I&#39;m trying to create an `NSTimer` in `Swift` but I&#39;m having some trouble.

    NSTimer(timeInterval: 1, target: self, selector: test(), userInfo: nil, repeats: true)

*`test()` is a function in the same class.*

---
I get an error in the editor: 

&gt; Could not find an overload for &#39;init&#39; that accepts the supplied
&gt; arguments

When I change `selector: test()` to `selector: nil` the error disappears.

I&#39;ve tried:

 - `selector: test()`
 - `selector: test`
 - `selector: Selector(test())`

But nothing works and I can&#39;t find a solution in the references.

@selector() in Swift?

I&#39;ve googled but not been able to find out what the swift equivalent to `respondsToSelector:` is.

This is the only thing I could find (https://stackoverflow.com/questions/24142906/swift-alternative-to-respondstoselector) but isn&#39;t too relevant in my case as its checking the existence of the delegate, I don&#39;t have a delegate I just want to check if a new API exists or not when running on the device and if not fall back to a previous version of the api.

What is the Swift equivalent of respondsToSelector?

I created a button and added an action for it, but as soon as it invoked, I got this error:

    -[NSCFDictionary numberButtonClick:]: unrecognized selector sent to instance
     0x3d03ac0 2010-03-16 22:23:58.811
     Money[8056:207] *** Terminating app
     due to uncaught exception
     &#39;NSInvalidArgumentException&#39;, reason:&#39;*** -[NSCFDictionary numberButtonClick:]:  unrecognized selector sent to instance 0x3d03ac0&#39;

This is my code:

    - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
        if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
		    UIButton *numberButton = [UIButton buttonWithType:UIButtonTypeCustom];        
		    numberButton.frame = CGRectMake(10, 435, 46, 38);
		    [numberButton setImage:[UIImage imageNamed:@&quot;one.png&quot;] forState:UIControlStateNormal];
		    [numberButton addTarget:self action:@selector(numberButtonClick:) forControlEvents:UIControlEventTouchUpInside];
		    [self.view addSubview: numberButton]; 
	    }
    return self;
    }

    -(IBAction)numberButtonClick:(id)sender{
	    NSLog(@&quot;---&quot;);
    }


&quot;unrecognized selector sent to instance&quot; error in Objective-C

I want to use a selector on an NSObject instance *without* the need for an implemented protocol. For example, there&#39;s a category method that should set an error property if the NSObject instance it&#39;s called on supports it. This is the code, and the code works as intended:

    if ([self respondsToSelector:@selector(setError:)])
    {
        [self performSelector:@selector(setError:) withObject:[NSError errorWithDomain:@&quot;SomeDomain&quot; code:1 userInfo:nil]];
    }

However, the compiler doesn&#39;t see any method around with the setError: signature, so it gives me a warning, for each line that contains the `@selector(setError:)` snippet:

    Undeclared selector &#39;setError:&#39;

I don&#39;t want to have to declare a protocol to get rid of this warning, because I don&#39;t want all classes that may use this to implement anything special. Just by convention I want them to have a `setError:` method or property.

Is this doable? How?

Cheers,  
EP

How to get rid of the &#39;undeclared selector&#39; warning

In MyClass.m, I&#39;ve defined

    - (void) myTest: (NSString *) withAString{
    	NSLog(@&quot;hi, %@&quot;, withAString);
    }
    	
and the appropriate declaration in MyClass.h . Later I want to call

    [self performSelector:@selector(mytest:withAString:) withObject: mystring];


in MyClass.m but I get an error similar to
*** Terminating app due to uncaught exception &#39;NSInvalidArgumentException&#39;, reason: &#39;*** -[MyClass myTest:withAtring:]: unrecognized selector sent to instance 0xe421f0&#39;


I tried a simpler case with a selector that took no arguments that printed a string to console and that worked just fine. What&#39;s wrong with the code and how can I fix it? Thanks.

Objective-C: Calling selectors with multiple arguments

This is a button selector such that when normal it appears red, when pressed it appears grey.

I would like to ask how could the code be further directly modified such that when PRESSED the text size and color could also change? Many thanks!


