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  • How To Draw line on touch event ?

    - by AJPatel
    Hey i m beginner of objective C Please Help me i make following code but not work..... -(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; if ([touch view] == self.view) { CGPoint location = [touch locationInView:self.view]; loc1 = location; CGContextMoveToPoint(context, location.x, location.y); NSLog(@"x:%d y:%d At Touch Begain", loc1.x, loc1.y); } } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; if ([touch view] == self.view) { CGPoint location = [touch locationInView:self.view]; CGContextMoveToPoint(context, loc1.x, loc1.y); NSLog(@"x:%d y:%d At Touch Move", loc1.x, loc1.y); CGContextAddLineToPoint(context, location.x, location.y); NSLog(@"x:%d y:%d", location.x, location.y); } }

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  • When convert a void pointer to a specific type pointer, which casting symbol is better, static_cast or reinterpret_cast?

    - by BugCreater
    A beginner question with poor English: Here I got a void* param and want to cast(or change) it to a specific type. But I don't know which "casting symbol" to use. Either**static_cast** and reinterpret_cast works. I want to know which one is better? which one does the Standard C++ recommend? typedef struct { int a; }A, *PA; int foo(void* a) // the real type of a is A* { A* pA = static_cast<A*>(a); // or A* pA = reinterpret_cast<A*>(a);? cout<<pA->a<<endl; return 0; } Here I use A* pA = static_cast(a); or A* pA = reinterpret_cast(a); is more proper?

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  • Calling C++ function from C.

    - by claws
    I know this. Calling C function from C++: If my application was in C++ and I had to call functions from a library written in C. Then I would have used //main.cpp extern "C" void C_library_function(int x, int y);//prototype C_library_function(2,4);// directly using it. This wouldn't mangle the name C_library_function and linker would find the same name in its input *.lib files and problem is solved. Calling C++ function from C??? But here I'm extending a large application which is written in C and I need to use a library which is written in C++. Name mangling of C++ is causing trouble here. Well I cannot use C++ compiler over my C project because thats breaking lot of other stuff. What is the way out? By the way I'm using MSVC

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  • Getting 'choice' to work in Highline Ruby Gem without error and getting variable from it

    - by The Warm Jets
    I'm having a couple of problems using Highline in Ruby, and trying to get the choice element, detailed here, to work. At the moment the following code produces the error "error: wrong number of arguments (0 for 1). Use --trace to view backtrace" How do I get the variable out of choice? At the moment I have the 'do' setup, but I have no idea about how to get the variable the user has chosen out and into a variable for use elsewhere. Sorry if this is a bit beginner, I'm brand new to ruby and this is my first project, in at the deep end. Thanks in advance. if agree("Are these files going to be part of a set? ") set_title = ask("Title: ") set_desc = ask("Description:") set_genre = ask("Genre: ") set_label = ask("Record Label: ") set_date = ask_for_date("Release Date (yy-mm-dd): ") set_label = ask("EAN/UPC: ") set_buy = ask("Buy this set link: ") set_tags = ask_for_array("Tags (seperated by space): ") # Sort out license choose do |menu| menu.prompt = "Please choose the license for this set? " menu.choices(:all_rights_reserved, :cc_by) do # put the stuff in a variable end end end # End setup set

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  • QConnect find no such slot on QCombobox by Qt Creater

    - by user2534154
    I create a window inherit from QWidget I set grid layout to that Window I make a function called handleHeroChange(int index) in public slot inside that window I add a Qcombobox to call that function handleHeroChange(int index). Qtcreator keep telling: QObject::connect: No such slot QWidget::handleHeroChange(int) in ../Testing/Window.cpp:92 Why did i do wrong? THE CODE: Window::Window(QWidget *parent) : QWidget(parent) { QGridLayout *grid = new QGridLayout(this); QComboBox *comboHeroClass = new QComboBox(); comboHeroClass->addItem("Witcher"); comboHeroClass->addItem("Maurander"); comboHeroClass->setCurrentIndex(1); grid->addWidget(comboHeroClass, 2,3,1,1); QComboBox::connect(comboHeroClass, SIGNAL(currentIndexChanged(int)),this, SLOT(handleHeroChange(int))); } void Window::handleHeroChange(int index){ QPixmap myImage; if(index == 0){ }else if(index == 1){ } }

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  • g++: how to specify preference of library path?

    - by Heinrich Schmetterling
    I'm compiling a c++ program using g++ and ld. I have a .so library I want to be used during linking. However, a library of the same name exists in /usr/local/lib, and ld is choosing that library over the one I'm directly specifying. How can I fix this? For the examples below, my library file is /my/dir/libfoo.so.0. Things I've tried that don't work: my g++ command is "g++ -g -Wall -o my_binary -L/my/dir -lfoo bar.cpp" adding /my/dir to the beginning or end of my $PATH env variable adding /my/dir/libfoo.so.0 as an argument to g++ Thanks.

