Tilting web browser on windows phone 7

    - by marcus
    Hi guys, i'm working on a windows phone 7 emulator. I have a web browser which navigates to local host. So my problem i faced was that when i tilt the windows phone 7 emulator 90% right, the screen doesn't. Could there be any advice on how to do so? using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using Microsoft.Phone.Controls; namespace DSP { public partial class MainPage : PhoneApplicationPage { // Constructor public MainPage() { InitializeComponent(); } private void ContentPanel_Loaded(object sender, RoutedEventArgs e) { MessageBox.Show("Loading website. This might take a few seconds..."); webBrowser1.Navigate(new Uri("http://localhost/Liweiyi_fyp_082648y/homepage.html", UriKind.Absolute)); } private void webBrowser1_Loaded(object sender, RoutedEventArgs e) { } } }

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  • Why strings behave like ValueType

    - by AJP
    I was perplexed after executing this piece of code, where strings seems to behave as if they are value types. I am wondering whether the assignment operator is operating on values like equality operator for strings. Here is the piece of code I did to test this behavior. using System; namespace RefTypeDelimma { class Program { static void Main(string[] args) { string a1, a2; a1 = "ABC"; a2 = a1; //This should assign a1 reference to a2 a2 = "XYZ"; //I expect this should change the a1 value to "XYZ" Console.WriteLine("a1:" + a1 + ", a2:" + a2);//Outputs a1:ABC, a2:XYZ //Expected: a1:XYZ, a2:XYZ (as string being a ref type) Proc(a2); //Altering values of ref types inside a procedure //should reflect in the variable thats being passed into Console.WriteLine("a1: " + a1 + ", a2: " + a2); //Outputs a1:ABC, a2:XYZ //Expected: a1:NEW_VAL, a2:NEW_VAL (as string being a ref type) } static void Proc(string Val) { Val = "NEW_VAL"; } } } In the above code if I use a custom classes instead of strings, I am getting the expected behavior. I doubt is this something to do with the string immutability? welcoming expert views on this.

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  • Formatting the output of a custom tool so I can double click an error in Visual Studio and the file opens

    - by Ben Scott
    I've written a command line tool that preprocesses a number of files then compiles them using CodeDom. The tool writes a copyright notice and some progress text to the standard output, then writes any errors from the compilation step using the following format: foreach (var err in results.Errors) { // err is CompilerError var filename = "Path\To\input_file.xprt"; Console.WriteLine(string.Format( "{0} ({1},{2}): {3}{4} ({5})", filename, err.Line, err.Column, err.IsWarning ? "" : "ERROR: ", err.ErrorText, err.ErrorNumber)); } It then writes the number of errors, like "14 errors". This is an example of how the error appears in the console: Path\To\input_file.xrpt (73,28): ERROR: An object reference is required for the non-static field, method, or property 'Some.Object.get' (CS0120) When I run this as a custom tool in VS2008 (by calling it in the post-build event command line of one of my project's assemblies), the errors appear nicely formatted in the Error List, with the correct text in each column. When I roll over the filename the fully qualified path pops up. The line and column are different to the source file because of the preprocessing which is fine. The only thing that stands out is that the Project given in the list is the one that has the post-build event. The problem is that when I double click an error, nothing happens. I would have expected the file to open in the editor. I'm vaugely aware of the Microsoft.VisualStudio.Shell.Interop namespace but I think it should be possible just by writing to the standard output.

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  • Using an initializer_list on a map of vectors

    - by Hooked
    I've been trying to initialize a map of <ints, vector<ints> > using the new 0X standard, but I cannot seem to get the syntax correct. I'd like to make a map with a single entry with key:value = 1:<3,4 #include <initializer_list> #include <map> #include <vector> using namespace std; map<int, vector<int> > A = {1,{3,4}}; .... It dies with the following error using gcc 4.4.3: error: no matching function for call to std::map<int,std::vector<int,std::allocator<int> >,std::less<int>,std::allocator<std::pair<const int,std::vector<int,std::allocator<int> > > > >::map(<brace-enclosed initializer list>) Edit Following the suggestion by Cogwheel and adding the extra brace it now compiles with a warning that can be gotten rid of using the -fno-deduce-init-list flag. Is there any danger in doing so?

