draggingEntered：called但performDragOperation：不在IKImageBrowserView上

Question

我正在使用IKImageBrowserView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

显然必须实施draggingUpdated:。