将 NSUserDefaults 添加到 iPhone 清单

Question

我对 iPhone 开发非常陌生，我正在尝试获取一份包含持久数据的清单。我正在使用带有清单的表格，其中使用[本教程中的代码]。1

我已经自己尝试了一两周，试图使这项工作与 NSUserDefaults 一起工作，但正如我所说，我相当新，虽然我更喜欢在谷歌的帮助下解决这些问题，但我要么不太知道如何搜索我想要的东西，要么我还不够聪明，无法从我发现的东西中找出答案。基本上，清单部分有效，在检查和取消检查时，所有单元格都会获得适当的附件，但我希望它们在关闭时保持持久性。

我知道这是一个相当菜鸟的问题，所以如果有人可以发布我需要的代码，那将会非常有帮助，但是我能得到的任何帮助将非常感激。

编辑：添加代码

- (void)tableView:(UITableView *)tableView  didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [self tableView: self.tableView  accessoryButtonTappedForRowWithIndexPath: indexPath];
    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];
}
- (UITableViewCell *)tableView:(UITableView *)tableView  cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *kCustomCellID = @"MyCellID";
    UITableViewCell *cell = [tableView    dequeueReusableCellWithIdentifier:kCustomCellID];
    if (cell == nil)
    {
        cell = [[[UITableViewCell alloc]  initWithStyle:UITableViewCellStyleDefault reuseIdentifier:kCustomCellID] autorelease];
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
        cell.selectionStyle = UITableViewCellSelectionStyleBlue;
    }

    NSMutableDictionary *item = [dataArray bjectAtIndex:indexPath.row];
    cell.textLabel.text = [item objectForKey:@"text"];

    [item setObject:cell forKey:@"cell"];

    BOOL checked = [[item objectForKey:@"checked"] boolValue];
    UIImage *image = (checked) ? [UIImage   imageNamed:@"checked.png"] : [UIImage imageNamed:@"unchecked.png"];

    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    CGRect frame = CGRectMake(0.0, 0.0, image.size.width, image.size.height);
    button.frame = frame;
    [button setBackgroundImage:image forState:UIControlStateNormal];

    [button addTarget:self action:@selector(checkButtonTapped:event:)  forControlEvents:UIControlEventTouchUpInside];
    button.backgroundColor = [UIColor clearColor];
    cell.accessoryView = button;

    return cell;
}

- (void)checkButtonTapped:(id)sender event:(id)event
{
    NSSet *touches = [event allTouches];
    UITouch *touch = [touches anyObject];
    CGPoint currentTouchPosition = [touch locationInView:self.tableView];
    NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint: currentTouchPosition];
    if (indexPath != nil)
    {
        [self tableView: self.tableView accessoryButtonTappedForRowWithIndexPath: indexPath];
    }
}

- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
{
    NSMutableDictionary *item = [dataArray objectAtIndex:indexPath.row];

    BOOL checked = [[item objectForKey:@"checked"] boolValue];

    [item setObject:[NSNumber numberWithBool:!checked] forKey:@"checked"];

    UITableViewCell *cell = [item objectForKey:@"cell"];
    UIButton *button = (UIButton *)cell.accessoryView;

    UIImage *newImage = (checked) ? [UIImage imageNamed:@"unchecked.png"] : [UIImage imageNamed:@"checked.png"];
    [button setBackgroundImage:newImage forState:UIControlStateNormal];
}

Answer 1

这是使用 的示例NSUserDefaults

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
//Set a value
[defaults setBool:YES forKey:@"check1"];
//Save immediately
[defaults synchronize];

//Retrieve the value for check1
BOOL retrieved = [defaults boolForKey:@"check1"];

更新

如果您的 dataArray 仅包含带有布尔值和字符串的字典，那么您可以将整个 dataArray 保存到 NSUserDefaults。以下代码未经测试，但应该接近您保存值所需的代码。

-(id)yourInitMethod
{
    dataArray = [(NSArray*)[[NSUserDefaults standardUserDefaults] objectForKey:@"dataArrayKey"] mutableCopy];
    //Replace dictionaries with a mutable copy
    for(int i = 0; i < [dataArray count]; i++)
    {
        //Your dictionary that you want to be mutable
        NSMutableDictionary *aCopy = [(NSDictionary*)[dataArray objectAtIndex:i] mutableCopy];
        [dataArray replaceObjectAtIndex:i withObject:aCopy];
        [aCopy release];
    }
}

- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
{
    NSMutableDictionary *item = [dataArray objectAtIndex:indexPath.row];

    BOOL checked = [[item objectForKey:@"checked"] boolValue];

    [item setObject:[NSNumber numberWithBool:!checked] forKey:@"checked"];

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    //Save the updated data array
    [defaults setObject:dataArray forKey:@"dataArrayKey"];
    [defaults synchronize];
}