最终效果图.png
场景描述：一般情况下，加入购物车的动画效果都会是上图的3的路线，在这篇文章里，我们来实现1和2路线的加入购物车的动效（3路线的动画效果网上有很多，具体可以参考这篇文章来实现：https://www.cnblogs.com/greengage/p/7815842.html
）。
实现方式：不管是上图中的哪一种效果，我们都是用CSS3里的cubic-bezier（三次贝塞尔曲线）来实现的。具体什么是三次贝塞尔曲线，可以参考这篇文章：https://www.bbsmax.com/A/RnJWwpbRJq/
实现流程：
1、获取屏幕的高度大小
wx.getSystemInfo({// 获取页面的有关信息
success: function (res) {
wx.setStorageSync('systemInfo', res)
var ww = res.windowWidth;
var hh = res.windowHeight;
that.globalData.ww = ww;
that.globalData.hh = hh;
}
});
2、获取点击的位置（购物车的位置我们定为最上方或者最下方），定义移动距离
/*加入购物车动效*/
_flyToCartEffect: function (events) {
//获得当前点击的位置，距离可视区域左上角
var touches = events.touches[0];
var diff = {
x: '25px',
y: app.globalData.hh -touches.clientY-40 + 'px'//向下
// y: 25- touches.clientY + 'px'//向上
},
style = 'display: block;-webkit-transform:translate(' + diff.x + ',' + diff.y + ') rotate(350deg) scale(0)'; //移动距离
this.setData({
isFly: true,
translateStyle: style
});
var that = this;
setTimeout(() => {
that.setData({
isFly: false,
translateStyle: '-webkit-transform: none;', //恢复到最初状态
isShake: true,
});
setTimeout(() => {
var counts = that.data.cartTotalCounts + that.data.productCounts;
that.setData({
isShake: false,
cartTotalCounts: counts
});
}, 200);
}, 1000);
},
3、在css里调用beizer函数
.fiexd-cart.animate{
animation: aCartScale 200ms cubic-bezier(.17,.67,.83,.67);
animation-fill-mode: backwards;
}
aCartScale是，在曲线的最后，实现了个购物车抖动的动画
@-webkit-keyframes aCartScale{
0%{
-webkit-transform: scale(1.1);
}
100% {
-webkit-transform: scale(1);
}
}
至此，流程全部介绍完毕，下面是全部的代码（里面可能有一些没用的css样式代码，读者可以自行根据需要删除）：
js代码：
var app = getApp();
Page({
/**
* 页面的初始数据
*/
data: {
isFly:false
},
/*添加到购物车*/
onAddingToCartTap: function (events) {
//防止快速点击
if (this.data.isFly) {
return;
}
this._flyToCartEffect(events);
},
/*加入购物车动效*/
_flyToCartEffect: function (events) {
//获得当前点击的位置，距离可视区域左上角
var touches = events.touches[0];
var diff = {
x: '25px',
y: app.globalData.hh -touches.clientY-40 + 'px'//向下
// y: 25- touches.clientY + 'px'//向上
},
style = 'display: block;-webkit-transform:translate(' + diff.x + ',' + diff.y + ') rotate(350deg) scale(0)'; //移动距离
this.setData({
isFly: true,
translateStyle: style
});
var that = this;
setTimeout(() => {
that.setData({
isFly: false,
translateStyle: '-webkit-transform: none;', //恢复到最初状态
isShake: true,
});
setTimeout(() => {
var counts = that.data.cartTotalCounts + that.data.productCounts;
that.setData({
isShake: false,
cartTotalCounts: counts
});
}, 200);
}, 1000);
},
})
wxml代码：
<view class="container detail-container">
<view class="fixed-btns-box" bindtap="onCartTap">
<view class="fiexd-cart {{isShake?'animate':''}}">
<image src="../../imgs/icon/cart@top.png"></image>
<view wx:if="{{cartTotalCounts>0}}">{{cartTotalCounts}}</view>
</view>
</view>
<view
style="position: fixed;right: 50rpx;bottom:100rpx;width: 100rpx;"
class="add-cart-btn {{product.stock==0?'disabled':''}}" bindtap="onAddingToCartTap">
<text style="width: 360rpx">加入分享</text>
<image class="cart-icon" src="../../imgs/icon/cart.png"></image>
<image id="small-top-img" class="small-top-img {{isFly?'animate':''}}" src="https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1575871576&di=dda9d07660c88bea6553c3279b0a8cf0&imgtype=jpg&er=1&src=http%3A%2F%2Fpic.pc6.com%2Fup%2F2011-9%2F2011926155953.jpg"
mode="aspectFill" style="{{translateStyle}}"></image>
</view>
<view class="fixed-btns-box2" bindtap="onCartTap">
<view class="fiexd-cart {{isShake?'animate':''}}">
<image src="../../imgs/icon/cart@top.png"></image>
<view wx:if="{{cartTotalCounts>0}}">{{cartTotalCounts}}</view>
</view>
</view>
</view>
wxss代码：
.detail-container {
background-color:#F9F9F9
}
.detail-header-box,.detail-bottom-box{
background-color: #fff;
}
.detail-topic-img{
display: flex;
justify-content: center;
}
.detail-topic-img image{
width: 100%;
}
.fixed-btns-box{
position: fixed;
top:50rpx;
right:12px;
width: 80rpx;
}
.fixed-btns-box2{
position: fixed;
right:12px;
width: 80rpx;
bottom: 50rpx;
}
.fiexd-cart image{
height: 64rpx;
width: 64rpx;
}
.fiexd-cart view{
font-size: 24rpx;
background-color: #AB956D;
color: white;
position: absolute;
right: 64rpx;
top: 0rpx;
height: 36rpx;
width: 36rpx;
line-height: 36rpx;
border-radius: 36rpx;
text-align: center;
}
.fiexd-cart.animate{
animation: aCartScale 200ms cubic-bezier(.17,.67,.83,.67);
animation-fill-mode: backwards;
}
@-webkit-keyframes aCartScale{
0%{
-webkit-transform: scale(1.1);
}
100% {
-webkit-transform: scale(1);
}
}
.product-counts,.add-cart-btn{
height: 100%;
display: flex;
font-size: 24rpx;
align-items: center;
justify-content: center;
}
.product-counts{
width: 50%;
}
.add-cart-btn{
position: relative;
flex: 1;
}
.add-cart-btn:active{
color: #fff;
}
.add-cart-btn.disabled{
color: #D5D5DB;
}
.small-top-img{
height: 160rpx;
width: 160rpx;
right:6rpx;
position: absolute;
opacity: 0;
}
.small-top-img.animate{
opacity: 1;
-webkit-transition:all 1000ms cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.add-cart-btn .cart-icon{
margin-left: 40rpx;
height: 32rpx;
width: 32rpx;
}
.disabled{
pointer-events: none;
}