&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
&lt;selector xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt;

    &lt;item android:state_pressed=&quot;true&quot; &gt;         
        &lt;shape xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt; 
            &lt;stroke android:width=&quot;2dp&quot; android:color=&quot;@color/black&quot; /&gt;
            &lt;solid android:color=&quot;@color/grey&quot;/&gt;
            &lt;padding android:left=&quot;5dp&quot; android:top=&quot;2dp&quot; 
                android:right=&quot;5dp&quot; android:bottom=&quot;2dp&quot; /&gt; 
            &lt;corners android:radius=&quot;5dp&quot; /&gt; 
        &lt;/shape&gt;    
    &lt;/item&gt;

    &lt;item&gt;
        &lt;shape xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt; 
            &lt;stroke android:width=&quot;2dp&quot; android:color=&quot;@color/black&quot; /&gt;
            &lt;solid android:color=&quot;#FF6699&quot;/&gt;
            &lt;padding android:left=&quot;5dp&quot; android:top=&quot;2dp&quot; 
                android:right=&quot;5dp&quot; android:bottom=&quot;2dp&quot; /&gt; 
            &lt;corners android:radius=&quot;5dp&quot; /&gt; 
        &lt;/shape&gt;
    &lt;/item&gt;

&lt;/selector&gt;
 	

android button selector

First, I&#39;m not sure I really understand what a selector is.   From my understanding, it&#39;s the name of a method, and you can assign it to a class of type &#39;SEL&#39; and then run methods such as respondToSelector to see if the receiver implements that method.   Can someone offer up a better explanation?

Secondly, to this point, I have the following code:  

    NSString *thing = @&quot;Hello, this is Craig&quot;;
    	
    SEL sel = @selector(lowercaseString:);
    NSString *lower = (([thing respondsToSelector:sel]) ? @&quot;YES&quot; : @&quot;NO&quot;);
    NSLog (@&quot;Responds to lowercaseString: %@&quot;, lower);
    if ([thing respondsToSelector:sel]) //(lower == @&quot;YES&quot;)
    	NSLog(@&quot;lowercaseString is: %@&quot;, [thing lowercaseString]);

However, even though `thing` is clearly a kind of NSString, and should respond to lowercaseString, I cannot get the &#39;respondsToSelector&#39; conditional to return &quot;YES&quot;...

Selectors in Objective-C?

does anybody know if it is possible to cancel already queued selector events from the event stack or timer stack (or whatever mechanism it is that is utilized by the API) when you call `performSelector:withObject:afterDelay`?

I was using this event stack to alter the attributes of an image within a TabBar tab, and would sometimes queue up to 10 seconds worth of changes in one quickly executed for loop... maybe 5 milliseconds or so.

the problem arises if the user switches tabs... like say I have the image alterations queued for an image that is displayed as soon as Tab #4 is enabled, and then the user quickly switches to Tab #3 and then right back to Tab #4... this would then re-queue another 10 seconds worth of alterations while the old queue was still playing, probably around 2 or 3 seconds in to the queue if switched quick enough... but even arriving at 5 seconds in to the stream was a problem.

so I needed some way to cancel the old stack of changes before putting a new stack on...

I&#39;m writing this query in the past tense because I already came up with an alternative solution to this problem by adding a hawk-eyed event filter on the playback function. however I am still curious if event cancellation is possible, because I have a feeling such knowledge will come in handy in the future. thank you for any assistance rendered :)



cancelling queued performSelector:afterDelay calls

I&#39;m still kind of new to Objective-C and I&#39;m wondering what is the difference between the following two statements?

    [object performSelector:@selector(doSomething)]; 

    [object doSomething];

Using -performSelector: vs. just calling the method

I am trying to make a button with a selector my button can have the following states:

 - Enabled/Disabled
 - Pressed/Not Pressed

According to the states mentioned above. I need to manipulate the button&#39;s:

 - Text color 
 - background image

The button starts off my being disabled so it should have the disabled textColor and the disabled button background. But I can see the default textColor (specified in style) and NO background image!

Here is my selector button_selector.xml

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    
    &lt;selector xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt;
        
        &lt;item android:state_pressed=&quot;false&quot;
            android:state_enabled=&quot;false&quot;
            android:textColor=&quot;#9D9FA2&quot;
            android:drawable=&quot;@drawable/button&quot; /&gt;    
        
        &lt;item android:state_pressed=&quot;true&quot;
            android:state_enabled=&quot;true&quot;
            android:drawable=&quot;@drawable/button_pressed&quot;/&gt;
        
        &lt;item android:state_pressed=&quot;true&quot;
            android:state_enabled=&quot;false&quot;
            android:textColor=&quot;#9D9FA2&quot;
            android:drawable=&quot;@drawable/button&quot;/&gt;
    
