Search Results

Search found 7722 results on 309 pages for 'pitfalls to avoid'.

Page 200/309 | < Previous Page | 196 197 198 199 200 201 202 203 204 205 206 207  | Next Page >

• Why does C++ linking use virtually no CPU? (updated)

  - by John

  On a native C++ project, linking right now can take a minute or two, yet during this time CPU drops from 100% during compilation to virtually zero. Does this mean linking is primarily a disk activity? If so, is this the main area an SSD would make big changes? But, why aren't all my OBJ files (or as many as possible) kept in RAM after compilation to avoid this? With 4Gb of RAM I should be able to save a lot of disk access and make it CPU-bound again, no? update: so the obvious follow-up is, can VC++ compiler and linker talk together better to streamline things and keep OBJ files in memory, similar to how Delphi does?

  Read the article

• In few words, what can be said about Func<>

  - by Richard77

  Hello, I've been seing Func< for sometime now, and I've manage to avoid it (for now). But, now it looks like I can't dodge it forever. For instance, I tried Dynamic Linq, but almost everything was in terms of Func<. I've tried one of my book (C# 2008/Deitel&Deitel) and also MSDN but I'm not getting it yet. They all jump straight in the subject. What can be said (in few words) about Func< Can I get some links on the web that can get me started on that matter? Thanks for helping

  Read the article

• Long key press handling in android 1.5

  - by Kaillash

  Hi, I want to handle key press and long key press for the key code KEYCODE_BACK(back button). can any one suggest me how to do this in android 1.5(API level 3). Here is the code. public boolean onKeyDown(int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_BACK) { if(event.getRepeatCount()==0) { // normal key press // But problem is, this code is hitting for long press also, how to avoid this } else { // Long key press //Do something here } // Always consume back key event by returning true //so that default behavior of back is overrided return true; } return super.onKeyDown(keyCode, event); }

  Read the article

• Alternative to singleton for unique resources

  - by user1320881

  I keep reading over and over again that one should avoid using singletons for various reasons. I'm wondering how to correctly handle a situation where a class represents a unique system resource. For example, a AudioOutput class using SDL. Since SDL_OpenAudio can only be open once at a time it makes no sense having more then one object of this type and it seems to me preventing accidentally making more then one object would actually be good. Just wondering what experienced programmers think about this, am i missing another option ?

  Read the article

• Makefile rule depending on change of number of files instead of change in content of files.

  - by goathens

  I'm using a makefile to automate some document generation. I have several documents in a directory, and one of my makefile rules will generate an index page of those files. The list of files itself is loaded on the fly using list := $(shell ls documents/*.txt) so I don't have to bother manually editing the makefile every time I add a document. Naturally, I want the index-generation rule to trigger when number/title of files in the documents directory changes, but I don't know how to set up the prerequisites to work in this way. I could use .PHONY or something similar to force the index-generation to run all the time, but I'd rather not waste the cycles. I tried piping ls to a file list.txt and using that as a prerequisite for my index-generation rule, but that would require either editing list.txt manually (trying to avoid it), or auto-generating it in the makefile (this changes the creation time, so I can't use list.txt in the prerequisite because it would trigger the rule every time).

  Read the article

• How can I load an MP3 or similar music file for display and anaysis in wxWdigets?

  - by Jon Cage

  I'm developing a GUI in wxPython which allows a user to generate sequences of colours for some toys I'm building. Part of the program needs to load an MP3 (and potentially other formats further down the line) and display it to the user. That shuold be sufficient to get started but later I'd like to add features like identifying beats and some crude frequency analysis. Is there any simple way of loading / understanding an MP3's contents to display a plot of it's amplitudes to the screen using wxWidgets? I later intend to port to C++/wxWidgets for speed and to avoid having to distribute wxPython.

  Read the article

• What is the difference between panic and an assert?

