从NSOutlineView中拖放

2 回答

• 7

  我创建了一个small sample project，它有一个 NSOutlineView ，您可以在其中添加和删除项目 .

  今天我基于@Monolo的答案（See changes）实现了拖放支持 .

  

  回复于 2024-05-17T17:35:35+08:00
• 14

  我发现这个文档有点不清楚，除此之外，还有新的方法在Lion中添加 .

  假设您需要10.7或更高版本，那么这可能是您实现的框架：

  在您的数据源/委托类中，实现：

  // A method to register the view for dragged items from itself. 
  // Call it during initialization
  -(void) enableDragNDrop
  {
      [self.outlineView registerForDraggedTypes: [NSArray arrayWithObject: @"DragID"]];
  }
  
  
  - (id <NSPasteboardWriting>)outlineView:(NSOutlineView *)outlineView pasteboardWriterForItem:(id)item 
  {
      // No dragging if <some condition isn't met>
  
      if ( dontDrag )  {
          return nil;
      }
  
      // With all the blocking conditions out of the way,
      // return a pasteboard writer.
  
      // Implement a uniqueStringRepresentation method (or similar)
      // in the classes that you use for your items.
      // If you have other ways to get a unique string representation
      // of your item, you can just use that.
      NSString *stringRep = [item uniqueStringRepresentation];
  
      NSPasteboardItem *pboardItem = [[NSPasteboardItem alloc] init];
  
      [pboardItem setString:stringRep forType: @"DragID"];
  
      return pboardItem;
  }
  
  
  - (NSDragOperation)outlineView:(NSOutlineView *)outlineView validateDrop:(id < NSDraggingInfo >)info proposedItem:(id)item proposedChildIndex:(NSInteger)index
  {
      BOOL dragOK = // Figure out if your dragged item(s) can be dropped
                    // on the proposed item at the index given
  
      if ( dragOK ) {
          return NSDragOperationMove;
      }
      else {
          return NSDragOperationNone;
      }
  }
  
  
  - (BOOL)outlineView:(NSOutlineView *)outlineView acceptDrop:(id < NSDraggingInfo >)info item:(id)item childIndex:(NSInteger)index
  {           
      // Move the dragged item(s) to their new position in the data model
      // and reload the view or move the rows in the view.
      // This is of course quite dependent on your implementation        
  }
  

  对于最后一种方法，需要填写大量代码，对于动画运动，在samir的评论中提到的Apple的complex table view demo code非常有用，如果解密起来有些复杂的话 .

  回复于 2024-05-17T17:35:35+08:00