数组参数在像“didSelectRowAtIndexPath”和“prepareForSegue”这样的函数中没有被调用

Question

这是我的代码。 “ViewController.m”

-(void)viewDidLoad { 
    [super viewDidLoad]; 
    Fruit *item1 = [Fruit new]; 
    item1.name = @"Apple"; 
    item1.price = @"1$ for one"; 
    item1.image = @"apple.jpeg"; 
    item1.location = [NSArray arrayWithObjects:@"Japan", @"Apple is good for health.", nil]; 
    Fruit *item2 = [Fruit new]; 
    item2.name = @"Banana"; 
    item2.price = @"80 cents for one"; 
    item2.image = @"banana.jpeg"; 
    item2.location = [NSArray arrayWithObjects:@"Taiwan",@"Banana is good after exercise.", nil] 
    fruit = [NSMutableArray arrayWithObjects:item1,item2, nil]; 
} 

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath 
{ 
    Fruit *newRow = [fruit objectAtIndex:indexPath.row]; 
    NSString * selectedFruit = newRow.name; 
    UIAlertView * messageAlert = [[UIAlertView alloc]initWithTitle:@"Row Selected"message:selectedFruit delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:@"hi", nil]; 
    [messageAlert show]; 
} 

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender 
{ 
    if ([segue.identifier isEqualToString:@"showFruitDetail"]) 
    { 
     NSIndexPath * indexPath = [self.tableView indexPathForSelectedRow]; 
     FruitDetailViewController * destViewController = segue.destinationViewController; 
     Fruit *newRow = [fruit objectAtIndex:indexPath.row];     
     destViewController.detailFruit = newRow; 
    } 
} 

我在两个函数中都放入了断点，并检查参数“location”。他们都显示“无”。

参数“位置”也是一个数组。如何在函数之间传递数组？

Answer 1

“location”属性应该使用“strong”引用来避免ARC自动释放。

@property(nonatomic, strong) NSArray * location; 

入住＃1以下链接了解强VS弱引用Differences between strong and weak in objective-c