try using this

    [self.view endEditing:YES];

This will hide keyboard if its presented due to a subview of your self.view

I&#39;ve read several articles about this, and I just want to see if I understand this correctly:

Apple will reject your app if you use a Private API...

1. What is the main difference between a &quot;Private API&quot; and a &quot;Non-private API?&quot;

2. Are the &quot;Non-private&quot; APIs only the APIs provided and verified by Apple?

3. Isn&#39;t an API just a way of interacting with a Framework, and a Framework is just a set of encapsulated classes/headers that people can use for trivial purposes?

4. Wouldn&#39;t this mean that I cannot reuse anyone&#39;s code (other than Apple&#39;s) at all in my app?

5. If this is true, whenever a programmer makes his or her own custom classes and methods, isn&#39;t he technically designing a mini Framework just for his specific purpose? So wouldn&#39;t this mean that he is using his own private API?

6. What would even be the difference between using someone else&#39;s classes/methods alongside my classes/methods, how could they even tell the difference, and why would this be a problem?

My understanding of this sounds absurd, and don&#39;t believe I am understanding what a &quot;Private API&quot; is correctly. I did read that it was to protect against any changes in the API that could render your App dysfunctional. Does this mean APIs are linked during run time (as opposed to compile time) and can be updated automatically without you knowing or something? (See, I was originally thinking of APIs/frameworks as being set in stone whenever you compile, maybe this is where I am wrong)

Can someone please help me out? I&#39;m really confused about this policy. Thank you!

What exactly is a Private API, and why will Apple reject an iOS App if one is used?

I would like to find the greatest common divisor using JavaScript. 

Anyone done that before and willing to share?

JS how to find the greatest common divisor

I&#39;m working on an iphone app with multiple `textfields` on a `viewcontroller`. I&#39;m a bit confused with `resignfirstresponder` and setting `textfield delegates`.I&#39;ve been able to resign text fields when I set the delegate for one then call `resignfirstresponder` for that particular textfield. 
I have a `view controller` with about 7 text fields and don&#39;t want to call each individually. Does anyone have any example code that will close all of the `textfields` on a `view controller`? Also how do you set the delegate for all textfields? 

Thanks! 





resignFirstResponder for all textfields

<p>I'm working on an iphone app with multiple <code>textfields</code> on a <code>viewcontroller</code>. I'm a bit confused with <code>resignfirstresponder</code> and setting <code>textfield delegates</code>.I've been able to resign text fields when I set the delegate for one then call <code>resignfirstresponder</code> for that particular textfield.
I have a <code>view controller</code> with about 7 text fields and don't want to call each individually. Does anyone have any example code that will close all of the <code>textfields</code> on a <code>view controller</code>? Also how do you set the delegate for all textfields?</p>
<p>Thanks!</p>


I have a method which should support being called from any queue, and should expect to.

It runs some code in a background thread itself, and then uses `dispatch_get_main_queue` when it returns a value to its block argument.

I don&#39;t want it to force it onto the main queue if it wasn&#39;t when it entered the method. Is there a way to get a pointer to the current dispatch queue?

Get current dispatch queue?

I would like to print all values I saved via `NSUserDefaults` without supplying a specific Key. 

Something like printing all values in an array using `for` loop. Is there a way to do so?

Is there a way to get all values in NSUserDefaults?

I&#39;m trying to get my CAGradientLayers, that i&#39;m using to create nice gradient backgrounds, to resize nicely on rotation and modal view presentation, but they will not play ball.

Here is a video I just created showing my problem: Notice the tearing on rotation.

Also please note this video was created by filming the iPhone Simulator on OS X. I have slowed down the animations in the video to highlight my issue.

[Video of Problem...][1]

Here is an Xcode project which I just created (which is the source for the app shown in the video), basically as illustrated the issue occurs on rotation and especially when views are presented modally:

[Xcode Project, modally presenting views with CAGradientLayer backgrounds...][2]

For what it&#39;s worth I understand that using:

        [[self view] setBackgroundColor:[UIColor blackColor]];

does a reasonable job of making the transitions a bit more seamless and less jarring, but if you look at the video when I, whilst currently in landscape mode, modally present a view, you will see why the above code will not help.

Any ideas what I can do to sort this out?

