Question

onchange事件在以下代码中不起作用。我有一个选择标签，如果选择了“是”，我想显示一个文本框。当我选择“是”时，该文本框不会出现。

代码：

private static IScheduler MakeScheduler(IContext ctx) {
    ... // the code from your lambda goes here
}
...
ForSingletonOf<IScheduler>().Use(ctx => MakeScheduler(ctx));

Answer 1

选项Yes的值实际上是"1"，而不是"Yes"。

<script type = "text/javascript">
            function showfield(name) {
                if (name == "1") {
                    document.getElementById("div1").innerHTML = '<input type = "text" cols = "10" rows = "9" name = "yes" />';
                } else {
                    document.getElementById("div1").innerHTML = "";
                }
            }
</script>

<select name = "Prior_Knowledge" class = "user" id = "prior_knowledge" onchange = "showfield(this.options[this.selectedIndex].value);">
            <option> </option>
            <option value = "1">Yes</option>
            <option value = "2">No</option>
</select>
<div class = "user" id = "div1"></div>

Answer 2

尝试一下

var priorKnowledge =  document.getElementById("prior_knowledge");

priorKnowledge.addEventListener("change", function() {
    if(this.options[this.selectedIndex].text == "Yes"){
      document.getElementById("div1").innerHTML = '<input type = "text" cols = "10" rows = "9" name = "yes" />';
    }else{
    document.getElementById("div1").innerHTML = "";
    }
});

<select name = "Prior_Knowledge" class = "user" id ="prior_knowledge">
  <option> </option>
  <option value = "1">Yes</option>
  <option value = "2">No</option>
</select>
<div class = "user" id = "div1"></div>

或者您的原始代码

<script type = "text/javascript">
            function showfield(name) {
                if (name == "Yes") {
                    document.getElementById("div1").innerHTML = '<input type = "text" cols = "10" rows = "9" name = "yes" />';
                } else {
                    document.getElementById("div1").innerHTML = "";
                }
            }
</script>

<select name = "Prior_Knowledge" class = "user" id = "prior_knowledge" onchange = "showfield(this.options[this.selectedIndex].text);">
            <option> </option>
            <option value = "1">Yes</option>
            <option value = "2">No</option>
</select>
<div class = "user" id = "div1"></div>

更改this.options[this.selectedIndex].value中的this.options[this.selectedIndex].text

onchange事件不起作用

2 个答案: