iphone - 如何在配件复选标记-iPhone 的用户默认值中保存状态

Question

我正在开发一个具有UItableView的应用程序。在表的行中，我可以放置复选标记。现在如何保存复选标记的状态，以便即使用户关闭应用程序该状态应该被删除，并且在下次启动应用程序时应该显示复选标记。我已经按照 NSUSerDefaults 上的教程进行操作，但是我很烦恼如何放置保存和检索的代码。我尝试过，但每次错误都让我感到困惑并且无法修复。我的代码:

MY.h文件

**@protocol LocationSelectionViewControllerDelegate <NSObject>

@required
- (void)rowSelected:(NSString *)selectedValue selectedIndex:(NSInteger)index;
@end**

@interface LocationSelection : UIViewController <UITableViewDelegate,UITableViewDataSource>{

UITableView *table;
***NSInteger       selectedIndex;***
NSMutableArray *menuList;
***id <LocationSelectionViewControllerDelegate>    delegate;***

}
@property (nonatomic,retain) NSMutableArray *menuList;  
@property (nonatomic,retain) IBOutlet UITableView *table;  
***@property (nonatomic, assign) id <LocationSelectionViewControllerDelegate> delegate;**  
**@property NSInteger selectedIndex;***  
@end  

我的 .m 文件:

@implementation LocationSelection  
***@synthesize menuList, table,selectedIndex,delegate;***

- (void)viewDidLoad
{
    menuList = [[NSMutableArray alloc] initWithObjects:
                [NSArray arrayWithObjects:@"LOCATION1", nil],
                [NSArray arrayWithObjects:@"LOCATION2", nil],
                [NSArray arrayWithObjects:@"LOCATION3", nil],
                nil];

    self.title = @"Location Selection";

    [table reloadData];
    [super viewDidLoad];
}

//MY CELLFORROWATINDEXPATH  

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
    static NSString *CellIdentifier = @"CellIdentifier";

    UITableViewCell *cell = [table dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero] autorelease];
    }
    cell.highlighted = NO;

    ***NSArray * rowArray = [menuList objectAtIndex:indexPath.row];***

    UILabel * nameLabel = [[[UILabel alloc] initWithFrame:CGRectMake(15, 8, 200, 20)] autorelease];
    nameLabel.text = [NSString stringWithFormat:@"%@", [rowArray objectAtIndex:0]];
    [cell.contentView addSubview:nameLabel];

    ***cell.accessoryType = (rowArray == selectedIndex && selectedIndex > -1 && selectedIndex < [menuList count]) ? UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;
    return cell;
    ***
}

//MY DIDSELECTROWATINDEXH  

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    int newRow = [indexPath row];

    if (newRow != selectedIndex)
    {
        UITableViewCell *newCell = [tableView cellForRowAtIndexPath:indexPath];
        newCell.accessoryType = UITableViewCellAccessoryCheckmark;

        if (selectedIndex > - 1 && selectedIndex < [menuList count])
        {
            NSUInteger newIndex[] = {0, selectedIndex};
            NSIndexPath *lastIndexPath = [[NSIndexPath alloc] initWithIndexes:newIndex length:2];
            UITableViewCell *oldCell = [tableView cellForRowAtIndexPath: lastIndexPath]; 
            oldCell.accessoryType = UITableViewCellAccessoryNone;
        }       

        selectedIndex = newRow;  
        NSString *selectedValue=[menuList objectAtIndex:selectedIndex];
        [self.delegate rowSelected:selectedValue selectedIndex:selectedIndex];
    }
}

Answer 1

- (void)applicationDidEnterBackground:(UIApplication *)application {
}

使用此方法将数据保存到 NSUserDefaults并在LocationSelection

的 viewDidLoad中设置数据