功能介绍:
2.触摸滚动.速度较小时,随手指滚动,手指抬起,滚动停止;速度较大时,还会自动滚动一段时间;
上一张真机截图:
上代码:
1.index.js
},buttonMove: function (e) {
//获取滑动时的时间
var downTime = Date.now();
this.setData({
downTime: downTime
})
var that = this;
var endPoint = e.touches[e.touches.length - 1]
//根据触摸位置计算角度
var x = endPoint.clientX - this.data.dotPoint.clientX;
var y = endPoint.clientY - this.data.dotPoint.clientY;
var moveAngle = Math.asin(y / Math.hypot(x,y)) 180 / Math.PI
var quadrant = 1;
if (x >= 0) {
quadrant = y >= 0 ? 4 : 1;
} else {
quadrant = y >= 0 ? 3 : 2;
}
var tempAngle = 0;
// 如果是一、四象限，则直接end角度-start角度，角度值都是正值
if (quadrant == 1 || quadrant == 4) {
tempAngle += moveAngle - this.data.startAngle;
} else
// 二、三象限，色角度值是负值
{
tempAngle += this.data.startAngle - moveAngle;
}
var menuConfig = app.menuConfig.menu;
var menuList = [];
for (var i = 0; i < this.data.menuList.length; i++) {
menuList.push({ deg: this.data.menuList[i].deg + tempAngle,src: menuConfig[i].src });
}
this.setData({
menuList: menuList
})
//重置开始角度
this.setData({
startPoint: e.touches[e.touches.length - 1]
})
var endX = this.data.startPoint.clientX - this.data.dotPoint.clientX;
var endY = this.data.startPoint.clientY - this.data.dotPoint.clientY;
var startAngle = Math.asin(endY / Math.hypot(endX,endY)) 180 / Math.PI;
this.setData({
startAngle: startAngle,tempAngle: tempAngle
})
},buttonEnd: function (e) {
// 计算，每秒移动的角度
var that = this;
var upTime = Date.now();
var angleSpeed = this.data.tempAngle * 1000 / (upTime - this.data.downTime);
if (Math.abs(angleSpeed) < 100) {
//速度小于100时,停止滚动
return
} else {
//速度大于100时,自动滚动
if (angleSpeed > 0) {
if (angleSpeed > 500) angleSpeed = 500
var animationRun = wx.createAnimation({
duration: 2000,//ease-out结束时减速
timingFunction: 'ease-out'
})
that.animationRun = animationRun
animationRun.rotate(angleSpeed).step()
that.setData({
animationData: animationRun.export(),})
}
else {
if (angleSpeed < -500) angleSpeed = -500
angleSpeed = Math.abs(angleSpeed);
var animationRun = wx.createAnimation({
duration: 2000,// ease-out结束时减速
timingFunction: 'ease-out'
})
that.animationRun = animationRun
animationRun.rotate(-angleSpeed).step()
that.setData({
animationData: animationRun.export(),})
}
}
}
})
2.index.wxml
3.index.wxss
margin: 75px auto;
position: relative;
width: 350px;
height: 350px;
border-radius: 50%;
background-color: #415cab;
}
.userinfo-avatar {
width: 70px;
height: 70px;
border-radius: 50%;
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 0;
margin: auto;
}
/*子控件的透明度等于父控件透明度子控件透明度,父控件的opacity设置后,所以子控件opacity设置为1依然无效,必须分离开
*/
.circle-in {
position: absolute;
width: 330px;
height: 330px;
border-radius: 50%;
top: 0;
bottom: 0;
left: 0;
right: 0;
margin: auto;
background-color: #fff;
}
/*菜单/
.menu-list {
position: absolute;
left: 0;
top: 0;
width: inherit;
height: inherit;
}
.menu-item {
position: absolute;
left: 0;
top: 0;
width: 100%;
height: 100%;
font-weight: 500;
}
.menu-circle-item {
-webkit-transform-origin: 50% 150px;
transform-origin: 50% 150px;
margin: 0 auto;
margin-top: 15px;
position: relative;
height: 50px;
width: 50px;
background-color: #77c2fc;
text-align: center;
border-radius: 50%;
}
.image-style {
height: 25px;
width: 25px;
color: #f00;
margin: 12.5px auto;
}
.text-style {
margin: 5px auto;
font-size: 15px;
}
/***/
.menu-circle-text-item {
-webkit-transform-origin: 50% 100px;
transform-origin: 50% 100px;
margin: 0 auto;
position: relative;
height: 25px;
width: auto;
text-align: center;
}
js注释补充:
获取手指抬起时的角速度
1.获取角度.借图说话.
Math.sqrt( x * x + y * y )是斜边长，乘以 sin a 就是 y 的长度；
获取a的角度：Math.asin(y / Math.hypot(x,y) ；
[ hypot是x * x + y * y ]
2.根据角度差计算角速度
3.当角速度小于100的时候触摸滑动停止,不自动滚动;大于100时,自动滚动.我这里用动画,有个问题:很难把握动画持续时间和速度的关系.总感觉不够流畅.我表示不能忍.
4.分象限的问题.看看代码就知道了.主要是根据up时的触摸点相对于圆点的X轴差值来计算.大于0就是一四象限.小于0就是二三象限.
