It returns the number of seconds, as an `NSTimeInterval` value.

From [this documentation page][1]:

&gt;NSTimeInterval is always specified in seconds; it yields sub-millisecond precision over a range of 10,000 years.

[1]:https://developer.apple.com/documentation/foundation/nstimeinterval?language=objc#

Well the `NSDate` [docs][1] show the function prototype as:

`- (NSTimeInterval)timeIntervalSinceDate:(NSDate *)anotherDate`

And the Foundation Data Types [doc][2] states:

&gt; NSTimeInterval is always specified in seconds; it yields
&gt; sub-millisecond precision over a range of 10,000 years.


  [1]: http://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//apple_ref/occ/instm/NSDate/timeIntervalSinceDate:
  [2]: http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Miscellaneous/Foundation_DataTypes/Reference/reference.html

In my app, I write to an excel file. After writing, the user is able to view the file by opening it. But if the user forgets to close the file before any further writing, a warning message should appear. So I need a way to check this file is open before the writing process. Could you supply me with some python code to do this task?

check if a file is open in Python

Is this a valid URL? (from a standard point of view)

    http://test.com/some/path/version/1.2/thing 



Can urls contain dots in the path part?

What unit of time does timeIntervalSinceDate return? Is it seconds, milliseconds or something else?

The documentation says that it returns an NSTimeInterval, but what *unit of time* is that value?

What unit of time does timeIntervalSinceDate return?

What unit of time does timeIntervalSinceDate return? Is it seconds, milliseconds or something else?
The documentation says that it returns an NSTimeInterval, but what unit of time is that value?

I use the NSUserDefaults dictionary to store basic information such as high scores etc so that when the user closes the app data is not lost. Anyways I use:

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

to store data. If I wish to store a new high score for example then I would do:

    [prefs setInteger:1023 forKey:@&quot;highScore&quot;];
    [prefs synchronize];  //this is needed in case the app is closed. 

and later if I wish to retrieve the high score I would do:

    [prefs integerForKey:@&quot;highScore&quot;];


anyways the point is that I store a lot of other things because the `NSUserDefaults enable` you to store `booleans`, `integers`, `objects` etc.   what method would I have to execute to delete all keys so that NSUserDefaults becomes like the fist time I launch the app?

I am looking for something like:

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    [prefs deleteAllKeysAndObjectsInTheDictionary];

or maybe there is a way of getting all keys and I have to loop through each object but I don&#39;t know how to remove them. 


EDIT:


I have tried :

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    [NSUserDefaults resetStandardUserDefaults];
    [prefs synchronize];

and I still am able to retrieve a high score....



Delete all keys from a NSUserDefaults dictionary iOS

How can I add text alignment attribute to an NSAttributedString to center the text?

Edit:
Am I doing anything wrong? It doesn&#39;t seem to change the alignment.

	CTParagraphStyleSetting setting;
	setting.spec = kCTParagraphStyleSpecifierAlignment;
	setting.valueSize = kCTCenterTextAlignment;
	
	CTParagraphStyleSetting settings[1] = {
		{kCTParagraphStyleSpecifierAlignment, sizeof(CGFloat), &amp;setting},			
	};
	
	CTParagraphStyleRef paragraph = CTParagraphStyleCreate(settings, sizeof(setting));
	
	NSMutableAttributedString *mutableAttributed = [[NSMutableAttributedString alloc] initWithAttributedString:self.attributedString];
	[mutableAttributed addAttributes:[NSDictionary dictionaryWithObjectsAndKeys:(NSObject*)paragraph ,(NSString*) kCTParagraphStyleAttributeName, nil] range:_selectedRange];

NSAttributedString add text alignment

I saw there are several apps on App Store that allow other computers to make a http connection to the iPhone/iPad devices to transfer files.  It seemed like a web service is running on the iOS device.  Just curious how is it done /what class was used?

Thanks.


iOS devices as web server

I have a project that has one target dependency. The target dependency is dependent on a framework called Three20. 

The dependency tree looks like this.

    myProject
       -&gt; myCustomFramework
             -&gt; Three20

When I tried to build and run I get the following error message. 

&gt; Workspace Integrity Couldn&#39;t load Three20.xcodeproj because it is
&gt; already opened from another projet or workspace.

I have only one project open. Any suggestions on why I am getting this message?