  - by acidzombie24

  Go doesn't provide assertions. They are undeniably convenient, but our experience has been that programmers use them as a crutch to avoid thinking about proper error handling and reporting. However it has print and println which does panic like print, aborts execution after printing panicln like println, aborts execution after printing Isnt that the same thing as an assert? Why would they claim the above but have panic? i can see it leading to the same problems but adding an error msg to the end of it which can easily be abused. Am i missing something?

  Read the article

• oracle call stored procedure inside select

  - by CC

  Hi everybody. I'm working on a query (a SELECT) and I need to insert the result of this one in a table. Before doing the insert I have some checking to do, and if all columns are valid, I will do the insert. The checking is done in a stored procedure. The same procedure is used somewhere else too. So I'm thinking using the same procedure to do my checks. The procedure does the checkings and insert the values is all OK. I tryied to call the procedure inside my SELECT but it does not works. SELECT field1, field2, myproc(field1, field2) from MYTABLE. This kind of code does not works. I think it can be done using a cursor, but I would like to avoid the cursors. I'm looking for the easiest solution. Anybody, any idea ? Thanks alot. C.C.

  Read the article

• Do I have to hash twice in C#?

  - by Joe H

  I have code like the following: class MyClass { string Name; int NewInfo; } List<MyClass> newInfo = .... // initialize list with some values Dictionary<string, int> myDict = .... // initialize dictionary with some values foreach(var item in newInfo) { if(myDict.ContainsKey(item.Name)) // 'A' I hash the first time here myDict[item.Name] += item.NewInfo // 'B' I hash the second (and third?) time here else myDict.Add(item.Name, item.NewInfo); } Is there any way to avoid doing two lookups in the Dictionary -- the first time to see if contains an entry, and the second time to update the value? There may even be two hash lookups on line 'B' -- one to get the int value and another to update it.

  Read the article

• Sharing base object with inheritance

  - by max

  I have class Base. I'd like to extend its functionality in a class Derived. I was planning to write: class Derived(Base): def __init__(self, base_arg1, base_arg2, derived_arg1, derived_arg2): super().__init__(base_arg1, base_arg2) # ... def derived_method1(self): # ... Sometimes I already have a Base instance, and I want to create a Derived instance based on it, i.e., a Derived instance that shares the Base object (doesn't re-create it from scratch). I thought I could write a static method to do that: b = Base(arg1, arg2) # very large object, expensive to create or copy d = Derived.from_base(b, derived_arg1, derived_arg2) # reuses existing b object but it seems impossible. Either I'm missing a way to make this work, or (more likely) I'm missing a very big reason why it can't be allowed to work. Can someone explain which one it is? [Of course, if I used composition rather than inheritance, this would all be easy to do. But I was hoping to avoid the delegation of all the Base methods to Derived through __getattr__.]

  Read the article

• On which Windows versions and configurations does my C++ app run?

  - by saas

  I've built a C++ application using MSVC 2010, default compile settings (note: Using "Multithreaded" instead of "Multithreaded DLL" to avoid the Microsoft C++ runtime being needed). I used only the STL and a few, old functions from the Win32 API (Windows.h). Where will my app run? (98-7?) Can the be any differences on how my app works on different PCs? As said: It's only a simple console app. I'd be glad if you could add some additional information if you have it!

  Read the article

• Perl array and hash manipulation using map

  - by somebody

  I have the following test code use Data::Dumper; my $hash = { foo => 'bar', os => 'linux' }; my @keys = qw (foo os); my $extra = 'test'; my @final_array = (map {$hash->{$_}} @keys,$extra); print Dumper \@final_array; The output is $VAR1 = [ 'bar', 'linux', undef ]; Shouldn't the elements be "bar, linux, test"? Why is the last element undefined and how do I insert an element into @final_array? I know I can use the push function but is there a way to insert it on the same line as using the map command? Basically the manipulated array is meant to be used in an SQL command in the actual script and I want to avoid using extra variables before that and instead do something like: $sql->execute(map {$hash->{$_}} @keys,$extra);

  Read the article

• What's the most simple way to retrieve all data from a table and save it back in .NET 3.5?