John



  [1]: http://youtu.be/H_TryCoTTx8 &quot;Video of CAGradientLayer Problem&quot;
  [2]: http://www.fileconvoy.com/dfl.php?id=gc669d6a9626a713c999325656a298aba76ffb30af

CAGradientLayer, not resizing nicely, tearing on rotation

I have a UIView, in which I have arranged UIButtons. I want to find the positions of those UIButtons. 

I am aware that `buttons.frame` will give me the positions, but it will give me positions only with respect to its immediate superview. 

Is there is any way we can find the positions of those buttons, withe respect to UIButtons superview&#39;s superview? 

For instance, suppose there is UIView named &quot;firstView&quot;.

Then, I have another UIView, &quot;secondView&quot;. This &quot;SecondView&quot; is a subview of &quot;firstView&quot;. 

Then I have UIButton as a subview on the &quot;secondView&quot;. 

    -&gt;UIViewController.view
    ---&gt;FirstView A
    -------&gt;SecondView B
    ------------&gt;Button

Now, is there any way we can find the position of that UIButton, with respect to &quot;firstView&quot;?


Get position of UIView in respect to its superview&#39;s superview

Greets,
I&#39;m reading that the default behaviour of `UITableView` is to pin section header rows to the top of the table as you scroll through the sections until the next section pushes the previos section row out of view.


I have a `UITableView` inside a `UIViewController` and this does not seem to be the case.

Is that just the defualt behaviour for `UITableViewController`?

Here&#39;s some simplified code based on what I have.
I&#39;ll show the `UIController` interface and each table view method I&#39;ve implemented to create the table view.
I have a helper data source class that helps me index my objects for use with the table.

        @interface MyUIViewController ()&lt;UITableViewDelegate, UITableViewDataSource&gt;
            @property (nonatomic, readonly) UITableView *myTableView;
            @property (nonatomic, readonly) MyCustomHelperDataSource *helperDataSource;
        @end
        
        //when section data is set, get details for each section and reload table on success
        - (void)setSectionData:(NSArray *)sections {
            super.sectionData = sections; //this array drives the sections
            
            //get additional data for section details
            [[RestKitService sharedClient] getSectionDetailsForSection:someId 
            success:^(RKObjectRequestOperation *operation, RKMappingResult *details) {
                NSLog(@&quot;Got section details data&quot;);
                _helperDataSource = [[MyCustomHelperDataSource alloc] initWithSections:sections andDetails:details.array];
                [myTableView reloadData];
            } failure:^(RKObjectRequestOperation *operation, NSError *error) {
                NSLog(@&quot;Failed getting section details&quot;);
            }];
        }
        
        #pragma mark &lt;UITableViewDataSource, UITableViewDelegate&gt;
        
        - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
            if (!_helperDataSource) return 0;
        	return [_helperDataSource countSectionsWithDetails]; //number of section that have details rows, ignore any empty sections
        }
        
        - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
            //get the section object for the current section int
            SectionObject *section = [_helperDataSource sectionObjectForSection:section];
            //return the number of details rows for the section object at this section
            return [_helperDataSource countOfSectionDetails:section.sectionId];
        }
        
        - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
            
            UITableViewCell * cell;
        
            NSString *CellIdentifier = @&quot;SectionDetailCell&quot;;
            
            cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
            if (cell == nil) {
                initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier];
                cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
                cell.textLabel.font = [UIFont systemFontOfSize:12.0f];
            }
            
            //get the detail object for this section
            SectionObject *section = [_helperDataSource sectionObjectForSection:indexPath.section]; 
            
            NSArray* detailsForSection = [_helperDataSource detailsForSection:section.sectionId] ;
            SectionDetail *sd = (SectionDetail*)[detailsForSection objectAtIndex:indexPath.row];
            
            cell.textLabel.text = sd.displayText;
            cell.detailTextLabel.text = sd.subText;
            cell.detailTextLabel.textColor = [UIColor blueTextColor];
            
            return cell;
        }
    
    - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
        return 50.0f;
    }
    
    - (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
        return 30.0f;
    }
    
    - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger) section {
        //get the section object for the current section
        SectionObject *section = [_helperDataSource sectionObjectForSection:section]; 
            
        NSString *title = @&quot;%@ (%d)&quot;;
    
    	return [NSString stringWithFormat:title, section.name, [_helperDataSource countOfSectionDetails:section.sectionId]];
    }
    
