ios - 如何使用 UIViewController 将数据传递给 ViewController

Question

如何使用这段代码将数据传递给 ViewController？

UIStoryboard *main = [UIStoryboard storyboardWithName:@"Main" bundle:nil];

UIViewController *vc = [main instantiateViewControllerWithIdentifier:@"Catalog"];

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

我想将示例中的数据传递给 itemId，如下所示:

ViewController *vc = [[ViewController alloc] initWithNibName:nil bundle:nil];

vc.itemId = 0;

[[[[UIApplication sharedApplication] keyWindow] rootViewController] presentViewController:vc animated:YES completion:nil];

Answer 1

类型转换你的 UIViewController 如果它是 ViewController

ViewController *vc = (ViewController*)[main instantiateViewControllerWithIdentifier:@"Catalog"];
vc.itemId = 0;
[self presentViewController:vc animated:YES completion:nil];