NSOutlineView數據源

Question

我在Xcode中創建了一個NSOutlineView（Sourcelist），給它一個插座，並讓我的類實現NSOutlineViewDataSource。然後我[outlineview setDataSource:]，我看到它創建了我的數組中的項目數的單元格，但它們都是空白的。

sub1 = [NSArray arrayWithObjects:@"General Data",@"Most Played", @"Misc",@"Log", nil]; 
sub2 = [NSArray arrayWithObjects:@"General Data", @"Most Played", @"Misc",@"Log", nil]; 

items = [NSArray arrayWithObjects:sub1,sub2,nil]; 

[outlin setDataSource:self]; 
[outlin reloadData]; 

- (BOOL)outlineView:(NSOutlineView *)outlineView isItemExpandable:(id)item 
{   
    return [self outlineView:outlineView numberOfChildrenOfItem:item] != 0; 
} 

- (NSInteger)outlineView:(NSOutlineView *)outlineView numberOfChildrenOfItem:(id)item 
{  
    if (item) 
     if ([item isKindOfClass:[NSArray class]]) 
      return [item count]; 
     else 
      return 0; 
    else 
     return [items count]; 
} 

- (id)outlineView:(NSOutlineView *)outlineView child:(NSInteger)index ofItem:(id)item 
{ 
    if (item) { 
     return [item objectAtIndex:index]; 
    } 
    else 
     return [items objectAtIndex:index]; 
} 

- (id)outlineView:(NSOutlineView *)outlineView objectValueForTableColumn:(NSTableColumn *)theColumn byItem:(id)item 
{ 
    if (item) { 
     if ([item isKindOfClass:[NSArray class]]) 
      return @"YES"; // Return name for this node 
     else 
      return item; 
    } 
    else 
     return @"List Root"; 
} 

一切似乎是按順序，這是一種作品，除了所有的文字是空白的。它創建了所有的根項目，並且只是沒有文本。

Answer 1

也許你忘了建一個表列的NSOutlineView這樣的：

NSTableColumn *titleColumn = [[[NSTableColumn alloc] initWithIdentifier:@"identifier"] autorelease]; 
[[titleColumn headerCell] setStringValue:@"Header"]; 
[self addTableColumn:titleColumn]; 
[self setOutlineTableColumn:titleColumn];