Search Results

Search found 3255 results on 131 pages for 'pointers'.

Page 86/131 | < Previous Page | 82 83 84 85 86 87 88 89 90 91 92 93  | Next Page >

• Why is the 'this' keyword not a reference type in C++ [closed]

  - by Dave Tapley

  Possible Duplicates: Why ‘this’ is a pointer and not a reference? SAFE Pointer to a pointer (well reference to a reference) in C# The this keyword in C++ gets a pointer to the object I currently am. My question is why is the type of this a pointer type and not a reference type. Are there any conditions under which the this keyword would be NULL? My immediate thought would be in a static function, but Visual C++ at least is smart enough to spot this and report static member functions do not have 'this' pointers. Is this in the standard?

  Read the article

• VB.NET custom user control graphics rotation

  - by AtharvaI

  Hi, this is my first question on here. I'm trying to build a dial control as a custom user control in VB.NET. I'm using VS2008. so far I have managed to rotate image using graphics.rotatetransform . however, this rotate everything. Now I have a Bitmap for the dial which should stay stable and another Bitmap for the needle which I need to rotate. so far i've tried this: Dim gL As Graphics = Graphics.FromImage(bmpLongNeedle) gL.TranslateTransform(bmpLongNeedle.Width / 2, bmpLongNeedle.Height * 0.74) gL.RotateTransform(angleLongNeedle) gL.TranslateTransform(-bmpLongNeedle.Width / 2, -bmpLongNeedle.Height * 0.74) gL.DrawImage(bmpLongNeedle, 0, 0) As I understand it, the image of the needle should be rotated at angle "angleLongNeedle" although i'm placing the rotated image at 0,0. However, the result is that the Needle doesn't get drawn on the control. any pointers as to where I might be going wrong or something else I should be doing? Thanks in advance

  Read the article

• In game programming are global variables bad?

  - by Joe.F

  I know my gut reaction to global variables is "badd!" but in the two game development courses I've taken at my college globals were used extensively, and now in the DirectX 9 game programming tutorial I am using (www.directxtutorial.com) I'm being told globals are okay in game programming ...? The site also recommends using only structs if you can when doing game programming to help keep things simple. I'm really confused on this issue, and all the research I've been trying to do is very confusing. I realize there are issues when using global variables (threading issues, they make code harder to maintain, the state of them is hard to track etc) but also there is a cost associated with not using globals, I'd have to pass a loooot of information around very often which can be confusing and I imagine time-costing, although I guess pointers would speed the process up (this is my first time writing a game in C++.) Anyway, I realize there is probably no "right" or "wrong" answer here since both ways work, but I want my code to be as proper as I can so any input would be good, thank you very much!

  Read the article

• Secure password transmission over unencrypted tcp/ip

  - by academicRobot

  I'm in the designing stages of a custom tcp/ip protocol for mobile client-server communication. When not required (data is not sensitive), I'd like to avoid using SSL for overhead reasons (both in handshake latency and conserving cycles). My question is, what is the best practices way of transmitting authentication information over an unencrypted connection? Currently, I'm liking SRP or J-PAKE (they generate secure session tokens, are hash/salt friendly, and allow kicking into TLS when necessary), which I believe are both implemented in OpenSSL. However, I am a bit wary since I don't see many people using these algorithms for this purpose. Would also appreciate pointers to any materials discussing this topic in general, since I had trouble finding any.

  Read the article

• Drawing rubber band line during user drag

  - by Pete W

  In my iPhone app, I would like the user to be able to "connect" two of my views by: 1) starting a drag in View A 2) as they drag towards View B, a straight line with one end in View A and the other end under at the current drag point, animates in a rubber-band fashion 3) when/if they release in View B, the line is then shown between the two views I've seen examples of dragging and dropping views, and other examples of animations, but I haven't seen one that is a simple example of this kind of user-directed animation. Any pointers towards examples or the specific docs I should be looking at would be appreciated. If this turns out to be trivial - my apologies. Although I've done quite a bit of development, I'm just getting started in the iPhone SDK and Core Graphics.