    - (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
        UIView *header = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 260, 0)];
        header.autoresizingMask = UIViewAutoresizingFlexibleWidth;
        
        header.backgroundColor = [UIColor darkBackgroundColor];
    
        SSLabel *label = [[SSLabel alloc] initWithFrame:CGRectMake(3, 3, 260, 24)];
        label.font = [UIFont boldSystemFontOfSize:10.0f];
        label.verticalTextAlignment = SSLabelVerticalTextAlignmentMiddle;
        label.backgroundColor = [UIColor clearColor];
        label.text = [self tableView:tableView titleForHeaderInSection:section];
        label.textColor = [UIColor whiteColor];
        label.shadowColor = [UIColor darkGrayColor];
        label.shadowOffset = CGSizeMake(1.0, 1.0);
        [header addSubview:label];
        
        return header;
    }


UITableView with fixed section headers

I have discovered a strange behavior in my application, where a connected `IBOutlet` has its connected view&#39;s frame between the calls in my view controller to `viewWillAppear:` and `viewDidAppear:`. Here is the relevant code in my `UIViewController` subclass:

    -(void)viewWillAppear:(BOOL)animated {
        NSLog(@&quot;%@&quot;, self.scrollView);
    }
    
    -(void)viewDidAppear:(BOOL)animated {
        NSLog(@&quot;%@&quot;, self.scrollView);
    }

and the resulting log output:

    MyApp[61880:c07] &lt;UIScrollView: 0x1057eff0; frame = (0 0; 0 0); clipsToBounds = YES; autoresize = TM+BM; gestureRecognizers = &lt;NSArray: 0x10580100&gt;; layer = &lt;CALayer: 0x1057f210&gt;; contentOffset: {0, 0}&gt;
    MyApp[61880:c07] &lt;UIScrollView: 0x1057eff0; frame = (0 44; 320 416); clipsToBounds = YES; autoresize = TM+BM; gestureRecognizers = &lt;NSArray: 0x10580100&gt;; layer = &lt;CALayer: 0x1057f210&gt;; contentOffset: {0, 0}&gt;

Which clearly shows that the frame is changing between the two calls. I wanted to do setup with the view in the `viewDidLoad` method, but if the content is not available for me to change until it is on the screen, that seems pretty useless. What could be happening?

View frame changes between viewWillAppear: and viewDidAppear:

I have a UITableViewCell which has two UITextFields (without borders). The following constraints are used to set up the horizontal layout. 

`@&quot;|-10-[leftTextField(&gt;=80)]-(&gt;=10)-[rightTextField(&gt;=40)]-10-|&quot;`

Nothing fancy, and works as expected. 

![enter image description here][1]

As you can see the upper textField has the correct size. The lower textField started with an empty text, and because of the empty text it is 80 points wide. When I type text into the editing textField the text scrolls to the left, it does not change its width. 

I don&#39;t like that, the width of the textField should adjust while the user types into that textField. 

In my opinion that should work out of the box. By implementing a `IBAction` for the `UIControlEventEditingChanged` event I can confirm that typing actually changes the `intrinsicContentSize` of the UITextField.  

But well, the width does not change until the textField is no longer the first responder. If I put the cursor into another textField the width of the edited textField is set. That&#39;s a bit late for what I want. 


These commented out lines is what I tried without any success: 

    - (IBAction)textFieldDidChange:(UITextField *)textField {
        [UIView animateWithDuration:0.1 animations:^{
    //        [self.contentView removeConstraints:horizontalConstraints];
    //        [self.contentView addConstraints:horizontalConstraints];
    //        [self.contentView layoutIfNeeded];
    
    //        [self.contentView setNeedsLayout];
    
    //        [self.contentView setNeedsUpdateConstraints];
        }];
        NSLog(@&quot;%@&quot;, NSStringFromCGSize(textField.intrinsicContentSize));
    }

Does anybody know what I am missing? What could I try to make this work? 




