iOS10 coreData简单使用

创建项目需要勾选上use coredata
在自动生成的文件里添加需要的列，

把项目改为不使用自动生成，

然后点edit里的create nsmanageObject...

在AppDelegate里需要写的代码

给delegate添加三个属性，coredata的模型，上下文，和永久存储助手

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    // Override point for customization after application launch.    [self persistentContainer];    return YES;}#pragma mark - Core Data stack@synthesize persistentContainer = _persistentContainer;- (NSPersistentContainer *)persistentContainer {    // The persistent container for the application. This implementation creates and returns a container, having loaded the store for the application to it.    @synchronized (self) {        if (_persistentContainer == nil) {            _persistentContainer = [[NSPersistentContainer alloc] initWithName:@"__"];            [_persistentContainer loadPersistentStoresWithCompletionHandler:^(NSPersistentStoreDescription *storeDescription, NSError *error) {                NSLog(@"%@",storeDescription);                if (error != nil) {                    NSLog(@"Unresolved error %@, %@", error, error.userInfo);                    abort();                }            }];        }    }    _model = _persistentContainer.managedObjectModel;    _context = _persistentContainer.viewContext;    _storeCoor = _persistentContainer.persistentStoreCoordinator;    return _persistentContainer;}#pragma mark - Core Data Saving support- (void)saveContext {    NSManagedObjectContext *context = self.persistentContainer.viewContext;    NSError *error = nil;    if ([context hasChanges] && ![context save:&error]) {        NSLog(@"Unresolved error %@, %@", error, error.userInfo);        abort();    }}

把txt的文字成功保存在sql中

////  ViewController.m//  数据////  Created by MrWu on 2017/2/13.//  Copyright © 2017年 TTYL. All rights reserved.//#import "ViewController.h"#import "AppDelegate.h"#import "POSTCODE+CoreDataClass.h"#import "POSTCODE+CoreDataProperties.h"@interface ViewController ()<UITableViewDelegate,UITableViewDataSource,UISearchBarDelegate>@property (nonatomic, strong) UITableView *tableview;@property (nonatomic, strong) NSArray *datasource;@property (nonatomic, strong) UISearchBar *searchBar;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    [self readData];}- (void)readData {     AppDelegate *del = [UIApplication sharedApplication].delegate;    NSFetchRequest *request = [NSFetchRequest                               fetchRequestWithEntityName:@"POSTCODE"];    request.sortDescriptors = @[                                [NSSortDescriptor                                 sortDescriptorWithKey:@"province" ascending:NO],                                [NSSortDescriptor                                 sortDescriptorWithKey:@"city" ascending:NO],                                [NSSortDescriptor                                 sortDescriptorWithKey:@"district" ascending:NO]];    NSError *error = nil;    NSArray *data = [del.context executeFetchRequest:request error:&error];    if (error) {        NSLog(@"%@",error);    }    if (!data || [data isKindOfClass:[NSArray class]] || [data count] <= 0) {        dispatch_async(dispatch_get_global_queue(0, 0), ^{        NSString *path = [[NSBundle mainBundle] pathForResource:@"城市邮编最终整理_方便导入数据库" ofType:@"txt"];        NSString *contentStr = [NSString stringWithContentsOfFile:path encoding:NSUTF16StringEncoding error:nil];        NSArray *info = [contentStr componentsSeparatedByString:@"\n"];        NSEntityDescription *entity = [NSEntityDescription entityForName:@"POSTCODE" inManagedObjectContext:del.context];        //给模型对象赋值        for (NSString *line in info) {            NSArray *items = [line componentsSeparatedByString:@"\t"];            //创建模型对象            POSTCODE *code = [[POSTCODE alloc] initWithEntity:entity insertIntoManagedObjectContext:del.context];            code.id = items[0];            code.province = items[1];            code.city = items[2];            code.district = items[3];            code.cityId = ((NSString *)items[4]).length >=4 ? items[4]:[@"0" stringByAppendingString:items[4]];            code.postCode = items[5];        }          [del saveContext];            NSError *error = nil;;        NSArray *data_in_db = [del.context executeFetchRequest:request error:&error];        self.datasource = data_in_db;       });    } else {        self.datasource = data;    }}