示例代码

UIViewController *modalViewController = [[UIViewController alloc] init];
modalViewController.view.backgroundColor = [UIColor whiteColor];

if (@available(iOS 16.0, *)) {
    modalViewController.modalPresentationStyle = UIModalPresentationPageSheet;

    // iOS 15 提供 SheetPresentation
    UISheetPresentationController *sheet = modalViewController.sheetPresentationController;

    // iOS 16 支持为 SheetPresentation 自定义高度
    UISheetPresentationControllerDetent *customDetent = [UISheetPresentationControllerDetent customDetentWithIdentifier:@"customDetent" resolver:^CGFloat(id<UISheetPresentationControllerDetentResolutionContext> context) {
        // 根据上下文的信息来调整高度
        return SGScreen_Height - 200;
    }];

    if (sheet) {
        sheet.detents = @[
            [UISheetPresentationControllerDetent mediumDetent],
            [UISheetPresentationControllerDetent largeDetent],
            customDetent
        ];
        
        sheet.prefersGrabberVisible = YES;
        sheet.selectedDetentIdentifier = @"customDetent";
        sheet.prefersScrollingExpandsWhenScrolledToEdge = NO;
    }
} else {
    // Fallback on earlier versions
    modalViewController.modalPresentationStyle = UIModalPresentationAutomatic;
}

[self presentViewController:modalViewController animated:YES completion:nil];

UISheetPresentationController 是 iOS 15 及以上版本中引入的一种用于呈现底部弹出视图（Sheet）的控制器，提供了一种标准化的方式来管理模态视图的展示。在 iOS 16 及以上版本中，UISheetPresentationController 更加强大，允许开发者通过 customDetentWithIdentifier:resolver: 方法自定义弹出视图的高度。