        &lt;item android:state_pressed=&quot;false&quot;
            android:state_enabled=&quot;true&quot;
            android:drawable=&quot;@drawable/button&quot;/&gt;    
        
    &lt;/selector&gt;

And here is my button declaration in the my layout.xml

		&lt;Button android:id=&quot;@+id/reserve_button&quot;
		  	android:text=&quot;@string/reserve_button&quot;
			android:layout_width=&quot;120dp&quot;
			android:layout_height=&quot;40dp&quot;
			android:layout_marginTop=&quot;10dp&quot;
			android:layout_marginLeft=&quot;20dp&quot;
			android:paddingRight=&quot;15dp&quot;
			android:layout_gravity=&quot;left&quot;
			style=&quot;@style/buttonStyle&quot;
			android:background=&quot;@drawable/button_selector&quot; /&gt;

And finally this is my style (where my default textColor is set)

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    
     &lt;resources&gt;
    	
    	 &lt;style name=&quot;buttonStyle&quot;&gt;
    	  &lt;item name=&quot;android:textStyle&quot;&gt;bold&lt;/item&gt;
    	  &lt;item name=&quot;android:textColor&quot;&gt;#282780&lt;/item&gt;
    	  &lt;item name=&quot;android:textSize&quot;&gt;18sp&lt;/item&gt;
    	 &lt;/style&gt;
    	 
    &lt;/resources&gt;

Please help!



Android: textColor of disabled button in selector not showing?

In Swift, I see some methods like:

    @objc private func doubleTapGestureRecognized(recognizer: UITapGestureRecognizer)

I was wondering, when to use @objc? I read some documents, but they are saying when you want it to be callable in Objective-C, you should add @objc flag

However, this is a private function in Swift, what does the @obj do?


When to use @objc in Swift?

I am an iOS newbie. I have a selector method as follows - 

    - (void) fooFirstInput:(NSString*) first secondInput:(NSString*) second
    {
    
    }

I am trying to implement something like this - 

    [self performSelector:@selector(fooFirstInput:secondInput:) withObject:@&quot;first&quot; withObject:@&quot;second&quot; afterDelay:15.0];

But that gives me an error saying -

    Instance method -performSelector:withObject:withObject:afterDelay: not found

Any ideas as to what I am missing?

iOS - How to implement a performSelector with multiple arguments and with afterDelay?

I&#39;m programmatically adding a UITapGestureRecognizer to one of my views:

    let gesture = UITapGestureRecognizer(target: self, action: #selector(self.handleTap(modelObj:myModelObj)))
        
    self.imageView.addGestureRecognizer(gesture)

    func handleTap(modelObj: Model) {
      // Doing stuff with model object here
    }

The first problem I encountered was &quot;Argument of &#39;#selector&#39; does not refer to an &#39;@Objc&#39; method, property, or initializer.

Cool, so I added @objc to the handleTap signature:

    @objc func handleTap(modelObj: Model) {
      // Doing stuff with model object here
    }

Now I&#39;m getting the error &quot;Method cannot be marked @objc because the type of the parameter cannot be represented in Objective-C.

It&#39;s just an image of the map of a building, with some pin images indicating the location of points of interest. When the user taps one of these pins I&#39;d like to know which point of interest they tapped, and I have a model object which describes these points of interest. I use this model object to give the pin image it&#39;s coordinates on the map so I thought it would have been easy for me to just send the object to the gesture handler.


Passing arguments to selector in Swift

In Objective-C, you can&#39;t declare method names where the last component doesn&#39;t take an argument. For example, the following is illegal.

    -(void)take:(id)theMoney andRun;
    -(void)take:(id)yourMedicine andDontComplain;

Why was Objective-C designed this way? Was it just an artifact of Smalltalk that no one saw a need to be rid of? 

This limitation makes sense in Smalltalk, since Smalltalk doesn&#39;t have delimiters around message invocation, so the final component would be interpreted as a unary message to the last argument. For example, `BillyAndBobby take:&#39;$100&#39; andRun` would be parsed as `BillyAndBobby take:(&#39;$100&#39; andRun)`. This doesn&#39;t matter in Objective-C where square brackets are required.