  [1]: http://i.stack.imgur.com/Fs0he.png

Resize a UITextField while typing (by using Autolayout)

I&#39;m changing the placeholder text color with the following code, but when I try to add NSFontAttribute I get the compiler error `&quot;too many arguments to method call, expect 2 have 3&quot;`

     UIColor *color = [UIColor blackColor];
            _nameField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@&quot;Your Name&quot; attributes:@{NSForegroundColorAttributeName: color},@{NSFontAttributeName:@&quot;Roboto-Bold&quot;}]; 

**This Works Fine:**

     UIColor *color = [UIColor blackColor];
            _nameField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@&quot;Your Name&quot; attributes:@{NSForegroundColorAttributeName: color}]; 

Changing UITextField Placeholder font

The code below works on iOS6 (and before) but the UITextField does not display in iOS7...any ideas on how to get a UITextField to display in an UIAlterView in iOS7?

    UIAlertView* dialog = [[UIAlertView alloc] init];
    [dialog setDelegate:self];
    [dialog setTitle:@&quot;Enter ESC Score&quot;];
    [dialog setMessage:@&quot; &quot;];
    [dialog addButtonWithTitle:@&quot;Cancel&quot;];
    [dialog addButtonWithTitle:@&quot;OK&quot;];
    dialog.tag = 5;
		
    nameField = [[UITextField alloc] initWithFrame:CGRectMake(20.0, 45.0, 245.0, 25.0)];
    [nameField setKeyboardType:UIKeyboardTypeNumberPad];
    [nameField becomeFirstResponder];
    [nameField setBackgroundColor:[UIColor whiteColor]];
    [dialog addSubview:nameField];
    CGAffineTransform moveUp = CGAffineTransformMakeTranslation(0.0, 0.0);
    [dialog setTransform: moveUp];
    [dialog show];
    [dialog release];
         
    [nameField release];

Code run for iOS6 displays this:

![enter image description here][1]


same code in iOS7 displays this (notice how UITextField is missing and there is no keyboard):

![enter image description here][2]


  [1]: http://i.stack.imgur.com/je6Kw.png
  [2]: http://i.stack.imgur.com/JIvLR.png

Unable to add UITextField to UIAlertView on iOS7...works in iOS 6

I created a `UITextField` programmatically making the `UITextField` a property of the viewController. I need to dismiss the keyboard with the return and the touch on the screen. I was able to get the screen touch to dismiss, but pressing return is not working.  

I&#39;ve seen how to do it with storyboards and by allocating and initializing the `UITextField` object directly without creating it as a property. Possible to do?

### .h
    
    #import &lt;UIKit/UIKit.h&gt;
    
    @interface ViewController : UIViewController &lt;UITextFieldDelegate&gt;
    
    @property (strong, atomic) UITextField *username;
    
    @end
    
    
### .m
    #import &quot;ViewController.h&quot;
    
    @interface ViewController ()
    
    @end
    
    @implementation ViewController
    
    - (void)viewDidLoad
    {
        [super viewDidLoad];
        
        // Do any additional setup after loading the view, typically from a nib.
        
        self.view.backgroundColor = [UIColor blueColor];
        self.username = [[UITextField alloc] initWithFrame:CGRectMake(100, 25, 80, 20)];
        self.username.placeholder = @&quot;Enter your username&quot;;
        self.username.backgroundColor = [UIColor whiteColor];
        self.username.borderStyle = UITextBorderStyleRoundedRect;
        if (self.username.placeholder != nil) {
            self.username.clearsOnBeginEditing = NO;
        }
        _username.delegate = self; 
        
        [self.view addSubview:self.username];
        [_username resignFirstResponder];
        
    }
    
    - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
        NSLog(@&quot;touchesBegan:withEvent:&quot;);
        [self.view endEditing:YES];
        [super touchesBegan:touches withEvent:event];
    }
    
    @end


How to dismiss keyboard iOS programmatically when pressing return

I have UITextView with some text in it. Everything was fine with iOS 6 but now with iOS 7 it leaves the blank space on top and then place the text below the middle of the textview.![enter image description here][1]


  [1]: http://i.stack.imgur.com/vzpUC.png
I didn&#39;t set any contentOffSet. 
Please Help!

Content Type	Original Author	Original Content on Stackoverflow
Question	Andrea F	View Question on Stackoverflow
Solution 1 - Iphone	HarshIT	View Answer on Stackoverflow

resignFirstResponder for all textfields

Iphone Problem Overview

Iphone Solutions

Solution 1 - Iphone

JS how to find the greatest common divisor

What exactly is a Private API, and why will Apple reject an iOS App if one is used?

Attributions