添加密钥到NSDictionary（iPhone SDK）

Hey guys, really quickly trying to add a key to a .plist, almost have it, what is the correct version of the fourth line? Thanks!

嘿伙计们，真的很快就试图在.plist中添加一个密钥，几乎拥有它，第四行的正确版本是什么？谢谢！

    NSString *path = [[NSBundle mainBundle] pathForResource:@"Favourites" ofType:@"plist"];
    NSDictionary *rootDict = [[NSDictionary alloc] initWithContentsOfFile:path];
    [rootDict addKey:@"Test"]; //guessed code
    [rootDict writeToFile:path atomically: YES];

2 个解决方案

#1

almost have it

几乎拥有它

not really.

不是真的。

You can't change a NSDictionary. You can't write to the mainbundle.

您无法更改NSDictionary。你不能写到mainbundle。

working code:

工作代码：

NSString *path = [[NSBundle mainBundle] pathForResource:@"Favourites" ofType:@"plist"];
NSMutableDictionary *rootDict = [[NSMutableDictionary alloc] initWithContentsOfFile:path];
[rootDict setObject:@"Test" forKey:@"Key"];
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSString *writablePath = [documentsDirectory stringByAppendingPathComponent:@"Favourites.plist"];
[rootDict writeToFile:writablePath atomically: YES];
[rootDict release];

#2

You can't add elements to a NSDictionary, you need to use a NSMutableDictionary then use the setObject:forKey: method.

您不能向NSDictionary添加元素，您需要使用NSMutableDictionary然后使用setObject：forKey：方法。

[rootDict setObject:someObject forKey:@"someKey"];

See NSMutableDictionary class reference

请参见NSMutableDictionary类引用

#1