title: How does the flutter parent component call a child component?
body: <p>How does the parent component trigger the methods of the child component? How do I trigger the click method of son in fathor? As shown below:</p>
  <p><a href="https://i.stack.imgur.com/9iAYu.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9iAYu.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/qyUTx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qyUTx.png" alt="enter image description here" /></a></p>