  Read the article

• How to write syntax highlighting? c++

  - by ML

  Hi All, I am embarking on some learning and I want to write my own syntax highlighting for files in C++. Can anyone give me ideas on how to go about doing this? To me it seems that when a file is opened: 1. it would need to be parsed and decided what type of source file it is. Trusting the extension might not be full-proof a way to know what keywords/commands apply to what language a way to decide what color each keyword/command gets I want to do this on OS X, C++ or Objective-C Can anyone provide pointers on how I might get started with this?

  Read the article

• Linq to NHibernate - How to return a parent object with only certain child objects included

  - by vakman

  Given a simplified model like the following: public class Enquiry { public virtual DateTime Created { get; set; } public virtual Sender Sender { get; set; } } public class Sender { public virtual IList<Enquiry> Enquiries { get; set; } } How can you construct a Linq to Nhibernate query such that it gives you back a list of senders and their enquiries where the enquiries meet some criteria. I have tried something like this: return session.Linq<Enquiry>() .Where(enquiry => enquiry.Created < DateTime.Now) .Select(enquiry => enquiry.Sender) In this case I get an InvalidCastException saying you can't cast type Sender to type Enquiry. Any pointers on how I can do this without using HQL?

  Read the article

• "Winamp style" spectrum analyzer

  - by cvb

  I have a program that plots the spectrum analysis (Amp/Freq) of a signal, which is preety much the DFT converted to polar. However, this is not exactly the sort of graph that, say, winamp (right at the top-left corner), or effectively any other audio software plots. I am not really sure what is this sort of graph called (if it has a distinct name at all), so I am not sure what to look for. I am preety positive about the frequency axis being base two exponential, the amplitude axis puzzles me though. Any pointers?

  Read the article

• How to implement an abstract class in ruby?

  - by Chirantan

  I know there is no concept of abstract class in ruby. But if at all it needs to be implemented, how to go about it? I tried something like... class A def self.new raise 'Doh! You are trying to instantiate an abstract class!' end end class B < A ... ... end But when I try to instantiate B, it is internally going to call A.new which is going to raise the exception. Also, modules cannot be instantiated but they cannot be inherited too. making the new method private will also not work. Any pointers?

  Read the article

• Single page app with high number of images working extremely slow on iOS8 safari/Webview

  - by NikhilWanpal

  We are working on a WebView (not WKWebView, yet) app, are are observing that the app runs extremely slow on iOS 8. The same app runs smooth on lower versions of OS like iOS7 and iOS6. So we tried it in safari on iOS8 and the performance is similar to iOS6 and 7. The app is filled with images and many are high resolution. While trying to trace the issue (trial and error!) we reduced the sizes and resolutions of the images and the performance improved, but it is still not at par with versions 6 and 7. We are unable to find any such issues reported elsewhere and are stuck. It would be great if we could get some pointers on this one.

  Read the article

• Rails: Ajax-enabled form without a model object

  - by Caffeine Coma

  I'm new to Rails and having a hard time figuring out how to create a form that submits over Ajax without having a corresponding model object. My use case is a simple form that collects an email address and sends it an email; there's nothing to be persisted, so no model. In cases where I do have a model, I've had success with form_for(@model, remote: true). I can't seem to find the right helper for the case where there is no model. I tried form_tag(named_path, remote: true) and that works, but does not use Ajax. Pointers to an example with an example with a proper controller, .html.erb and routes.rb would be really appreciated.

  Read the article

• What is the best way to organize Java code since you can't pass by reference?

  - by Adam

  I'm learning how to code in Java after after coming from C. In C I always separated everything into individual functions to make the code easier to follow and edit. I was trying to do this in java but now since I realized that you can't use pointers, I am a bit confused as to what the best way to do this is. So for example I want to have a method that creates four alerts for me. So I pass it an alert builder that can then create the alerts. I can return them in an array, but in my code I already have the alerts individually named, and I would like to keep it that way so I wouldn't need to refer to them as alert[1], alert[2]... etc. So that means I would have to rename them, which would add additional code which would probably be longer than the code in the actual method! Am I thinking about this the right way? Is there anything I can do?

  Read the article

• malloc hangs in Linux

  - by Rahul

  I am using Linux on a 16 G with 2 quad core CPU. There are 8 processes which are doing some work (CPU intensive/network i/o). Out of which 4 have a memory leak (These are test conditions so no problem in having leaks here). Total space is occupied by all processes is around 15.4 G only 200 MB is free in system. Things are fine for some hours. But after that malloc hangs (for a process which doesn't have a memory leak). Its stuck for for more than 4 minutes (Note CPU is not 100% but io has gone up signficantly). Now there is no problem in the hanged process. (It has not corrupted the memory). What malloc is doing? (is it tryibg to defragment or builidng up swap space).I am using SUSE 10. Any pointers?

