1、flex布局的一些小知识
.container{
display: flex;
flex-direction:row;//flex方向:row水平 column纵向
justify-content: space-evenly;//水平排布时均分空白
flex-wrap: wrap;//wrap为换行,nowrap为不换行
box-sizing: border-box;//边框在内容内(不在向外扩展)
}
2、图标库
阿里巴巴矢量库
https://www.iconfont.cn/
3、b站三倍速
控制台内输入
document.querySelector('video').playbackRate = 3
4、*this禁止复用
<view wx:for="{{testloop}}" wx:key="*this"><switch/>{{item}}</view>
<button bindtap="add">增加</button>
wx:key在没有唯一索引值的时候需要给数据加一个唯一索引id
注意微信:index是会变的,会根据item的多少变动,不可靠,最好使用自定义id
5、实时更新数据使用this.setData
onReady: function () {
setTimeout(()=>{
let newitem={
courseImage:"/asset/images/gril05.jpg",
courseTitle:"python",
courseTeacher:"maba",
courseStudyCount:23000,
isstar:true,
}
this.data.courseItems.push(newitem);
this.setData({
courseItems:this.data.courseItems
})
},3000)
},
6、输出绑定的id
wxml
<view id="click1" bindtap="myclick">event1</view>
<view id="click2" bindtap="myclick">event2</view>
js
myclick(e){
console.log(e.target.id);
},
7、data-绑定数据
携带数据
<view id="click1" data-name="zhangsan" data-age='18' bindtap="myclick">event1</view>
js
myclick(e){
console.log(e);
},
7、catch绑定事件(不会冒泡)
bind:会冒泡(bindtap)
catch:不会冒泡(catchtap)
capture:捕获阶段绑定,与冒泡阶段的顺序是反序的(captur-catch:tap)
8、小程序的父子传值properties
- 1、数据写在引用页面的js里
mytest.js
// pages/test/mytest.js
Page({
/**
* 页面的初始数据
*/
data: {
teacherItems:[
{
id:1,
teacherImg:'/asset/images/gril01.jpg',
name:'张三丰'
},
{
id:2,
teacherImg:'/asset/images/gril02.jpg',
name:'岳不群'
},
{
id:3,
teacherImg:'/asset/images/gril03.jpg',
name:'令狐冲'
},
{
id:4,
teacherImg:'/asset/images/gril04.jpg',
name:'向问天'
},
{
id:5,
teacherImg:'/asset/images/gril05.jpg',
name:'虚竹'
},
{
id:6,
teacherImg:'/asset/images/gril06.jpg',
name:'逍遥子'
},
{
id:7,
teacherImg:'/asset/images/gril07.jpg',
name:'桃谷六仙'
},
{
id:8,
teacherImg:'/asset/images/gril08.jpg',
name:'黄老邪'
},
{
id:9,
teacherImg:'/asset/images/gril09.jpg',
name:'欧阳锋'
}
]
},
})
- 2、在引用页引用的组件上,自定义一个属性用于传值,并将引用页的js数据赋值给这个属性,从而将数据注入到组件中
mytest.wxml
<view class="container">
<block wx:for="{{teacherItems}}" wx:key='id'>
<mycomp teacherItem="{{item}}"/><!--实际上是把item对象传给了teacherItem,组件就拿到了item,从而完成了父传子-->
</block>
</view>
- 3、数据传给组件后,要到组件js的properties里注册一下,一遍能够在组件内部使用
mycom.js
Component({
/**
* 组件的属性列表
*/
properties: {
teacherItem:Object//给传过来的属性设定类型
},
})
- 4、在组件内部通过属性使用传来的数据
mycomp.js
<view class="mycomp">
<image class="image" src="{{teacherItem.teacherImg}}" mode="scaleToFill"/>
<text class="text">{{teacherItem.name}}</text>
</view>
最终效果
9、删除教师列表小案例
- 1、应用页数据构建
mytest.wxjs
// pages/test/mytest.js
Page({
/**
* 页面的初始数据
*/
data: {
teacherItems:[
{
id:1,
teacherImg:'/asset/images/gril01.jpg',
name:'张三丰'
},
{
id:2,
teacherImg:'/asset/images/gril02.jpg',
name:'岳不群'
},
{
id:3,
teacherImg:'/asset/images/gril03.jpg',
name:'令狐冲'
},
{
id:4,
