我有这段代码，如果我点击发送，它会以空字段发送...我可以阻止这种情况吗？例如:如果用户提交空字段，将出现一个警报..
<!-- Author: Michael Milstead / Mode87.com
for Untame.net
Twitter Bootstrap Tutorial
Modal Contact Demo, 2013
-->
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Twitter Bootstrap Modal Contact Form Demo</title>
<meta name="description" content="Creating Modal Window with Twitter Bootstrap">
<link href="assets/bootstrap.min.css" rel="stylesheet">
<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
<script src="assets/bootstrap.min.js"></script>
<script>
$(document).ready(function () {
$("input#submit").click(function(){
$.ajax({
type: "POST",
url: "process.php", //
data: $('form.contact').serialize(),
success: function(msg){
$("#thanks").html(msg)
$("#form-content").modal('hide');
},
error: function(){
alert("failure");
}
});
});
});
</script>
<style type="text/css">
body { margin: 50px; background: url(assets/bglight.png); }
.well { background: #fff; text-align: center; }
.modal { text-align: left; }
</style>
</head>
<body>
<div class="container">
<div class="well well-large">
<h2>Twitter Bootstrap Modal Contact Form Demo</h2>
<div id="form-content" class="modal hide fade in" style="display: none;">
<div class="modal-header">
<a class="close" data-dismiss="modal">×</a>
<h3>Send me a message</h3>
</div>
<div class="modal-body">
<form class="contact" name="contact">
<label class="label" for="name" required>Your Name</label><br>
<input type="text" name="name" class="input-xlarge"><br>
<label class="label" for="email">Your E-mail</label><br>
<input type="email" name="email" class="input-xlarge"><br>
<label class="label" for="message">Enter a Message</label><br>
<textarea name="message" class="input-xlarge"></textarea>
</form>
</div>
<div class="modal-footer">
<input class="btn btn-success" type="submit" value="Send!" id="submit">
<a href="#" class="btn" data-dismiss="modal">Nah.</a>
</div>
</div>
<div id="thanks"><p><a data-toggle="modal" href="#form-content" class="btn btn-primary btn-large">Modal powers, activate!</a></p></div>
</div>
</div>
</body>
</html>
我尝试了一些方法来做到这一点，但我不能，我使用了 ev.preventDefault(); 但按钮 send 不起作用:ss
最佳答案
对于您的发送方法，请使用 return true 和 return false。
$("input#submit").click(function(){
If(userInputs === null){
Alert("please fill out form");
event.preventDefault();
return false;
}
$.ajax({
type: "POST",
url: "process.php", //
data: $('form.contact').serialize(),
success: function(msg){
$("#thanks").html(msg)
$("#form-content").modal('hide');
},
error: function(){
alert("failure");
}
});
});
});
</script>
关于javascript - 如何防止空输入？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30418951/