我有一个带有两个文本框的表单,一个选择下拉框和一个单选按钮。当按下enter键时,我想调用JavaScript函数,但当我按下它时,表单就提交了。

当按下回车键时,如何防止表单被提交?


当前回答

跨浏览器解决方案

一些旧的浏览器以非标准的方式实现keydown事件。

KeyBoardEvent。Key是在现代浏览器中应该实现的方式。

哪一个 和keyCode现在已经被弃用了,但检查这些事件并没有什么害处,这样代码就可以为仍然使用IE等旧浏览器的用户工作。

isKeyPressed函数检查按下的键是否为enter, event.preventDefault()会阻止表单提交。

  if (isKeyPressed(event, 'Enter', 13)) {
    event.preventDefault();
    console.log('enter was pressed and is prevented');
  }

最小工作示例

JS

function isKeyPressed(event, expectedKey, expectedCode) {
  const code = event.which || event.keyCode;

  if (expectedKey === event.key || code === expectedCode) {
    return true;
  }
  return false;
}

document.getElementById('myInput').addEventListener('keydown', function(event) {
  if (isKeyPressed(event, 'Enter', 13)) {
    event.preventDefault();
    console.log('enter was pressed and is prevented');
  }
});

HTML

<form>
  <input id="myInput">
</form>

https://jsfiddle.net/tobiobeck/z13dh5r2/

其他回答

原生js(获取api)

document.onload = (() => { alert('ok'); let keyListener = document.querySelector('#searchUser'); // keyListener.addEventListener('keypress', (e) => { if(e.keyCode === 13){ let username = e.target.value; console.log(`username = ${username}`); fetch(`https://api.github.com/users/${username}`,{ data: { client_id: 'xxx', client_secret: 'xxx' } }) .then((user)=>{ console.log(`user = ${user}`); }); fetch(`https://api.github.com/users/${username}/repos`,{ data: { client_id: 'xxx', client_secret: 'xxx' } }) .then((repos)=>{ console.log(`repos = ${repos}`); for (let i = 0; i < repos.length; i++) { console.log(`repos ${i} = ${repos[i]}`); } }); }else{ console.log(`e.keyCode = ${e.keyCode}`); } }); })(); <input _ngcontent-inf-0="" class="form-control" id="searchUser" placeholder="Github username..." type="text">

使用两个事件。which和event.keyCode:

function (event) {
    if (event.which == 13 || event.keyCode == 13) {
        //code to execute here
        return false;
    }
    return true;
};
<div class="nav-search" id="nav-search">
        <form class="form-search">
            <span class="input-icon">
                <input type="text" placeholder="Search ..." class="nav-search-input" id="search_value" autocomplete="off" />
                <i class="ace-icon fa fa-search nav-search-icon"></i>
            </span>
            <input type="button" id="search" value="Search" class="btn btn-xs" style="border-radius: 5px;">
        </form>

</div>

<script type="text/javascript">
    $("#search_value").on('keydown', function(e) {
        if (e.which == 13) {
             $("#search").trigger('click');
            return false;
        }
    });
    $("#search").on('click',function(){
        alert('You press enter');
    });
</script>

跨浏览器解决方案

一些旧的浏览器以非标准的方式实现keydown事件。

KeyBoardEvent。Key是在现代浏览器中应该实现的方式。

哪一个 和keyCode现在已经被弃用了,但检查这些事件并没有什么害处,这样代码就可以为仍然使用IE等旧浏览器的用户工作。

isKeyPressed函数检查按下的键是否为enter, event.preventDefault()会阻止表单提交。

  if (isKeyPressed(event, 'Enter', 13)) {
    event.preventDefault();
    console.log('enter was pressed and is prevented');
  }

最小工作示例

JS

function isKeyPressed(event, expectedKey, expectedCode) {
  const code = event.which || event.keyCode;

  if (expectedKey === event.key || code === expectedCode) {
    return true;
  }
  return false;
}

document.getElementById('myInput').addEventListener('keydown', function(event) {
  if (isKeyPressed(event, 'Enter', 13)) {
    event.preventDefault();
    console.log('enter was pressed and is prevented');
  }
});

HTML

<form>
  <input id="myInput">
</form>

https://jsfiddle.net/tobiobeck/z13dh5r2/

react js解决方案

 handleChange: function(e) {
    if (e.key == 'Enter') {
      console.log('test');
    }


 <div>
    <Input type="text"
       ref = "input"
       placeholder="hiya"
       onKeyPress={this.handleChange}
    />
 </div>