myDocument (NSPersistentDocument) -> myDocument.xib (windows xib)
                                           |
                                           |-> view (the self.view) --> ... "other view"
                                           |
                                           |-> some NSArrayController 
                                           |
                                           |-> myResourceViewController --> myResourceViewController.xib
                                                                                          |
                                                                                          |-> view (the self.view)
                                                                                          |
                                                                                          |-> myTreeController (a NSTreeController subclass)

基本上,myResourceViewController是一个viewController的一个实例,它管理resourceView并管理他们的数据.

在awakeFromNib方法myDocument我有以下代码

- (void)windowControllerDidLoadNib:(NSWindowController *)aController
{
    ...
    [leftBar addSubview:resourceViewController.view]; //i add resourceViewController's view 
    resourceViewController.view.frame = leftBar.bounds;
    ...
}

在myResourceViewController awakeFromNib方法我有：

-(void)awakeFromNib;
{
    NSLog(@"%@",[self description]);

    [removeButton bind:@"enabled" toObject:resourceTreeController withKeyPath:@"selection" options:[NSDictionary dictionaryWithObject:NSIsNotNilTransformerName forKey:NSValueTransformerNameBindingOption]];

    NSArray *draggedTypes = [NSArray arrayWithObjects:ResourceURIPasteBoardType,nil];
    [resourceOutlineView registerForDraggedTypes:draggedTypes];
}

NSLog表示,同一个myResourceViewController实例的awakeFromNib被称为4次,我不明白为什么.我唯一的ResourceViewController是在myDocument xib中创建的.我不使用NSNib加载方法到处.