给定模型对象，如何在 NSTreeController 中找到索引路径？

Question

给定 NSTreeController 表示的模型对象，如何在树中找到它们的索引路径并随后选择它们？这似乎是一个非常明显的问题，但我似乎找不到任何参考。有什么想法吗？

Answer 1

没有“简单”的方法，您必须遍历树节点并找到匹配的索引路径，例如：

Objective-C:

Category

@implementation NSTreeController (Additions)

- (NSIndexPath*)indexPathOfObject:(id)anObject
{
    return [self indexPathOfObject:anObject inNodes:[[self arrangedObjects] childNodes]];
}

- (NSIndexPath*)indexPathOfObject:(id)anObject inNodes:(NSArray*)nodes
{
    for(NSTreeNode* node in nodes)
    {
        if([[node representedObject] isEqual:anObject])
            return [node indexPath];
        if([[node childNodes] count])
        {
            NSIndexPath* path = [self indexPathOfObject:anObject inNodes:[node childNodes]];
            if(path)
                return path;
        }
    }
    return nil; 
}
@end    

Swift:

扩展

extension NSTreeController {

    func indexPathOfObject(anObject:NSObject) -> NSIndexPath? {
         return self.indexPathOfObject(anObject, nodes: self.arrangedObjects.childNodes)
    }

    func indexPathOfObject(anObject:NSObject, nodes:[NSTreeNode]!) -> NSIndexPath? {
         for node in nodes {
            if (anObject == node.representedObject as! NSObject)  {
                 return node.indexPath
            }
            if (node.childNodes != nil) {
                if let path:NSIndexPath = self.indexPathOfObject(anObject, nodes: node.childNodes)
                {
                     return path
                }
            }
        }
        return nil
    }
}

Answer 2

为什么不使用 NSOutlineView 来获取这样的父项：

NSMutableArray *selectedItemArray = [[NSMutableArray alloc] init];

[selectedItemArray addObject:[self.OutlineView itemAtRow:[self.OutlineView selectedRow]]];

while ([self.OutlineView parentForItem:[selectedItemArray lastObject]]) {
  [selectedItemArray addObject:[self.OutlineView parentForItem:[selectedItemArray lastObject]]];
}

NSString *selectedPath = @".";
while ([selectedItemArray count] > 0) {
  OBJECTtype *singleItem = [selectedItemArray lastObject];
  selectedPath = [selectedPath stringByAppendingString:[NSString stringWithFormat:@"/%@", singleItem.name]];
  selectedItemArray removeLastObject];
}

NSLog(@"Final Path: %@", selectedPath);

这将输出： ./item1/item2/item3/...

我假设您正在此处查找文件路径，但您可以根据数据源进行调整代表。