javascript - 我的 JS 函数不会 "alert"按键

Question

我有这段代码，它似乎没有提醒我按下某个键(这应该在我单击“开始”后发生)。为什么不呢？ :/

function dynamic_buttons() {
    var start_button = document.getElementById('start');
    var stop_button = document.getElementById('stop');
    start_button.onclick = log_keypress;
    stop_button.onclick = log_keypress;
    }

function log_keypress() {
    alert('click event happened'); 
    }

这是“完整的” fiddle :code

Answer 1

您需要调用dynamic_buttons函数来绑定(bind)事件。

更新的 fiddle

http://fiddle.jshell.net/dQR6j/5/

function dynamic_buttons() {
var start_button = document.getElementById('start');
var stop_button = document.getElementById('stop');
start_button.onclick = log_keypress;
stop_button.onclick = log_keypress;
}

function log_keypress() {
  alert('click event happened'); 
}

dynamic_buttons(); // <--- this is important