Yes, you can build with the latest SDK (ie: 5.1) and still run on devices with earlier versions of the firmware (SDK).  

 - Set your Deployment Target to the earliest version you want to be able to run with, ie: 3.0.  
 - You set your Base SDK to the latest version that you are compiling with, ie: 5.0.  This way you can reference the newer definitions and symbols in your code.  This article [&quot;SDK and Deployment Targets&quot;][1] discusses Deployment vs Base SDK in detail.
 - Weak link to the libraries/frameworks with symbols that are only available in the newer iOS.  This is so your app will run on a device that doesn&#39;t have the newer symbols.
 - You must [check to see that a newer method is available][2] before calling it.  You have to make sure not to call a method that is 5.0 or 4.X only when your app is on a &lt; 4.0 device.  Of course you have to gracefully handle working on older versions by either using older methods or not supporting particular features that need newer SDK support.
 - **NEW w/XCode 4.2:** To support older devices you need to [add armv6][3] to the build architectures *and* [remove armv7][4] from the plist of required device capabilities.

See these SO questions and answers for more details:

 - [deployment target vs base/active sdk][5]
 - [recommended way to support backward compatibility][6]
 - [How do you optionally use iPhone 3.0 features in a 2.0 compatible app][7]
 - [iPhone dev weak link framework][8]
 - [weak linking with IB][9]
 - [universal iphone/ipad app compilation error][10]
 - [iphone apps should include armv6][11]

  [1]: http://www.clarkcox.com/blog/2009/06/23/sdks-and-deployment-targets/
  [2]: http://developer.apple.com/iphone/library/documentation/DeveloperTools/Conceptual/cross_development/Using/using.html#//apple_ref/doc/uid/20002000-1114537
  [3]: https://stackoverflow.com/questions/7488657
  [4]: https://stackoverflow.com/a/7788362/154803
  [5]: https://stackoverflow.com/questions/1920542/iphone-minimum-os-deployment-target-base-active-sdk/1932887#1932887
  [6]: https://stackoverflow.com/questions/2954342/recommended-way-to-support-backward-forward-compatibility-in-iphone-app
  [7]: https://stackoverflow.com/questions/986589/how-do-you-optionally-use-iphone-os-3-0-features-in-a-2-0-compatible-app
  [8]: https://stackoverflow.com/questions/2627797/iphone-dev-weak-link-framework/2629693#2629693
  [9]: https://stackoverflow.com/questions/1727879/weak-linking-with-interface-builder/1799854#1799854
  [10]: https://stackoverflow.com/questions/2618889/universal-iphone-ipad-application-debug-compilation-error-for-iphone-testing/2622027#2622027
  [11]: https://stackoverflow.com/q/4198676/154803

I am trying create an accordion type of uitableviewcell that, when the user selects the cell, it expands to display a detailed info view inline similar to how the digg app works. I initially tried replacing the current tablecell with a customcell in cellForRowAtIndex, however the animation looks a bit choppy as you can see the cell being replaced and overall the effect doesn&#39;t work too well.

If you look at the digg app and others who have done this it seems that they aren&#39;t replacing the current cell but instead perhaps adding a subview to the cell? The original cell however doesn&#39;t seem to animate at all and only the new view accordions into the table.

Does anyone have any ideas how to accomplish a similar effect?

I have made some progress using neha&#39;s method below and while the cell is animating the correct way it is wreaking havoc with the other cells in the table. What I have done is subclassed UITableViewCell with a custom class which contains an instance of a UIView which actually draws the view which I then add to the table cell&#39;s contentview. 

