拖放不適用於NSBox的子類

Question

我已經創建了NSBox的子類來實現拖放操作。我有以下代碼：

@interface DropView : NSBox { 

} 
- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender; 
- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender; 
@end 

@implementation DropView 
- (void)awakeFromNib 
{ 
    [self registerForDraggedTypes: 
    [NSArray arrayWithObject: NSFilenamesPboardType]]; 
} 
- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender 
{ 
NSDragOperation sourceDragMask = [sender 
      draggingSourceOperationMask]; 
if (sourceDragMask & NSDragOperationLink) { 
    return NSDragOperationLink; 
} else if (sourceDragMask & NSDragOperationCopy) { 
    return NSDragOperationCopy; 
} 
return NSDragOperationNone; 
} 

-(BOOL)performDragOperation:(id <NSDraggingInfo>)sender 
{ 
NSPasteboard *pboard=[sender draggingPasteboard]; 
NSArray *files = [pboard propertyListForType:NSFilenamesPboardType]; 
NSEnumerator *e=[files objectEnumerator]; 
NSString *str=nil; 
while(str=[e nextObject]) { 
    NSLog(@"Got %@\n", str); 
} 

return (TRUE); 
} 
@end 

但是，拖放不起作用。當我嘗試將某些東西拖入盒子時，我看不到綠色加上。

謝謝

Answer 1

解決了這個問題。而不是將NSView的類設置爲DropView，將NSBox的類設置爲DropView效果很好:-)