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  • Segmentation fault on returning from main (very short and simple code, no arrays or pointers)

    - by Gábor Kovács
    I've been wondering why the following trivial code produces a segmentation fault when returning from main(): //Produces "Error while dumping state (probably corrupted stack); Segmentation fault" #include <iostream> #include <fstream> #include <vector> using namespace std; class Test { vector<int> numbers; }; int main() { Test a; ifstream infile; cout << "Last statement..." << endl; // this gets executed return 0; } Interestingly, 1) if only one of the two variables is declared, I don't get the error, 2) if I declare a vector variable instead of an object with a vector member, everything's fine, 3) if I declare an ofstream instead of an ifstream, again, everything works fine. Something appears to be wrong with this specific combination... Could this be a compiler bug? I use gcc version 3.4.4 with cygwin. Thanks for the tips in advance. Gábor

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  • How to find an XPath query to Element/Element without namespaces (XmlSerializer, fragment)?

    - by Veksi
    Assume this simple XML fragment in which there may or may not be the xml declaration and has exactly one NodeElement as a root node, followed by exactly one other NodeElement, which may contain an assortment of various number of different kinds of elements. <?xml version="1.0"> <NodeElement xmlns="xyz"> <NodeElement xmlns=""> <SomeElement></SomeElement> </NodeElement> </NodeElement> How could I go about selecting the inner NodeElement and its contents without the namespace? For instance, "//*[local-name()='NodeElement/NodeElement[1]']" (and other variations I've tried) doesn't seem to yield results. As for in general the thing that I'm really trying to accomplish is to Deserialize a fragment of a larger XML document contained in a XmlDocument. Something like the following var doc = new XmlDocument(); doc.LoadXml(File.ReadAllText(@"trickynodefile.xml")); //ReadAllText to avoid Unicode trouble. var n = doc.SelectSingleNode("//*[local-name()='NodeElement/NodeElement[1]']"); using(var reader = XmlReader.Create(new StringReader(n.OuterXml))) { var obj = new XmlSerializer(typeof(NodeElementNodeElement)).Deserialize(reader); I believe I'm missing just the right XPath expression, which seem to be rather elusive. Any help much appreciated!

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  • C++ iterator and const_iterator problem for own container class

    - by BaCh
    Hi there, I'm writing an own container class and have run into a problem I can't get my head around. Here's the bare-bone sample that shows the problem. It consists of a container class and two test classes: one test class using a std:vector which compiles nicely and the second test class which tries to use my own container class in exact the same way but fails miserably to compile. #include <vector> #include <algorithm> #include <iterator> using namespace std; template <typename T> class MyContainer { public: class iterator { public: typedef iterator self_type; inline iterator() { } }; class const_iterator { public: typedef const_iterator self_type; inline const_iterator() { } }; iterator begin() { return iterator(); } const_iterator begin() const { return const_iterator(); } }; // This one compiles ok, using std::vector class TestClassVector { public: void test() { vector<int>::const_iterator I=myc.begin(); } private: vector<int> myc; }; // this one fails to compile. Why? class TestClassMyContainer { public: void test(){ MyContainer<int>::const_iterator I=myc.begin(); } private: MyContainer<int> myc; }; int main(int argc, char ** argv) { return 0; } gcc tells me: test2.C: In member function ‘void TestClassMyContainer::test()’: test2.C:51: error: conversion from ‘MyContainer::iterator’ to non-scalar type ‘MyContainer::const_iterator’ requested I'm not sure where and why the compiler wants to convert an iterator to a const_iterator for my own class but not for the STL vector class. What am I doing wrong?

