iphone - Xcode 4.2 编译错误

Question

已关闭。这个问题是 off-topic 。目前不接受答案。

---

想要改进这个问题吗？ Update the question所以它是on-topic用于堆栈溢出。

已关闭12 年前。

Improve this question

好吧，我想我正式疯了...尝试在 xcode 4.2 上使用 iOS 5.0 模拟器运行此代码并收到各种错误。在此应用程序中，我要做的就是运行核心位置 API。

我的位置“ Controller ”类:

.h:

#import Foundation/Foundation.h
#import CoreLocation/CoreLocation.h

@protocol locationReceiverDelegate
@required

- (void)locationUpdate:(CLLocation *)location;
- (void)locationError:(NSError *)error;

@end

@interface locationReceiver : NSObject <CLLocationManagerDelegate> {
    CLLocationManager *locMgr;
    id delegate;
}

@property (nonatomic, retain) CLLocationManager *locMgr;
@property (nonatomic, assign) id delegate;

@end

.m:

#import "locationReceiver.h"

@implementation locationReceiver

@synthesize locMgr, delegate;


- (id)init
{
    self = [super init]; 
    if(self != nil) {
        self.locMgr = [[CLLocationManager alloc] init];
        self.locMgr.delegate = self;
    }

    return self; 
}

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation     *)newLocation fromLocation:(CLLocation *)oldLocation {
//  if([self.delegate conformsToProtocol:@protocol(locationReceiverDelegate)]) {
        [self.delegate locationUpdate:newLocation];
//      }
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
//  if([self.delegate conformsToProtocol:@protocol(locationReceiverDelegate)]) {
        [self.delegate locationError:error];
//  }
}


@end

我在 .m 文件中收到错误“@synthesize locMgr, delegate;” “用于分配属性‘委托(delegate)’的现有 ivar‘委托(delegate)’必须是 _unsafe_unretained”

Answer 1

您不应该分配您的委托(delegate)，而应该这样做

 @property (nonatomic, retain) id delegate;

这应该可以解决你的问题。