1. 今天的课程、 大家在学习之后肯定会有另一番想法、
至少、 你们会收藏我的博客吧、嘿嘿、 新开的人气可不怎么高
2. 好、 废话不多说、 直接切入正题、 网上讲coreData的有好多、 但大多数不怎么细致、 也不会完整的敲代码、
所以、 今天上午我自己简单的封装一下coreData供自己使用。 大家可以借鉴一下。 又不足之处还望指出。
3. 开始编码:
1. 导入 coreData.FrameWork 我们今天封装的东西、 不实用系统自带的coreData、 而是导入库自己去写。 加深印象
思想: 单例 + 中间层 (中间层继承于NSManagedObject 方便我们操作、 也有住于在业务量大的时候优化代码)
总共4个文件 我们开始编码:
1、单例 ADCoreData.h
1 // 2 // ADCoreData.h 3 // CoreData_CE 4 // 5 // Created by Dylan on 14-10-11. 6 // Copyright (c) 2014年 Dylan. All rights reserved. 7 // 8 9 /*! 10 * @Author Dylan. 11 * 12 * Please add CoreData.FrameWork 13 */ 14 15 #import <Foundation/Foundation.h> 16 #import <CoreData/CoreData.h> 17 18 @interface ADCoreData : NSObject 19 20 /*! 21 * @Author Dylan. 22 * 23 * context 24 */ 25 @property (nonatomic, strong, readonly) NSManagedObjectContext * manageContext; 26 27 + (instancetype)shareInstanceWithStoreName: (NSString *)storeName; 28 29 /*! 30 * @Author Dylan. 31 * 32 * Methods 33 */ 34 35 - (NSMutableArray *)findByModel: (id)model; 36 - (NSMutableArray *)findByModel: (id)model 37 predicateString: (NSString *)predicateString; 38 /*! 39 * Update 40 */ 41 - (BOOL)create: (id)model; 42 43 - (BOOL)remove: (id)model; 44 - (BOOL)remove: (id)model 45 predicateString: (NSString *)predicateString; 46 - (BOOL)modify: (id)model 47 predicateString: (NSString *)predicateString; 48 49 @end
ADCoreData.m
1 // 2 // ADCoreData.m 3 // CoreData_CE 4 // 5 // Created by Dylan on 14-10-11. 6 // Copyright (c) 2014年 Dylan. All rights reserved. 7 // 8 9 #import "ADCoreData.h" 10 #import "ADCoreDataManager.h" 11 #import <objc/runtime.h> 12 13 #define CLASS_NAME(PRAM) NSStringFromClass([PRAM class]) 14 15 @interface ADCoreData () 16 17 @property (nonatomic, strong) NSManagedObjectModel * managedobjectModel; 18 @property (nonatomic, strong) NSPersistentStoreCoordinator * persistentStoreCoordinator; 19 20 /*! 21 * @Author Dylan. 22 * 23 * storeName 24 */ 25 @property (nonatomic, strong) NSString * storeName; 26 27 - (NSURL *)applicationDomainUrl; 28 29 @end 30 31 static ADCoreData * coreData; 32 33 @implementation ADCoreData 34 35 + (instancetype)shareInstanceWithStoreName:(NSString *)storeName { 36 static dispatch_once_t onceToken; 37 dispatch_once(&onceToken, ^{ 38 coreData = [[self alloc] init]; 39 coreData.storeName = storeName; 40 }); 41 42 return coreData; 43 } 44 45 /*! 46 * @Author Dylan. 47 * 48 * synthesize 49 */ 50 @synthesize manageContext = _manageContext; 51 @synthesize managedobjectModel = _managedobjectModel; 52 @synthesize persistentStoreCoordinator = _persistentStoreCoordinator; 53 54 #pragma mark - 55 #pragma mark - GET 56 - (NSManagedObjectContext *)manageContext { 57 58 if (_manageContext) { 59 return _manageContext; 60 } 61 62 NSPersistentStoreCoordinator * coordinator = [self persistentStoreCoordinator]; 63 if (coordinator != nil) { 64 _manageContext = [[NSManagedObjectContext alloc] init]; 65 [_manageContext setPersistentStoreCoordinator:coordinator]; 66 } 67 return _manageContext; 68 } 69 70 - (NSPersistentStoreCoordinator *)persistentStoreCoordinator { 71 72 if (_persistentStoreCoordinator) { 73 return _persistentStoreCoordinator; 74 } 75 76 NSURL * storeUrl = [[self applicationDomainUrl] URLByAppendingPathComponent:[NSString stringWithFormat:@"%@.sqlite", _storeName]]; 77 _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:self.managedobjectModel]; 78 [_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:nil]; 79 return _persistentStoreCoordinator; 80 } 81 82 - (NSManagedObjectModel *)managedobjectModel { 83 84 if (_managedobjectModel) { 85 return _managedobjectModel; 86 } 87 88 NSURL * modelUrl = [[NSBundle mainBundle] URLForResource:_storeName withExtension:@"momd"]; 89 _managedobjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelUrl]; 90 return _managedobjectModel; 91 } 92 93 #pragma mark - Methods 94 - (NSMutableArray *)findByModel: (id)model { 95 96 NSError * error = nil; 97 NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:nil] error:&error]; 98 NSMutableArray * resultArray = [NSMutableArray array]; 99 100 for (ADCoreDataManager * manager in listArray) { 101 102 for (NSString * propertyName in [self ClassAttributes:model]) { 103 [model setValue:[manager valueForKey:propertyName] forKey:propertyName]; 104 } 105 [resultArray addObject:model]; 106 } 107 return resultArray; 108 } 109 110 - (NSMutableArray *)findByModel: (id)model 111 predicateString: (NSString *)predicateString; { 112 113 NSError * error = nil; 114 NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:predicateString] error:&error]; 115 NSMutableArray * resultArray = [NSMutableArray array]; 116 117 if (listArray.count >= 1) { 118 for (ADCoreDataManager * manager in listArray) { 119 120 for (NSString * propertyName in [self ClassAttributes:model]) { 121 [model setValue:[manager valueForKey:propertyName] forKey:propertyName]; 122 } 123 [resultArray addObject:model]; 124 } 125 } 126 return resultArray; 127 } 128 129 #pragma mark update 130 - (BOOL)create: (id)model { 131 ADCoreDataManager * manager = [NSEntityDescription insertNewObjectForEntityForName:CLASS_NAME(model) inManagedObjectContext:_manageContext]; 132 133 for (NSString * propertyName in [self ClassAttributes:model]) { 134 [manager setValue:[model valueForKey:propertyName] forKey:propertyName]; 135 } 136 BOOL result = [self saveContext]; 137 return result; 138 } 139 140 - (BOOL)remove: (id)model { 141 142 NSError * error = nil; 143 NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:nil] error:&error]; 144 if (listArray.count > 0) { 145 for (ADCoreDataManager * manager in listArray) { 146 [_manageContext deleteObject:manager]; 147 } 148 } 149 return [self saveContext]; 150 } 151 152 - (BOOL)remove: (id)model 153 predicateString: (NSString *)predicateString { 154 155 NSError * error = nil; 156 NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:predicateString] error:&error]; 157 158 if (listArray.count > 0) { 159 for (ADCoreDataManager * manager in listArray) { 160 [_manageContext deleteObject:manager]; 161 } 162 } 163 return [self saveContext]; 164 } 165 166 - (BOOL)modify: (id)model 167 predicateString: (NSString *)predicateString { 168 169 NSError * error = nil; 170 NSArray * listArray = [_manageContext executeFetchRequest:[self bindRequest:CLASS_NAME(model) predicate:predicateString] error:&error]; 171 172 if (listArray.count > 0) { 173 174 for (ADCoreDataManager * manager in listArray) { 175 for (NSString * propertyName in [self ClassAttributes:model]) { 176 [manager setValue:[model valueForKey:propertyName] forKey:propertyName]; 177 } 178 } 179 } 180 return [self saveContext]; 181 } 182 183 #pragma mark - collect 184 - (NSFetchRequest *)bindRequest: (NSString *)className 185 predicate: (NSString *)predicateString { 186 NSFetchRequest * request = [[NSFetchRequest alloc] init]; 187 [request setEntity:[NSEntityDescription entityForName:className inManagedObjectContext:_manageContext]]; 188 189 if (predicateString != nil) { 190 NSPredicate * predicate = [NSPredicate predicateWithFormat:predicateString]; 191 NSLog(@"%@", predicate); 192 NSLog(@"%@", predicateString); 193 [request setPredicate:predicate]; 194 } 195 return request; 196 } 197 198 199 #pragma mark - save 200 - (BOOL)saveContext { 201 202 NSManagedObjectContext * context = [self manageContext]; 203 if (context != nil) { 204 205 NSError * error = nil; 206 if ([context hasChanges] && ![context save:&error]) { 207 NSLog(@"%@", [error userInfo]); 208 abort(); 209 return NO; 210 } 211 } 212 213 return YES; 214 } 215 216 217 - (NSURL *)applicationDomainUrl { 218 return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject]; 219 } 220 221 #pragma mark - allAttributes 222 - (NSMutableArray *) ClassAttributes: (id)classModel { 223 224 NSMutableArray * array = [NSMutableArray array]; 225 NSString *className = NSStringFromClass([classModel class]); 226 const char * cClassName = [className UTF8String]; 227 228 id classM = objc_getClass(cClassName); 229 unsigned int outCount, i; 230 objc_property_t * properties = class_copyPropertyList(classM, &outCount); 231 for (i = 0; i < outCount; i++) { 232 objc_property_t property = properties[i]; 233 NSString * attributeName = [NSString stringWithUTF8String:property_getName(property)]; 234 235 [array addObject:attributeName]; 236 } 237 return array; 238 } 239 240 @end
在m文件中, 我使用了运行时。 运行时拿到一个模型的属性 这样我们可以更加方便的使用KVC
大家仔细看一下这种封装的过程
2.中间层: ADCoreDataManager.h
1 // 2 // ADCoreDataManager.h 3 // CoreData_CE 4 // 5 // Created by Dylan on 14-10-11. 6 // Copyright (c) 2014年 Dylan. All rights reserved. 7 // 8 9 #warning add Model properties Here 10 11 #import <CoreData/CoreData.h> 12 #import <Foundation/Foundation.h> 13 14 @interface ADCoreDataManager : NSManagedObject 15 16 /*! 17 * @Author Dylan. 18 * 19 * e.g 20 */ 21 @property (nonatomic, strong) NSString * name; 22 23 @end
.m文件
1 // 2 // ADCoreDataManager.m 3 // CoreData_CE 4 // 5 // Created by Dylan on 14-10-11. 6 // Copyright (c) 2014年 Dylan. All rights reserved. 7 // 8 9 #warning don't forget write @synthesize 10 11 #import "ADCoreDataManager.h" 12 13 @implementation ADCoreDataManager 14 15 @synthesize name = _name; 16 17 - (void)setValue:(id)value forUndefinedKey:(NSString *)key { 18 19 } 20 21 @end
大家可以把所有模型的属性 扔到中间层里边。 使用中间层去做中介传值。
使用:
1. 创建自己的momd文件。 新建-》coredata-》model 创建之后添加模型
2. 初始化单例
附上测试代码
1 // test 2 ADCoreData * coreData = [ADCoreData shareInstanceWithStoreName:@"CoreData"]; 3 4 Dylan * dylan = [[Dylan alloc] initWithEntity:[NSEntityDescription entityForName:@"Dylan" inManagedObjectContext:coreData.manageContext] insertIntoManagedObjectContext:nil]; 5 [dylan setName:@"Dylan"]; 6 7 NSLog(@"**************************************************"); 8 9 NSLog(@"first = %@", [coreData findByModel:dylan]); 10 11 NSLog(@"**************************************************"); 12 13 [coreData create:dylan]; 14 NSLog(@"second = %@", [coreData findByModel:dylan]); 15 NSLog(@"third = %@", [coreData findByModel:dylan predicateString:@"name = 'Dylan'"]); 16 NSLog(@"**************************************************"); 17 18 [coreData remove:dylan]; 19 NSLog(@"fourth = %@", [coreData findByModel:dylan]); 20 NSLog(@"**************************************************"); 21 22 [coreData create:dylan]; 23 NSLog(@"fifth = %@", [coreData findByModel:dylan]); 24 25 NSLog(@"**************************************************"); 26 27 Dylan * dylan1 = [[Dylan alloc] initWithEntity:[NSEntityDescription entityForName:@"Dylan" inManagedObjectContext:coreData.manageContext] insertIntoManagedObjectContext:nil]; 28 dylan1.name = @"dylan-1"; 29 30 [coreData modify:dylan1 predicateString:nil]; 31 NSLog(@"sixth = %@", [coreData findByModel:dylan]); 32 NSLog(@"seventh = %@", [coreData findByModel:dylan1]);
CoreData书写虽然比较难, 但是操作方便
大家在使用谓词的时候 要特别的注意 在你的值上边加单引号 类似: name = 'Dylan' 防止CoreData在操作request请求时候出现错误
@Dylan.