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  • Pointing class property to another class with vectors

    - by jmclem
    I've got a simple class, and another class that has a property that points to the first class: #include <iostream> #include <vector> using namespace std; class first{ public: int var1; }; class second{ public: first* classvar; }; Then, i've got a void that's supposed to point "classvar" to the intended iteration of the class "first". void fill(vector<second>& sec, vector<first>& fir){ sec[0].classvar = &fir[0]; } Finally the main(). Create and fill a vector of class "first", create "second" vector, and run the fill function. int main(){ vector<first> a(1); a[0].var1 = 1000; vector<second> b(1); fill(b, a); cout << b[0].classvar.var1 << '\n'; system("PAUSE"); return 0; } This gives me the following error: 1>c:\...\main.cpp(29) : error C2228: left of '.var1' must have class/struct/union 1> type is 'first *' And I can't figure out why it reads the "classvar" as the whole vector instead of just the single instance. Should I do this cout << b[0].classvar[0].var1 << '\n'; it reads perfectly. Can anyone figure out the problem? Thanks in advance

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  • Path String Concatenation Question.

    - by Nano HE
    Hi. Please see my code below. ifstream myLibFile ("libs//%s" , line); // Compile failed here ??? I want to combine the path string and open the related file again. #include <iostream> #include <fstream> #include <string> using namespace std; int main () { string line; ifstream myfile ("libs//Config.txt"); // There are several file names listed in the COnfig.txt file line by line. if (myfile.is_open()) { while (! myfile.eof() ) { getline (myfile,line); cout << line << endl; // Read details lib files based on the each line file name. string libFileLine; ifstream myLibFile ("libs//%s" , line); // Compile failed here ??? if (myLibFile.is_open()) { while (! myLibFile.eof() ) { cout<< "success\n"; } myLibFile.close(); } } myfile.close(); } else cout << "Unable to open file"; return 0; } Assume my [Config.txt] include the content below. And all the *.txt files located in libs folder. file1.txt file2.txt file3.txt

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  • Complicated .NET factory design

    - by Tom W
    Hello SO; I'm planning to ask a fairly elaborate question that is also something of a musing here, so bear with me... I'm trying to design a factory implementation for a simulation application. The simulation will consist of different sorts of entities i.e. it is not a homogenous simulation in any respect. As a result, there will be numerous very different concrete implementations and only the very general properties will be abstracted at the top level. What I'd like to be able to do is create new simulation entities by calling a method on the model with a series of named arguments representing the parameters of the entity, and have the model infer what type of object is being described by the inbound parameters (from the names of the parameters and potentially the sequence they occur in) and call a factory method on the appropriate derived class. For example, if I pass the model a pair of parameters (Param1=5000, Param2="Bacon") I would like it to infer that the names Param1 and Param2 'belong' to the class "Blob1" and call a shared function "getBlob1" with named parameters Param1:=5000, Param2:="Bacon" whereas if I pass the model (Param1=5000, Param3=50) it would call a similar factory method for Blob2; because Param1 and Param3 in that order 'belong' to Blob2. I foresee several issues to resolve: Whether or not I can reflect on the available types with string parameter names and how to do this if it's possible Whether or not there's a neat way of doing the appropriate constructor inference from the combinatoric properties of the argument list or whether I'm going to have to bodge something to do it 'by hand'. If possible I'd like the model class to be able to accept parameters as parameters rather than as some collection of keys and values, which would require the model to expose a large number of parametrised methods at runtime without me having to code them explicitly - presumably one for every factory method available in the relevant namespace. What I'm really asking is how you'd go about implementing such a system, rather than whether or not it's fundamentally possible. I don't have the foresight or experience with .NET reflection to be able to figure out a way by myself. Hopefully this will prove an informative discussion.

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  • C++ template member specialization - is this a compiler limitation?

    - by LoudNPossiblyRight
    Is it possible to do this kind of specialization? If so, how? The specialization in question is marked //THIS SPECIALIZATION WILL NOT COMPILE I have used VS2008, VS2010, gcc 4.4.3 and neither can compile this. #include<iostream> #include<string> using namespace std; template <typename ALPHA> class klass{ public: template <typename BETA> void func(BETA B); }; template <typename ALPHA> template <typename BETA> void klass<ALPHA>::func(BETA B){ cout << "I AM A BETA FUNC: " << B <<endl; } //THIS SPECIALIZATION WILL NOT COMPILE template <typename ALPHA> template <> void klass<ALPHA>::func(string B){ cout << "I AM A SPECIAL BETA FUNC: " << B <<endl; } int main(){ klass<string> k; k.func(1); k.func("hello"); return 0; }