    - (void)setSelected:(BOOL)selected animated:(BOOL)animated {
   
  	if (selected) {	
	    [self expandCell];
  	}
    }

    -(void)expandCell {	
        self.contentView.frame = CGRectMake(0.0, 0.0, self.contentView.bounds.size.width, 110);
    }


Here are all the table delegate methods I am using:


    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
		
	if (isSearching &amp;&amp; indexPath.row == selectedIndex) {
		
		static NSString *CellIdentifier = @&quot;SearchCell&quot;;
		CustomTableCell *cell = (CustomTableCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
		if (cell == nil) {
			cell = [[[CustomTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
		}
		
		[cell setCustomTitle:[timeZoneNames objectAtIndex:indexPath.row] detail:[timeZoneNames objectAtIndex:indexPath.row]];
	
	    UILabel *theText = [[UILabel alloc] initWithFrame:CGRectMake(10.0, 10.0, cell.contentView.bounds.size.width -20, 22.0)];
	    theText.text = @&quot;Title Text&quot;;
	    [cell.contentView addSubview:theText];
	
	
	    UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(10.0, 10 + 46.0, cell.contentView.bounds.size.width - 20, 40.0)];
	    textField.borderStyle = UITextBorderStyleLine;
	    [cell.contentView addSubview:textField];		
	
	    UILabel *testLabel = [[UILabel alloc] initWithFrame:CGRectMake(5.0, 88.0, cell.contentView.bounds.size.width - 20, 22.0)];
	    testLabel.text = [NSString stringWithFormat:@&quot;Some text here&quot;];
	    [cell.contentView addSubview:testLabel];
	
	    [theText release];
	    [textField release];
	    [testLabel release];

	    return cell; 		
	} else {
		
		static NSString *CellIdentifier = @&quot;Cell&quot;;
		CustomTableCell *cell = (CustomTableCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
		if (cell == nil) {
			cell = [[[CustomTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
		}

		[cell setCustomTitle:[timeZoneNames objectAtIndex:indexPath.row] detail:[timeZoneNames objectAtIndex:indexPath.row]];
		return cell; 
	}


    - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
	
	[tableView deselectRowAtIndexPath:indexPath animated:NO];	
	
	selectedIndex = indexPath.row;
	isSearching = YES;
	

	[tableView beginUpdates];
	[tableView endUpdates];
	
    }


    - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {		
	if (isSearching &amp;&amp; indexPath.row == selectedIndex) {
		return 110;
	}
	return rowHeight;			
    } 


It seems now that the cell is expanding but not actually being refreshed so the labels, and textfield aren&#39;t being shown. They do however show up when I scroll the cell off and on the screen.  

Any ideas?

Accordion table cell - How to dynamically expand/contract uitableviewcell?

I have a super class like this:

    class Parent
    {
    public:
        virtual void Function(int param);
    };
    
    void Parent::Function(int param)
    {
        std::cout &lt;&lt; param &lt;&lt; std::endl;
    }

..and a sub-class like this:

    class Child : public Parent
    {
    public:
        void Function(int param);
    };
    
    void Child::Function(int param)
    {
        ;//Do nothing
    }

When I compile the sub-class .cpp file, I get this error

    warning C4100: &#39;param&#39; : unreferenced formal parameter

As a practice, we used to treat warnings as errors. How to avoid the above warning?

Thanks.

Avoid warning &#39;Unreferenced Formal Parameter&#39;

With iOS 4 coming out soon, I have already planned to include an iAd in a future update of an app of mine. I assume that this will make my app unusable for anyone on a firmware lower than 4.0. Is there a way to change those variables and the .xib file based on the user&#39;s firmware?



How to make an iPhone app compatible with multiple SDK (firmware) versions

<p>With iOS 4 coming out soon, I have already planned to include an iAd in a future update of an app of mine. I assume that this will make my app unusable for anyone on a firmware lower than 4.0. Is there a way to change those variables and the .xib file based on the user's firmware?</p>


I am using navigation based application. I push First ViewController to Second ViewController and from Second ViewController to Third ViewController. Now I want to pop from Third ViewController to First ViewController.I am performing this task using the below code but my application crashed.

Please any body give me some proper guidelines. I can&#39;t use pop to rootViewController because it&#39;s different viewController. Thanks in advance...

**In Third ViewControler i have written this:**

    FirstViewCtr *x=[[FirstViewCtr alloc] initWithNibName:@&quot;FirstViewCtr&quot; bundle:nil];
    [self.navigationController popToViewController:x animated:NO];

Can i pop to Specific ViewController?

