Delegate method not working ios - iphone

Question

I used delegate mehod for pass data between view controllers. This is not working.
#protocol PassCountry <NSObject>
#required
- (void) setPickedCountry:(NSString *)pickedCountry;
#end
#interface SelectCountryViewController : UIViewController<UIPickerViewDelegate, UIPickerViewDataSource> {
id <PassCountry> delegate;
}
#property (copy) NSString *pickedCountry;
#property (retain) id delegate;
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent (NSInteger)component {
pickedCountry = [self.countries objectAtIndex:row];
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
return self.countries.count;
}
- (void)viewWillDisappear:(BOOL)animated {
[[self delegate] setPickedCountry:pickedCountry];
}

Answer 1

#import <UIKit/UIKit.h>
#protocol PassCountry <NSObject>
#required
- (void) setPickedCountry:(NSString *)pickedCountry;
#end
#interface secondViewViewController : UIViewController<UIPickerViewDelegate, UIPickerViewDataSource>
{
id <PassCountry> delegate;
IBOutlet UIButton *aButton;
}
#property (copy) NSString *pickedCountry;
#property (assign) id<PassCountry> delegate; // for delegate use assign don't retain
// in another class you are creating instance of this class
secondViewViewController *secController = [[secondViewViewController alloc]init];
secController.delegate = self;//check this added or not
[self presentViewController:secController animated:YES completion:nil];
//and implementation of deleagte method
- (void) setPickedCountry:(NSString *)pickedCountry
{
// do some stuff
}

Answer 2

Firstly, delegate instance can not be retained.
Secondly, delegate should be synthesized using "#synthesize delegate" before invoke the method [self delegate].

Answer 3

Try this::
.h File
#protocol delegateTextSize <NSObject>
#optional
-(void)selectedTextSize:(double)textSize;
#end
#interface CustomFontSizeCell : UITableViewCell
#property (nonatomic,retain) id delegateTextSize;
-(IBAction)changeSize:(id)sender;
#end
.m File
-(IBAction)changeSize:(id)sender
{
[delegateTextSize selectedTextSize:app.selectedFontSize];
}
Where to use,
.h File
Controller <delegateTextSize>
.m File
-(void)selectedTextSize:(double)textSize
{
}
Hopefully, this will work
Thanks.