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  • InputManager ignores cut/copy/paste when initiated from menu

    - by Wallstreet Programmer
    I'm using the InputManager to check if changes to controls are done by user or code. This works fine, except when user uses the context menu for cut/copy/paste. If the user do ctrl+v in a textbox, InputManager correctly notices it. However, if the paste is done from the context menu of the textbox, the InputManager never fires the PreNotifyInput or PostNotifyInput events. Anyone knows why? Or how to detect that these user actions? Below is a working sample. The lower textblock never gets updated when user uses the cut/copy/paste menu in the above textbox since PreNotifyInput never fires. XAML: <Window x:Class="InputMgrDemo.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Height="300" Width="300"> <StackPanel> <TextBox TextChanged="TextBox_TextChanged" /> <TextBlock Name="_text" /> </StackPanel> </Window> Code behind: using System.Windows; using System.Windows.Controls; using System.Windows.Input; namespace InputMgrDemo { public partial class Window1 : Window { public Window1() { InitializeComponent(); InputManager.Current.PreNotifyInput += ((sender, e) => _userInput = true); InputManager.Current.PostNotifyInput += ((sender, args) => _userInput = false); } private void TextBox_TextChanged(object sender, TextChangedEventArgs e) { if (_userInput) { _text.Text = (sender as TextBox).Text; } } private bool _userInput; } }

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  • Console in VS 2012 Express for C++?

    - by Live2Code
    I'm very new to programming, so be nice. I was using Eclipse for C/C++ devs for a while, but it seemed quite buggy so I was advised to switch to Visual Studio Express. I'm just testing out with a simple "Hello World" program #include <iostream> #include <string> using namespace std; int main( int argc, char ** argv ) { string response; cout << "Gimme a string: " << flush; cin >> response; cout << "The string is: " << response << endl; system("pause"); return 0; } not much to go wrong there anyway, I noticed that there is no "console" like in Eclipse. All of the text pops up in a little command prompt window. And, also, this window closes right after displaying new text if there is no other things to do after it (like a cin). I have been told that I can use system("pause") but there has to be a better way. In Eclipse, the text would not suddenly disappear because the console window closed. i know this question might be a little confusing, comment and I'll try to explain what I'm saying. Or paste the codes into your Visual Studio 2012 Express Edition. But is there a way to display all of my text and whatever in a "console" as opposed to a command prompt-type window; and why does it always close before I can read the last thing?

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  • The program fails to display `cout` when it is run

    - by Jeff - FL
    Hello, I justed started a C++ course & I wrote, compiled, debugged & ran my first program: // This program calculates how much a little league team spent last year to purchase new baseballs. #include <iostream> using namespace std; int baseballs; int cost; int total; int main() { baseballs, cost, total; // Get the number of baseballs were purchased. cout << "How many baseballs were purchased? "; cin >> baseballs; // Get the cost of baseballs purchased. cout << "What was the cost of each baseball purchased? "; cin >> cost; // Calculate the total. total = baseballs * cost; // Display the total. cout << "The total amount spent $" << total << endl; return 0; } The only probelm that I encountered was that when I ran the program it failed to display the total amount spent (cout). Could someone please explain why? Thanks Jeff H - Sarasota, FL

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  • error: expected ',' or '...' before numeric constant

    - by goldfrapp04
    Just a Qt Gui Application with QDialog as the Base Class, the simplest type you can expect. I've programmed on Qt for several times but this is the first time I meet this problem... I've added minimal code to the program, and here's the code in dialog.h (which is mostly automatically generated) #ifndef DIALOG_H #define DIALOG_H #include <QDialog> #include <QPixmap> #include "bmp.h" namespace Ui { class Dialog; } class Dialog : public QDialog { Q_OBJECT public: explicit Dialog(QWidget *parent = 0); ~Dialog(); private slots: void on_openButton_clicked(); private: Ui::Dialog *ui; BMP srcImage; QImage compressedImage[3]; }; #endif // DIALOG_H While I edit, the "public:" is underlined and says "unexpected token '('". When I try to build the program, it says in the line "Q_OBJECT", "error: expected ',' or '...' before numeric constant". I'm sure I've defined nothing related to it (to be exact, I defined an N and an n in file bmp.h, both are int). Any idea of what's wrong here? Thanks.

