Passing parameters on button action selector

Question

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

User · Answer

I have another solution in some cases   store your parameter in a hidden UILabel  then add this UILabel as subview of UIButton   when button is clicked  we can have a check on UIButton s all subviews  normally only 2 UILabel in it   one is UIButton s title  the other is the one you just added  read that UILabel s text property  you will get the parameter    This only apply for text parameter

User · Answer

You can sub-class a UIButton named MyButton  and pass the parameter by MyButton s properties   Then  get the parameter back from  id sender

User · Answer

Add the hidden titleLabel to the parameter is the best solution   I generated a array arrUrl which store the NSURL of the mov files in my phone album by enumerate assets block   After that   I grab on Frame  lets say  get the frame at 3 00 second in the movie file  and generated the image file from the frame    Next  loop over the arrUrl  and use program generate the button with image in the button  append the button to subview of the self view   Because I have to pass the movie Url to playMovie function  I have to assign the button titleLabel text with one movie url  and the the button events function  retrieve the url from the buttontitleLable txt   - void listVideos       for index 0 index lt  self arrUrl count  index          UIButton  imageButton    UIButton buttonWithType UIButtonTypeCustom         imageButton frame   CGRectMake 20 50 60 index 50 50          NSURL  dUrl    self arrUrl objectAtIndex index           imageButton setImage   UIImage allow  initWithCGImage   self getFrameFromeVideo dUrl   forState UIControlStateNormal          imageButton addTarget self action  selector playMovie   forControlEvents UIControlEventTouchUpInside         imageButton titleLabel text    NSString strinfWithFormat       dUrl         imageButton titleLabel hidden   YES          self view addSubView imageButton           - void playMovie  id  sender     UIButton  btn    UIButton   sender     NSURL  movUrl    NSURL URLWithString btn titleLabel text      moviePlayer     MPMoviePlayerViewController alloc  initWithContentURL movUrl       self presentMoviePlayerViewControllerAnimated moviePlayer      - CGIImageRef   getFrameFromVideo  NSURL   mUrl     AVURLAsset  asset     AVURLAsset alloc  initWithURL mUrl option nil      AVAssetImageGenerator  generator     AVAssetImageGenerator alloc  initWithAsset asset      generator appliesPreferredTrackTransform   YES     NSError  error  nil     CMTime   CMTimeMake 3 1      CGImageRef imageRef    generator copyCGImageAtTime time actualTime nil error  amp error      if error   nil          NSLog       sekf error            return  imageRef

User · Answer

You can set tag of the button and access it from sender in action   btnHome addTarget self action  selector btnMenuClicked       forControlEvents UIControlEventTouchUpInside                       btnHome userInteractionEnabled   YES                      btnHome tag   123    In the called function  - void btnMenuClicked  id sender    sender tag        if   sender tag     123               Do Anything

User · Answer

To add to Tristan s answer  the button can also receive  id event in addition to  id sender   -  IBAction  buttonTouchUpInside  id sender forEvent  id event            This can be useful if  for example  the button is in a cell in a UITableView and you want to find the indexPath of the button that was touched  although I suppose this can also be found via the sender element

User · Answer

tl dr  Use Blocks  For Obj-C  for example  there s a CocoaPod SHControlBlocks  whose usage would be    self btnFirst SH addControlEvents UIControlEventTouchDown withBlock   UIControl  sender         weakSelf performSegueWithIdentifier   second  sender nil       NSLog   first            For Swift  I love the pod Actions  which allows blocks for UIControls  1       UIControl let button   UIButton   button add event   touchUpInside        print  Button tapped       playMusic from  speakers mp4  withSongAtPosition  indexPath row      Not that anyone is reading a 3-year old thread    crickets     1  And UIView  UITextField  UIGestureRecognizer  UIBarButtonItem  Timer  formally NSTimer   and NotificationCenter  formally NSNotificationCenter

User · Answer

Edit  Found a neater way   One argument that the button can receive is  id sender  This means you can create a new button  inheriting from UIButton  that allows you to store the other intended arguments  Hopefully these two snippets illustrate what to do     myOwnbutton argOne   someValue    myOwnbutton addTarget self action  selector buttonTouchUpInside   forControlEvents UIControlEventTouchUpInside     and  -  IBAction  buttonTouchUpInside  id sender     MyOwnButton  buttonClicked    MyOwnButton   sender       do as you please with buttonClicked argOne       This was my original suggestion   There is a way to achieve the same result  but it s not pretty  Suppose you want to add a parameter to your navigate method  The code below will not allow you to pass that parameter to navigate     button addTarget self action  selector navigate  forControlEvents UIControlEventTouchUpInside     To get around this you can move the navigate method to a class of it s own and set the  parameters  as attributes of that class     NavigationAid  navAid     NavigationAid alloc  init   navAid firstParam   someVariableOne navAid secondParam   someVariableTwo  button addTarget navAid action  selector navigate  forControlEvents UIControlEventTouchUpInside     Of course you can keep the navigate method in the original class and have it called by navAid  as long as it knows where to find it   NavigationAid  navAid     NavigationAid alloc  init   navAid whereToCallNavigate   self navAid firstParam   someVariableOne navAid secondParam   someVariableTwo  button addTarget navAid action  selector navigate  forControlEvents UIControlEventTouchUpInside     Like I said  it s not pretty  but it worked for me and I haven t found anyone suggesting any other working solution

User · Answer

UIButton responds to addTarget action forControlEvents  since it inherits from UIControl  But it does not respond to addTarget action withObject forControlEvents   see reference for the method and for UIButton  You could extend UIButton with a category to implement that method  thought

User · Answer

I think the correct method should be    -  void addTarget  id target action  SEL action forControlEvents  UIControlEvents controlEvents  UIControl Reference  Where do you get your method from   I see that your selector has an argument  that argument will be filled by the runtime system  It will send you back the button through that argument   Your method should look like   -  void buttonPressed  id BUTTON HERE

User · Answer

I found solution  The call   - void  someMethod      UIButton   but      but tag   1   some id button that you choice       but addTarget self action  selector buttonPressed   forControlEvents UIControlEventTouchUpInside        And here the method called   - void  buttonPressed    id  sender      UIButton  clicked    UIButton    sender      NSLog    d  clicked tag    Here you know which button has pressed

User · Answer

I made a solution based in part by the information above  I just set the titleLabel text to the string I want to pass  and set the titleLabel hidden   YES  Like this        UIButton  imageclick     UIButton buttonWithType UIButtonTypeCustom  retain       imageclick frame   photoframe      imageclick titleLabel text    NSString stringWithFormat           ti mediaImage  ti mediaExtension       imageclick titleLabel hidden   YES    This way  there is no need for a inheritance or category and there is no memory leak

[iphone] Passing parameters on button action:@selector

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