数据持久化存储回顾

不是每个程序员都是天才

集合写入文件

NSDictionary *dic1=@{@"aaa":@"aaa",@"cccc":@"vvvv"};

NSDictionary *dic2=@{@"ddd":@"ddd"};

NSArray *arr=@[dic1,dic2];

NSString *path=[[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject]stringByAppendingPathComponent:@"arr.plist"];

NSLog(@"%@",path);

NSLog(@"增加 : %d",[arr writeToFile:path atomically:YES]);

集合读取

NSString *path=[[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject]stringByAppendingPathComponent:@"data.plist"];

NSData *newData=[NSData dataWithContentsOfFile:path];

NSLog(@"%@",newData);

NSString *newStr= [[NSString alloc] initWithData:newData encoding:NSUTF8StringEncoding];

NSLog(@"%@",newStr);

熟练就能很快的敲出来，就是要从低级一步步的来

tableView增删改

@interface RootTableViewController ()<PostValueDelegate>

{

//记录选中行的索引值

NSIndexPath *CurrentIndexPath;

}

@end

@implementation RootTableViewController

- (void)viewDidLoad

{

[super viewDidLoad];

self.view.backgroundColor=[UIColor colorWithPatternImage:[UIImage imageNamed:@"106.jpg"]];

//导航栏右按钮

self.navigationItem.rightBarButtonItem = self.editButtonItem;

self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addItem)];

self.Students=[NSMutableArray arrayWithCapacity:3];

[self.Students addObject:@"zs"];

[self.Students addObject:@"ls"];

[self.Students addObject:@"ww"];

//单元格复用 唯一标识

[self.tableView registerClass:[UITableViewCell class]forCellReuseIdentifier:@"reuseIdentifier"];

}

-(void)addItem

{

UIAlertController *alertC=[UIAlertController alertControllerWithTitle:@"增加学生信息" message:@"输入姓名" preferredStyle:UIAlertControllerStyleAlert];

UIAlertAction *alertA1=[UIAlertAction actionWithTitle:@"添加" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

UITextField *textName=alertC.textFields[0];

//将输入框里的值赋给UITableView里面

[self.Students addObject:textName.text];

[self.tableView reloadData];//刷新

NSLog(@"真正的操作对象");

}];

//在提示框添加输入框

[alertC addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {

textField.placeholder=@"输入姓名";

}];

[alertC addAction:alertA1];

[self presentViewController:alertC animated:YES completion:^{

}];

}

-(void)viewWillAppear:(BOOL)animated

{

[super viewWillAppear:YES];

//刷新数据

[self.tableView reloadData];

}

//5.实现协议方法

-(void)PostValue:(NSString *)UserName

{

//为集合指定索引位置元素赋值

self.Students[CurrentIndexPath.row]=UserName;

//刷新

[self.tableView reloadData];

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

#pragma mark - Table view data source 多少个分区

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView

{

return 1;

}

#pragma mark 每个分区返回多少

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

return self.Students.count;

}

#pragma

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"reuseIdentifier" forIndexPath:indexPath];

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

return cell;

}

#pragma 把信息推到下一页

-(void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath

{

ViewController *vc=[[ViewController alloc] init];

vc.Name=self.Students[indexPath.row];

//指定代理

vc.delegate=self;

[self.navigationController pushViewController:vc animated:YES];

}

//修改

// Override to support conditional editing of the table view.

- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath

{

// Return NO if you do not want the specified item to be editable.

return YES;

}

//删除某行

// Override to support editing the table view.

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath

{

if (editingStyle == UITableViewCellEditingStyleDelete)

{

// Delete the row from the data source

[self.Students removeObjectAtIndex:indexPath.row];

[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];

}

else if (editingStyle == UITableViewCellEditingStyleInsert)

{

// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view

}

}

//移动moveRow

// Override to support rearranging the table view.

- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath

{

//找到指定位置元素

NSString *name=self.Students[fromIndexPath.row];

//删除找到的元素

[self.Students removeObject:name];

//插入删除集合元素到指定位置

[self.Students insertObject:name atIndex:toIndexPath.row];

NSLog(@"%@",self.Students);

}

//让没格可以移动

// Override to support conditional rearranging of the table view.

- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath

{

// Return NO if you do not want the item to be re-orderable.

return YES;

}