  Read the article

• Simple wrapping of C code with cython

  - by Jose

  Hi, I have a number of C functions, and I would like to call them from python. cython seems to be the way to go, but I can't really find an example of how exactly this is done. My C function looks like this: void calculate_daily ( char *db_name, int grid_id, int year, double *dtmp, double *dtmn, double *dtmx, double *dprec, double *ddtr, double *dayl, double *dpet, double *dpar ) ; All I want to do is to specify the first three parameters (a string and two integers), and recover 8 numpy arrays (or python lists. All the double arrays have N elements). My code assumes that the pointers are pointing to an already allocated chunk of memory. Also, the produced C code ought to link to some external libraries.

  Read the article

• How do I output an individual character when using char *[] = "something"

  - by Matt

  I've been playing with pointers to better understand them and I came across something I think I should be able to do, but can't sort out how. The code below works fine - I can output "a", "dog", "socks", and "pants" - but what if I wanted to just output the 'o' from "socks"? How would I do that? char *mars[4] = { "a", "dog", "sock", "pants" }; for ( int counter = 0; counter < 4; counter++ ) { cout << mars[ counter ]; } Please forgive me if the question is answered somewhere - there are 30+ pages of C++ pointer related question, and I spent about 90 minutes looking through them, as well as reading various (very informative) articles, before deciding to ask.

  Read the article

• Suggested C++ books?

  - by Josh Bradley

  Ok, I've had one semester of C++ and will be taking a second semester in it after I have taken a Data Structure class this fall. In the first class, we dealt mainly with C++ syntax and the textbook we used was ok, but now I'm wanting to go ahead and purchase a great C++ book that encompasses a lot of the programming concepts used today. I'm learning Objective-C on my own and was able to get through the whole object-oriented stuff pretty easily, along with other things like pointers, inheritance, delegation, etc. It doesn't have to exactly have EVERYTHING in it, but I do want to buy the book with the most information in it. Money is no problem. So my question is what book did you use or still use for C++? Is it a book that you can reference back to if you ever forget how to do something small, or would you have to go online and find the answer.

  Read the article

• Regex - Format with tabs and alphabetical

  - by Sam

  Is it possible to use regex to turn this <site-ui:header title="error" backURL="javascript:history.go(-1);" /> into this <site-ui:header backURL="javascript:history.go(-1);" title="error" /> Basically, my goal is to format this xml so that the fields are in alphabetical order (e.g. backURL comes before title), and each field should be tabbed two spaces. If this can be done, any pointers would be really helpful! Even more helpful is an exact regex for vim.

  Read the article

• weird access denied issue with WMI

  - by stackunderflow1

  I'm seeing a weird access denied issue with WMI. we're trying to create a diff disk based on a parent vhd in a windows service app that runs under network service (machine account is an admin). everything works fine when we create the diff disk on other machine using wmi - we use an admin user account. however, we cannot do this on a local machine as wmi doesn't take user cred for the local machine. so thought network service account already should have access for this, it seems like it doesn't and even if we run the service under an admin service account, it fails. any pointers???

  Read the article

• New to Drupal -- how should I create a main page with a mix of dynamic and static content?

  - by Erode

  I apologize for the terribly basic question but I'm not even a particularly adept web dev. I've read that Drupal is great if you know exactly what you want to do (then the API is handy) but I don't even know what I need yet. That is what I am hoping to gain from this discussion. I want a main content page which has a fancy content slider (using jQuery or something) which will be a selector for showing some basic information on these 2 or 3 subjects. I'm stuck on where I should be writing this mix of markup. In the template? Create "content" through a content type? Since there's a fair share of CSS and markup required to do this, I don't know if I can do that through the "basic page" content type that was there. I'm looking for pointers that can teach me how I would become aware of what Drupal can and can not do. Thanks for reading, let me know if I need to clarify anything.