When my paid developer membership runs out with Apple, what happens to my existing apps on the app store?

I know that I cannot add new apps then, but do my existing apps stay? Can I change prices? Can I get paid for sales? Can I update those apps? (Am I missing any questions here?)

What happens to my apps after my developer account membership expires?

Let&#39;s say we have a view controller with one sub view. the subview takes up the center of the screen with 100 px margins on all sides. We then add a bunch of little stuff to click on inside that subview. We are only using the subview to take advantage of the new frame ( x=0, y=0 inside the subview is actually 100,100 in the parent view). 

Then, imagine that we have something behind the subview, like a menu. I want the user to be able to select any of the &quot;little stuff&quot; in the subview, but if there is nothing there, I want touches to pass through it (since the background is clear anyway) to the buttons behind it. 

How can I do this? It looks like touchesBegan goes through, but buttons don&#39;t work. 

How can I click a button behind a transparent UIView?

Does `overflow:hidden` applied to `&lt;body&gt;` work on iPhone Safari? It seems not.
I can&#39;t create a wrapper on the whole website to achieve that...

Do you know the solution?

Example: I have a long page, and simply I want to hide the content that goes underneath the &quot;fold&quot;, and it should work on iPhone/iPad.

Does overflow:hidden applied to &lt;body&gt; work on iPhone Safari?

I have a `UITableViewController` where the user should be able to edit the items. In order to enable editing I use this :

    self.navigationItem.rightBarButtonItem = self.editButtonItem;

For everyone who does not know where self.editButtonItem comes from, it is predefined by the SDK.

So, now when I press on any item, this method is called :

    - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath 

but as soon as I hit the edit button and while editing is active, this method does not seemed to be called.

Any idea what I missing ? 

This is the rest of the code that is related to editing :

    // Override to support conditional editing of the table view.
    - (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath 
    {
    	// Return NO if you do not want the specified item to be editable.
    	return YES;
    }
    
    - (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath 
    {
    	return UITableViewCellEditingStyleNone;
    }
    
    
    - (BOOL)tableView:(UITableView *)tableView shouldIndentWhileEditingRowAtIndexPath:(NSIndexPath *)indexPath 
    {
    	return NO;
    }


Thanks for the help.

mcb



When editing, `UITableView` does not call didSelectRowAtIndexPath ??

Is there a simple way to delete all the annotations on a map without iterating through all the displayed annotations in Objective-c?

How to delete all Annotations on a MKMapView

I just changed some code in my program and got this error:

&gt; Couldn&#39;t register com.yourcompany.XXX with the bootstrap server.
&gt; Error: unknown error code.
&gt; 
&gt; This generally means that another instance of this process was already
&gt; running or is hung in the debugger.Program received signal: 
&gt; “SIGABRT”.

I tried restoring my program to a version that worked, rebooted, restarted, empty caches and rebuild on versions that even worked before.

Any help would be appreciated.


Couldn&#39;t register with the bootstrap Server

How can I detect when the keyboard is shown and hidden from my application?

How to detect when keyboard is shown and hidden

I have developed my app in Xcode for iPhone, in start I have just named it without secnec now I want to change my app name I have replace my old app name with new one as I have found the name in my app, but its still giving me one error...

&gt;Desktop/New name/old name_Prefix.pch: No such file or directory

when I have change oldname_prefix.pch with newname_prefix.pch ..


How to change Xcode Project name

I want to use font &quot;MgOpen Modata&quot; in my iphone App. But I dont see it in the font list in Property inspector. 

How do I include that font so that I can use it?



How to include and use new fonts in iPhone SDK?

I&#39;m building a small Java app and hoping to use logback for logging.

My app has a dependency on an older project that does its logging via 

    org.apache.commons | com.springsource.org.apache.commons.logging | 1.1.1

...so my plan was to use 

    org.slf4j | jcl-over-slf4j | 1.5.6

...to redirect the JCL logging to 

    org.slf4j | slf4j-api | 1.6.0

...and ultimately to 

    ch.qos.logback | logback-classic | 0.9.22
    ch.qos.logback | logback-core | 0.9.22

so my app can log through logback via its slf4j API while the old library code can log into the same location via the redirection.