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  • a macro question for c language (#define)

    - by Daniel
    I am reading source code of hoard memory allocator, and in the file of gnuwrapper.cpp, there are the following code #define CUSTOM_MALLOC(x) CUSTOM_PREFIX(malloc)(x) What's the meaning of CUSTOM_PREFIX(malloc)(x)? is CUSTOM_PREFIX a function? But as a function it didn't defined anywhere. If it's variable, then how can we use variable like var(malloc)(x)? more code: #ifndef __GNUC__ #error "This file requires the GNU compiler." #endif #include <string.h> #include <stdlib.h> #include <stdio.h> #include <malloc.h> #ifndef CUSTOM_PREFIX ==> here looks like it's a variable, so if it doesn't define, then define here. #define CUSTOM_PREFIX #endif #define CUSTOM_MALLOC(x) CUSTOM_PREFIX(malloc)(x) ===> what's the meaning of this? #define CUSTOM_FREE(x) CUSTOM_PREFIX(free)(x) #define CUSTOM_REALLOC(x,y) CUSTOM_PREFIX(realloc)(x,y) #define CUSTOM_MEMALIGN(x,y) CUSTOM_PREFIX(memalign)(x,y)

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  • [ADVICE] .NET Desktop Application - Client Server C#, SQL

    - by Rillanon
    Hi guys, Recently I've being given a chance to develop a PMS (Practice Management System) software for a small physiotherapy clinic. I'm a computer science student and my course is predominately told on Linux. However, my client runs all their computers on vista or Windows 7. My ideas are to develop the client front end in Visual C# and access a central postgresql server. I'm a beginner in Windows Programming so I'm after advice on best practice on implement user rights and access levels in C# (WPF or Windows FORM). I've had a look into Credential class in Visual C# and access control list but please share your thoughts. I'm probably way over my head on this but this is my first commercial project so I'm keen to test the waters. Cheers Ian

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  • Class templating std::set key types

    - by TomFLuff
    I have a class to evaluate set algebra but wish to template it. At the minute it looks a bit like this set.h: template<typename T> class SetEvaluation { public: SetEvaluation<T>(); std::set<T> evaluate(std::string in_expression); } set.cpp template<typename T> std::set<T> SetEvaluation<T>::evaluate(std::string expression) { std::set<T> result; etc etc... } But i'm getting undefined reference errors when compiling. Is it possible to declare the return type as std::set<T> and then pass std::string as the class template param. There are no errors in the class but only when I try to instantiate SetEvaluation<std::string> Can anyone shed light on this problem? thanks

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  • C# Object Array CopyTo links both arrays' values?

    - by Dutchie432
    Okay, I have what I think is a simple question.. or just a case of me being a C# beginner. I have an array of custom objects (clsScriptItem) that I am populating from a database. Once the items are loaded, I want to back them up to "backup" array so I can revert the information back after changing the main array. However, when I use CopyTo to copy the array and then alter the original array, the backup array is also being altered... I though CopyTo merely copied values + structure from one array to another. private void backupItems() { lastSavedItems = new clsScriptItem[items.Length]; items.CopyTo(lastSavedItems, 0); //items[0].nexts[0] is 2 //lastSavedItems[0].nexts[0] is 2 items[0].nexts[0] = "-1"; //items[0].nexts[0] is -1 //lastSavedItems[0].nexts[0] is also -1 } How do I backup this data without having the two arrays be 'linked'??

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  • Compiling without setting up a project in NetBeans or Visual Studio

    - by aLostMonkey
    Hi, In short: is there a way to compile and run single file in NetBeans or Visual Studio without having to setup and tinker with projects? I'm currently using code::blocks as my IDE. It's fast and very simple: perfect for my needs as a begginner. I wanted to dive a little deeper and try out a more advanced IDE such as NetBeans or Visual Studio. It appears I have to mess with projects and have a setup that seems overkill for having to compile and run one very simple .c/.cpp source file that contains less than 50-100 lines of code etc. Is there a way around this?

