将 UITextView 中的文本保存到 NSUserDefaults 中的方式与将 UITextFIeld 保存在 Notes 应用程序中的方式相同

Posted 2023-05-07

【中文标题】将 UITextView 中的文本保存到 NSUserDefaults 中的方式与将 UITextFIeld 保存在 Notes 应用程序中的方式相同

【英文标题】：Saving text from a UITextView into NSUserDefaults the same way a UITextFIeld is saved in a Notes app

【发布时间】：2014-08-13 02:19:55

【问题描述】：

我是 Objective-C 的新手，但有一些编程知识。所以我按照 Todd Perkin 的教程在 Lynda.com 上制作笔记应用程序。为了更熟悉 Objective-C，我想在这个笔记应用程序中添加一些东西以了解更多信息，但我有点卡住了。

目前，notes 应用程序内置在 Master Detail 应用程序模板中。所以MasterDetailView控制器中有一个Table View，DetailViewController中有一个detail view。当用户点击添加按钮时，它会转到 Detail 控制器，并且有一个您可以输入的 UITextField，当您单击 Back 时，它会将 UITextField 保存到 NSUserDefaults，这就是用于填充表格视图中的单元格的内容。

所以基本上，我所做的是为详细视图中的另一个位置添加一个 UITextView。但我想不出保存笔记标题的最佳方式。显然，每个音符都需要不同。这是我正在使用的类和代码：

MasterDetailController.h

#import <UIKit/UIKit.h>

@interface MasterViewController : UITableViewController

@end

MasterDetailController.m

@interface MasterViewController () 
NSMutableArray *_objects;

@end

@implementation MasterViewController

- (void)awakeFromNib

[super awakeFromNib];


- (void)viewDidLoad

[super viewDidLoad];
[self makeObjects];
// Do any additional setup after loading the view, typically from a nib.
//self.navigationItem.leftBarButtonItem = self.editButtonItem;
self.navigationController.navigationBar.titleTextAttributes =         @NSForegroundColorAttributeName : [UIColor whiteColor];
self.navigationItem.titleView = [[UIImageView alloc] initWithImage:[UIImage     imageNamed:@"Logo-Small.png"]];


UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(insertNewObject:)];
self.navigationItem.rightBarButtonItem = addButton;

-(void)viewDidAppear:(BOOL)animated
[super viewWillAppear:animated];
[self makeObjects];
[self.tableView reloadData];

-(void)makeObjects
_objects = [NSMutableArray arrayWithArray:[[Data getAllNotes]allKeys]];

//Sorts notes by order they were created in
[_objects sortUsingComparator:^NSComparisonResult(NSDate * obj1, NSDate * obj2) 
    return [obj2 compare:obj1];
];


- (void)didReceiveMemoryWarning

[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.


- (void)insertNewObject:(id)sender


NSString *key=[[NSDate date]description];
[Data setNote:kDefaultText forKey:key];
[Data setCurrentKey:key];
[_objects insertObject:key atIndex:0];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.tableView insertRowsAtIndexPaths:@[indexPath]     withRowAnimation:UITableViewRowAnimationAutomatic];
[self performSegueWithIdentifier:kDetailView sender:self];


#pragma mark - Table View

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView

return 1;


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

return _objects.count;


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

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

NSString *object = _objects[indexPath.row];
cell.textLabel.text = [[Data getAllNotes]objectForKey:object];
return cell;


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

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


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

if (editingStyle == UITableViewCellEditingStyleDelete) 
    [Data removeNoteForKey:[_objects objectAtIndex:indexPath.row]];
    [Data saveNote];
    [_objects 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.



