NSKeyedArchiver archivedDataWithRootObject：

Question

是NSKeyedArchiver的參數archivedDataWithRootObject：應該是我想要保存的數組，或將數組轉換爲NSData？

Answer 1

要將通用數組轉換爲NSData，您需要存檔器！如果你知道如何餵養NSData，你知道如何使用NSKeyedArchiver。所以：

NSArray* array= ... ; 
NSData* data=[NSKeyedArchiver archivedDataWithRootObject:array]; 

當然你array需要的所有元素來實現encodeWithCoder:。

Answer 2

Yuji的回答是對的。但更準確的說，您的數組元素必須實現協議和FILLIN自己的代碼來的initWithCoder方法：和encodeWithCoder： 像：

- (id)initWithCoder:(NSCoder *)decoder { 
    if (self = [super init]) { 
     self.title = [decoder decodeObjectForKey:@"title"]; 
     self.author = [decoder decodeObjectForKey:@"author"]; 
     self.published = [decoder decodeBoolForKey:@"published"]; 
    } 
    return self; 
} 
- (void)encodeWithCoder:(NSCoder *)encoder { 
    [encoder encodeObject:title forKey:@"time"]; 
    [encoder encodeObject:author forKey:@"author"]; 
    [encoder encodeBool:published forKey:@"published"]; 
} 

，那麼你可以使用歸檔和unchariver，如：

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:notes]; 
[[NSUserDefaults standardUserDefaults] setObject:data forKey:@"notes"]; 

NSData *notesData = [[NSUserDefaults standardUserDefaults] objectForKey:@"notes"]; 
NSArray *notes = [NSKeyedUnarchiver unarchiveObjectWithData:notesData]; 

欲瞭解更多，可以參考「Archiving Objective-C Objects with NSCoding」。