我有以下代码，其中 <section id="form">
<div class="container">
<form id="contact_form" method="post" class="form" onsubmit="return confirm('Successfully submitted!');">
<div class="contact-form">
<div class="row">
<div class="col-md-6 col-sm-6 form-group ">
<input class="form-control" id="name" name="name" placeholder="Full name " type="text" required>
</div>
<div class="col-md-6 col-sm-6 form-group ">
<input class="form-control" id="email" name="email" placeholder="Email" type="text" required>
</div>
</div>
<div class="row">
<div class="col-md-6 col-sm-6 form-group ">
<input class="form-control" id="city" name="city" placeholder="City" type="text" required>
</div>
<div class="col-md-6 col-sm-6 form-group">
<input class="form-control" id="province" name="province" placeholder="Province" type="text" required>
</div>
</div>
<div class="row">
<div class="col-md-12">
<textarea class ="form-control" placeholder ="ISBNs with book conditions. One ISBN per line." id="message" name="message" required></textarea>
</div>
</div>
<div class="row mt20">
<div class="col-md-12 form-group">
<button id="submit_btn" name="submit_btn" type="submit" value="submit_btn" class="btn btn-outline btn-primary btn-icon pull-right btn-lg btn-rounded">Submit
<span class="fa fa-chevron-right icon-with-btn"></span>
</button>
</div>
</div>
</form>
</div> // this div should be before </form>
</div>
</section>
操作执行。以下代码有效，但我的问题是如何取消/终止async操作？
换句话说，当应用通过调用async在后台工作，然后用户导航到其他视图时，我应该终止此[self addAllImages]来电。
async