objective c - How do you use event handlers with parameters? -

i'm trying sort out how events work. in video 4 of stanford course on itunes u, alan cannistraro says there are

"3 different flavors of action method selector types - (void)actionmethod; - (void)actionmethod:(id)sender; - (void)actionmethod:(id)sender withevent:(uievent *)event;"

i thought i'd try them out simple adding program - enter 2 numbers , type sum gets places in 3rd uitextfield. have method no-parameter signature, , works fine. when change second sender parameter, code stops calling method.

this works:

-(void) setsum { float a1 = addend1.text.floatvalue; float a2 = addend2.text.floatvalue; float thesum = a1 + a2; nsstring * ssum = [nsstring stringwithformat:@"%g", thesum];  sum.text = ssum; }  -(void)awakefromnib { sel setsummethod = @selector(setsum); [addend1 addtarget: self action: setsummethod forcontrolevents: uicontroleventeditingchanged]; [addend2 addtarget: self action: setsummethod forcontrolevents: uicontroleventeditingchanged]; }// awakefromnib 

this runs setsum doesn't called:

-(void) setsum:(id) sender { float a1 = addend1.text.floatvalue; float a2 = addend2.text.floatvalue; float thesum = a1 + a2; nsstring * ssum = [nsstring stringwithformat:@"%g", thesum];  sum.text = ssum; }   -(void)awakefromnib { sel setsummethod = @selector(setsum:); [addend1 addtarget: self action: setsummethod forcontrolevents: uicontroleventeditingchanged]; [addend2 addtarget: self action: setsummethod forcontrolevents: uicontroleventeditingchanged]; }// awakefromnib 

so, question when other event method types work? first seems apply.

tia

mark

very old question, know...

i tested it:

- (void) onfield {     nslog(@"onfield"); }  - (void) onfield:(id) sender {     nslog(@"onfield: %@", sender); }  - (void) onfield:(id) sender event:(id)event {     nslog(@"onfield: %@\n%@", sender, event); }  - (bool)application:(uiapplication *)application didfinishlaunchingwithoptions:(nsdictionary *)launchoptions {     uitextfield *field = [[[uitextfield alloc] initwithframe:cgrectmake(0, 100, 100, 100)] autorelease];     [field settext:@"text"];     [field addtarget:self action:@selector(onfield) forcontrolevents:uicontroleventeditingchanged];     [field addtarget:self action:@selector(onfield:) forcontrolevents:uicontroleventeditingchanged];     [field addtarget:self action:@selector(onfield:event:) forcontrolevents:uicontroleventeditingchanged];     [window addsubview:field];      [window makekeyandvisible];      return yes; } 

the results:

2010-11-04 11:35:59.940 untitled[599:207] onfield 2010-11-04 11:35:59.941 untitled[599:207] onfield: <uitextfield: 0x6a0c1f0; frame = (0 100; 100 100); text = 'textsfr'; clipstobounds = yes; opaque = no; layer = <calayer: 0x6a0c350>> 2010-11-04 11:35:59.944 untitled[599:207] onfield: <uitextfield: 0x6a0c1f0; frame = (0 100; 100 100); text = 'textsfr'; clipstobounds = yes; opaque = no; layer = <calayer: 0x6a0c350>> (null) 

so works. problem somewhere else.