<html><body><p>本例演示如何将 "onkeypress" 事件分配给 input 元素。</p><p>Press a key inside the text field to set a red background color.</p><input type="text" id="demo" onkeypress="myFunction()"><script>function myFunction() { document.getElementById("demo").style.backgroundColor = "red";}</script></body></html>