1.新建一个工程，看一下自己的Bundle Id.这个Bundle Id 要和你用真机测试时的证书上面的Bundle Id相匹配。
比如我的是 house.xianrou.xianrou
2.Target - Capabilities - Keychain Sharing - ON
这步主要目的是打开Keychain Sharing,将它由灰色状态的OFF改为蓝色状态的ON。
打开之后的变化如下：
左侧的目录会自动生成Entitlements文件，不需要自己创建了。
也就是说，Bundle Identifier、Keychain Sharing的Keychain Groups、Entitlements文件的Keychain Access Groups的第一个元素，它们要保持上图所示的一致性。
设置好了以后可以运行下程序，没问题可以进行下一步。
3.uuid类和keychain类
既然苹果的keychain方法会崩溃而且有些复杂，我们只保存一个uuid的话可以用下面的简单方法：
（这也是我自己百度的keychain拷贝别人的，然后改改）
UUID.h
#import 尖括号（Foundation/Foundation.h）
@interface UUID : NSObject
+(NSString *)getUUID;
@end
UUID.m
#import "UUID.h"
#import "KeyChainStore.h"
@implementation UUID
+(NSString *)getUUID
{
NSString * strUUID = (NSString *)[KeyChainStore load:@"com.company.app.usernamepassword"];
//首次执行该方法时，uuid为空
if ([strUUID isEqualToString:@""] || !strUUID)
{
//生成一个uuid的方法
CFUUIDRef uuidRef = CFUUIDCreate(kCFAllocatorDefault);
strUUID = (NSString *)CFBridgingRelease(CFUUIDCreateString (kCFAllocatorDefault,uuidRef));
//将该uuid保存到keychain
[KeyChainStore save:KEY_USERNAME_PASSWORD data:strUUID];
}
return strUUID;
}
@end
KeyChainStore.h
#import 尖括号（Foundation/Foundation.h）
@interface KeyChainStore : NSObject
+ (void)save:(NSString *)service data:(id)data;
+ (id)load:(NSString *)service;
+ (void)deleteKeyData:(NSString *)service;
@end
KeyChainStore.m
#import "KeyChainStore.h"
@implementation KeyChainStore
+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
return [NSMutableDictionary dictionaryWithObjectsAndKeys:
(id)kSecClassGenericPassword,(id)kSecClass,
service, (id)kSecAttrService,
service, (id)kSecAttrAccount,
(id)kSecAttrAccessibleAfterFirstUnlock,(id)kSecAttrAccessible,
nil];
}
+ (void)save:(NSString *)service data:(id)data {
//Get search dictionary
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
//Delete old item before add new item
SecItemDelete((CFDictionaryRef)keychainQuery);
//Add new object to search dictionary(Attention:the data format)
[keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(id)kSecValueData];
//Add item to keychain with the search dictionary
SecItemAdd((CFDictionaryRef)keychainQuery, NULL);
}
+ (id)load:(NSString *)service {
id ret = nil;
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
//Configure the search setting
//Since in our simple case we are expecting only a single attribute to be returned (the password) we can set the attribute kSecReturnData to kCFBooleanTrue
[keychainQuery setObject:(id)kCFBooleanTrue forKey:(id)kSecReturnData];
[keychainQuery setObject:(id)kSecMatchLimitOne forKey:(id)kSecMatchLimit];
CFDataRef keyData = NULL;
if (SecItemCopyMatching((CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
@try {
ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge NSData *)keyData];
} @catch (NSException *e) {
NSLog(@"Unarchive of %@ failed: %@", service, e);
} @finally {
}
}
if (keyData)
CFRelease(keyData);
return ret;
}
+ (void)deleteKeyData:(NSString *)service {
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
SecItemDelete((CFDictionaryRef)keychainQuery);
}
@end
将这两个类添加到工程中
4.新建一个pch文件，然后pch文件的内容如下：
#ifndef PrefixHeader_pch
#define PrefixHeader_pch
#define KEY_USERNAME_PASSWORD @"com.company.app.usernamepassword"
#define KEY_USERNAME @"com.company.app.username"
#define KEY_PASSWORD @"com.company.app.password"
#endif
pch文件的创建方法可参考：http://blog.csdn.net/huang2009303513/article/details/40375235
你有可能会在填Prefix Header 即pch文件的路径那里报错，最近又学习到一种更好的方式$(SRCROOT)/$(PROJECT_NAME)/PrefixHeader.pch,其中$(PROJECT_NAME)是相对工程名,比上面的方法更便捷.
5.在viewcontroller.m里面执行如下代码