draggingEntered：已调用但 performDragOperation：不在 IKImageBrowserView 上

Question

我正在使用 IKImageBrowserView 设置拖放委托

[self.imageBrowserView setDraggingDestinationDelegate:self];

无论我 return 在 draggingEntered 中做什么：performDragOperation: 从未被调用

- (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:必须实施。