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  • Is it acceptable to wrap PHP library functions solely to change the names?

    - by Carson Myers
    I'm going to be starting a fairly large PHP application this summer, on which I'll be the sole developer (so I don't have any coding conventions to conform to aside from my own). PHP 5.3 is a decent language IMO, despite the stupid namespace token. But one thing that has always bothered me about it is the standard library and its lack of a naming convention. So I'm curious, would it be seriously bad practice to wrap some of the most common standard library functions in my own functions/classes to make the names a little better? I suppose it could also add or modify some functionality in some cases, although at the moment I don't have any examples (I figure I will find ways to make them OO or make them work a little differently while I am working). If you saw a PHP developer do this, would you think "Man, this is one shoddy developer?" Additionally, I don't know much (or anything) about if/how PHP is optimized, and I know that usually PHP performace doesn't matter. But would doing something like this have a noticeable impact on the performance of my application?

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  • Why is it that an int in C++ that isnt initialized (then used) doesn't return an error?

    - by omizzle
    I am new to C++ (just starting). I come from a Java background and I was trying out the following piece of code that would sum the numbers between 1 and 10 (inclusive) and then print out the sum: /* * File: main.cpp * Author: omarestrella * * Created on June 7, 2010, 8:02 PM */ #include <cstdlib> #include <iostream> using namespace std; int main() { int sum; for(int x = 1; x <= 10; x++) { sum += x; } cout << "The sum is: " << sum << endl; return 0; } When I ran it it kept printing 32822 for the sum. I knew the answer was supposed to be 55 and realized that its print the max value for a short (32767) plus 55. Changing int sum; to int sum = 0; would work (as it should, since the variable needs to be initialized!). Why does this behavior happen, though? Why doesnt the compiler warn you about something like this? I know Java screams at you when something isnt initialized. Thank you.

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  • Specializing function templates outside class temp. definition - what is the correct way of doing t

    - by LoudNPossiblyRight
    I am attempting to specialize a function template that is a member of a template class. The two of them have different template parameters. The template function specialization inside the temp. class definition is never called and the one func. spec. outside the class definition does not even compile. Should i expect this to work in the first place, and if so, what do i have to change in this code to both compile and make it work correctly: using VS2010 #include<iostream> using namespace std; template <typename T> class klass{ public: template <typename U> void func(const U &u){ cout << "I AM A TEMPLATE FUNC" << endl; } //THIS NEVER GETS CALLED !!! template <> void klass<T>::func(const string &s){ cout << "I AM A STRING SPECIALIST" << endl; } }; //THIS SPECIALIZATION WILL NOT COMPILE !!! template <typename T> template <> void klass<T>::func(const double &s){ cout << "I AM A DOUBLE SPECIALIST" << endl; } int main(){ double d = 3.14159265; klass<int> k; k.func(1234567890); k.func("string"); k.func(3.14159265); return 0; }

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  • Multithreading using pthread in C++ with shared variables

    - by Saviour Self
    I'm new to threading (and C/C++ for that matter), and I'm attempting to use multiple threads to access shared variables. In the main, I've created a variable char inputarray[100]; Thread 1: This thread will be reading data from stdin in 2 byte bursts, and appending them to the inputarray. (input by feeding a file in) Thread 2: This thread will be reading data 1 byte at a time, performing a calculation, and putting its data into an output array. Thread 3: This thread will be outputting data from the output array in 2 byte bursts. (stdout) I've attempted the input part and got it working by passing a struct, but would like to do it without using a struct, but it has been giving me problems. If I can get input down, I'm sure I'll be able to use a similar strategy to complete output. Any help would be greatly appreciated. Below is a rough template for the input thread. #include <stdio.h> #include <pthread.h> using namespace std; void* input(void* arg) { char reading[3]; fread(reading,1,2,stdin); //append to char inputarray[]..??? } int main() { char inputarray[100]; pthread_t t1; pthread_create(&t1, NULL, &input, &inputarray); void *result; pthread_join(t1,&result); return 0; }

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