Issues with touch scroll on iOS when focusing inpu

问题:

I am having some issues with a scrollable div on iOS. When trying to scroll by touching outside an input, it scrolls ok without any problem but when I try to scroll and I touch an input to start scrolling (there are a lot of chances that it happens because it is a div with a lot of inputs) it scrolls the whole window instead scrolling the div. I don't have that problem either in desktop or Android. I found a similar question (iOS HTML Input Tag Stops Scrolling in Scrollable Element) but it doesn't have any answer either. While I don't find any good solution, I decided to prevent the event touchmove when the user touches an input, but it is not exactly what I want.

Maybe someone already faced this problem and can help. I would really appreciate it, thanks in advance.

回答1:

To get native momentum scrolling on iOS 5+, you'll need:

div {
  overflow: scroll;
  -webkit-overflow-scrolling: touch;
}

Source: Overflow

Maybe you also need:

div > * {
    -webkit-transform: translateZ(0px);
}

Source: Similar question in Stack Overflow

Source 2: Another similar question

回答2:

This stuff made me crazy too, after testing everything, I found the following answer from Thomas Bachem here working and made it simpler in jquery.

Just add a class scrollFix to the inputs and you are ready to go. (or directly apply that js to any inputs/textarea using$('input, textarea')

Now when you touch and scroll on an input on iOS 8+, the input get all its "pointer-events" disabled (including the problematic behavior). Those "pointer-events" are enabled when we detect a simple touch.

$('.scrollFix').css("pointer-events","none");

$('body').on('touchstart', function(e) {
    $('.scrollFix').css("pointer-events","auto");
});
$('body').on('touchmove', function(e) {
    $('.scrollFix').css("pointer-events","none");
});
$('body').on('touchend', function(e) {
    setTimeout(function() {
        $('.scrollFix').css("pointer-events", "none");
    },0);
});

回答3:

html { 
    overflow: scroll; 
    -webkit-overflow-scrolling: touch;
}

回答4:

Hacky workaround, but by doing this I was able to make scrolling work even on form inputs. The JS forces a reflow in the rendering engine, which is where the bug in iOS8 Safari lies. Changing the height to auto also improved scrolling when focused on a form element, since scrolling is forcibly handled by the browser when focused.

Markup:

<div class="modal-backdrop-container">
  <div class="modal-backdrop">
    <div class="modal> <!-- Content --> </div>
  </div>
</div>

CSS:

.modal-backdrop-container {
    z-index: 10;
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    height: 100%;
}
.modal-backdrop {
    z-index: 10;
    height: 100%;
    background-color: rgba(255,255,255,0.5);
    overflow: auto;
    overflow-x: hidden;
    overflow-y: scroll;
    -webkit-overflow-scrolling: touch;
}
.modal {
    position: relative;
    width: 400px;
    max-width: 100%;
    margin: auto;
    background-color: white;
}

JS:

// reflow when changing input focus
        $modalInputs = $('.modal').find(':input');
        modalInputs.on('focus', function() {
            var offsetHeight = modal.$backdrop[0].offsetHeight;
            modal.$backdropContainer.css({
                'height': 'auto'
            });
        });
        modalInputs.on('blur', function() {
            var offsetHeight = modal.$backdrop[0].offsetHeight;
            modal.$backdropContainer.css({
                'height': ''
            });
        });

Not sure of the var offsetHeight = modal.$backdrop[0].offsetHeight; line is needed, since both this and changing the height value should force a reflow.