The IOS intercepts control events and continues the original message passing process after processing.

# Import
<Objc/objc. h>

# Import <objc/runtime. h>

-(Void) sendeventhooked :( uievent *) event {

// Do what you want to do here

Nslog (@ "interception event: % @",
[Eventdescription]);

// Execute the original message passing process

[Selfperformselector: @ selector (sendeventoriginal :) withobject: event];

}

-(Bool) Application :( uiapplication *) Application didfinishlaunchingwitexceptions :( nsdictionary
*) Launchoptions

{

Method sendevent = class_getinstancemethod ([uiwindowclass], @ selector (sendevent :));

Method sendeventmyself = class_getinstancemethod ([selfclass],
@ Selector (sendeventhooked :));

IMP sendevenibd = method_getimplementation (sendevent );

Class_addmethod ([uiwindowclass], @ selector (sendeventoriginal :),
Sendevenibd, method_gettypeencoding (sendevent ));

IMP sendeventmyselfimp = method_getimplementation (sendeventmyself );

Class_replacemethod ([uiwindowclass], @ selector (sendevent :),
Sendeventmyselfimp, method_gettypeencoding (sendevent ));

Self. Window = [[[uiappswalloc] initwithframe: [[uiscreenmainscreen] bounds] autorelease];

// Override point for customization after application launch.

If ([[uidevicecurrentdevice] userinterfaceidiom]
= Uiuserinterfaceidiomphone ){

Self. viewcontroller = [[[viewcontrolleralloc] initwithnibname: @ "viewcontroller_iphone" Bundle: Nil] autorelease];

} Else {

Self. viewcontroller = [[[viewcontrolleralloc] initwithnibname: @ "viewcontroller_ipad" Bundle: Nil] autorelease];

}

Self. Window. rootviewcontroller = self. viewcontroller;

[Self. windowmakekeyandvisible];

Return yes;

}

Then you can create a button elsewhere to capture the button touch event!