NSMutableArray:如何修复此"EXC_BAD_ACCESS"代码？

Question

我正在制作一个OpenGL应用程序,但是我收到了一条EXC_BAD_ACCESS消息.

这是我的代码:

//(draw function only, ask if you need more)
//objects: array of triangles/quads
//Triangle/Quad3D: should be obvious, I like OOP
//PS this is in a 'Composite Object' class
- (void)draw {
    //NSLog(@"%@",objects);
    NSMutableArray *quad, *tri;
    quad =  [NSMutableArray arrayWithCapacity:0];
    tri =   [NSMutableArray arrayWithCapacity:0];
    NSEnumerator *e = [objects objectEnumerator];
    id object;
    while (object = [e nextObject]) {
        if ([object isKindOfClass:[Triangle3D class]]) {
            [tri addObject:(Triangle3D *)object];
        } else if ([object isKindOfClass:[Quad3D class]]) {
            [quad addObject:(Quad3D *)object];
        }
    }
    NSLog(@"%d",[tri count]);
    NSLog(@"%d",[quad count]);
    [quad release];
    [tri release];
    [e release];
}

Answer 1

您正在发布您不拥有的对象,因为它们是根据http://developer.apple.com/library/ios/#documentation/cocoa/Conceptual/MemoryMgmt/Articles/mmRules.html中给出的命名约定自动释放的.

如果使用名称以"alloc"或"new"开头或包含"copy"(例如,alloc,newObject或mutableCopy)的方法创建对象,或者向其发送保留消息,则获取对象的所有权.

+arrayWithCapacity: 不以"alloc"或"new"开头且不包含"copy",因此除非您明确保留该对象,否则不应释放它返回的对象.