ios学习笔记——属性列表

一、介绍

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属性列表文件是一种XML文件，Foundation框架中的数组和字典等都可以与属性列表文件互相转换。

通过直接操作属性列表，可以实现数据持久化。

二、数组和字典读写

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NSArray读写属性列表的方法：

+ (NSArray<ObjectType> *)arrayWithContentsOfFile:(NSString *)aPath

类级构造方法，用于从属性列表中读取数据，创建NSArray对象

- (NSArray<ObjectType> *)initWithContentsOfFile:(NSString *)aPath

实例构造方法，用于从属性列表中读取数据，创建NSArray对象。

- (BOOL)writeToFile:(NSString *)path atomically:(BOOL)flag

改方法把NSArray对象写入属性列表中，他的第一个参数是文件名，第二个参数是否使用辅助文件，如果为YES先写入到一个辅助文件中，然后辅助文件再重新命名为目录文件，如果为NO，则直接写入到目标文件。

NSDictionary读写属性列表的方法与NSArray的方法基本类似，如下：

+ (NSDictionary<KeyType,ObjectType> *)dictionaryWithContentsOfFile:(NSString *)path

- (NSDictionary<KeyType,ObjectType> *)initWithContentsOfFile:(NSString *)path

- (BOOL)writeToFile:(NSString *)path atomically:(BOOL)flag

三、例子

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fileOperate.m文件操作类

#import "fileOperate.h"

@implementation fileOperate

//获取沙盒路径
- (NSString *)getDocumentPath
{
    NSString * pathArr = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
    NSString * strPath = [pathArr stringByAppendingPathComponent:@"sjz.plist"];
    return strPath;
}

//将新加入的数据保存在文件中
- (void)addNotepad:(NSMutableDictionary *)dict
{
    NSString * strPath = [self getDocumentPath];
    //读取文件保存在数组中
    NSMutableArray * arr = [NSMutableArray arrayWithContentsOfFile:strPath];
    if(!arr){
        arr = [[NSMutableArray alloc] init];
    }
    
    //将数据加入到数组中
    [arr addObject:dict];
    //将数组写的问价中
    [arr writeToFile:strPath atomically:YES];
}

- (void)removeNotepad:(NSMutableDictionary *)dict
{
    NSString * strPath = [self getDocumentPath];
    NSMutableArray * array = [NSMutableArray arrayWithContentsOfFile:strPath];

    for(NSMutableDictionary * dictionary in array){
        if([[dictionary objectForKey:@"date"] isEqualToString:[dict objectForKey:@"date"]]){
            //删除数据
            [array removeObject:dict];
            [array writeToFile:strPath atomically:YES];
            break;
        }
    }
}

- (NSMutableArray *)listArr
{
    NSString * strPath = [self getDocumentPath];
    NSMutableArray * arr = [NSMutableArray arrayWithContentsOfFile:strPath];
    
    return arr;
}

@end

JZViewController.m

#import "JZViewController.h"
#import "fileOperate.h"
#import "JZAddViewController.h"

@interface JZViewController ()<UITableViewDataSource, UITableViewDelegate, JZAddViewController>

@property (nonatomic, strong) UITableView * tableView;
@property (nonatomic, strong) fileOperate * operate;
@property (nonatomic, strong) NSMutableArray * listArr;

@end

@implementation JZViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.title = @"记事本";
    
    self.operate = [[fileOperate alloc] init];
    self.listArr = [self.operate listArr];
    
    [self initTableView];
    [self createNavButton];
}

- (void)createNavButton
{
//    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Edit" style:UIBarButtonItemStyleDone target:self action:@selector(editNotepad)];
    /**
     *将左键设置成编辑按钮，这个是视图控制器已经存在的，它可以获取编辑按钮的对象指针
     *编辑按钮的样式可以咋Edit和Done之间转换，如果切换取决于当前的视图是否处于编辑状态。
     *点击时，会调用会调用setEditing:animated:方法
     */
    self.navigationItem.leftBarButtonItem = self.editButtonItem;
    if(self.listArr.count <= 0){
        self.editButtonItem.enabled = NO;
    }
    
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Add" style:UIBarButtonItemStyleDone target:self action:@selector(addNotepad)];
}

- (void)initTableView
{
    UITableView * tableView = [[UITableView alloc] initWithFrame:self.view.bounds];
    tableView.backgroundColor = [UIColor whiteColor];
    tableView.delegate = self;
    tableView.dataSource = self;
    tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
    [self.view addSubview:tableView];
    
    self.tableView = tableView;
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return self.listArr.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString * strID = @"JZViewController";
    UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:strID];
    if(!cell){
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:strID];
    }else{
        for(UIView * view in [cell.contentView subviews]){
            [view removeFromSuperview];
        }
    }
    
    NSMutableDictionary * dict = [self.listArr objectAtIndex:indexPath.row];
    
    UILabel * label1 = [[UILabel alloc] initWithFrame:CGRectMake(15, 5, [UIScreen mainScreen].bounds.size.width - 30, 40)];
    label1.text = [dict objectForKey:@"text"];
    label1.font = [UIFont systemFontOfSize:17];
    label1.textAlignment = NSTextAlignmentLeft;
    label1.textColor = [UIColor blackColor];
    [cell.contentView addSubview:label1];
    
