Try option-return or pasting in the newline.

@Hot Licks explained the reason well in comment.

The only way is


 

    if ([self.mylabel.text isEqualToString:@&quot;\\n&quot;]) {
            
       [self.myTextView insertText:@&quot;\n&quot;];
    }

Manually, use `ALT+ENTER`


This simple batch file in relatively short order consumes all available memory on Windows 7 (x64). What&#39;s going on? and what precautions can be taken to ward against it?

    any-invalid-command-you-like-here ^

Apparently necessary preconditions to exhibit the effect: 

 - the caret `^` is the very last thing in the file, and the script is not terminated with a newline
 - the caret is preceded by at least 2 spaces or characters, e.g. if the dots in the following represent spaces the memory leak will not be triggered `.^`, while this one will `..^` (just slowly)

In this *Process Explorer* screen shot, the script had been running about 30 seconds, consumed 2.9GB, and was still climbing at a steady rate:

[![2.9GB memory consumed and still climbing][2]][1]

If you&#39;re going to experiment with this, make sure you can get at the Close Window [X] control or have a Task Manager or Process Explorer fired up and ready as &lt;kbd&gt;Ctrl-C&lt;/kbd&gt;, &lt;kbd&gt;Ctrl-Break&lt;/kbd&gt;, &lt;kbd&gt;Alt-F4&lt;/kbd&gt; **have no effect**.

It appears multiple carets will cause the memory usage to ramp up much more quickly. The first time I encountered this there wasn&#39;t enough memory available in 1 or 2 minutes to do simple things like &lt;kbd&gt;Alt-Tab&lt;/kbd&gt; and even the 3 finger salute &lt;kbd&gt;Ctrl-Alt-Del&lt;/kbd&gt; was ineffective. I had to hard power off the machine.
        

  [1]: http://i.stack.imgur.com/lKVfN.png
  [2]: http://i.stack.imgur.com/AJwB4.png

Simple caret (^) at end of Windows batch file consumes all memory

In a GPS app that allows the user to display a list of complex location points that we call tracks on various different types of map, each track can consist of between 2k to 10k of location points. The tracks are copiously clipped, pruned and path-simplified when they are rendered on non-Google map types. This is to keep memory usage down and performance up.  We typically only wind up submitting far less than a thousand (aggregate) transformed location points to the OpenGL pipeline, even in the worst cases.

In integrating the Google Maps SDK for iOS, we initially attempted to continue to leverage our own OpenGL track rendering system, but ran into issues with conflicting OpenGL context usage (rendering worked, but we couldn&#39;t get GMSMapView to and our own internal OpenGL resources to both release without someone touching deleted memory).  

So we are trying to leverage the GMSPolyline constructs and just let the Google SDK do the track rendering, but we&#39;ve run into major memory usage issues, and are looking for guidance in working around them.

Using Xcode Instruments, we&#39;ve monitored memory usage when creating about 25 poly lines with about 23k location points total (not each).  Over the course of poly line creation, app memory usage grows from about 14 MB to about 172 MB, a net peak of about 158 MB.  Shortly after all the poly lines are created, memory usage finally drops back down to around 19 MB and seems stable, for a cumulative net of around 5 MB, so it seems each location point requires around 220 bytes (5 MB / 23k points) to store.

What hurts us is the peak memory usage.  While our laboratory test only used 23k location points, in the real world there are often many more, and iOS seems to jettison our application after *Google Maps* has consumed around 450 MB on an *iPhone 5* (whereas our internal poly line rendering system peaks at around 12 MB for the same test case).

Clearly the `GMSPolyLine` construct is not intended for the heavy weight usage that we require.

We tried wrapping some of the poly line creation loops with separate autorelease pools, and then draining those at appropriate points, but this has no impact on memory use.  The peak memory use after the poly lines are created and control is returned to the main run loop didn&#39;t change at all.  Later it became clear why; the Google Map system isn&#39;t releasing resources until the first DisplayLink callback after the poly lines are created.  

Our next effort will be to manually throttle the amount of data we&#39;re pushing at GMSPolyline, probably using our own bounds testing, clipping, pruning &amp; minimization, rather than relying on Google Maps to do this efficiently.  

The drawback here is that it will mean many more GMSPolyline objects will be allocated and deallocated, potentially while the user is panning/zooming around the map.  Each of these objects will have far fewer location points, yet still, we&#39;re concerned about unforeseen consequences of this approach, hidden overhead of many GMSPolyline allocs and deallocate.

