iOS使用CoreData实现收藏功能

2016-03-25 本文已影响1573人 HeartPower

实现收藏有很多方式，我在自己练习的项目中用CoreData实现了一下收藏功能，注释很少，算是自己做的一个笔记。
首先创建一个工具类继承NSObject,在里面实现所需要的方法.

工具类的.h文件:

<pre>
typedef NS_ENUM(NSUInteger, SelectInEntities) {

InEntities,
NotInEntities,
SelectError,

};

typedef NS_ENUM(NSUInteger, Entities) {

   NewsEntity,
   PostEntity,
  TypeEntity,
  ForumEntity,

};

@interface BFFCoreDataManager : NSObject

// 管理对象上下文(管理者)
@property (readonly, strong, nonatomic) NSManagedObjectContext *managedObjectContext;
// 管理对象模型(表结构)
@property (readonly, strong, nonatomic) NSManagedObjectModel *managedObjectModel;
// 持久化存储协调器(助理)
@property (readonly, strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator;
// 保存上下文(保存对数据的修改)

(void)saveContext;
// 沙盒路径
(NSURL *)applicationDocumentsDirectory;

//-(SelectInEntities)isInEntities:(Entities)entities
// Model:(id)model;

+(BFFCoreDataManager *)shareBFFCoreDataManager;

(id)isInEntities:(Entities)entities model:(id)model;

(BOOL)has:(NSMutableDictionary *)dic arr:(NSArray *)array;
///地方分会
(BOOL)hass:(NSMutableDictionary *)dic arr:(NSArray *)array;
///推荐论坛
(BOOL)hasss:(BFFDiscussModel *)model arr:(NSArray *)array;
(BOOL)haspost:(BFFSelectModel *)model arr:(NSArray *)array;
(BOOL)state:(NSArray *)arr url:(NSString *)url;
(BOOL)states:(NSArray *)arr ids:(NSString *)ids;

(id)myModel:(id)model;
@property (nonatomic, strong) BFFCoreDataManager *manager;
@end</pre>

工具类的.m文件

<pre>
@implementation BFFCoreDataManager
#pragma mark - Core Data stack

@synthesize managedObjectContext = _managedObjectContext;
@synthesize managedObjectModel = _managedObjectModel;
@synthesize persistentStoreCoordinator = _persistentStoreCoordinator;

(BFFCoreDataManager *)shareBFFCoreDataManager
{
/// 单例不能释放
static BFFCoreDataManager *manager = nil;
// 保证线程安全, 该方法只走一次
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
manager = [BFFCoreDataManager new];
});
return manager;
}
// 获取到沙盒的Document路径

(NSURL *)applicationDocumentsDirectory {
// The directory the application uses to store the Core Data store file. This code uses a directory named "com.lanou3g.TheWorldCar" in the application's documents directory.
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
(NSManagedObjectModel *)managedObjectModel {
// The managed object model for the application. It is a fatal error for the application not to be able to find and load its model.
if (_managedObjectModel != nil) {
return _managedObjectModel;
}
NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"TheWorldCar" withExtension:@"momd"];
_managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
return _managedObjectModel;
}
(NSPersistentStoreCoordinator *)persistentStoreCoordinator {
// The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it.
if (_persistentStoreCoordinator != nil) {
return _persistentStoreCoordinator;
}

// Create the coordinator and store

_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"TheWorldCar.sqlite"];
NSError *error = nil;
NSString *failureReason = @"There was an error creating or loading the application's saved data.";

NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];

if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:options error:&error]) {
// Report any error we got.
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
dict[NSLocalizedDescriptionKey] = @"Failed to initialize the application's saved data";
dict[NSLocalizedFailureReasonErrorKey] = failureReason;
dict[NSUnderlyingErrorKey] = error;
error = [NSError errorWithDomain:@"YOUR_ERROR_DOMAIN" code:9999 userInfo:dict];
// Replace this with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}

return _persistentStoreCoordinator;
}
(NSManagedObjectContext *)managedObjectContext {
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.)
if (_managedObjectContext != nil) {
return _managedObjectContext;
}

NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (!coordinator) {
return nil;
}
_managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
[_managedObjectContext setPersistentStoreCoordinator:coordinator];
return _managedObjectContext;
}

pragma mark - Core Data Saving support

(void)saveContext {
NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
if (managedObjectContext != nil) {
NSError *error = nil;
if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
}
(id)myModel:(id)model{
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Type" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
NSError *error = nil;
NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];
if (fetchedObjects == nil) {
NSLog(@"%@", error);
}
BFFCollectModel *newsModel = model;
for (Type *type in fetchedObjects) {
if ([type.name isEqualToString:newsModel.name]) {
return type;
} else {
return nil;
}
}

return nil;
}

// 判断是否在数据库中

(id)isInEntities:(Entities)entities model:(id)model
{
switch (entities) {
case NewsEntity:
{
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"News" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
NSError *error = nil;
NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];
if (fetchedObjects == nil) {
NSLog(@"%@", error);
}
BFFNewsModel *newsModel = model;
for (News *news in fetchedObjects) {
if ([news.newsLink isEqualToString:newsModel.newsLink]) {
return news;
}
}
return nil;
}
break;
case PostEntity:
{
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Post" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
NSError *error = nil;
NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];
if (fetchedObjects == nil) {
NSLog(@"%@", error);
}
BFFHotModel *hot = model;
for (Post *post in fetchedObjects) {
if ([post.postLink isEqualToString:hot.postLink]) {
return post;
}
}
return nil;
}
break;
case TypeEntity:
{
```
  }
      break;
  case ForumEntity:
  {
      NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
      NSEntityDescription *entity = [NSEntityDescription entityForName:@"Line" inManagedObjectContext:self.managedObjectContext];
      [fetchRequest setEntity:entity];
      NSError *error = nil;
      NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];
      if (fetchedObjects == nil) {
          NSLog(@"%@", error);
      }
      BFFCarDetailModel *carDetail = model;
      for (Line *line in fetchedObjects) {
          if ([line.seriesId isEqualToString:[NSString stringWithFormat:@"%@", carDetail.seriesId]]) {
              return line;
          }
      }
      return nil;
  }

      break;
  default:
      break;
```
}
return nil;
}