Couldn&#39;t load a xcode project because it is already opened from another project or workspace

I have a UIImageView that allows a user to place and hold an image until it can be saved. The problem is, I can&#39;t figure out how to actually save and retrieve the image I&#39;ve placed in the view.

I have retrieved and placed the image in the UIImageView like this:

    //Get Image 
    - (void) getPicture:(id)sender {
        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.allowsEditing = YES;
        picker.sourceType = (sender == myPic) ? UIImagePickerControllerSourceTypeCamera : UIImagePickerControllerSourceTypeSavedPhotosAlbum;
        [self presentModalViewController:picker animated:YES];
        [picker release];
    }
    
    
    - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage (UIImage *)image editingInfo:(NSDictionary *)editingInfo {
        myPic.image = image;
        [picker dismissModalViewControllerAnimated:YES];
    }

It displays the selected image in my UIImageView just fine, but I have no idea how to save it. I&#39;m saving all the other pieces of the view (mostly UITextfield) in Core Data. I&#39;ve searched and searched, and tried many bits of code that people have suggested, but either I&#39;m not entering the code correctly, or those suggestions don&#39;t work with the way I have my code set up. It&#39;s likely the former. I&#39;d like to save the image in the UIImageView using the same action (a save button) I&#39;m using to save the text in the UITextFields. Here&#39;s how I&#39;m saving my UITextField info:
    
    // Handle Save Button
    - (void)save {
    	
    	// Get Info From UI
    	[self.referringObject setValue:self.myInfo.text forKey:@&quot;myInfo&quot;];
    
Like I said earlier, I have tried several methods to get this to work, but can&#39;t get a grasp on it. For the first time in my life I&#39;ve wanted to cause physical harm to an inanimate object, but I&#39;ve managed to restrain myself. 

I&#39;d like to be able to save the image the user places into the UIImageView in the application&#39;s documents folder, and then be able to retrieve it and place it in another UIImageView for display when the user pushes that view onto the stack. Any help is greatly appreciated!

Save An Image To Application Documents Folder From UIView On IOS

How To Add Month To NSDate Object?

    NSDate *someDate = [NSDate Date] + 30Days.....;

How to add one month to an NSDate?

What is the most efficient way to obtain an NSDate object that represents midnight of the current day?

How can I get an NSDate object for today at midnight?

It seems that I can&#39;t subtract 7 days from the current date. This is how i am doing it:
  

    NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSDateComponents *offsetComponents = [[NSDateComponents alloc] init];
    [offsetComponents setDay:-7];
    NSDate *sevenDaysAgo = [gregorian dateByAddingComponents:offsetComponents toDate:[NSDate date] options:0];

SevenDaysAgo gets the same value as the current date.

Please help.


EDIT: In my code I forgot to replace the variable which gets the current date with the right one. So above code is functional.




Subtract 7 days from current date

I want to get the minimum and maximum date from a date picker, but minimum date should be &quot;- 18&quot; of the current date and the maximum date should be &quot;- 100&quot; of current date.

Suppose current year is 2018 then I want minimum date 2000 and maximum date 1918.

What I have done so far is : 

       
    NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSDateComponents *components = [gregorian components:NSYearCalendarUnit fromDate:[NSDate date]];
    
    NSInteger year = [components year];
    
    int mindt = year - 18;
    
    int maxdt = year -100;
     
       // NSDate * MinDate = [components year] - 18;
    
       // NSDate * MaxDate =  [components year] - 100;
    
       // self.datePicker.minimumDate = MinDate;

       // self.datePicker.maximumDate = MaxDate;


but I cant get this integer to my date format..


Minimum and maximum date in UIDatePicker

My system&#39;s  date time is 26 May 22:55 but when i get date with `[NSDate date]` date time is 27 May 02:35 

is it  because of time zone ? 

if yes how to solve this problem, that when i get date time, give me the date of my system and doesn&#39;t check time zone

Content Type	Original Author	Original Content on Stackoverflow
Question	Moshe	View Question on Stackoverflow
Solution 1 - Objective C	esqew	View Answer on Stackoverflow
Solution 2 - Objective C	GarlicFries	View Answer on Stackoverflow

What unit of time does timeIntervalSinceDate return?

Objective C Problem Overview

Objective C Solutions

Solution 1 - Objective C

Solution 2 - Objective C

Can urls contain dots in the path part?

check if a file is open in Python

Attributions