So the question is, what is the best approach for dealing with this situation, and can someone from Google shed some light on any `GMSPolyline` best practices, upper bounds, bottlenecks, etc. ?




GMSPolyline very large memory spike

I have id&lt;UITextInput&gt; textInput and I insert new line(\n) OK with:

    [textInput insertText:@&quot;\n&quot;];

But when input Text from label.text (Input in Interface Builder) ,it NOT OK. Just input \n text.

    NSLog(@&quot;%@&quot;,label.text);
    [textInput insertText:label.text];


How to input special character when store it in label.text?

I don&#39;t want to compare `[inputStr isEqualToString:@&quot;\\n&quot;];`

*Log: \n

Thanks!

How to insert new line \n from UILabel text which typed in IB?

I have id<uitextinput> textInput and I insert new line(\n) OK with:</uitextinput>
<pre><code class="hljs language-csharp">[textInput insertText:@"\n"];
</code></pre>
But when input Text from label.text (Input in Interface Builder) ,it NOT OK. Just input \n text.
<pre><code class="hljs language-arduino">NSLog(@"%@",label.text);
[textInput insertText:label.text];
</code></pre>
How to input special character when store it in label.text?
I don't want to compare <code>[inputStr isEqualToString:@"\\n"];</code>
*Log: \n
Thanks!

I&#39;ve been working with the Parse SDK and I followed the quickstep guide. When I try to run, I get these 8 errors. Any ideas as to why? It looks like something to do with the Facebook part of Parse which I&#39;m not using.

     Undefined symbols for architecture armv7:
    &quot;_FBTokenInformationTokenKey&quot;, referenced from:
      -[PFFacebookTokenCachingStrategy accessToken] in Parse(PFFacebookTokenCachingStrategy.o)
      -[PFFacebookTokenCachingStrategy setAccessToken:] in Parse(PFFacebookTokenCachingStrategy.o)
     &quot;_FBTokenInformationExpirationDateKey&quot;, referenced from:
      -[PFFacebookTokenCachingStrategy cacheTokenInformation:] in     Parse(PFFacebookTokenCachingStrategy.o)
      -[PFFacebookTokenCachingStrategy expirationDate] in Parse(PFFacebookTokenCachingStrategy.o)
      -[PFFacebookTokenCachingStrategy setExpirationDate:] in Parse(PFFacebookTokenCachingStrategy.o)
     &quot;_OBJC_METACLASS_$_FBSessionTokenCachingStrategy&quot;, referenced from:
      _OBJC_METACLASS_$_PFFacebookTokenCachingStrategy in Parse(PFFacebookTokenCachingStrategy.o)
    &quot;_OBJC_CLASS_$_FBSessionTokenCachingStrategy&quot;, referenced from:
      _OBJC_CLASS_$_PFFacebookTokenCachingStrategy in Parse(PFFacebookTokenCachingStrategy.o)
    &quot;_FBTokenInformationUserFBIDKey&quot;, referenced from:
      -[PFFacebookTokenCachingStrategy facebookId] in Parse(PFFacebookTokenCachingStrategy.o)
      -[PFFacebookTokenCachingStrategy setFacebookId:] in Parse(PFFacebookTokenCachingStrategy.o)
    &quot;_OBJC_CLASS_$_FBRequest&quot;, referenced from:
      objc-class-ref in Parse(PFFacebookAuthenticationProvider.o)
    &quot;_OBJC_CLASS_$_FBSession&quot;, referenced from:
      objc-class-ref in Parse(PFFacebookAuthenticationProvider.o)
     ld: symbol(s) not found for architecture armv7
     clang: error: linker command failed with exit code 1 (use -v to see invocation)


Parse for iOS: Errors when trying to run the app

Within our web application we are displaying a PDF document in an `iframe` using the following line of code:

    &lt;iframe id=&quot;iframeContainer&quot; src=&quot;https://example.com/pdfdoc.pdf&quot; 
                                 style=&quot;width:100%; height:500px;&quot;&gt;&lt;/iframe&gt;

This works fine in all the major desktop browsers with the width of the PDF scaling to fit inside the confines of the iFrame and a vertical scroll bar to view all the pages within the document.

At the moment however I can&#39;t get the PDF to display correctly in Mobile Safari. In this instance only the top left portion of the PDF is visible without any horizontal or vertical scrollbars to see the rest of the document.

