Strange bug is fixed in XCode 4.2!
The problem was the hidden password dialog, so sometime it works and sometimes not. 
One of possible solutions was: 

1. Run Instruments
2. Cmd Tab to Xcode covering the instruments. Cycle and hide messages until password dialog is found. 
3. Close Xcode. 

PS: I know it is a few years to late for the answer, I was just looking for unanswered questions. Just check as answered - &gt; it&#39;s good for both of us. )


Is there a simple way to add a &quot;--Please select--&quot; default option to a DropDownListFor in MVC 3?

DropdownListFor default value

If I catch all touchend events from mobile devices with:

    $(document.body).bind(&#39;touchend&#39;, function (e) {
    var touch = e.touches[0]; // doesnt work
    ...

I need to get the touch.screenX, touch.screenY, touch.clientX and touch.clientX from the e paramter. All the examples I&#39;ve seen suggest that e.touches will be a collection, and you can get at the touch details with `e.touches[0]`. In my tests on an ipad, `e.touches` is always undefined. I&#39;m not using any jquery plugins.

Also tried e.targetTouches, which is also undefined.

Can anyone help?

touchend event properties

If I open Instruments and select a standard application (e.g. Mail or MS Word) it has no issue. 
If I am in Xcode and I go to **Product &gt; Profile** (or press &lt;kbd&gt;Cmd&lt;/kbd&gt; + &lt;kbd&gt;I&lt;/kbd&gt;), it launches Instruments, allows me to select a template, and loads the standard screen. Then the downward arrow starts tracing to the right as it should, and the iOS simulator launches the program. However, nothing is plotted in Instruments. It shows no changes to anything no matter what the app is doing. I can&#39;t click anything in Instruments: no menu&#39;s, can&#39;t stop recording, can&#39;t open tabs, etc. 

I randomly discovered that if I hit &lt;kbd&gt;Cmd&lt;/kbd&gt; + &lt;kbd&gt;Tab&lt;/kbd&gt;, Instruments will start behaving normally. This seems really strange to me. Either it&#39;s a bug or it&#39;s a hole in my knowledge about how to operate Instruments. 


Instruments 4.1 unresponsive to projects launched from Xcode 4.1 until pressing Cmd-Tab

If I open Instruments and select a standard application (e.g. Mail or MS Word) it has no issue.
If I am in Xcode and I go to Product > Profile (or press <kbd>Cmd</kbd> + <kbd>I</kbd>), it launches Instruments, allows me to select a template, and loads the standard screen. Then the downward arrow starts tracing to the right as it should, and the iOS simulator launches the program. However, nothing is plotted in Instruments. It shows no changes to anything no matter what the app is doing. I can't click anything in Instruments: no menu's, can't stop recording, can't open tabs, etc.
I randomly discovered that if I hit <kbd>Cmd</kbd> + <kbd>Tab</kbd>, Instruments will start behaving normally. This seems really strange to me. Either it's a bug or it's a hole in my knowledge about how to operate Instruments.

In Xcode 4.2, there is a new preference under the General tab called &quot;iOS Device Discovery&quot; with the checkbox option &quot;Support Wirelessly Connected Devices.&quot;

What does this option do?  Once checked, how can we use this new capability?

What does the Xcode 4.2 preference &quot;Support Wirelessly Connected Devices&quot; do?

![enter image description here][1]


  [1]: http://i.stack.imgur.com/KbMGQ.jpg

What are the significance of the letters beside the files in the Project Navigator? (e.g M,A)

Xcode letters beside files in Project Navigator

I&#39;d like to remove old (replaceable?) data and *DerivedData* contents seem a likely candidate. Since it&#39;s name *DerivedData*, I assume that it&#39;s info that, if missing, would be generated during a build phase and if present, is used during that same phase. It seems logical then that I could delete any old project data without fear and if I should ever build that old project, the first time through would take longer than normal sine it has to recreate all this derived data.

Am I mistaken here?

How can I safely delete in my ~/Library/Developer/Xcode/DerivedData directory?

In my little iPad app I have a &quot;switch language&quot; function that uses an observer. Every view controller registers itself with my observer during its `viewDidLoad:`.

    - (void)viewDidLoad
    {
        [super viewDidLoad];
        [observer registerObject:self];
    }

When the user hits the &quot;change language&quot; button, the new language is stored in my model and the observer is notified and calls an `updateUi:` selector on its registered objects.

This works very well, except for when I have view controllers in a TabBarController.  This is because when the tab bar loads, it fetches the tab icons from its child controllers without initializing the views, so `viewDidLoad:` isn&#39;t called, so those view controllers don&#39;t receive language change notifications. Because of this, I moved my `registerObject:` calls into the `init` method.

Back when I used `viewDidLoad:` to register with my observer, I used `viewDidUnload:` to unregister. Since I&#39;m now registering in `init`, it makes a lot of sense to unregister in `dealloc`.