Supporting parameterless selector components wouldn&#39;t gain us much in all the usual ways a language is measured, as the method name a programmer picks (e.g. `runWith:` rather than `take:andRun`) doesn&#39;t affect the functional semantics of a program, nor the expressiveness of the language. Indeed, a program with parameterless components is alpha equivalent to one without. I&#39;m thus not interested in answers that state such a feature isn&#39;t necessary (unless that was the stated reasons of the Objective-C designers; does anyone happen to know Brad Cox or Tom Love? Are they here?) or that say how to write method names so the feature isn&#39;t needed. The primary benefit is readability and writability (which is like readability, only... you know), as it would mean you could write method names that even more closely resemble natural language sentences. The likes of [`-(BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication*)theApplication`][1] (which Matt Gallagher points out [on &quot;Cocoa With Love&quot;][2] is a little bit confusing when you drop the formal parameter) could be named `-(BOOL)application:(NSApplication*)theApplication shouldTerminateAfterLastWindowClosed`, thus placing the parameter immediately next to the appropriate noun.

Apple&#39;s Objective-C runtime (for example) is perfectly capable of handling these kind of selectors, so why not the compiler? Why not support them in method names as well?

    #import &lt;Foundation/Foundation.h&gt;
    #import &lt;objc/runtime.h&gt;
    
    @interface Potrzebie : NSObject
    -(void)take:(id)thing;
    @end

    @implementation Potrzebie
    +(void)initialize {
        SEL take_andRun = NSSelectorFromString(@&quot;take:andRun&quot;);
        IMP take_ = class_getMethodImplementation(self, @selector(take:));
        if (take_) {
            if (NO == class_addMethod(self, take_andRun, take_, &quot;@@:@&quot;)) {
                NSLog(@&quot;Couldn&#39;t add selector &#39;%@&#39; to class %s.&quot;, 
                      NSStringFromSelector(take_andRun), 
                      class_getName(self));
            }
        } else {
            NSLog(@&quot;Couldn&#39;t find method &#39;take:&#39;.&quot;);
        }
    }
    
    -(void)take:(id)thing {
        NSLog(@&quot;-take: (actually %@) %@&quot;,NSStringFromSelector(_cmd), thing);
    }
    @end
    
    int main() {
        NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    
        Potrzebie *axolotl=[[Potrzebie alloc] init];
        [axolotl take:@&quot;paradichloroaminobenzaldehyde&quot;];
        [axolotl performSelector:NSSelectorFromString(@&quot;take:andRun&quot;) 
                      withObject:@&quot;$100&quot;];
        [axolotl release];
    
        [pool release];
        return 0;
    }


  [1]: http://developer.apple.com/library/mac/documentation/Cocoa/Reference/NSApplicationDelegate_Protocol/Reference/Reference.html#//apple_ref/occ/intfm/NSApplicationDelegate/applicationShouldTerminateAfterLastWindowClosed:
  [2]: http://cocoawithlove.com/2009/06/method-names-in-objective-c.html

Why must the last part of an Objective-C method name take an argument (when there is more than one part)?

I have applied a shape for a button like:

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;

	&lt;shape xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
		   android:shape=&quot;rectangle&quot; &gt;
		&lt;gradient android:startColor=&quot;#DD000000&quot; android:endColor=&quot;#DD2d2d2d&quot;  android:angle=&quot;90&quot;&gt;&lt;/gradient&gt;
		&lt;corners android:radius=&quot;15dip&quot;&gt;&lt;/corners&gt;
		 
	&lt;/shape&gt;

Now I want to use a selector like:

    &lt;selector xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt;
    &lt;item android:drawable=&quot;@drawable/active&quot;
          android:state_pressed=&quot;true&quot; /&gt;
    &lt;item android:drawable=&quot;@drawable/passive&quot;/&gt;
&lt;/selector&gt;

for this Button as well. Is it possible ...???

How to apply shape and selector simultaneously for Button?

Can you help me with this jQuery selector?

    $(&quot;.auctiondiv .auctiondivleftcontainer .countdown&quot;).each(function () {
        var newValue = parseInt($(this).text(), 10) - 1;
        $(this).text(newValue);
    
        if (newValue == 0) {
            $(this).parent().fadeOut();
            chat.verify($(this).parent().parent().attr(&#39;id&#39;));
        }
    });

Basically, I want to select the element with .bidbutton class that belongs in the same parent as the .countdown in the each loop:

    &lt;div class=&quot;auctiondivleftcontainer&quot;&gt;
        &lt;p class=&quot;countdown&quot;&gt;0&lt;/p&gt;
        &lt;button class=&quot;btn primary bidbutton&quot;&gt;Lance&lt;/button&gt;                            
    &lt;/div&gt;  

And then apply this to that button:

    $(button here).addClass(&quot;disabled&quot;);
    $(button here).attr(&quot;disabled&quot;, &quot;&quot;);

How do I select a sibling element using jQuery?

