排序数组上的iPhone内存泄漏和释放问题

I'm having some troubles with the code below:

我遇到以下代码的麻烦：

NSSortDescriptor *idDescriptor = [[[NSSortDescriptor alloc] initWithKey:key ascending:ascending] autorelease];
NSArray *sortDescriptors = [NSArray arrayWithObject:idDescriptor];
NSArray *orderArray = [array sortedArrayUsingDescriptors:sortDescriptors];  
NSMutableArray *result = [NSMutableArray arrayWithArray:orderArray];

If I use this code, Instruments says I have a memory leak, why?

如果我使用这个代码，仪器说我有内存泄漏，为什么？

Using this code:

使用此代码：

NSSortDescriptor *idDescriptor = [[[NSSortDescriptor alloc] initWithKey:key ascending:ascending] autorelease];
NSArray *sortDescriptors = [NSArray arrayWithObject:idDescriptor];
NSArray *orderArray = [array sortedArrayUsingDescriptors:sortDescriptors];

NSMutableArray *result = [[NSMutableArray alloc] initWithArray:orderArray];

I receive the leak warning too, however, if I autorelease the object result, a memory error happens.

我也收到泄漏警告，但是，如果我自动释放对象结果，则会发生内存错误。

1 个解决方案

#1

Here is a better answer I think.

我认为这是一个更好的答案。

- (NSMutableArray *) orderArray:(NSMutableArray *)array ByKey:(NSString *)key ascending:(BOOL)ascending 
{ 
    NSSortDescriptor *idDescriptor = [[[NSSortDescriptor alloc] initWithKey:key ascending:ascending]];
    NSArray *sortDescriptors = [NSArray arrayWithObject:idDescriptor]; 
    NSArray *orderArray = [array sortedArrayUsingDescriptors:sortDescriptors]; 
    NSMutableArray *result = [[[NSMutableArray alloc] initWithArray:orderArray]];

    [release idDescriptor]; 
    return [result autorelease]; 
}

So, you allocate idDescriptor, then you use it, finally release it. Since you're returning result, you can autorelease it with the return. I have one more question though. Do you reference result elsewhere in your code?

所以，你分配idDescriptor，然后你使用它，最后释放它。由于您返回结果，您可以使用返回自动发布。我还有一个问题。你在代码的其他地方引用了结果吗？