    UILabel * label2 = [[UILabel alloc] initWithFrame:CGRectMake(15, 45, [UIScreen mainScreen].bounds.size.width - 30, 20)];
    label2.text = [dict objectForKey:@"date"];
    label2.font = [UIFont systemFontOfSize:15];
    label2.textAlignment = NSTextAlignmentLeft;
    label2.textColor = [UIColor blackColor];
    [cell.contentView addSubview:label2];
    
    UIView * view = [[UIView alloc] initWithFrame:CGRectMake(0, 79.5, [UIScreen mainScreen].bounds.size.width, 0.5)];
    view.backgroundColor = [UIColor grayColor];
    [cell.contentView addSubview:view];
    return cell;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 80;
}

//在编辑状态下，设置单元格是增加还是删除
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return UITableViewCellEditingStyleDelete;
}

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    //删除完毕后，将左边按钮，设置为Edit
    [self setEditing:NO];
    
    NSMutableDictionary * dict = [self.listArr objectAtIndex:indexPath.row];
    [self.operate removeNotepad:dict];
    //删除数据，数据来源于哪里，就删除哪里的数据
    [self.listArr removeObjectAtIndex:indexPath.row];
    //删除cell的方法
    [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
    [self.tableView reloadData];
    
    if(self.listArr.count <= 0){
        self.editButtonItem.enabled = NO;
    }
}

//是否显示高亮状态
- (BOOL)tableView:(UITableView *)tableView shouldHighlightRowAtIndexPath:(NSIndexPath *)indexPath
{
    return NO;
}

//跳转到JZAddViewController
- (void)addNotepad
{
    JZAddViewController * add = [[JZAddViewController alloc] init];
    add.delegate = self;
    [self.navigationController pushViewController:add animated:YES];
}

//JZAddViewController代理方法，增加数据后，刷新列表
- (void)loadViewData
{
    self.listArr = [self.operate listArr];
    [self.tableView reloadData];
    if(self.listArr.count > 0){
        self.editButtonItem.enabled = YES;
    }
}

//该方法是UIViewController的生命周期方法，用于响应视图编辑状态的变化，也就是editing参数
- (void)setEditing:(BOOL)editing animated:(BOOL)animated
{
    [super setEditing:editing animated:animated];
    
    [self.tableView setEditing:editing animated:animated];
}

@end

JZAddViewController是增加数据类

#import <UIKit/UIKit.h>

@protocol JZAddViewController <NSObject>

- (void)loadViewData;

@end

@interface JZAddViewController : UIViewController

@property (nonatomic, strong) id<JZAddViewController> delegate;

@end

#import "JZAddViewController.h"
#import "fileOperate.h"

@interface JZAddViewController () <UITextViewDelegate>

@property (nonatomic, strong) UITextView * textView;
@property (nonatomic, strong) UIButton * button;

@end

@implementation JZAddViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    self.title = @"添加";
    self.automaticallyAdjustsScrollViewInsets = NO;
    
    //添加手势，让textView放弃第一响应者
    UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGesture)];
    [self.view addGestureRecognizer:tap];
    
    [self initTextView];
    [self initButton];
}

- (void)initTextView
{
    UITextView * textView = [[UITextView alloc] initWithFrame:CGRectMake(15, 74, [UIScreen mainScreen].bounds.size.width - 30, 150)];
    //画边框，圆角
    textView.layer.borderColor = [UIColor grayColor].CGColor;
    textView.layer.borderWidth = 0.5;
    textView.layer.cornerRadius = 5.0;
    
    textView.font = [UIFont systemFontOfSize:14];
    textView.textColor = [UIColor grayColor];
    
    [self.view addSubview:textView];
    
    self.textView = textView;
}

- (void)initButton
{
    UIButton * button = [[UIButton alloc] initWithFrame:CGRectMake(20, 150 + 74 + 10, [UIScreen mainScreen].bounds.size.width - 40, 40)];
    button.layer.borderColor = [UIColor grayColor].CGColor;
    button.layer.borderWidth = 0.5;
    button.layer.cornerRadius = 5.0;
    
    [button setTitle:@"确定" forState:UIControlStateNormal];
    [button setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];
    [button addTarget:self action:@selector(addNotes) forControlEvents:UIControlEventTouchUpInside];
    
    [self.view addSubview:button];
    
    self.button = button;
}

//添加nodes
- (void)addNotes
{
    NSMutableDictionary * dict = [[NSMutableDictionary alloc] init];
    [dict setObject:self.textView.text forKey:@"text"];
    
    NSDate * date = [NSDate date];
    NSDateFormatter * formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString * str = [formatter stringFromDate:date];
    [dict setObject:str forKey:@"date"];
    
    fileOperate * operater = [[fileOperate alloc] init];
    [operater addNotepad:dict];
    
    [self.navigationController popViewControllerAnimated:YES];
    
    if([self.delegate performSelector:@selector(loadViewData)]){
        [self.delegate loadViewData];
    }
}

//手势响应函数
- (void)tapGesture
{
    [self.textView resignFirstResponder];
}

@end