I&#39;m using the iPhone SDK (3.0) and I&#39;m trying to create an **array of selectors** to invoke a variety of methods within one class.

Obviously, I&#39;m doing something wrong (I think @selector isn&#39;t considered a class and so stuffing them into an NSArray isn&#39;t working).

I tried this, but it&#39;s obviously wrong.  

**Is there a simple way to have an array of selectors like this?  Or is there a better way to iterate through a collection of methods?**

    selectors = [NSArray arrayWithObjects:
                              @selector(method1),
                              @selector(method2),
                              @selector(method3),
                              @selector(method4),
                              @selector(method5),
                              @selector(method6),
                              @selector(method7), nil];
    
    for (int i = 0; i &lt; [selectors count]; i++) {
        if ([self performSelector:[selectors objectAtIndex:i]]) // do stuff;
    }

How to create an &quot;array of selectors&quot;

[**NOTE** This question was originally formulated under Swift 2.2. It has been revised for Swift 4, involving two important language changes: the first method parameter external is no longer automatically suppressed, and a selector must be explicitly exposed to Objective-C.]

Let&#39;s say I have these two methods in my class:

    @objc func test() {}
    @objc func test(_ sender:AnyObject?) {}

Now I want to use Swift 2.2&#39;s new `#selector` syntax to make a selector corresponding to the _first_ of these methods, `func test()`. How do I do it? When I try this:

    let selector = #selector(test) // error

... I get an error, &quot;Ambiguous use of `test()`.&quot; But if I say this:

    let selector = #selector(test(_:)) // ok, but...

... the error goes away, but I&#39;m now referring to the _wrong method_, the one _with_ a parameter. I want to refer to the one _without_ any parameter. How do I do it?

[Note: the example is not artificial. NSObject has both Objective-C `copy` and `copy:` instance methods, Swift `copy()` and `copy(sender:AnyObject?)`; so the problem can easily arise in real life.]

How do I resolve &quot;ambiguous use of&quot; compile error with Swift #selector syntax?

What the difference between a method, a selector and a message in Objective-C? 

What&#39;s the difference between a method and a selector?

I need to detect when the user taps the &quot;back&quot; button on the navigation bar, in order to perform some operations when that occurs. I&#39;m trying to set manually an action to such button, this way:

    [self.navigationItem.backBarButtonItem setAction:@selector(performBackNavigation:)];

    - (void)performBackNavigation:(id)sender
    {
       // Do operations

       [self.navigationController popViewControllerAnimated:NO];
    }

I firstly placed that code in the view controller itself, but I found that `self.navigationItem.backBarButtonItem` seemed to be `nil`, so I moved that same code to the parent view controller, which pushes the former to the navigation stack. But I&#39;m neither able to make it work. I&#39;ve read some posts regarding this issue, and some of them said that the selector needs to be set at the parent view controller, but for me it doesn&#39;t work anyway... What could I&#39;m doing wrong?

Thanks

Trying to handle &quot;back&quot; navigation button action in iOS

I have an `ImageButton` in my app and I need to change the tint of the image when the button is `pressed/focused`. I have the `ImageButton` set to get its &lt;code&gt;src&lt;/code&gt; from an XML file which as follows:

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;selector xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt;
    	&lt;!-- pressed --&gt;
    	&lt;item 
    		android:state_pressed=&quot;true&quot;
    		android:tint=&quot;@color/black&quot;
    		android:drawable=&quot;@drawable/search&quot;
    		/&gt;
    	
    	&lt;!-- focused --&gt;
    	&lt;item 
    		android:state_focused=&quot;true&quot;
    		android:tint=&quot;@color/black&quot;
    		android:drawable=&quot;@drawable/search&quot;
    		/&gt;
    	
    	&lt;!-- default --&gt;
    	&lt;item
    		android:tint=&quot;@null&quot;
    		android:drawable=&quot;@drawable/search&quot;
    		/&gt;
    
    &lt;/selector&gt;

However the tint isn&#39;t applied when the `ImageButton` is pressed or focused - the image just displays as normal. The color black is defined as `#000000` as always. Any ideas?

