http://blog.youkuaiyun.com/jiangcs520/article/details/17564065
http://www.cnblogs.com/mingforyou/archive/2013/02/18/2915151.html
function span_move_fun(){
var span = document.getElementById("move_k");
var span_left = $(span).offset().left;
var span_top = $(span).offset().top;
var start_left = $(span).offset().left;
var start_top = $(span).offset().top;
span.addEventListener('touchstart', function(event) {
event.preventDefault();
if (event.targetTouches.length == 1) {
var touch = event.targetTouches[0];
span.style.position = "absolute";
span_top = $(this).offset().top;
span_left = $(this).offset().left;
start_top = touch.pageY
start_left = touch.pageX
var left = parseFloat(touch.pageX - start_left + span_left-30);
var top = parseFloat(touch.pageY - start_top + span_top-73);
span.style.left = String(left) + 'px';
span.style.top = String(top) + 'px';
}
});
span.addEventListener('touchmove', function(event) {
event.preventDefault();
if (event.targetTouches.length == 1) {
var touch = event.targetTouches[0];
span.style.position = "absolute";
var left = parseFloat(touch.pageX - start_left + span_left-30);
var top = parseFloat(touch.pageY - start_top + span_top-73);
span.style.left = String(left) + 'px';
span.style.top = String(top) + 'px';
}
});
span.addEventListener('touchend', function(event) {
var touch = event.changedTouches[0];
if(parseFloat(touch.pageX - start_left + span_left-30) <= -5 || parseFloat(touch.pageX - start_left + span_left-30) >= 620 || parseFloat(touch.pageY - start_top + span_top-73) <= -38 || parseFloat(touch.pageY - start_top + span_top-73) >= 587){
span.style.left = String(span_left-30) + 'px';
span.style.top = String(span_top-73) + 'px';
}
event.stopPropagation();
});
}
js的左右滑动触屏事件,主要有三个事件:touchstart,touchmove,touchend。这三个事件最重要的属性是 pageX和 pageY,表示X,Y坐标。
touchstart在触摸开始时触发事件
touchend在触摸结束时触发事件
touchmove