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CoreData教学完整版（封装我们自己的CoreData工具）_Dylan

作者：佚名      IOS开发编辑：admin      更新时间：2022-07-23

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.