UISegmentedControl总是等于0

Question

answer.h：

#import <UIKit/UIKit.h> 
#import <Foundation/Foundation.h> 
#import "operator.h" 

@interface answer : NSObject/* Specify a superclass (eg: NSObject or NSView) */ { 
    IBOutlet operator *operator1; 
    IBOutlet operator *operator2; 
IBOutlet UILabel *answerLabel; 
IBOutlet UISegmentedControl *operation; 
} 
- (IBAction)compute:(id)sender; 
@end 

answer.m：

#import "answer.h" 

@implementation answer 
- (IBAction)compute:(id)sender { 

int selected = operation.selectedSegmentIndex; 

switch (selected) { 
    case 0: 
     answerLabel.text = [NSString stringWithFormat:@"%d", (int)[operator1 number] + (int)[operator2 number]]; 
     break; 
    case 1: 
     answerLabel.text = [NSString stringWithFormat:@"%d", (int)[operator1 number] - (int)[operator2 number]]; 
     break; 
    case 2: 
     answerLabel.text = [NSString stringWithFormat:@"%d", (int)[operator1 number] * (int)[operator2 number]]; 
     break; 
    case 3: 
     answerLabel.text = [NSString stringWithFormat:@"%d", (int)[operator1 number]/(int)[operator2 number]]; 
     break; 
    default: 
     break; 
} 

} 
@end 

我遇到的问题是，selectedSegmentIndex总是等于0

Answer 1

我仔细检查了与的确我没有连接UISegmentedControl lol。谢谢！