Does anybody know of I workaround for this problem in Mobile Safari?

**UPDATE - MARCH 2013** 

After hours of searching and experimentation I can conclude that this problem is a real mess!! There are a bunch of solutions but each far from perfect. Anybody else struggling with this one I advise to refer to &#39;[Strategies for the iFrame on the iPad Problem][1]&#39;. For me I need to write this one off and look for another solution for our iPad users. 

**UPDATE - MAY 2015**

Just a quick update on this question. Recently I have started using the Google Drive viewer, which has mostly solved the original problem. Just provide a full path to the PDF document and Google will return a HTML formatted interpretation of your PDF (don&#39;t forget to set `embedded=true`). e.g. 

https://drive.google.com/viewerng/viewer?embedded=true&amp;url=www.analysis.im%2Fuploads%2Fseminar%2Fpdf-sample.pdf

I&#39;m using this as a fallback for smaller viewports and simply embedding the above link into my `&lt;iframe&gt;`.


  [1]: https://blogs.magnolia-cms.com/christopher-zimmermann/detail~&amp;strategies-for-the-iframe-on-the-ipad-problem~.html
  

Problems displaying PDF in iFrame on Mobile Safari

I generate plist file for my application from file in csv format.

Everything seems to be correct but when I try to build application or open plist file in XCode i Get an error informing that:

&gt; mydata.plist:0: error: reading plist: The data couldn’t be read because it has been corrupted.

File contains a lot of data so it might be hard to manually find line which is incorrect.

Is it possible to validate file and get information which line is incorrect?



How to know which line of plist file is incorrect

I have an image view, declared programmatically, and I am setting its image, also programmatically.

However, I find myself unable to set the image to both fit the aspect and align centre to the image view.

In other words, I want the image to:

- Scale down to fit the aspect, if the image is large.
- Centre but not scale up, if the image is small.

How do I get that?

UIImageView aspect fit and center

I need to see how my webpages are looking on an iPhone and iPad on my windows desktop. Is this possible?

A quick search yielded some iPhone testing sites, which seemed like what I wanted. However, they are wildly inaccurate when I compared against my own iPhone! I really need something that is as close to 100% accurate as possible.

Does XCode have a simulator that is 100% accurate? I understand I&#39;d need a Mac to run XCode...

iPhone/iPad browser simulator?

I have a horizontal `UICollectionView` which works fine and scrolls. When I tap an item I update my data and call `reloadData`. This works and the new data is displayed in the `UICollectionView`.
The problem is the scroll position doesn&#39;t change and it is still viewing the last place. I want to reset the scrolling to the top (Or left in my case). How can I do this?

Reset scroll on UICollectionView

I want to customize `UITableView` header for each section. So far, I&#39;ve implemented 

    -(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
this `UITabelViewDelegate` method. What I want to do is to get current header for each section and just add `UILabel` as a subview. 

So far, I&#39;m not able to accomplish that. Because, I couldn&#39;t find anything to get default section header. First question,**is there any way to get default section header**?

If it&#39;s not possible, I need to create a container view which is a `UIView` but,this time I need to set default background color,shadow color etc. Because, if you look carefully into section&#39;s header, it&#39;s already customized. 

How can I get these default values for each section header?

Customize UITableView header section

What I&#39;m using the tap event for is very time-sensitive, so I&#39;m curious if it&#39;s possible to make UITapGestureRecognizer activate when the user simply touches down, rather than requiring them to touch up as well?

UITapGestureRecognizer - make it work on touch down, not touch up?

Upon cell selection, I want to handle changing the cell appearance. I figured the delegate method `collectionView:didSelectItemAtIndexPath:` &amp; `collectionView:didDeselectItemAtIndexPath:` is where I should edit the cell.

    -(void)collectionView:(UICollectionView *)collectionView 
           didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
        
        DatasetCell *datasetCell = 
          (DatasetCell *)[collectionView cellForItemAtIndexPath:indexPath];
        
        [datasetCell replaceHeaderGradientWith:[UIColor skyBlueHeaderGradient]];
        datasetCell.backgroundColor = [UIColor skyBlueColor];
    }

###and

    -(void)collectionView:(UICollectionView *)collectionView 
           didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {
        
        DatasetCell *datasetCell = 
          (DatasetCell *)[collectionView cellForItemAtIndexPath:indexPath];
        
        [datasetCell replaceHeaderGradientWith:[UIColor grayGradient]];
        datasetCell.backgroundColor = [UIColor myDarkGrayColor];
    }


This works fine, except when the cell gets reused. If I select cell at index (0, 0), it changes the appearance but when I scroll down, there is another cell in the selected state.