teacherImg:'/asset/images/gril04.jpg',
name:'向问天'
},
{
id:5,
teacherImg:'/asset/images/gril05.jpg',
name:'虚竹'
},
{
id:6,
teacherImg:'/asset/images/gril06.jpg',
name:'逍遥子'
},
{
id:7,
teacherImg:'/asset/images/gril07.jpg',
name:'桃谷六仙'
},
{
id:8,
teacherImg:'/asset/images/gril08.jpg',
name:'黄老邪'
},
{
id:9,
teacherImg:'/asset/images/gril09.jpg',
name:'欧阳锋'
}
]
},
})
- 2、引用页应用数组,并传递子组件数据
mytest.wxml
<view class="container">
<block wx:for="{{teacherItems}}" wx:key='id'>
<mycomp teacherItem="{{item}}"/><!--实际上是把item对象传给了teacherItem,组件就拿到了item,从而完成了父传子-->
</block>
</view>
- 3、组件页面绑定各类事件和数据,其中使用从应用页(父组件)传来的属性
mycomp.wxml
<view class="mycomp {{isdelete ? 'deleteItem' : ''}}" bind:longpress="deleteItemHandler" bindtap="undeleteItemHandler">
<image class="image" src="{{teacherItem.teacherImg}}" mode="scaleToFill"/>
<text class="text">{{teacherItem.name}}</text>
<view class="deltex" hidden="{{!isdelete}}" bindtap="deletehandlerx">X</view>
</view>
- 4、要在子组件页的js中注册一下父组件传来的属性,并编写各类事件的回调函数
mycomp.js
Component({
/**
* 组件的属性列表
*/
properties: {
teacherItem:Object
},
/**
* 组件的初始数据
*/
data: {
isdelete:false
},
/**
* 组件的方法列表
*/
methods: {
deleteItemHandler(){
this.setData({
isdelete:true
})
},
/*
undeleteItemHandler(){
this.setData({
isdelete:false
})
},
*/
deletehandlerx(){
//使用弹窗提示API
wx.showModal({
title:'删除确认',
content:'是否确认删除该教师',
success:(res)=>{
if(res.confirm){
wx.showToast({
title: '你已经成功删除了该教师',
})
this.setData({
isdelete:false
})
//要从子组件向父组件传值删除父组件js的数据
}else if(res.cancel){
console.log('点击了取消');
}
},
})
}
}
})
- 5、应为使用了css动画,一并把组件css代码附上
/* components/mycomp.wxss */
.mycomp{ width: 100px; height: 130px; background-color: royalblue; border:1px solid gray;
border-radius: 10px; margin:5rpx 0}
.mycomp .image{width: 100px; height: 100px; margin:0; border-radius: 50%; border:3px solid white; box-sizing: border-box;}
.mycomp .text{ text-align-last: center; color: white; display: block;}
.deltex{position: relative; top:-130px; right:-88px;color:white; background-color:rgb(20, 71, 224); border-radius: 5px;
width:20px; height:20px; font-size: 16px; line-height: 20px; text-align: center;}
.deleteItem{
animation:ani-dou 1s 0s infinite;/*执行ani-dou动画,执行1s,延时0s 无线循环*/
}
/*d定义关键帧动画*/
@keyframes ani-dou{
0%{/*0%是时间上的0%,下面执行rotate的transform*/
transform:rotate(0deg)
}
10%,20%,30%,40%,50%{
transform:rotate(-4deg)
}
15%,25%,35%,45%,55%{
transform:rotate(4deg)
}
100%{/*0%是时间上的0%,下面执行rotate的transform*/
transform:rotate(0deg)
}
效果:
10、另一个事件绑定,在上一层上绑定事件
wxml
<view bindtap="taphandler">
<courselist id="1" data-title="第一个课程"/>
<courselist/>
<courselist/>
<courselist/>
</view>
js
taphandler(event){
//console.log(event.currentTarget.id,event.currentTarget.dataset.title);
console.log(event.target.id,event.target.dataset.title);
},