Cocoa touch NSMUTABLEARRY在ViewDidLoad中工作，但在DidSelectRowAtIndexPath中不工作

菜单

菜单m

ViewDidLoad正常工作

@interface Menu : UITableViewController {    
    NSMutableArray *arrayCellCollectionOrder;
    NSMutableDictionary *dictCellCollection;
    NSMutableDictionary *dictCellIndividual;
}

@property (nonatomic, retain) NSMutableArray *arrayCellCollectionOrder;

@end

cellForRowAtIndexPath正常工作。我可以访问

arrayCellCollectionOrder

@synthesize arrayCellCollectionOrder;

- (void)viewDidLoad {

    // Codes to read in data from PLIST
    // This part works

    NSString *errorDesc = nil;
    NSPropertyListFormat format;
    NSString *plistPath;
    NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];

    plistPath = [rootPath stringByAppendingPathComponent:@"InfoTableDict.plist"];
    if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath]) {
        plistPath = [[NSBundle mainBundle] pathForResource:@"InfoTableDict" ofType:@"plist"];
    }

    NSData *plistXML = [[NSFileManager defaultManager] contentsAtPath:plistPath];
    NSDictionary *temp = (NSDictionary *)[NSPropertyListSerialization
                                        propertyListFromData:plistXML
                                        mutabilityOption:NSPropertyListMutableContainersAndLeaves
                                        format:&format
                                        errorDescription:&errorDesc];

    if (!temp) {
        NSLog(@"Error reading plist: %@, format: %d", errorDesc, format);
    }

    arrayCellCollectionOrder = [[[NSMutableArray alloc] init] retain];
    arrayCellCollectionOrder = [temp objectForKey:@"CellCollectionOrder"]; 

    // I can access `arrayCellCollectionOrder` here, it's working.

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"PhotoCell";
    PhotoCell *cell = (PhotoCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"PhotoCell" owner:self options:nil];
        for (id currentObject in topLevelObjects) {
            if ([currentObject isKindOfClass:[PhotoCell class]]) {
                cell = (PhotoCell *) currentObject;
                break;
            }
        }
    }

    // Copy the specific dictionary from CellCollection to Cell Individual
    dictCellIndividual = [dictCellCollection objectForKey:[NSString stringWithFormat:@"%@", [arrayCellCollectionOrder objectAtIndex:indexPath.row]]];

    cell.photoCellTitle.text = [dictCellIndividual objectForKey:@"Title"];     // Load cell title
    cell.photoCellImage.image = [UIImage imageNamed:[NSString stringWithFormat:@"%@", [dictCellIndividual objectForKey:@"ThumbnailFilename"]]];        // Load cell image name

    return cell;

}

未选择行索引路径不工作。我无法访问

arrayCellCollectionOrder

@synthesize arrayCellCollectionOrder;

- (void)viewDidLoad {

    // Codes to read in data from PLIST
    // This part works

    NSString *errorDesc = nil;
    NSPropertyListFormat format;
    NSString *plistPath;
    NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];

    plistPath = [rootPath stringByAppendingPathComponent:@"InfoTableDict.plist"];
    if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath]) {
        plistPath = [[NSBundle mainBundle] pathForResource:@"InfoTableDict" ofType:@"plist"];
    }

    NSData *plistXML = [[NSFileManager defaultManager] contentsAtPath:plistPath];
    NSDictionary *temp = (NSDictionary *)[NSPropertyListSerialization
                                        propertyListFromData:plistXML
                                        mutabilityOption:NSPropertyListMutableContainersAndLeaves
                                        format:&format
                                        errorDescription:&errorDesc];

    if (!temp) {
        NSLog(@"Error reading plist: %@, format: %d", errorDesc, format);
    }

    arrayCellCollectionOrder = [[[NSMutableArray alloc] init] retain];
    arrayCellCollectionOrder = [temp objectForKey:@"CellCollectionOrder"]; 

    // I can access `arrayCellCollectionOrder` here, it's working.

