找不到MDCBottomDrawerViewController符号

Question

我正在使用iOS应用，并使用material-io的导航抽屉。 我使用示例代码，但是运行它时会收到错误消息。

- (void) viewDidAppear:(BOOL)animated {
    MDCBottomDrawerViewController *bottomDrawerViewController = [[MDCBottomDrawerViewController alloc] init];
    bottomDrawerViewController.contentViewController = [UIViewController new];
    bottomDrawerViewController.headerViewController = [UIViewController new];
    [self presentViewController:bottomDrawerViewController animated:YES completion:nil];
}

dyld: Symbol not found: _OBJC_CLASS_$_MDCBottomDrawerViewController
Referenced from: ***
in: ***/Frameworks/MaterialComponents.framework/MaterialComponents