But here is my problem. When I write:

    - (void) dealloc
    {
        [observer unregisterObject:self];
        [super dealloc];
    }

I get this error:

&gt; ARC forbids explicit message send of &#39;dealloc&#39;

Since I need to call `[super dealloc]` to ensure superclasses clean up properly, but ARC forbids that, I&#39;m now stuck. Is there another way to get informed when my object is dying?

Custom dealloc and ARC (Objective-C)

Xcode underlines all occurrences of a symbol that the cursor is on. However, the underline doesn&#39;t exactly &quot;pop out&quot; in the source code. Is it possible to make Xcode highlight the background color of the symbol, like Eclipse does it? I can&#39;t find anything in the Preferences panel.

Xcode:

![Xcode][1]

Eclipse:

![Eclipse][2]


  [1]: http://i.stack.imgur.com/jgxnI.png
  [2]: http://i.stack.imgur.com/VhoOr.png

Make Xcode highlight selected symbol more

On my Lion app, I have this data model:

![enter image description here][1]

The relationship `subitems` inside `Item` **is ordered**.
 
Xcode 4.1 (build 4B110) has created for me the file `Item.h`, `Item.m`, `SubItem.h` and `SubItem.h`.
 
Here is the content (autogenerated) of `Item.h`:

    #import &lt;Foundation/Foundation.h&gt;
    
    #import &lt;CoreData/CoreData.h&gt;
    
    @class SubItem;
    
    @interface Item : NSManagedObject {
    @private
    }
    
    @property (nonatomic, retain) NSString * name;
    @property (nonatomic, retain) NSOrderedSet *subitems;
    @end
    
    @interface Item (CoreDataGeneratedAccessors)
    
    - (void)insertObject:(SubItem *)value inSubitemsAtIndex:(NSUInteger)idx;
    - (void)removeObjectFromSubitemsAtIndex:(NSUInteger)idx;
    - (void)insertSubitems:(NSArray *)value atIndexes:(NSIndexSet *)indexes;
    - (void)removeSubitemsAtIndexes:(NSIndexSet *)indexes;
    - (void)replaceObjectInSubitemsAtIndex:(NSUInteger)idx withObject:(SubItem *)value;
    - (void)replaceSubitemsAtIndexes:(NSIndexSet *)indexes withSubitems:(NSArray *)values;
    - (void)addSubitemsObject:(SubItem *)value;
    - (void)removeSubitemsObject:(SubItem *)value;
    - (void)addSubitems:(NSOrderedSet *)values;
    - (void)removeSubitems:(NSOrderedSet *)values;
    
    @end

And here is the content (autogenerated) of `Item.m`:

    #import &quot;Item.h&quot;
    #import &quot;SubItem.h&quot;
    
    @implementation Item
    
    @dynamic name;
    @dynamic subitems;
    
    @end
 
As you can see, the class `Item` offers a method called `addSubitemsObject:`. Unfortunately, when trying to use it in this way:

    Item *item = [NSEntityDescription insertNewObjectForEntityForName:@&quot;Item&quot; inManagedObjectContext:self.managedObjectContext];
    item.name = @&quot;FirstItem&quot;;
    
    SubItem *subItem = [NSEntityDescription insertNewObjectForEntityForName:@&quot;SubItem&quot; inManagedObjectContext:self.managedObjectContext];
    
    [item addSubitemsObject:subItem];

this error appear:

    2011-09-12 10:28:45.236 Test[2002:707] *** -[NSSet intersectsSet:]: set argument is not an NSSet

Can you help me?

**Update:**

After just 1,787 days from my bug report, today (August 1, 2016) Apple wrote me this: *&quot;Please verify this issue with the latest iOS 10 beta build and update your bug report at bugreport.apple.com with your results.&quot;*. Let&#39;s hope this is the right time :)

  [1]: http://i.stack.imgur.com/CYI00.png

Exception thrown in NSOrderedSet generated accessors

I&#39;d like to check the contents of an XML file at a specific point of execution while debugging in Xcode. Is it possible to view the contents of the file, either through the Organizer (I&#39;m debugging using actual hardware devices, not the simulator), or by typing in some sort of command into the output/console?

I am using Xcode 4.

Is it possible to view the contents of files in the iOS Application sandbox while debugging?

I have an iOS app that I want to convert to using **ARC**. I would just use the migration tool, but it errors out for me consistently during the preview phase.

I know I can use the `-fobjc-arc` compiler directive on a file-by-file basis, but I want to enable **ARC** on the entire project, then turn off individual classes using `-fno-objc-arc`. 

New projects in 4.2 can use ARC by default, so there must be a switch somewhere.

Can anyone help me to convert the project to `ARC`



How do you enable ARC project-wide in Xcode 4.2

I use Apple Reachability class from Apple Sample code
[Reachability][1]

in Xcode 4.2 and new Apple 3.0 compiler I get warning in this class that

    + (Reachability*) reachabilityWithAddress: (const struct sockaddr_in*) hostAddress;

*declaration of &#39;struct sockaddr_in*&#39; will not be visible outside of this function* 

I am not good at classic C %) so I dont understand how I can fix this warning or may be I can ignore it at all. 