/*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath


*/

/*
// 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;

*/

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender

if ([[segue identifier] isEqualToString:@"showDetail"]) 
    NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
    NSString *object = _objects[indexPath.row];
    [[segue destinationViewController] setDetailItem:object];



@end

DetailViewController.h

#import <UIKit/UIKit.h>

@interface DetailViewController : UIViewController

@property (strong, nonatomic) id detailItem;

@property (weak, nonatomic) IBOutlet UITextView *rTView;
@property (weak, nonatomic) IBOutlet UITextField *tView;


@end

DetailViewController.m

#import "DetailViewController.h"
#import "Data.h"

@interface DetailViewController ()
- (void)configureView;
@end

@implementation DetailViewController

#pragma mark - Managing the detail item

- (void)setDetailItem:(id)newDetailItem

if (_detailItem != newDetailItem) 
    _detailItem = newDetailItem;
    [Data setCurrentKey:_detailItem];
    // Update the view.
    [self configureView];



- (void)configureView

NSString *currentNote = [[Data getAllNote]objectForKey:[Data getCurrentKey]];
if (![currentNote isEqualToString:kDefaultText]) 
    self.tView.text = currentNote;


else 
    self.tView.text = @"";


//Brings up the keyboard when you go into a note
//[self.tView becomeFirstResponder];



-(void) viewDidDisappear:(BOOL)animated
[super viewWillDisappear:animated];
if (![self.tView.text isEqualToString:@""]) 
    [Data setNoteForCurrentKey:self.tView.text];
 else
    [Data removeNoteForKey:[Data getCurrentKey]];


[Data saveNotes];


- (void)viewDidLoad

[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self configureView];
[[UITextField appearance] setTintColor:[UIColor orangeColor]];
self.rTView.tintColor = [UIColor orangeColor];




- (void)didReceiveMemoryWarning

[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.

-(UIStatusBarStyle)preferredStatusBarStyle

return UIStatusBarStyleLightContent;



@end

以及教程中的数据模型：

数据.h

#import <Foundation/Foundation.h>

#define kDefaultText @"New Note"
#define kAllNote @"notes"
#define kDetailView @"showDetail"


@interface Data : NSObject

+(NSMutableDictionary *)getAllNotes;
+(void)setCurrentKey: (NSString *)key;
+(NSString *)getCurrentKey;
+(void)setNoteForCurrentKey:(NSString*)note;
+(void)setNote:(NSString*)note forKey:(NSString*)key;
+(void)removeNoteForKey:(NSString*)key;
+(void)saveNotes;

@end

数据.m

@implementation Data

static NSMutableDictionary *allNotes=nil;
static NSString *currentKey=nil;

+(NSMutableDictionary *)getAllNotes
if (allNotes == nil) 
    allNotes = [[NSMutableDictionary alloc]initWithDictionary:[[NSUserDefaults standardUserDefaults]objectForKey:kAllNotes]];

return allNotes;


+(void)setCurrentKey: (NSString *)key
currentKey = key;


+(NSString *)getCurrentKey
return currentKey;


+(void)setNoteForCurrentKey:(NSString*)note
[self setNote:note forKey:currentKey];


+(void)setNote:(NSString*)note forKey:(NSString*)key
[allNotes setObject:note forKey:key];


+(void)removeNoteForKey:(NSString*)key
[allNotes removeObjectForKey:key];


+(void)saveNotes
[[NSUserDefaults standardUserDefaults]setObject:allNotes forKey:kAllNotes];


@end

呸。对不起。这是很多代码。所以 tView 是被保存的值。我已将 UITextView 定义为 rTView。但我不知道如何像为 UITextFIeld 所做的那样，为每个注释保存该文本视图。

我将不胜感激。请。

【参考方案1】：

这个想法是，现在您将为每个节点保存更多属性，并且它们应该聚集在一个集合中，例如 NSArray、NSDictionary 等。但是，要回答您的问题需要很多时间，我要去仅提供一些提示：

您需要先更改您的模型类，以包含您需要的所有属性。 在 DetailViewController.h 中，需要更改 configureView 方法，这一行：

NSString *currentNote = [[Data getAllNote]objectForKey:[Data getCurrentKey]];

应该是这样的：

NSDictionary *currentNote = [[Data getAllNote] objectForKey:[Data getCurrentKey]];

大概是这样的：

if (![[currentNote objectForKey:@"title"] isEqualToString:kDefaultTitle]) self.tView.text = [currentNote objectForKey:@"title"]; self.rView.text = [currentNote objectForKey:@"description"]; 别的 self.tView.text = @""; self.rView.text = @"";

另外，应该在该文件中更改 viewDidDisappear。

我的建议是先改变Model，然后一步步分析View Controller中的每一个方法，你就会明白了。