一.SQLite数据库（手机端）
//添加fmdb这个第三方库：需要修改两个步骤：
1）添加 -fno-objc-arc
2）添加libsqlite3.dylib

• (instancetype)initWithCoder:(NSCoder *)aDecoder
  {
  self = [super initWithCoder:aDecoder];
  if (self) {

    //创建数据库表格
    
    //指定数据可存储的路径（沙盒下）
    self.dbPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/user.db"];  //数据库文件的尾椎是 .db
    
    //创建表的sql语句
    NSString *createSql = @"create table if not exists userInfo1(id integer primary key autoincrement,name varchar(256),age integer default 0,image blob)";
    if (![self.fmd open]) {
        NSLog(@"打开失败");
    }
    //让数据库开始创建一张表
    BOOL isSuccess = [self.fmd executeUpdate:createSql];
    if (isSuccess) {
        NSLog(@"创建成功-%@",self.dbPath);
    }else
    {
        NSLog(@"创建失败");
    }
  

  }
  return self;
  }

//懒加载
-(FMDatabase *)fmd
{
if (!_fmd) {
//如果这个数据库不存在，表示创建
//如果已经存在，那么表示打开数据库
_fmd = [[FMDatabase alloc] initWithPath:self.dbPath];

}
return _fmd;

}

//添加数据

• (IBAction)addItem:(id)sender {

  NSString *addSql = @"insert into userInfo1(name,age,image)values(?,?,?)";
  NSString *name = @"张三";
  NSNumber *age = @25;
  UIImage *image = [UIImage imageNamed:@"00.png"];
  //把image对象转换成NSData
  NSData *imageData = UIImagePNGRepresentation(image);

  //开始插入数据
  if([self.fmd executeUpdate:addSql,name,age,imageData])
  {
  NSLog(@"插入成功");
  }else
  {
  NSLog(@"插入失败");
  }

}

//删除数据

• (IBAction)deleteItem:(id)sender {

  NSString *sql = @"delete from userInfo1 where id = ?";

  if([self.fmd executeUpdate:sql,@2])
  {
  NSLog(@"删除成功");
  }

}

//修改数据

• (IBAction)updateItem:(id)sender {

  NSString *sql = @"update userInfo1 set name=?,age=? where id=?";
  NSString *name = @"李四";
  NSNumber *age = @30;

  if([self.fmd executeUpdate:sql,name,age,@3])
  {
  NSLog(@"修改成功");
  }

}

//查询数据

• (IBAction)selectData:(id)sender {

  //
  NSString *selectSql = @"select *from userInfo1";

  //返回的是查询结果的集合
  FMResultSet *reslutSet = [self.fmd executeQuery:selectSql];
  //遍历这个集合，取出里面的数据，并打印
  while ([reslutSet next]) {

    NSString *name = [reslutSet stringForColumn:@"name"];
    NSInteger ID= [reslutSet intForColumn:@"id"];
    NSInteger age = [reslutSet intForColumn:@"age"];
    NSData *imageData = [reslutSet dataForColumn:@"image"];
    //根据一个二进制数据加载UIImage对象
    UIImage *image = [UIImage imageWithData:imageData];
    
    NSLog(@"name:%@ ID:%ld age:%ld image:%@",name,ID,age,image);
  

  }

}

二.用数据库做界面，具有增，删，改的功能

三.上拉刷新、下拉加载

• (void)viewDidLoad {
  [super viewDidLoad];

  self.dataArray = [NSMutableArray array];

  for (int i=0; i<30; i++) {
  NSString *str = [NSString stringWithFormat:@"我是第%d行",i+1];

    [self.dataArray addObject:str];
  

  }

  //注册cell
  [self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"CellID"];

  //UITableViewController自带的下拉刷新效果
  self.refreshControl = [[UIRefreshControl alloc] init];

  //添加下拉刷新的功能
  [self.refreshControl addTarget:self action:@selector(refresh) forControlEvents:UIControlEventValueChanged];

FooterView *footView = [[FooterView alloc] initWithFrame:CGRectMake(0, 0, self.tableView.frame.size.width,你 30)];
self.tableView.tableFooterView = footView;

}
-(void)refresh
{
NSLog(@"开始加载数据。。。。");

//模拟一个耗时的请求功能
[self performSelector:@selector(stopRefresh) withObject:nil afterDelay:5];

}

-(void)stopRefresh
{
NSLog(@"停止加载");
[self.refreshControl endRefreshing];
}

pragma mark - Table view data source

• (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {

  return 1;
  }

• (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

  return self.dataArray.count;
  }

• (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CellID" forIndexPath:indexPath];

  cell.textLabel.text = self.dataArray[indexPath.row];

  return cell;
  }

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 60;
}

pragma mark -UIScrollViewDelegate

-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
//根据偏移量去判断该不该加载
if (scrollView.contentOffset.y+scrollView.frame.size.height-scrollView.contentSize.height>64) {

    NSLog(@"开始加载");
    FooterView *fView = (FooterView *)self.tableView.tableFooterView;
    fView.myLabel.text = @"正在加载中";
    [fView.activityView startAnimating];
    
}

[self performSelector:@selector(stop) withObject:nil afterDelay:4];

}

-(void)stop
{
for (int i=0; i<10; i++) {
NSString *str = @"我是新加载的内容";
[self.dataArray addObject:str];
}
[self.tableView reloadData];

FooterView *fView = (FooterView *)self.tableView.tableFooterView;
fView.myLabel.text = @"上拉加载";
[fView.activityView stopAnimating];

}