  Read the article

• std::string constructor corrupts pointer

  - by computergeek6

  I have an Entity class, which contains 3 pointers: m_rigidBody, m_entity, and m_parent. Somewhere in Entity::setModel(std::string model), it's crashing. Apparently, this is caused by bad data in m_entity. The weird thing is that I nulled it in the constructor and haven't touched it since then. I debugged it and put a watchpoint on it, and it comes up that the m_entity member is being changed in the constructor for std::string that's being called while converting a const char* into an std::string for the setModel call. I'm running on a Mac, if that helps (I think I remember some problem with std::string on the Mac). Any ideas about what's going on?

  Read the article

• Reliably converting C preprocessor macros to python code

  - by manual-manuel

  Hi, I have a bunch of C macros the operation of which I need to simulate in python. I saw some pointers to pygccxml or ctypeslib etc. Are these the ways to go ? Or is there something out there that is better ? The C macros if and when they change, I would like the python implementation to be auto generated rather than having to make manual modifications. Hence the question. <my_c_header.h> /* #defines type 1 */ #ifdef OS #define NUM_FLAGS (uint16_t)(3) #define NUM_BITS (uint16_t)(8) #else #define NUM_FLAGS (uint16_t)(6) #define NUM_BITS (uint16_t)(16) #endif #define MAKE_SUB_FLAGS (uint16_t)((1<<NUMFLAGS) -1) #define MAKE_TOTAL_FLAGS(x) (uint16_t)((x & MAKE_SUB_FLAGS) >> NUM_BITS) /* #defines type 2 */ #ifdef OS #DO_SOMETHING(X) os_specifc_process(x) #else #DO_SOMETHING(x) #endif /* #defines type 3 */ enum { CASE0, CASE1, CASE2 } #define MY_CASE_0 ((uint16_t)CASE0) #define MY_CASE_1 ((uint16_t)CASE1) #define MY_CASE_2 ((uint16_t)CASE2) #define /*End of file <my_c_header.h> */ Thanks M

  Read the article

• How to create an iPad directory view like animation?

  - by mahes25

  In the recent iOS 4.2 update, Apple introduced a nice animation for creating one level directories. I am trying to figure out how to implement a similar animation in my project. I would deeply appreciate it if anyone could give me any pointers to do this efficiently. From my investigation, I believe this animation or effect could be done very efficiently using Core Image which would allow me to write a custom filter. Unfortunately, Core Image is not available in iPhone. So how can do it? I read a blog post that explained a core animation scheme to create an iPad flip clock. The problem I have is similar but has important differences. Besides, I not excited about saving the subimage combinations, which I believe can cause a memory issue. Please enlighten me on the possible ways of doing this animation. I am relatively new to iOS programming, so I might have missed obvious ways of doing this animation or effect.

  Read the article

• How do you mentally handle going from writing managed to non-managed code?

  - by Glenn Sandoval

  ~80% of the code I write is in C#. The other ~20% is in C++. Whenever I have to switch from C# to C++, it takes me quite a while to mentally "shift gears" to thinking in C++. I make simple mistakes using pointers and memory allocation that I would not have made when I was in university. Is this normal? Does anyone else experience something similar and if so, what do you do to cut down on the time this wastes?

  Read the article

• Tomcat application: Frequent OutOfMemory PermGen exception while image uploads

  - by rabbit

  Hi, I have a tomcat 6 application which I have set parameters of -Xms512m -Xmx1024m. I thought 1 GB of memory in a 4 GB RAM would be enough, but that is not the case. On application stop/start multiple times (from tomcat manager) and also on image uploads (sometimes) I run into the OutOfMemory PermGen space error and the site stops responding. Should I increase the memory still some more? Is there anything else that I can do to from the tomcat side so that it does not run into the PermGen space issue? Thanks in advance for pointers/tips etc.

  Read the article

• Passing an object as a parameter to a windows service

  - by user220723

  Is there some way to pass an object to a windows service? I know the method myServiceController.Star(string[] arg) but i need to pass a more complex object than a string array. Actually, i don't need the object to be passed as a parameter, what i really needs is that the service can use an object created in a windows forms application. I've tried using System.Web.Script.Serialization.JavaScriptSerializer.Serialize method to convert the object into a Json but i couldn't because the object contains a circular reference. I also tried using pointers, but i couldn't becouse it is a managed type object. Any idea what can i do?

  Read the article

< Previous Page | 82 83 84 85 86 87 88 89 90 91 92 93  | Next Page >