Question

要支持与Swift和ObjC不同的语言，我需要了解如何为NSTreeController设置NSOutlineView。

我已经能够在代码中创建NSOutlineView，同时提供我自己的DataSource委托。但现在我想切换到使用NSTreeController。我无法弄清楚如何设置绑定和其他关系，因为我可以找到的所有示例都假设使用Interface Builder进行设置。

Answer 1

我想我现在已经找到了基础知识。为了记录，这是我必须添加到我已经管理了NSOutlineView的视图控制器，我自己管理数据源：

为树节点创建一个类：

@property (nonatomic, retain) NSTreeController *treeController;
@property (nonatomic, retain) NSMutableArray *treeContents;

将这些属性添加到视图控制器：

awakeFromNib

初始化树控制器，例如来自视图控制器的self.treeContents = [NSMutableArray array]; // holds the add nodes self.treeController = [[NSTreeController alloc] init]; [self.treeController setLeafKeyPath:@"isLeaf"]; // refers to DataNode [self.treeController setChildrenKeyPath:@"children"]; // refers to DataNode // set up the bindings [self.treeController bind:@"contentArray" toObject:self withKeyPath:@"treeContents" options:@{NSRaisesForNotApplicableKeysBindingOption:@YES, NSConditionallySetsEditableBindingOption:@YES}]; [self.table bind:@"content" toObject:self.treeController withKeyPath:@"arrangedObjects" options:@{NSAlwaysPresentsApplicationModalAlertsBindingOption:@YES}]; [self.table bind:@"selectionIndexPaths" toObject:self.treeController withKeyPath:@"selectionIndexPaths" options:@{}]; [self.table bind:@"sortDescriptors" toObject:self.treeController withKeyPath:@"sortDescriptors" options:@{}];：

DataNode *node = [[DataNode alloc] init];
node.firstText = [NSString stringWithFormat:@"1 - %d", i1];
node.secondText = [NSString stringWithFormat:@"2 - %d", i1];
NSIndexPath *loc = [NSIndexPath indexPathWithIndex:self.contents.count]; // appends to end of list
[self.treeController insertObject:node atArrangedObjectIndexPath:loc];

将节点添加到树的根目录：

-(NSInteger)outlineView:(NSOutlineView *)outlineView numberOfChildrenOfItem:(id)item {
    return 0;   // never called (due to using NSTreeController)
}

-(id)outlineView:(NSOutlineView *)outlineView child:(NSInteger)index ofItem:(id)item {
    return nil; // never called (due to using NSTreeController)
}

-(BOOL)outlineView:(NSOutlineView *)outlineView isItemExpandable:(id)item {
    return NO;  // never called (due to using NSTreeController)
}

-(id)outlineView:(NSOutlineView *)outlineView objectValueForTableColumn:(NSTableColumn *)tableColumn byItem:(id)item {
    DataNode *node = [item representedObject];
    return [node valueForKey:tableColumn.identifier];
}

由于我的NSOutlineView是基于单元格的，我还一直在实现DataSource方法，以便为单元格提供值，因为我无法弄清楚如何为此进行绑定：

objectValueForTableColumn

firstText方法假设表格列的标识符分别设置为secondText和id。

以编程方式将NSTreeController绑定到NSOutlineView

1 个答案: