objective-c - 拖动输入: called but performDragOperation: not on IKImageBrowserView

Question

我正在使用 IKImageBrowserView 设置拖放委托(delegate)

[self.imageBrowserView setDraggingDestinationDelegate:self];

无论我在 DraggingEntered 中返回什么:performDragOperation:都不会被调用

- (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

显然必须实现draggingUpdated:。