  - by zoman

  I have a number of tables containing some basic (business related) mapping data. What's the most simple way to load the data from those tables, then save the modified values back. (all data should be replaced in the tables) An ORM is out of question as I would like to avoid creating domain objects for each table. The actual editing of the data is not an issue. (it is exported into Excel where the data is edited, then the file is uploaded with the modified data) The technology is .NET 3.5 (ASP.NET MVC) and SQL Server 2005. Thanks.

  Read the article

• How to handle added input data colums without having to maintain multiple versions of SSIS packages?

  - by GLFelger

  I’m writing to solicit ideas for a solution to an upcoming problem. The product that provides data to our ETL process currently has multiple versions. Our clients are all using some version of the product, but not all use the same version and they will not all be upgraded at the same time. As new versions of the product are rolled out, the most common change is to add new data columns. Columns being dropped or renamed may happen occasionally, but our main focus right now is how to handle new columns being added. The problem that we want to address is how to handle the data for clients who use an older version of the product. If we don’t account for the new columns in our SSIS packages, then the data in those columns for clients using an older product version will not be processed. What we want to avoid is having to maintain a separate version of the SSIS packages for each version of the product. Has anyone successfully implemented a solution for this situation?

  Read the article

• Best practices to test protected methods with PHPUnit

  - by GrGr

  Hello, I found the discussion on Do you test private method informative. I have decided, that in some classes, I want to have protected methods, but test them. Some of these methods are static and short. Because most of the public methods make use of them, I will probably be able to safely remove the tests later. But for starting with a TDD approach and avoid debugging, I really want to test them. I thought of the following: Method Object as adviced in an answer seems to be overkill for this. Start with public methods and when code coverage is given by higher level tests, turn them protected and remove the tests. Inherit a class with a testable interface making protected methods public Which is best practice? Is there anything else? It seems, that JUnit automatically changes protected methods to be public, but I did not have a deeper look at it. PHP does not allow this via reflection.

  Read the article

• jQuery: Quick question. How to select string variable?

  - by user317563

  Hello world, EDIT: I would like to avoid doing something like this: var str = 'Hello'; if ( str == 'Hello') { alert(str); } I would rather do: var str = 'Hello'; $(str).filter(':contains("Hello")').each(function(){ alert(this) }); I've tried a lot of things: $(str).text().method1().method2().method3(); $(str).val().method1().method2().method3(); $(str).contents().method1().method2().method3(); Nothing worked. Is it possible to do this? Thank you for your time. Kind regards, Marius

  Read the article

• dates when saving to mysql database

  - by Patrick

  in my php code I was asking the user to choose day, month and year from some dropdown fields where values where 1, 2, 3 etc instead of 01, 02, 03. these were then combined to form a string like "YYYY-MM-DD" for the insertion in a db (in a date field). Having missed the initial 0, I thought I was sending strings in the wrong format, eg "YYYY-M-D" or YYYY-MM-D", but then I've noticed they appear in the right format in the database anyway: even if I submitted YYYY-M-D, it appeared as YYYY-MM-DD. is this the normal behaviour of mysql? if so, can i just avoid worrying about changing the code in my application?

  Read the article

• Fast, cross-platform timer?

  - by dsimcha

  I'm looking to improve the D garbage collector by adding some heuristics to avoid garbage collection runs that are unlikely to result in significant freeing. One heuristic I'd like to add is that GC should not be run more than once per X amount of time (maybe once per second or so). To do this I need a timer with the following properties: It must be able to grab the correct time with minimal overhead. Calling core.stdc.time takes an amount of time roughly equivalent to a small memory allocation, so it's not a good option. Ideally, should be cross-platform (both OS and CPU), for maintenance simplicity. Super high resolution isn't terribly important. If the times are accurate to maybe 1/4 of a second, that's good enough. Must work in a multithreaded/multi-CPU context. The x86 rdtsc instruction won't work.