Thx


  [1]: http://developer.apple.com/library/ios/#samplecode/Reachability/Listings/ReadMe_txt.html

Xcode 4.2 - declaration of &#39;...&#39; will not be visible outside of this function warning

I&#39;ve created a simple javascript for my `iOS` app that I&#39;d like to run simultaneously on multiple `iOSDevices` connected via USB to one host Mac machine. Launching instruments connected to an `iPhone` from the command line works fine but if I attempt to launch a second instruments connected to an `iPad`, the first instruments session hangs.  


----------


Upon terminating the first instruments session, I get one of more of the following lines printed:

&gt; Stopped: Script stopped due to device being disconnected

After extensive research on the subject, with no results on the phrase, I&#39;ve been trying to read into what is meant by Apple&#39;s Instruments Guide:

&gt; When you choose All Processes, Attach to Process, or Choose Target from the Target menu, Instruments sets the default target for all instruments to the program you choose. There are occasions, however, when you might want to set a different target for each instrument. You might want to sample two different programs at the same time, for example, using the Sampler instrument. If you have some instruments that are capable of tracing all processes, you might want them to do just that while single-process instruments sample just one process.

I&#39;m wondering if the `Automation.tracetemplate` is a single-process only instrument and that if another process is started with the same Automation trace then the first is usurped.

Any advice would be grateful as this is a major block for running our time intensive automation tests over multiple `iOSDevices`.


----------


**Update 27 Mar 2012**

The following is from an email received after submitting a bug to Apple on the matter (developer.apple.com/bugreporter):

&gt;I heard back from a UI Automation engineer. UI Automation is a single process Instrument. As such, you cannot use it simultaneously on multiple devices.


Instruments automation trace only allows one target connection?

Is it possible to track the allocation and deallocation of my Objective-C objects? For instance if I have a class Book, I want to track all the allocations and deallocations of the objects of Book type. I can track all the default SKD classes, such as UIViewController, UIWindow, UIView, NSDictionary and all that, but I want to track also the objects that are created from my defined classes.

Instruments Allocations track alloc and dealloc of objects of user defined classes

I have all my code signing entitlements set correctly. Running the app on my phone is fine, but launching it in instruments gives me an error message:

    Error Starting Recording
    At least one target failed to launch; aborting run

And then:

    Target failed to run. Permisson to debug [app name] was denied. The app must be signed with a development identity (i.e. iOS Developer)

Any ideas how I could stop this from happening? Doesn&#39;t happen on my iPad.

Can&#39;t launch my app in Instruments: At least one target failed to launch

In Xcode&#39;s Instruments, there is a tool called [Counters][1] that exposes low-level counter information provided by the CPU, such as the number of instructions executed or number of cache misses:

[![screenshot of Counters tool in Instruments][2]][1]

This is similar to the Linux syscall [`perf_event_open`](http://man7.org/linux/man-pages/man2/perf_event_open.2.html) introduced in Linux 2.6.32. On Linux, I can use `perf_event_open` then start/stop profiling around the section of my code I&#39;m interested in. I&#39;d like to record the same type of stats on OS X: counting the instructions (etc.) that a certain piece of code takes, and getting the result in an automated fashion. (I don&#39;t want to use the Instruments GUI to analyze the data.)

Are there any APIs that allow this (ex: using dtrace or similar)? From some searching it sounds like the private AppleProfileFamily.framework might have the necessary hooks, but it&#39;s unclear how to go about linking to or using it.


  [1]: https://developer.apple.com/library/mac/documentation/AnalysisTools/Reference/Instruments_User_Reference/CountersInstrument/CountersInstrument.html
  [2]: http://i.stack.imgur.com/lG4K1.png

Record values of Performance Monitor Counters (PM events) on OS X without Instruments

I recently update my Xcode to version 9.3, so is instruments. After that, time profiler won&#39;t work anymore, it usually works fine before.

I tried to run it via Xcode, and I tried to run it manually. Doesn&#39;t work.
The life cycle row stuck in initializing, and I got a bunch of warnings complain about **the data volume is too high for a recording mode of &quot;immediate&quot; and some data had to be dropped to move forward**. 

Then I switch to delay mode, still got nothing. Then I create a simple new project, which should have &quot;little data volume&quot;, still got nothing.

I checked help, I googled, seems like no one has encountered this before. Does anyone have any clue about this?

![enter image description here][1]

  [1]: https://i.stack.imgur.com/gyGGq.png

Content Type	Original Author	Original Content on Stackoverflow
Question	James Paul Mason	View Question on Stackoverflow
Solution 1 - Xcode	Watsche	View Answer on Stackoverflow

Instruments 4.1 unresponsive to projects launched from Xcode 4.1 until pressing Cmd-Tab

Xcode Problem Overview

Xcode Solutions

Solution 1 - Xcode

touchend event properties

DropdownListFor default value

Attributions