详解IOS 单例的两种方式
方法一：
#pragma mark -
#pragma mark sharedSingleton methods
//单例函数
static RtDataModel *sharedSingletonManager = nil;
+ (RtDataModel *)sharedManager
{
@synchronized(self) {
if (sharedSingletonManager == nil) {
sharedSingletonManager = [[self alloc] init];
}
}
return sharedSingletonManager;
}
+ (id)allocWithZone:(NSZone *)zone
{
@synchronized(self) {
if (sharedSingletonManager == nil) {
sharedSingletonManager = [super allocWithZone:zone];
return sharedSingletonManager; // assignment and return on first allocation
}
}
return nil; //on subsequent allocation attempts return nil
}
- (id)copyWithZone:(NSZone *)zone
{
return sharedSingletonManager;
}
- (id)retain
{
return sharedSingletonManager;
}
- (NSUInteger)retainCount
{
return UINT_MAX; //denotes an object that cannot be released
}
- (oneway void)release
{
//do nothing
}
- (id)autorelease
{
return sharedSingletonManager;
}
//单例函数结束
方法二：
.h文件
#import <Foundation/Foundation.h>
@interface RtTestDataModel : NSObject
{
NSMutableArray * _buyDataTArray;
NSMutableArray * _sellDataTArray;
}
+ (RtTestDataModel *)sharedManager;
- (void)addOptionBuyDataArrayModel: (NSMutableArray *)DataArray;
- (NSMutableArray *)getOptionBuyDataArrayModel;
@end
.m文件
#import "RtTestDataModel.h"
@implementation RtTestDataModel
+ (RtTestDataModel *)sharedManager
{
static RtTestDataModel *sharedManager = nil;
static dispatch_once_t predicate;
dispatch_once(&predicate,^{
sharedManager = [[RtTestDataModel alloc]init];
});
return sharedManager;
}
- (void)dealloc
{
[_buyDataTArray removeAllObjects];
[_buyDataTArray release];
[super dealloc];
}
- (id)init
{
self = [super init];
if (self != nil) {
_buyDataTArray = [[NSMutableArray alloc] initWithCapacity:8];
}
return self;
}
- (void)addOptionBuyDataArrayModel: (NSMutableArray *)DataArray{
if (DataArray != nil) {
[_buyDataTArray removeAllObjects];
[_buyDataTArray addObjectsFromArray:DataArray];
}
}
- (NSMutableArray *)getOptionBuyDataArrayModel{
return _buyDataTArray;
}
@end
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