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"PhotoCell";
    PhotoCell *cell = (PhotoCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"PhotoCell" owner:self options:nil];
        for (id currentObject in topLevelObjects) {
            if ([currentObject isKindOfClass:[PhotoCell class]]) {
                cell = (PhotoCell *) currentObject;
                break;
            }
        }
    }

    // Copy the specific dictionary from CellCollection to Cell Individual
    dictCellIndividual = [dictCellCollection objectForKey:[NSString stringWithFormat:@"%@", [arrayCellCollectionOrder objectAtIndex:indexPath.row]]];

    cell.photoCellTitle.text = [dictCellIndividual objectForKey:@"Title"];     // Load cell title
    cell.photoCellImage.image = [UIImage imageNamed:[NSString stringWithFormat:@"%@", [dictCellIndividual objectForKey:@"ThumbnailFilename"]]];        // Load cell image name

    return cell;

}

错误是： *由于未捕获的异常“NSRangeException”而终止应用程序，原因：“-[\u NSCFArray objectAtIndex:]：索引（1）超出边界（0）”

i、 e:我单击了行

1

，但

arrayCellCollectionOrder

为空。

arrayCellCollectionOrder

中应该有ViewDidLoad中声明的数据

有什么我错过的吗？ 先谢谢你

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

// Browser
NSMutableArray *arrayPhotos = [[NSMutableArray alloc] init];

    NSLog(@"indexPath.row = %d", indexPath.row);        // Returns the row number i touched, works.

    NSLog(@"arrayCellCollectionOrder = %@", [NSString stringWithFormat:@"%@", [arrayCellCollectionOrder objectAtIndex:indexPath.row]]);        // DOES NOT WORK.

    // Copy the specific dictionary from CellCollection to Cell Individual
    dictCellIndividual = [dictCellCollection objectForKey:[NSString stringWithFormat:@"%@", [arrayCellCollectionOrder objectAtIndex:indexPath.row]]];        // This similar line gives error too.

    ...   ...
    ...   ...
    ...   ...
    ...   ...

}

您是否看到正在对

arrayCellCollectionOrder

执行的操作？首先将其分配给一个新的NSMutableArray（并且不必要地保留它），然后立即孤立该数组，并将

arrayCellCollectionOrder

分配给从

temp

字典中获取的另一个对象。换句话说，第一行除了创建一个泄漏的可变数组之外，对您没有任何帮助

如果第二行是正确的，并且您得到的是一个有效的对象，而这正是您想要的，那么问题是我看不到该对象被保留在哪里。只要它在字典中，它就可能被保留，但是如果临时被丢弃，那么它的成员就会被释放。如果你做了一件事

arrayCellCollectionOrder = [[[NSMutableArray alloc] init] retain];
arrayCellCollectionOrder = [temp objectForKey:@"CellCollectionOrder"]; 

---

然后二传手会保留它。

谢谢！我发现了我的错误。。改成下面这行也行。arrayCellCollectionOrder=[[NSMutableArray alloc]init]；arrayCellCollectionOrder=[[temp objectForKey:@“CellCollectionOrder”]保留]；如果你那样做的话，你就是在泄密。你为什么要做alloc和init呢？其次，您已经定义了一个@property，并且设置了setter和getter（@synthesis），那么当您可以使用setter时，为什么还要进行手动保留呢？执行我的建议：1）删除arrayCellCollectionOrder=[[NSMutableArray alloc]init]retain]；2） 将另一行更改为：self.arrayCellCollectionOrder=[temp objectForKey:@“CellCollectionOrder]”；内存管理对我来说是新事物。我想你是对的

self.arrayCellCollectionOrder

是正确的方法。谢谢。试着去理解你为什么要做出这些改变，我想这会在将来避免头痛。如果将一个对象分配给一个变量，并将另一个对象分配给同一个变量，那么第一个对象很可能已成为孤立对象，并且可能已泄漏。此外，您不必使用setter和getter，因此，如果您像将要做的那样手动执行保留，则不需要定义属性或合成。但是property和Synthesis允许您做的是允许其他类访问您的类的实例变量。（我过于简单化了）