Alas, this results in 

    java.lang.NoSuchMethodError: org.slf4j.spi.LocationAwareLogger.log(Lorg/slf4j/Marker;Ljava/lang/String;ILjava/lang/String;Ljava/lang/Throwable;)V
	at   org.apache.commons.logging.impl.SLF4JLocationAwareLog.info(SLF4JLocationAwareLog.java:141)

I&#39;ve tried higher and lower verision numbers on some of these jars and also digging through API documentation and such... but I&#39;m unable to find and solve the problem. 

Help, please?

Although logback is considered the &quot;strategic&quot; logging framework, I have some leeway in which logging mechanism I ultimately use. I&#39;d hope to use either logback or log4j, though, and I definitely want to merge the old project&#39;s logging into whatever the &quot;new&quot; logging framework ends up being, via a common configuration.

Logging framework incompatibility

I do most of my programming in Python 3.x on Windows 7, but now I need to use the Python Imaging Library (PIL), ImageMagick, and wxPython, all of which require Python 2.x.

Can I have both Python 2.x and Python 3.x installed in Windows 7? When I run a script, how would I &quot;choose&quot; which version of Python should run it? Will the aforementioned programs be able to handle multiple versions of Python installed at once? I have searched for hours and hours for how to do this to no avail.

Thanks.

How to install both Python 2.x and Python 3.x in Windows

Greetings all,

This has confused me ever since I first started coding in C#.  My goal is to create an assembly that will run on the most recent .NET framework the user has, whatever that may be.  I don&#39;t want to require .NET 4 to be installed, but I want to use it if the user has it, and more importantly, I want it to still work if the user has _only_ .NET 4 and nothing below.  I&#39;m beginning to suspect this is not even possible.

I don&#39;t really understand what I&#39;m selecting when I change the &quot;Target Framework&quot; in Visual Studio.  Does that mean &quot;will be compatible with this version and up&quot;?  Or &quot;will be compatible with only this version&quot;?  It seems like it&#39;s the latter so far; my tests in virtual machines show .NET 4 targeted assemblies failing without .NET 4, and .NET 3.5 targeted assemblies failing without .NET 3.5.  Is there no way to set this so I can achieve maximum compatibility?

UPDATE: To clarify, I have a program that targets .NET 2.  The posters here seem to indicate that it should load with .NET 4.  But in an environment with only .NET 4 and nothing before it, it fails to load.

UPDATE2: Okay, figured it out, but it&#39;s far more complex than the posters here seem to think.  I&#39;m opening a different question to discuss the intricacies, but the short version is, you need an app.config with `&lt;supportedRuntime version=&quot;v4.0&quot; /&gt;` in it if you want to run non-.NET 4 assemblies on .NET 4.  They won&#39;t load without it.

What does it really mean to target a framework, and how do I maximize compatibility?

I had two versions of Python installed on my machine (versions 2.6 and 2.5). I want to run 2.6 for one project and 2.5 for another. 

How can I specify which I want to use?

I am working on Windows XP SP2.

How to run multiple Python versions on Windows

When I want to create a Ruby on Rails project, I get the message below.

    /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:55: uninitialized constant ActiveSupport::Dependencies::Mutex (NameError)
    	from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require&#39;
    	from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `require&#39;
    	from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support.rb:57
    	from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require&#39;
    	from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `require&#39;
    	from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/rails_generator.rb:31
    	from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require&#39;
    	from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `require&#39;
    	from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/bin/rails:15
    	from /usr/bin/rails:19:in `load&#39;
    	from /usr/bin/rails:19

What has gone wrong? How do I to fix it?


