iphone - Cocoa Touch : What to release, 什么时候发布？

Question

我正在努力了解何时以及必须在 Cocoa Touch 中发布什么内容，因为它没有垃圾收集功能。

此代码块来自苹果 iPhone 示例 periodicElements，他们释放 anElement 和 rawElementArray，但不释放 thePath、firstLetter、existingArray 和 tempArray？

我本以为至少应该释放 tempArray 和existingArray。

有聪明人可以解释一下为什么吗？

谢谢:)

- (void)setupElementsArray {
NSDictionary *eachElement;

// create dictionaries that contain the arrays of element data indexed by
// name
self.elementsDictionary = [NSMutableDictionary dictionary];
// physical state
self.statesDictionary = [NSMutableDictionary dictionary];
// unique first characters (for the Name index table)
self.nameIndexesDictionary = [NSMutableDictionary dictionary];

// create empty array entries in the states Dictionary or each physical state
[statesDictionary setObject:[NSMutableArray array] forKey:@"Solid"];
[statesDictionary setObject:[NSMutableArray array] forKey:@"Liquid"];
[statesDictionary setObject:[NSMutableArray array] forKey:@"Gas"];
[statesDictionary setObject:[NSMutableArray array] forKey:@"Artificial"];

// read the element data from the plist
NSString *thePath = [[NSBundle mainBundle]  pathForResource:@"Elements" ofType:@"plist"];
NSArray *rawElementsArray = [[NSArray alloc] initWithContentsOfFile:thePath];

// iterate over the values in the raw elements dictionary
for (eachElement in rawElementsArray)
{
    // create an atomic element instance for each
    AtomicElement *anElement = [[AtomicElement alloc] initWithDictionary:eachElement];

    // store that item in the elements dictionary with the name as the key
    [elementsDictionary setObject:anElement forKey:anElement.name];

    // add that element to the appropriate array in the physical state dictionary 
    [[statesDictionary objectForKey:anElement.state] addObject:anElement];

    // get the element's initial letter
    NSString *firstLetter = [anElement.name substringToIndex:1];
    NSMutableArray *existingArray;

    // if an array already exists in the name index dictionary
    // simply add the element to it, otherwise create an array
    // and add it to the name index dictionary with the letter as the key
    if (existingArray = [nameIndexesDictionary valueForKey:firstLetter]) 
    {
    [existingArray addObject:anElement];
    } else {
        NSMutableArray *tempArray = [NSMutableArray array];
        [nameIndexesDictionary setObject:tempArray forKey:firstLetter];
        [tempArray addObject:anElement];
    }

    // release the element, it is held by the various collections
    [anElement release];

}
// release the raw element data
[rawElementsArray release];



// create the dictionary containing the possible element states
// and presort the states data
self.elementPhysicalStatesArray = [NSArray arrayWithObjects:@"Solid",@"Liquid",@"Gas",@"Artificial",nil];
[self presortElementsByPhysicalState];

// presort the dictionaries now
// this could be done the first time they are requested instead

[self presortElementInitialLetterIndexes];

self.elementsSortedByNumber = [self presortElementsByNumber];
self.elementsSortedBySymbol = [self presortElementsBySymbol];

}

Answer 1

它们通过向类发送 +alloc 来创建 rawElementsArray，因此该对象由上面示例中的代码拥有，必须释放。与 anElement 类似。请注意，thePath 和 tempArray 不是通过发送 +alloc、+new 或 -copy< 创建的 消息，因此调用代码不负责这些对象的生命周期。请看一下 Cocoa 内存管理文章集:

http://iamleeg.blogspot.com/2008/12/cocoa-memory-management.html