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  • Compilation failing - no #include - boost

    - by jwoolard
    Hi, I'm trying to compile a third-party library, but g++ is complaining about the following line: typedef boost::shared_ptr<MessageConsumer> MessageConsumerPtr; The strange thing is, there is no #include directive in the file - and it is clearly supposed to be this way; there are about 60 files with the same (or very similar) issues. Clearly if there was an #include directive referencing the relevant boost header this would compile cleanly. My question is: how can I get g++ to somehow automagically find the relevant symbol (in all instances of this issue, it is a namespace that can't be found - usually std:: or boost::) by either automatically processing the relevant header (or some other mechanism). Thanks. Edit My current g++ call looks like: g++ -fPIC -O3 -DUSING_PCH -D_REENTRANT -I/usr/include/boost -I./ -c MessageInterpreter.cpp -o MessageInterpreter.o

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  • (database) im trying to create a form in access 2007 with 2 drop down boxes to view a report by state or name

    - by jeff orris
    im an intern at a database mngmt company and the boss is training me in access...i took the access tutorials and were definitely not enough info involved to do a what seems a simple task.my problem is this: i have a simple table with contact info with 16 colums (Local_Utility, Requested_User_Type, First_Name, Last_Name, Address 1, Address 2, Country, State, City, Zip, Phone_Number, Username\Email, Password, Confirm Password, and Parcel_Number), with 6 rows of names (keep in mind this is just a test to help me from the boss) I created a form and with 2 drop down boxes (Last Name and State) and im trying to create a view button to view an individual report for a query i made for just simple contact info with 6 colums (Last_Name, First_Name, Address1, City, State, and Phone_Number) Problem1 is that i can view the query with the view by name or state button but cant view a simple individual report from the query using the button Problem2 is that for criteria on the query i put Forms!frmMyparamForm!txtMyStateParamField for the state drop box it works, but when i use Forms!frmMyparamForm!txtMyNameParamField it doesnt and that annoying parameter box pops up Problem3 is that after i close the query, all the states and names in my dropdown box on the form disappear Im a beginner at this please help me

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  • NetBeans/C++ - how to choose the "main file" other than when creating a project?

    - by Petike
    Hello, when I am creating a C++ project in NetBeans, there is a toggle button "Create main file" - I just enter a name for it and that's all. The problem is that I cannot put that file in a "different" folder than right in the main project folder. And I am "used" to put all the source files in a "src" folder (and its subfolders), but at the "project creation time" I "cannot" put the main file there. So I tried "not" to create the main file at project creation, but after that create manually the "src" file and then create a "cpp" file in that folder (this is "allowed" in NetBeans). But NetBeans could not find "which" is the main file. So how can I choose the main file other than when creating a project (if it is possible)?

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  • C++ Static Array Initialization - Memory Issue

    - by donalmg
    Hi, I have a header file which contains a member variable declaration of a static char array: class ABC { public: static char newArray[4]; // other variables / functions private: void setArray(int i, char * ptr); } In the CPP file, I have the array initialized to NULL: char ABC::newArray[4] = {0}; In the ABC constructor, I need to overwrite this value with a value constructed at runtime, such as the encoding of an integer: ABC::ABC() { int i; //some int value defined at runtime memset(newArray, 0, 4); // not sure if this is necessary setArray(i,newArray); } ... void setArray(int i, char * value) { // encoding i to set value[0] ... value [3] } When I return from this function, and print the modified newArray value, it prints out many more characters than the 4 specified in the array declaration. Any ideas why this is the case. I just want to set the char array to 4 characters and nothing further. Thanks...

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  • How to use default.ctp in cakephp

    - by Louis Stephens
    I just finished the "15 min Blog Post tutorial" included in the documentation for cakephp. I was asked for another tutorial to change the layout for first tutorial. However, I am fairly new to MVC programming/Cakephp and I have no real clue how to do so. Well, I know I need "default.ctp" placed in app/views/layouts/ and I presume I need to include to include my data? . . . I am really at a loss of what to do. I set up my default.ctp as I mentioned above, but when I go to localhost:9999/posts the layout is still the same. I guess I need to include a stylesheet (and if so, where?) I guess if someone can point me in the right direction to a beginner's guide to layout styling or how to use it I would greatly appreciate any help.

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  • I'm making a resume...what would you consider as intermediate python programming skills?

    - by user285884
    I've made a couple of scripts. One is a stock screener that can search through every stock. Another creates a heatmap that tells you what's performed well and badly over the past day. They aren't really that useful, just did them to work on my programming skills. I was able to throw some SQL in my scripts too. Would you call that intermediate? Thanks? How do you guys list your programming skills on your resume? Maybe there's a better way of putting it on my resume than "intermediate" or "beginner."

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  • Two phase Construction in C++

    - by tommieb75
    I have as part of assignment to look into a development kit that uses the "two-phase" construction for C++ classes: // Include Header class someFubar{ public: someFubar(); bool Construction(void); ~someFubar(); private: fooObject _fooObj; } In the source // someFubar.cpp someFubar::someFubar : _fooObj(null){ } bool someFubar::Construction(void){ bool rv = false; this->_fooObj = new fooObject(); if (this->_fooObj != null) rv = true; return rv; } someFubar::~someFubar(){ if (this->_fooObj != null) delete this->_fooObj; } Why would this "two-phase" be used and what benefits are there? Why not just instantiate the object initialization within the actual constructor?