How do I change the tint of an ImageButton on focus/press

here is my `button` object 


        let loginRegisterButton:UIButton = {
        let button = UIButton(type: .system)
        button.backgroundColor = UIColor(r: 50 , g: 80, b: 130)
        button.setTitle(&quot;Register&quot;, for: .normal)
        button.translatesAutoresizingMaskIntoConstraints = false
        button.setTitleColor(.white, for: .normal)
        button.addTarget(self, action:#selector(handleRegister), for: .touchUpInside)
        return button
    }()


and here is my function 

        func handleRegister(){
      
        FIRAuth.auth()?.createUser(withEmail: email, password: password,completion: { (user, error) in
            
            if error != nil
            { print(&quot;Error Occured&quot;)}
                
            else
            {print(&quot;Successfully Authenticated&quot;)}
        })        
    }


I&#39;m getting compile error, if addTarget removed it compiles successfully 

How to use addTarget method in swift 3

How can I pass a parameter to the method called by a NSTimer? My timer looks like this:

    [NSTimer scheduledTimerWithTimeInterval:4 target:self selector:@selector(updateBusLocation) userInfo:nil repeats:YES];

and I want to be able to pass a string to the method updateBusLocation. Also, where am supposed to define the method updateBusLocation? In the same .m file that I create the timer?

**EDIT:**

Actually I am still having problems. I am getting the error message:

Terminating app due to uncaught exception &#39;NSInvalidArgumentException&#39;, reason: &#39;*** -[MapKitDisplayViewController updateBusLocation]: unrecognized selector sent to instance 0x4623600&#39;

Here is my code:

    - (IBAction) showBus {
	
	//do something
	
	[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(updateBusLocation) userInfo:txtFieldData repeats:YES];
	[txtFieldData release];
     }


     - (void) updateBusLocation:(NSTimer*)theTimer
     {
	      NSLog(@&quot;timer method was called&quot;);
	      NSString *txtFieldData = [[NSString alloc] initWithString:(NSString*)[theTimer userInfo]];
	if(txtFieldData == busNum.text) {
		//do something else
	    }
        }



EDIT #2:
Never mind your example code works fine thanks for the help.


Passing parameters to the method called by a NSTimer

I have a code sample that gets a `SEL` from the current object, 

    SEL callback = @selector(mymethod:parameter2);

And I have a method like 

     -(void)mymethod:(id)v1 parameter2;(NSString*)v2 {
    }

Now I need to move `mymethod` to another object, say `myDelegate`.

I have tried:

    SEL callback = @selector(myDelegate, mymethod:parameter2);

but it won&#39;t compile. 



Creating a selector from a method name with parameters

Here is what I used previously,

    var barButtonItem = UIBarButtonItem(image: backImgs, style: UIBarButtonItemStyle.plain, target: self, action: Selector(&quot;menuButtonTapped:&quot;))

But there is some syntax changes for Swift 3.

How to programmatically set action for barButtonItem in swift 3?

I&#39;d like to declare a property with type `SEL` like this:

    @property (nonatomic, assign) SEL mySelector;

Is &quot;`assign`&quot; correct here? Perhaps `assign` can be omitted?

Property with type SEL in Objective-c

I am trying to figure out the syntax for selecting a nth-child of an element by its class, however I don&#39;t know the exact path to the element. I can&#39;t do `$(&#39;parent &gt; child &gt; grandchild &gt; hereIam&#39;);`

So basically I need to be able to say 

    $(&#39;#thisElement&#39;).AllRelativesWithClass(&#39;.classToSelect&#39;)

How exactly do I do that?

jQuery select child element by class with unknown path

Is there a way to store a selector in an `NSDictionary`, without storing it as an `NSString`?

Store selector as value in an NSDictionary

For the method:

    [NSThread detachNewThreadSelector:@selector(method:) toTarget:self withObject:(id)SELECTOR];

How do I pass in a @selector? I tried casting it to (id) to make it compile, but it crashes in runtime.

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More specifically, I have a method like this:

    +(void)method1:(SEL)selector{
	[NSThread detachNewThreadSelector:@selector(method2:) toTarget:self withObject:selector];	
    }

It crashes. How do I pass in the selector without crashing, so that the new thread can call the selector when the thread is ready?

How to I pass @selector as a parameter?

I want to pass the movie url from my dynamically generated button to MediaPlayer:

    [button addTarget:self action:@selector(buttonPressed:) withObject:[speakers_mp4 objectAtIndex:[indexPath row]] forControlEvents:UIControlEventTouchUpInside];

but `action:@selector() withObject:` does not work?

Is there any other solution?

Thanks for help!

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