小编Joh*_*nes的帖子

我正在尝试为新程序创建一个源列表,并且我在使用基于视图的NSOutlineView时遇到了一些问题.我的代码使用基于单元格的NSOutlineView工作正常,所以我对发生的事情有点困惑.

这是代理和数据源的代码:

#pragma mark -
#pragma mark NSOutlineView Delegate

- (BOOL)outlineView:(NSOutlineView *)outlineView isGroupItem:(id)item {
    return (item == nil) ? YES : [(SourceListNode *)item groupItem];
}

- (id)outlineView:(NSOutlineView *)outlineView viewForTableColumn:(NSTableColumn *)tableColumn item:(id)item {
    if ([(SourceListNode *)item groupItem]) {
        return [outlineView makeViewWithIdentifier:@"HeaderCell" owner:self];
    }
    else {
        return [outlineView makeViewWithIdentifier:@"DataCell" owner:self];
    }
}

#pragma mark -
#pragma mark NSOutlineView Data Source

- (NSInteger)outlineView:(NSOutlineView *)outlineView numberOfChildrenOfItem:(id)item {
    return (item == nil) ? [sourceListNodes count] : [(SourceListNode *)item numberOfChildren];
}

- (BOOL)outlineView:(NSOutlineView *)outlineView isItemExpandable:(id)item { …