I believe I should use the `UICollectionViewCell` method `-(void)prepareForReuse` to prep the cell for resuse (ie, set the cell appearance to non selected state) but its giving me difficulties.

    -(void)prepareForReuse {
        if ( self.selected ) {
            [self replaceHeaderGradientWith:[UIColor skyBlueHeaderGradient]];
            self.backgroundColor = [UIColor skyBlueColor];
        } else {
            [self replaceHeaderGradientWith:[UIColor grayGradient]];
            self.backgroundColor = [UIColor myDarkGrayColor];
        }
    }

When I scroll back to the top, the cell at index (0, 0) is in the deselected state.

When I just used the cell.backgroundView property, to prevent this from happening was to:

    -(void)prepareForReuse {
        self.selected = FALSE;
    }

and the selection state worked as intended.

Any ideas?

UICollectionView cell selection and cell reuse

I am trying to understand the correct way of getting an `NSString` from a `CFStringRef` in ARC?
Same for going the opposite direction, `CFStringRef` to `NSString` in ARC?

What is the correct way to do this without creating memory leaks?

NSString to CFStringRef and CFStringRef to NSString in ARC?

I have the following data saved as an `NSString` : 

     {
        Key = ID;
        Value =         {
            Content = 268;
            Type = Text;
        };
    },
        {
        Key = ContractTemplateId;
        Value =         {
            Content = 65;
            Type = Text;
        };
    },

I want to convert this data to an `NSDictionary` containing the key value pairs.

I am trying first to convert the `NSString` to a **JSON** objects as follows :

     NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
    id json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];

However when I try :

    NSString * test = [json objectForKey:@&quot;ID&quot;];
    NSLog(@&quot;TEST IS %@&quot;, test);

I receive the value as `NULL`. 

Can anyone suggest what is the problem ?


Converting NSString to NSDictionary / JSON

In iOS 7, the method:

    - (CGSize)sizeWithFont:(UIFont *)font
         constrainedToSize:(CGSize)size
             lineBreakMode:(NSLineBreakMode)lineBreakMode 

and the method:

    - (CGSize)sizeWithFont:(UIFont *)font

are deprecated. How can I replace 

    CGSize size = [string sizeWithFont:font
                     constrainedToSize:constrainSize
                         lineBreakMode:NSLineBreakByWordWrapping];

and:

    CGSize size = [string sizeWithFont:font];


Replacement for deprecated -sizeWithFont:constrainedToSize:lineBreakMode: in iOS 7?

In iOS7, `sizeWithFont` is deprecated, so I am using `boundingRectWithSize`(which returns a CGRect value). My code:


     UIFont *fontText = [UIFont fontWithName:[AppHandlers zHandler].fontName size:16];
                        // you can use your font.
                
     CGSize maximumLabelSize = CGSizeMake(310, 9999);
    
     CGRect textRect = [myString boundingRectWithSize:maximumLabelSize   
                                 options:NSStringDrawingUsesLineFragmentOrigin
                                 attributes:@{NSFontAttributeName:fontText}
                                 context:nil];
                
     expectedLabelSize = CGSizeMake(textRect.size.width, textRect.size.height);


In `textRect`, I&#39;m getting a size greater than my `maximumLabelSize`, a different size than when using `sizeWithFont`. How can I resolve this issue?

sizeWithFont method is deprecated. boundingRectWithSize returns an unexpected value

In `Objective-C` the code to check for a substring in an `NSString` is: 

    NSString *string = @&quot;hello Swift&quot;;
    NSRange textRange =[string rangeOfString:@&quot;Swift&quot;];
    if(textRange.location != NSNotFound)
    {
        NSLog(@&quot;exists&quot;);
    }

But how do I do this in Swift?

Content Type	Original Author	Original Content on Stackoverflow
Question	Alex	View Question on Stackoverflow
Solution 1 - Ios	tc.	View Answer on Stackoverflow
Solution 2 - Ios	Shamsudheen TK	View Answer on Stackoverflow

How to insert new line \n from UILabel text which typed in IB?

Ios Problem Overview

Ios Solutions

Solution 1 - Ios

Solution 2 - Ios

GMSPolyline very large memory spike

Simple caret (^) at end of Windows batch file consumes all memory

Attributions