How do I stack subviews on iOS?

Question

I have a graph view that I would like to overlay some buttons on. When I create a nib with buttons and add that as a subview after adding the graph, it just shows the buttons over a white screen.

GraphViewController *graphViewController = [[GraphViewController alloc] init];
[self.view addSubview:graphViewController.view];
GraphButtonViewController *graphButtonViewController = [[GraphButtonViewController alloc] initWithNibName:@"GraphButtonView" bundle:nil];
[self.view addSubview:graphButtonViewController.view];

Answer 1

您是否尝试过使GraphButtonView xib的（主）视图具有透明背景？