objective-c - draggingEntered：调用但 performDragOperation：不在 IKImageBrowserView

Question

我正在使用 IKImageBrowserView 来设置 drop deleagte

[self.imageBrowserView setDraggingDestinationDelegate:self];

无论我在 draggingEntered 中返回什么：performDragOperation: 永远不会被调用

- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender {
    // GETS CALLED 
    return NSDragOperationEvery;
}

- (BOOL)prepareForDragOperation:(id <NSDraggingInfo>)sender {
    // NOT CALLED
    return YES;
}

- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender {
    // NOT CALLED
    return YES;
}

Answer 1

显然draggingUpdated:必须执行。