Uninitialized constant ActiveSupport::Dependencies::Mutex (NameError)

In iOS 4.0 Apple has redesigned the backup process.  

iTunes used to store a list of filenames associated with backup files in the Manifest.plist file, but in iOS 4.0 it has moved this information to a Manifest.mbdb

You can see an example of this file by making a backup with your iOS 4.0 devices and looking in your ~/Library/Application Support/MobileSync/Backup folder (Look inside the subfolders with the most recent date)

Here&#39;s a screenshot of what the file looks like in a text editor:

[![alt text][1]][1]  
&lt;sub&gt;(source: [supercrazyawesome.com](http://supercrazyawesome.com/images/mbdb.png))&lt;/sub&gt;  


How do I parse this into a Cocoa application so that I can update my (free) iPhone Backup Extractor app (http://supercrazyawesome.com) for iOS 4.0?

  [1]: https://i.stack.imgur.com/xhwcc.png


How to parse the Manifest.mbdb file in an iOS 4.0 iTunes Backup

Now that iOS 4 is no longer NDA, I would like to know what Gyroscope has to offer over the Accelerometer for developers. Is there a difference in APIs? Other things?

Gyroscope vs Accelerometer?

I am trying to implement a game using the iPhone OS 4.0 (iOS4?) SDK. In the previous versions of the SDK, I&#39;ve been using the [UIView beginAnimations:context:] and [UIView commitAnimations] to create some animations. However, when I look at the documentation of the functions in 4.0, I see this comment.

&gt; Use of this method is discouraged in
&gt; iPhone OS 4.0 and later. You should
&gt; use the block-based animation methods
&gt; instead.

You can find it here:
http://developer.apple.com/iphone/library/documentation/uikit/reference/UIView_Class/UIView/UIView.html#//apple_ref/occ/clm/UIView/commitAnimations

My question is, what are block-based animations in iPhone OS 4.0? I though that the beginAnimations:context: and commitAnimations functions were used to create animation blocks..

What are block-based animation methods in iPhone OS 4.0?

I created this community wiki to bind together a number of
other Q/A&#39;s I&#39;ve seen here on SO. If you&#39;re here, you&#39;ve probably
installed the final version of Xcode 3.2.3 with iPhone SDK 4 ([download
link][xcode_download], reg reqd), and then encountered one or both of these problems:

* In your previously working Xcode iPhone project, you get &quot;Base SDK Missing&quot; somewhere. Something like this:
 
 ![Ruh-roh!][base_sdk_missing_image]
 
* In a related but more general observation, none of the previously available panoply of Device or Simulator SDK choices (e.g. 3.0, 3.1, 3.1.3, ...) is available where you used to see them.

  [xcode_download]: https://developer.apple.com/iphone/download.action?path=%2Fiphone%2Fiphone_sdk_4__final%2Fxcode_3.2.3_and_iphone_sdk_4__final.dmg
  [base_sdk_missing_image]: https://i.stack.imgur.com/j9itE.png

Install Xcode 3.2.3 w/ iPhone SDK 4, get &quot;Base SDK missing&quot;, can&#39;t see other SDKs

The [documentation for AVPlayer][1] states the following:

&gt; [The] player works equally well with local and remote media files

However, the [documentation for AVAudioPlayer][2] states the following:

&gt; Apple recommends that you use this class for audio playback unless you are playing audio captured from a network stream

For the work I am doing I need some of the capabilities of AVAudioPlayer, but all my audio is being streamed. The main thing I need from AVAudioPlayer that AVPlayer does not have is the &quot;playing&quot; property. It is difficult to build a player UI without that property, among others.

So what is the difference between AVPlayer and AVAudioPlayer that makes the latter unsuitable for network streaming? Is there a way to get some of the info from AVPlayer that AVAudioPlayer provides such as the &quot;playing&quot; property?

  [1]: https://developer.apple.com/reference/avfoundation/avplayer
  [2]: https://developer.apple.com/reference/avfoundation/avaudioplayer

Content Type	Original Author	Original Content on Stackoverflow
Question	Dyldo42	View Question on Stackoverflow
Solution 1 - Iphone	progrmr	View Answer on Stackoverflow

How to make an iPhone app compatible with multiple SDK (firmware) versions

Iphone Problem Overview

Iphone Solutions

Solution 1 - Iphone

Avoid warning 'Unreferenced Formal Parameter'

Accordion table cell - How to dynamically expand/contract uitableviewcell?

Attributions