Question

我试图从已经存在的不同类别中获取一个NSMutableArray。但是,如果说是安全记录仪,那就是无效的。我的节目以2级开始,然后是I segue到1级,用一个或一个以上的行文来制造我的NSMutableArray,然后我想我的班子2获得最新的NSMutable Array,但所有这些都是无效的。法典如下:

//class1.m

#import "FocusTagTableViewController.h"
#import "STATableViewController.h"

@implementation FocusTagTableViewController

@synthesize focusArray = _focusArray;
@synthesize allSelectedFocus = _allSelectedFocus;

- (void)viewDidLoad
{
_focusArray = [[NSArray alloc]initWithObjects:@"Balance",@"Bevægelse",@"Elementskift",@"Vejrtrækning",@"Alle",nil];

[super viewDidLoad];

}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *selectedFocus = [[_focusArray objectAtIndex:indexPath.row] stringByAppendingString:@","];
if(_allSelectedFocus == nil)
{
    _allSelectedFocus = [[NSMutableArray alloc]init];
    [_allSelectedFocus addObject:selectedFocus]; 
}
else if(![_allSelectedFocus containsObject:selectedFocus])
{
    [_allSelectedFocus addObject:selectedFocus];
}
}

//class2.m

#import "STATableViewController.h"
#import "FocusTagTableViewController.h"

@implementation STATableViewController
- (void)viewDidLoad
{
[super viewDidLoad];

 FocusTagTableViewController *focusTag = [[FocusTagTableViewController alloc]init];

[focustag addObserver:self forKeyPath:@"allSelectedFocus" options:NSKeyValueObservingOptionNew context:NULL];
}

-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
if([keyPath isEqualToString:@"allSelectedFocus"])
{
    NSLog(@"%@", [object valueForKeyPath:keyPath]);
}
}

Answer 1

That s because in class 2 you create a new instance of class 1, wich has empty array. If you want to access that array from class 2, you should make a reference to that first class. Or you could use Key-Value-Observing for that.

Here is the docs about KVO http://developer.apple.com/library/mac/ipad/#documentation/Cocoa/Conceptual/KeyValueObserving/KeyValueObserving.html

In first class, when you create class two, add self as an observer for that array, and implement observeValueForKeyPath: method in class 1

Answer 2

采用这种方式:

(1) 进口贵类2.h文档。

(2) 在你的类别2.h档案中,在全球范围创建NSMutableArray *foo。

3) 在您的类别1 档案中制造2级物体

4) instead Of using allSelectedFocus in your class1 file, set objects to foo in that file itself like this [class2Object.foo addObject:selectedFocus];

友情链接