如何在plist中写入数据？

Question

我已按照这个答案将数据写入plist

如何将数据写入plist？

但到目前为止,我的plist根本没有变化.

这是我的代码: -

- (IBAction)save:(id)sender
{
    NSString *path = [[NSBundle mainBundle] pathForResource:@"drinks" ofType:@"plist"];
    NSString *drinkName = self.name.text;
    NSString *drinkIngredients = self.ingredients.text;
    NSString *drinkDirection = self.directions.text;
    NSArray *values = [[NSArray alloc] initWithObjects:drinkDirection, drinkIngredients, drinkName, nil];
    NSArray *keys = [[NSArray alloc] initWithObjects:DIRECTIONS_KEY, INGREDIENTS_KEY, NAME_KEY, nil];
    NSDictionary *dict = [[NSDictionary alloc] initWithObjects:values forKeys:keys];
    [self.drinkArray addObject:dict];
    NSLog(@"%@", self.drinkArray);
    [self.drinkArray writeToFile:path atomically:YES];
}

我需要执行额外的操作吗？

我是iPhone SDK的新手,所以任何帮助将不胜感激.

Answer 1

您正在尝试将文件写入应用程序包,这是不可能的.而是将文件保存到Documents文件夹.

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

pathForResource方法只能用于读取您在Xcode中添加到项目中的资源.

以下是您在应用程序中修改plist时通常执行的操作:
1.首次启动时,将drinks.plist从应用程序包复制到应用程序的Documents文件夹(使用NSFileManager).
2.读/写时仅使用Documents文件夹中的文件.

UPDATE

这是初始化drinkArray属性的方法:

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

// If the file doesn't exist in the Documents Folder, copy it.
NSFileManager *fileManager = [NSFileManager defaultManager];

if (![fileManager fileExistsAtPath:destPath]) {
    NSString *sourcePath = [[NSBundle mainBundle] pathForResource:@"drinks" ofType:@"plist"];
    [fileManager copyItemAtPath:sourcePath toPath:destPath error:nil];
}

// Load the Property List.
drinkArray = [[NSArray alloc] initWithContentsOfFile:destPath];