//爱车俱乐部.人车生活

(BOOL)has:(NSMutableDictionary *)dic arr:(NSArray *)array{
NSNumber *num = dic[@"forumId"];
for (Forum *forum in array) {
if ([forum.postId isEqualToString:num.description]) {
return YES;
}
}
return NO;
}

///地方分会

(BOOL)hass:(NSMutableDictionary *)dic arr:(NSArray *)array{
NSNumber *num = dic[@"id"];
for (Forum *forum in array) {
if ([forum.postId isEqualToString:num.description]) {
return YES;
}
}
return NO;
}

///论坛推荐

(BOOL)hasss:(BFFDiscussModel *)model arr:(NSArray *)array{
for (Forum *forum in array) {
if ([forum.postId isEqualToString:model.forumId.description]) {
return YES;
}
}
return NO;
}

///帖子收藏

(BOOL)haspost:(BFFSelectModel *)model arr:(NSArray *)array{
for (Post *post in array) {
if ([post.postLink isEqualToString:model.postLink]) {
return YES;
}
}
return NO;
}

///改变帖子收藏按钮图标

(BOOL)state:(NSArray *)arr url:(NSString *)url{
for (Post *post in arr) {
if ([post.postLink isEqualToString:url]) {
return YES;
}
}
return NO;
}

///改变论坛收藏按钮图标

(BOOL)states:(NSArray *)arr ids:(NSString *)ids{
for (Forum *forum in arr) {
if ([forum.postId.description isEqualToString:ids]) {
return YES;
}
}
return NO;
}

/**-(SelectInEntities)isInEntities:(Entities)entities
Model:(id)model
{
switch (entities) {
case NewsEntity:
{
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"News" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
NSError *error = nil;
NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];
if (fetchedObjects == nil) {
NSLog(@"%@", error);
}
BFFNewsModel *newsModel = model;

        for (News *news in fetchedObjects) {

            if ([news.newsLink isEqualToString:newsModel.newsLink]) {
                return InEntities;
            } else {
                return NotInEntities;
            }

        }

    }
        break;
        case PostEntity:
    {

   }
        break;
        case LineEntity:
    {

   }
        break;
        case ForumEntity:
    {

    }
       break;
   default:
        break;
}
return SelectError;

}
@end

*/
</pre>

接下来在收藏页面创建一个Button实现收藏

<pre>

(void)collectionBut:(id)sender{

BFFCollectModel *model = self.tempModel;
if ([self.manager myModel:model] == nil) {
Type *type = [NSEntityDescription insertNewObjectForEntityForName:@"Type" inManagedObjectContext:self.manager.managedObjectContext];
type.name = model.name;
type.priceRange = model.priceRange;
type.photo = model.photo;
type.uid = [NSString stringWithFormat:@"%@", model.uid];
[self.manager saveContext];
```
  self.collectLabel.text = @"已经收藏";
  self.collectLabel.hidden = NO;
  dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
      self.collectLabel.hidden = YES;
  });
```
} else {
[self.manager.managedObjectContext deleteObject:[self.manager myModel:model]];
[self.manager saveContext];
self.collectLabel.text = @"已取消收藏";
self.collectLabel.hidden = NO;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
self.collectLabel.hidden = YES;
});
}
}

///在我的收藏页面把数据取出

(void)createLineData
{
self.typeArr = [NSMutableArray array];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Type" inManagedObjectContext:self.manager.managedObjectContext];
[fetchRequest setEntity:entity];
NSError *error = nil;
NSArray *fetchedObjects = [self.manager.managedObjectContext executeFetchRequest:fetchRequest error:&error];

if (fetchedObjects == nil) {
NSLog(@"%@", error);
}
[self.typeArr addObjectsFromArray:fetchedObjects];
[self.tableView reloadData];

}

///这些数据都铺在了tableView上接下来实现删除的操作

(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
if (self.titleSegment.selectedSegmentIndex == 0) {
News *news = self.newsArr[indexPath.row];
[self.manager.managedObjectContext deleteObject:news];
[self.manager saveContext];
[self.newsArr removeObjectAtIndex:indexPath.row];
[self.tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationLeft];
}else if (self.titleSegment.selectedSegmentIndex == 1){
Post *post = self.postArr[indexPath.row];
[self.manager.managedObjectContext deleteObject:post];
[self.manager saveContext];
[self.postArr removeObjectAtIndex:indexPath.row];
[self.tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationLeft];
}else if (self.titleSegment.selectedSegmentIndex == 2){
Forum *forum = self.forumArr[indexPath.row];
[self.manager.managedObjectContext deleteObject:forum];
[self.manager saveContext];
[self.forumArr removeObjectAtIndex:indexPath.row];
[self.tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationLeft];
```
  }else{
  
      Type *type = self.typeArr[indexPath.row];
      [self.manager.managedObjectContext deleteObject:type];
       [self.manager saveContext];
      [self.typeArr removeObjectAtIndex:indexPath.row];
      [self.tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationLeft];
  
  }
```
}
[self.tableView reloadData];
}</pre>

这些就是实现收藏的过程

iOS使用CoreData实现收藏功能

工具类的.h文件:

工具类的.m文件

pragma mark - Core Data Saving support

接下来在收藏页面创建一个Button实现收藏

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