Question

I created a class (UIView) which has a UIScrollview inside. Through the delegate “scrollViewDidEndDecelerating” I can have 3 results (1,2,3).
How do I send this result to the main ViewController?

ViewController header

#import "Picker.h"

ViewController implementation

picker = [[Picker alloc]initWithFrame:CGRectMake(10, 10, 300, 300)];
[self.view addSubview:picker];

Picker implementation

(...)

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {

    if (scrollView.contentOffset.x <= 100) {

        int result = 1;

    } else if (scrollView.contentOffset.x > 100 && scrollView.contentOffset.x <= 200) {

        int result = 2;

    } else {

        int result = 3;

    }
}

(...)

I had to create a UIView class because it has other things in addition to Scrollview.

Thank you!

Answer 1

I suggest you create a PickerDelegate protocol with a method to return the required value to the main view controller.

@protocol PickerDelegate <NSObject>

-(void)picker:(Picker *)picker didScrollToResult:(NSInteger)result;

@end

The Picker has a property:

@property (nonatomic, assign) id<PickerDelegate> delegate;

Then you can set your view controller as the picker delegate using picker.delegate = self;

In the Picker UIView’s scrollview delegate method, you can pass the message to the view controller by using:

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
    if (scrollView.contentOffset.x <= 100) {
        int result = 1;
    } else if (scrollView.contentOffset.x > 100 && scrollView.contentOffset.x <= 200) {
        int result = 2;
    } else {
        int result = 3;
    }
    [self.delegate picker:self didScrollToResult:result];
}

The view controller needs to implement the picker delegate method:

-(void)picker:(Picker *)picker didScrollToResult:(NSInteger)result {
    // View controller now has result variable to action upon.
}