NSTableView的委托在创建行时收到awakeFromNib消息

Question

在我的项目中有一个xib文件，其文件所有者被设置为NSViewController的子类。这个xib文件有一个NSView，里面有一个基于视图的NSTableView。 NSViewController子类实现了协议NSTableViewDelegate，并且在IB中，NSTableView的委托连接到文件的所有者。当通过绑定创建视图，该的viewController的awakeFromNib方法被调用这个调用堆栈：

#0 0x000000010000584b in -[TheViewController awakeFromNib] 
#1 0x00007fff890f9bd8 in -[NSIBObjectData nibInstantiateWithOwner:topLevelObjects:]() 
#2 0x00007fff893101d6 in -[NSNib _instantiateNibWithExternalNameTable:]() 
#3 0x00007fff89310c7a in -[NSNib instantiateNibWithExternalNameTable:]() 
#4 0x00007fff892bcac4 in -[NSTableRowData _unarchiveViewWithIdentifier:owner:]() 
#5 0x00007fff892be57b in -[NSTableView(NSTableViewViewBased) makeViewForTableColumn:row:]() 
#6 0x00007fff892be1b2 in -[NSTableRowData _addViewToRowView:atColumn:row:]() 
#7 0x00007fff892bde7f in -[NSTableRowData _addViewsToRowView:atRow:]() 
#8 0x00007fff892bc415 in -[NSTableRowData _addRowViewForVisibleRow:withPriorView:]() 
#9 0x00007fff892bc19a in -[NSTableRowData _addRowViewForVisibleRow:withPriorRowIndex:inDictionary:withRowAnimation:]() 
#10 0x00007fff892bb469 in -[NSTableRowData _unsafeUpdateVisibleRowEntries]() 
#11 0x00007fff892bb001 in -[NSTableRowData updateVisibleRowViews]() 
#12 0x00007fff892930fb in -[NSTableView viewWillDraw]() 
#13 0x00007fff89170bed in __22-[NSView viewWillDraw]_block_invoke_0() 
#14 0x00007fff884d50b6 in __NSArrayEnumerate() 
#15 0x00007fff8917092d in -[NSView viewWillDraw]() 
#16 0x00007fff89170bed in __22-[NSView viewWillDraw]_block_invoke_0() 
#17 0x00007fff884d50b6 in __NSArrayEnumerate() 
#18 0x00007fff8917092d in -[NSView viewWillDraw]() 
#19 0x00007fff891fb455 in -[NSScrollView viewWillDraw]() 
#20 0x00007fff89170bed in __22-[NSView viewWillDraw]_block_invoke_0() 
#21 0x00007fff884d50b6 in __NSArrayEnumerate() 
#22 0x00007fff8917092d in -[NSView viewWillDraw]() 
#23 0x00007fff89170bed in __22-[NSView viewWillDraw]_block_invoke_0() 
#24 0x00007fff884d50b6 in __NSArrayEnumerate() 
#25 0x00007fff8917092d in -[NSView viewWillDraw]() 
#26 0x00007fff89247e0d in -[NSBox viewWillDraw]() 
#27 0x00007fff89170bed in __22-[NSView viewWillDraw]_block_invoke_0() 
#28 0x00007fff884d50b6 in __NSArrayEnumerate() 
#29 0x00007fff8917092d in -[NSView viewWillDraw]() 
#30 0x00007fff89170bed in __22-[NSView viewWillDraw]_block_invoke_0() 
#31 0x00007fff884d50b6 in __NSArrayEnumerate() 
#32 0x00007fff8917092d in -[NSView viewWillDraw]() 
#33 0x00007fff89170bed in __22-[NSView viewWillDraw]_block_invoke_0() 
#34 0x00007fff884d50b6 in __NSArrayEnumerate() 
#35 0x00007fff8917092d in -[NSView viewWillDraw]() 
#36 0x00007fff89170bed in __22-[NSView viewWillDraw]_block_invoke_0() 
#37 0x00007fff884d50b6 in __NSArrayEnumerate() 
#38 0x00007fff8917092d in -[NSView viewWillDraw]() 
#39 0x00007fff8916ff84 in -[NSView _sendViewWillDrawInRect:clipRootView:]() 
#40 0x00007fff8913c3f1 in -[NSView displayIfNeeded]() 
#41 0x00007fff891f93f8 in -[NSWindow _reallyDoOrderWindow:relativeTo:findKey:forCounter:force:isModal:]() 
#42 0x00007fff891f8a18 in -[NSWindow _doOrderWindow:relativeTo:findKey:forCounter:force:isModal:]() 
#43 0x00007fff891f85ff in -[NSWindow orderWindow:relativeTo:]() 
#44 0x00007fff890f9c96 in -[NSIBObjectData nibInstantiateWithOwner:topLevelObjects:]() 
#45 0x00007fff890d8b7d in loadNib() 
#46 0x00007fff890d80a9 in +[NSBundle(NSNibLoading) _loadNibFile:nameTable:withZone:ownerBundle:]() 
#47 0x00007fff890d7ede in -[NSBundle(NSNibLoading) loadNibNamed:owner:topLevelObjects:]() 
#48 0x00007fff890d7cbe in +[NSBundle(NSNibLoading) loadNibNamed:owner:]() 
#49 0x00007fff890d447f in NSApplicationMain() 
#50 0x0000000100001432 in main 

的awakeFromNib方法，不仅要在以后的viewController被称为实例化？

Answer 1

好像从我的经验，每当有新的观点是从厦门国际银行文件加载任何厦门国际银行文件的File's Owner将收到-awakeFromNib消息。正如您注意到的那样，当基于视图的表视图从xib文件创建新行时会发生这种情况。

而且我知道没有办法阻止这种情况的发生，除了可能记录多少次您调用awakeFromNib并仅在第一次执行初始化代码时。

或者，更好的是，把你的初始化逻辑在具有更坚实的时序另一种方法 - 例如在-loadView之后，致电super。我这样做：

- (void)loadView { 
    [self vvViewWillLoad]; 
    [super loadView]; 
    [self vvViewDidLoad]; 
} 

- (void)vvViewDidLoad { 
    ... // initialization material here 
}