  Read the article

• How to organize Windows Phone code base to target both 7.x and 8 platforms

  - by ljubomir

  I took over a Windows Phone project which was previously targeting WP 7.1 platform, and with the recent announcement of the new platform it should target WP 8 as well. My VS 2010 solution consists on several projects (Data access, Model, Tests and WP7 client app) and i am wandering on how to include support for WP8. I have to note that the code-base is not compatible with WP8, due to usage of Toolkit controls and other 3rd party libraries targeted for WP7.1 specifically. Also there is another problem with the Visual Studio versions - WP7.1 can work with VS 2010, but WP8 requires VS 2012. Should i move the whole code-base to VS 2012? Any good advice on how to organize code-base in a most meaningful way in order to avoid duplication and possible painful maintenance? I am thinking between one solution - multiple projects vs. multiple solutions - reusable projects approach. Code duplication (like two separate folders/solutions) should be the least possible approach (fallback).

  Read the article

• div Height: 0 problem in IE

  - by meo

  to clear: both my content i use this: CSS: .clr { clear: both; height: 0; /* i have tried 0.001em to */ line-height: .001em; overflow: hidden; } HTML: <div class="clr">&nbsp;</div> it works perfectly in every navigator. But in IE 7 & 8 the div still have a height of a few pixels. How can i avoid this?

  Read the article

• h3 tag text/image replacement, does this hurt seo?

  - by Mike007

  I'm trying to "replace" text with an image in all of my h3 tags. I want the image to be in the html to avoid multiple h3 classes as this is being done for a portfolio and there will be about 10 h3 tags on the page. My question is, will this be viewed as an attempt to hide, stuff keywords by google for seo purposes? If it will then does anyone know a better way to accomplish this? CSS: h3 { display: block; width: 156px; height: 44px; overflow: hidden; } Html: <h3><img src="images/project001.png" alt="Recent Projects" />Recent Projects</h3>

  Read the article

• The Scala way to use one actor per socket connection

  - by Stefan

  I am wondering how it is possible to avoid one socket connection pr. thread in Scala. I have thought a lot about it, but I always end up with some code which is listening for incoming data for each client connection. The problem is that I want to develop an application which should simultanously handle perhaps a couple of thousand connections. However I will of course not want to create a thread for each connection because of the lack of scalability and context switching. What would be the "right" way to do this. In my world it should be possible to have one actor for each connection without the need to block one thread per actor.

  Read the article

• How do I ensure my abstract class's function can only operate on extenders of the same type as the c

  - by incrediman

  For example, let's say this is my abstract class: abstract class A{ int x; int y; void foo(A fooMe); } ...and B and C are two classes which extend A. What I want is for B to only be able to call foo() on other Bs, and for C to only be able to call foo() on other Cs. But I want this to be out of the hands of the programmer who's extending my A class - that is, I want a way to ensure this functionality within As code alone. What can I do? (If possible) I'd like to avoid any hack or generics solution that's too messy - I still want foo to be able to be called like this, for example: B b=new B(); B bb=new B(); bb.foo(b);

  Read the article

• How can you check if a file exists before including/importing it in JSP?

  - by codeninja

  Assuming that requestScope.importMe is expecting a path to a jsp file <c:choose> <c:when test="${!empty requestScope.importMe && fileExists(requestScope.importMe) }"> <c:import url="${requestScope.importMe}" /> ... How can I check if the file exists before trying to include it so that an error is not thrown? I'd like to avoid using inline Java. Something using one of the JSTL tags is the preferred approach.

  Read the article

• html5 offline storage for Windows Mobile 6.1 or an alternative?

  - by SimonNet

  I understand that there are no browsers currently which support offline storage for mobile 6.1. I am trying to find a web form based solution avoiding the loss of data when my device has no connectivity. Have ruled out Gears and would like to avoid a win forms application as the forms change so often. Are there any other approaches that I should look at which are viable in C#? Are there any estimated dates for when we might see a browser for mobile 6.1 which can offer offline storage? Thanks

  Read the article

< Previous Page | 196 197 198 199 200 201 202 203 204 205 206 207  | Next Page >