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  • How to set the focus on the first <select> element of the page using JQuery?

    - by user605660
    Hi. I would like to set the focus on the first element of the page using JQuery when the page is loaded. I could successfully set the focus for first element by using $(":input:visible:first").focus(); or $(':input:enabled:visible:first').focus(); , according to jquery, set focus on the first enabled input or select or textarea on the page . I tried to use something like $('select:first').focus(); or $("select").first().focus(); or $(':visible:first').focus(); or $('enabled:visible:first').focus(); or other variations I could think of, but have not succeeded. Could anyone help me on this problem? I am a beginner for JQuery. I would like this function to work for all major browsers. Thank you very much!

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  • Grouped table with image in first row (and section), the remaining ones having text with different l

    - by Structurer
    Hi I have a grouped table with two sections where I display text with different length and therefore cell height. I have solved the problem with the different length/height with constrainedToSize in cellForRowAtIndexPath. Now I want to add a section with one single row in which I want to show a picture. How should I best implement that? (still a bit of a beginner with the Objective C) I would guess that I would have to create an UIImageView and somehow link that to the cell, but my biggest concern is how do I do with the dequeueReusableCellWithIdentifier now that I will have two different type of cells? Appreciate any advice that will help me save time from trial and error!

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  • How much Java should I have learnt before trying Android programming?

    - by Sidney Yin
    Hi - I have been seeking beginner learning books in Android, and of course found out that I should learn Java first. So I began studying Java and now I am quite comfortable with objects, classes, inheritance, interfaces, and just moved onto Layouts in Swing as well as Swing Features. But I am starting to wonder.... do I know enough about Java now? Can I start programming Android yet? Of course I can keep going in Java, but have been itching to begin programming Android apps. Any definitive answer here about how much Java I need to know before Android? Thanks so much!

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  • Can't figure out what's wrong with my php/sql statement

    - by Olegious
    So this is probably a dumb beginner question, but I've been looking at it and can't figure it out. A bit of background: just practicing making a web app, a form on page 1 takes in some values from the user, posts them to the next page which contains the code to connect to the DB and populate the relevant tables. I establish the DB connection successfully, here's the code that contains the query: $conn->query("SET NAMES 'utf9'"); $query_str = "INSERT INTO 'qa'.'users' ('id', 'user_name','password' ,'email' ,'dob' ,'sx') VALUES (NULL, $username, $password, $email, $dob, $sx);"; $result = @$conn->query($query_str); Here's the error that is returned:Insert query failed: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''qa'.'users' ('id', 'user_name' ,'password' ,'email' ,'dob' ,'s' at line 1 Thanks in advance!

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  • Are unspecified and undefined behavior required to be consistent between compiles?

    - by sharptooth
    Let's pretend my program contains a specific construct the C++ Standard states to be unspecified behavior. This basically means the implementation has to do something reasonable but is allowed not to document it. But is the implementation required to produce the same behavior every time it compiles a specific construct with unspecified behavior or is it allowed to produce different behavior in different compiles? What about undefined behavior? Let's pretend my program contains a construct that is UB according to the Standard. The implementation is allowed to exhibit any behavior. But can this behavior differ between compiles of the same program on the same compiler with same settings in the same environment? In other words, if I dereference a null pointer on line 78 in file X.cpp and the implementation formats the drive in such case does it mean that it will do the same after the program is recompiled?

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  • Android app display different blocks of text using the same views.

    - by user465131
    I am sure there is a better way to do what I am doing in my apps. The current one I am trying to improve is a list of military cadences. The way I am doing it now is by loading html files in a web view. What I would like to be able to do is have one view set up and just be able to add the text portion of what I would be displaying with the html file. What would be the best method. I know this is probably a pretty simple thing to do with a sting or array but I am at the very beginner level and would need to be pointed in the right direction to do it.

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  • The pImpl idiom and Testability

    - by Rimo
    The pImpl idiom in c++ aims to hide the implementation details (=private members) of a class from the users of that class. However it also hides some of the dependencies of that class which is usually regarded bad from a testing point of view. For example if class A hides its implementation details in Class AImpl which is only accessible from A.cpp and AImpl depends on a lot of other classes, it becomes very difficult to unit test class A since the testing framework has no access to the methods of AImpl and also no way to inject dependency into AImpl. This has been a problem for me lately and I am beginning to think that the pImpl idiom and writing testable code don't mix well. Has anyone come across this problem before? and have you found a solution?

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