How do you tell what object is being touched in touchesBegan?

浪尽此生 提交于 2019-12-04 16:22:18

问题


I know that this is a very commonly asked question, but all of the answers on every website don't work! If you still don't know what I mean, then maybe this line of code will help you understand.


- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [[event allTouches] anyObject];
    CGPoint location = [touch locationInView:self.view];
    if (touch.view == nextbutton)
        [self performSelector:@selector(next)];
    if (touch.view == prevbutton)
        [self performSelector:@selector(previous)];
    if (touch.view == moreoptionsbutton)
        [self performSelector:@selector(moresettings)];
}

It doesn't do anything when you touch nextbutton, prevbutton, and more optionsbutton, which are UIImageViews by the way. I have also tried using isEqual: instead of ==, but that hasn't worked out either. Any suggestions?


回答1:


You have to set userinteractionEnabled = YES for all your UIImageViews otherwise they will not receive touch events. Also change the line:

 UITouch *touch = [[event allTouches] anyObject];

to

 UITouch *touch = [touches anyObject];



回答2:


I created a check to be sure its the view I expect to be clicked before going on.

if( [touch.view isKindOfClass:[Custom class]] ){
    CGPoint touchPoint = [touch locationInView:self.view];

    if( CGRectContainsPoint( self.customClassOne.frame, touchPoint )
       || CGRectContainsPoint( self.customClassTwo.frame, touchPoint ) ){
        [self touchOnCustomClass];
    }
}


来源:https://stackoverflow.com/questions/2648529/how-do-you-tell-what-object-is-being-touched-in-touchesbegan

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