js判断手指滑动方向（移动端）
var startx, starty
//获得角度
function getAngle(angx, angy) {
return Math.atan2(angy, angx) * 180 / Math.PI
}
//根据起点终点返回方向 1向上 2向下 3向左 4向右 0未滑动
function getDirection(startx, starty, endx, endy) {
var angx = endx - startx
var angy = endy - starty
var result = 0
//如果滑动距离太短
if (Math.abs(angx) <2 &&Math.abs(angy) <2) {
return result
}
var angle = getAngle(angx, angy)
if (angle >= -135 &&angle <= -45) {
result = 1
} else if (angle >45 &&angle <135) {
result = 2
} else if ((angle >= 135 &&angle <= 180) || (angle >= -180 &&angle <-135)) {
result = 3
} else if (angle >= -45 &&angle <= 45) {
result = 4
}
return result
}
//手指接触屏幕
document.addEventListener("touchstart", function(e) {
startx = e.touches[0].pageX
starty = e.touches[0].pageY
}, false)
//手指离开屏幕
document.addEventListener("touchend", function(e) {
var endx, endy
endx = e.changedTouches[0].pageX
endy = e.changedTouches[0].pageY
var direction = getDirection(startx, starty, endx, endy)
switch (direction) {
case 0:
alert("未滑动！")
break
case 1:
alert("向上！")
break
case 2:
alert("向下！")
break
case 3:
alert("向左！")
break
case 4:
alert("向右！")
break
default:
}
}, false)
<script language="javascript" type="text/javascript">//图片滚动展示 Start
var counts = 4
//大图//
img1 = new Image()
img1.src = 'images/1.jpg'
img2 = new Image()
img2.src = 'images/2.jpg'
img3 = new Image()
img3.src = 'images/3.jpg'
img4 = new Image()
img4.src = 'images/4.jpg'
var smallImg = new Array()
//小图
smallImg[0] = 'images/index_adb1.gif'
smallImg[1] = 'images/index_adb2.gif'
smallImg[2] = 'images/index_adb3.gif'
smallImg[3] = 'images/index_adb4.gif'
//链接地址
url1 = new Image()
url1.src = ' http://www.baidu.com'
url2 = new Image()
url2.src = ' http://www.qzxtg.com'
url3 = new Image()
url3.src = ' http://www.soso.com'
url4=new Image()
url4.src=' http://www.sina.com.cn'
//alt值
alt1 = new Image()
alt1.alt = ''
alt2 = new Image()
alt2.alt = ''
alt3 = new Image()
alt3.alt = ' '
alt4 = new Image()
alt4.alt=''
////欢迎来到标准之路.
var nn = 1
var key = 0
function change_img() {
if (key == 0) {
key = 1
} else if (document.all) {
document.getElementById("pic").filters[0].Apply()
document.getElementById("pic").filters[0].Play(duration = 2)
}
eval('document.getElementById("pic").src=img' + nn + '.src')
eval('document.getElementById("url").href=url' + nn + '.src')
eval('document.getElementById("pic").alt=alt' + nn + '.alt')
if (nn == 1) {
document.getElementById("url").target = "_blank"
document.getElementById("url").style.cursor = "pointer"
} else {
document.getElementById("url").target = "_blank"
document.getElementById("url").style.cursor = "pointer"
}
for ( var i = 1i <= countsi++) {
document.getElementById("xxjdjj" + i).className = 'axx'
}
document.getElementById("xxjdjj" + nn).className = 'bxx'
nn++
if (nn >counts) {
nn = 1
}
tt = setTimeout('change_img()', 7000)
}
function changeimg(n) {
nn = n
window.clearInterval(tt)
change_img()
}
function imageshow() {
document.write('<div class="picshow_main">')
document.write('<div><a id="url"><img id="pic" class="imgbig" /></a></div>')
document.write('<div class="picshow_change">')
for ( var i = 0i <countsi++) {
document.write('<a href="javascript:changeimg(' + (i + 1)
+ ')" id="xxjdjj' + (i + 1)
+ '" class="axx" target="_self"><img src="' + smallImg[i]
+ '"></a>')
}
document.write('</div></div>')
change_img()
}
//图片滚动展示 End
</script>
<script language="javascript" type="text/javascript">
imageshow()
</script>
