ios 将 NSArray 保存到 NSUserDefaults 并在 NSMutableArray 中获取它
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Saving NSArray to NSUserDefaults and getting it in NSMutableArray
提问by Omer Waqas Khan
How can I save NSArrayin NSUserDefaultsand then load it back in an NSMutableArrayto populate the UIPickerView?
我如何保存NSArray在NSUserDefaults，然后加载回以NSMutableArray填充UIPickerView？
Also the issue is that new values would be added to that NSMutableArrayand then that array will be converted to NSArrayto be saved in NSUserDefaults(as NSMutableArraycan't be saved in NSUserDefaults).
还有一个问题是，新值将被添加到其中NSMutableArray，然后该数组将被转换为NSArray保存在NSUserDefaults（因为NSMutableArray不能保存在NSUserDefaults）。
Any help appreciated..
任何帮助表示赞赏..
Thanks
谢谢
回答by Vignesh
[[NSUserDefaults standardUserDefaults] setObject:yourMutableArray forKey:@"Key"];
A mutable array can be stored since it is a subclass of NSArray.
可变数组可以存储，因为它是 NSArray 的子类。
To get the value as an NSMutableArray:
将值作为 NSMutableArray 获取：
NSMutableArray *array = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:@"Key"]];
or
或者
NSMutableArray *array = [[[NSUserDefaults standardUserDefaults] objectForKey:@"Key"] mutableCopy];
回答by Jonny
// Store it
[[NSUserDefaults standardUserDefaults] setObject:yourMutableArray forKey:@"Key"];
[[NSUserDefaults standardUserDefaults] synchronize];
// Read it back
NSMutableArray* myMutableArrayAgain = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:@"Key"]];
回答by vakio
To convert from NSArray to NSMutableArray:
要将 NSArray 转换为 NSMutableArray：
[array mutableCopy];
To convert from NSMutableArray to NSArray:
要将 NSMutableArray 转换为 NSArray：
[NSArray arrayWithArray:array];
Edit: mutableCopy will need a release later, since it is a copy.
编辑：mutableCopy 稍后需要发布，因为它是copy.
回答by barley
Obtain NSMutableArrayinstance using [[NSMutableArray alloc] initWithArray:]after recovering NSArrayfrom NSUserDefaults.
获得NSMutableArray使用实例[[NSMutableArray alloc] initWithArray:]恢复后NSArray从NSUserDefaults。
回答by Omer Waqas Khan
As this question is being viewed by many new iOS developers. I want to add more to help newbie's.
由于许多新的 iOS 开发人员正在查看这个问题。我想添加更多内容来帮助新手。
-(void)arraysFunction:(NSArray*)array mutArray:(NSMutableArray*)mArray{
if (array == nil || [array count] == 0) {
[[NSUserDefaults standardUserDefaults] setObject:mArray forKey:@"mutableArray"];
[[NSUserDefaults standardUserDefaults] synchronize];
NSLog(@"Mutable Array: %@",[[NSUserDefaults standardUserDefaults] objectForKey:@"mutableArray"]);
NSArray * simpleArray = [ NSArray arrayWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:@"mutableArray"]];
NSLog(@"Simple Array: %@", simpleArray);
}
else{
[[NSUserDefaults standardUserDefaults] setObject:array forKey:@"array"];
[[NSUserDefaults standardUserDefaults] synchronize];
NSLog(@"Simple Array: %@",[[NSUserDefaults standardUserDefaults] objectForKey:@"array"]);
NSMutableArray * mutableArray = [NSMutableArray arrayWithArray:[[[NSUserDefaults standardUserDefaults] objectForKey:@"array"] mutableCopy]];
NSLog(@"Mutable Array: %@", mutableArray);
}
}
I hope this will help you to save NSArrayinto NSUserDefaultsand then retrieving it as NSMutableArrayvice versa.
我希望这将帮助您节省NSArray到NSUserDefaults，然后检索它作为NSMutableArray反之亦然。
You can call this method like:
你可以像这样调用这个方法：
NSArray * array = [[NSArray alloc] initWithObjects:@"A", @"B", @"C", nil];
NSMutableArray * mutableArray = [[NSMutableArray alloc] initWithObjects:@"D", @"E", @"F", nil];
[self arraysFunction:array mutArray:nil];
[self arraysFunction:nil mutArray:mutableArray];
