从另一个视图控制器写入全局数组

Question

我在viewController中有一个数组，我想从另一个viewController写入该数组，所以我将该数组定义为全局数组，但我无法写入它！

视图控制器1.h

extern NSArray *xArray;
@property (nonatomic, retain) NSArray *xArray;

视图控制器1.m

@synthesize xArray;
NSArray *xArray;
xArray = [[NSArray alloc] init];

视图控制器2.m

#import "ViewController1.h"
NSArray *zArray = [NSArray arrayWithObjects:@"a",@"b",nil];
ViewController1.xArray = zArray;

我收到以下错误：在类型为"ViewController1"的对象上找不到属性"xArray">

Answer 1

找到解决方案，在应用程序委托中定义数组并在任何类中使用它

AppDelegate.h

NSArray *xArray;
..
@property (nonatomic, retain) NSArray *xArray;
..
@synthesize *xArray;

视图控制器1.m

NSArray *tmpArray1;
AppDelegate *mainDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
mainDelegate.xArray = tmpArray1;

视图控制器2.m

NSArray *tmpArray2;
AppDelegate *mainDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
mainDelegate.xArray = tmpArray2;