Vue购物车一些参考，插槽传值，循环改对象值收集表单 main.js

1. 子组件给父子件传参然后循环
2 v -for = "(sel,selindex) in selectalls" 括号中间逗号
3. 给数据的每个对象插入属性值
　　vm.$data.all.map(item => {
　　vm.$set(item, 'selectNum', 0)
　　vm.$set(item, 'selectColor', item.colors[0])
　　vm.$set(item, 'totalPrice', 0)
　　　　})
4.　　　　 < span: class = "{active: colorindex==item.cn}"
　　　　　　@click = "selectcolor(item,colorindex)"
　　　　　　class = "colors"
　　　　　　v -for = "(color,colorindex) in item.colors" > {{color}} < /span>selectcolor(item, shopindex) {vm.$set(item, 'cn', shopindex)}
　　　　思路: 1. 把li最开始循环的 index拿下, 然后给li的对象添加个属性 CN 为index
　　　　　　　　2. 在循环的时候() in all 把这个括号里面的index 和 li对象的CN做比较
5. 计算属性算总价
　　　　allprice() {
　　　　nums = 0;
　　　　this.selectall.forEach(item => {
　　　　nums += item.totalPrice
　　　　　　})
　　　　　　return nums;
　　　　　　　　}
6.数组想要增加一条,先判断这个数组有没有,再增加
　　　　let data =this.select.find(item => item.id == items.id); 有就返回数据没有就是undefined
　　　　data ? items : this.select.push(items);
7.如果我们需要在数组中查找满足某个条件的元素，就可以使用数组方法findIndex()。
　　　　这个方法会依次遍历数组中的元素，找到第一个满足条件的元素，然后返回该元素的索引值。如果没有满足条件的元素，
　　　　findIndex()就会返回-1。
　　　　let index = this.selectall.findIndex(obj => obj.id === item);
　　　　console.log(index)
　　　　if (index !== -1) {
　　　　this.selectall.splice(index, 1); 删除数组一个对象
　　　　}

8.传值

9 循环改对象值

var tianjia=[
            ['美金','英镑'],['日元','加币']
        ]   
        function up(){
            lists.map((item,i)=>{
                item.result.map(item=>{
                    item['Gasoline92']=item['Gasoline92']+tianjia[i][0]
                    item['Gasoline95']=item['Gasoline95']+tianjia[i][1]
                })
            })
        }

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <link rel="stylesheet" type="text/css" href="https://www.layuicdn.com/layui-v2.8.0/css/layui.css" />
        <script src="js/vue.js"></script>
        <title></title>
        <style>
            img {
                width: 6rem;
                height: 6rem;
                vertical-align: -1.5rem;
 
            }
 
            * {
                cursor: pointer;
            }
 
            #app {
                width: 800px;
                margin: 0 auto;
                padding: 0 1rem;
            }
 
            ul {
                border: 1px solid red;
            }
 
            li {
                border: 1px solid #e5e5ea;
                background: #e5e5ea;
                margin-top: 1rem;
            }
 
            .center {
                display: inline-block;
                width: 18%;
            }
 
            .center .colors {
                background: blue;
                color: white;
                padding: 0.5rem;
                margin: 0.5em;
            }
 
            .center .colors.active {
                background: red;
            }
 
            .center button {
                width: 3rem;
            }
 
            .num {
                background-color: white;
                padding: 0 .51rem;
            }
 
            .center .cars {
                width: 6rem;
                background-color: red;
                color: white;
                float: right;
            }
 
            .carsel h1 {
                text-align: center;
                background: #f40;
                color: white;
            }
 
            .carsel {
                margin-top: 1rem;
            }
 
            .aa h2 {
                margin-bottom: 1rem;
            }
        </style>
    </head>
    <body>
        <div id="app">
            <shopalls :all='all' @adds="addlist" ></shopalls>
            <selectall :selectalls='selectall' @cute="cute"></selectall>
            <!--     <ul class="carall">
                <li>
                    <img src="img/0-1.png" alt="">
                    <div class="center aa">
                        <h2>圆珠笔1</h2>
                        <span class="colors active">红色</span> <span class="colors">红色</span>
                    </div>
                    <div class="center">
                        <h1>21.00元</h1>
                    </div>
                    <div class="center">
                        <button>-</button>
                        <span class="num">0</span>
                        <button>+</button>
                    </div>
                    <div class="center">
                        <button class="cars">加入购物车</button>
                    </div>
                </li>
            </ul> -->
            <!-- <div class="carsel">
                <h1>已选中商品</h1>
                <br>
                <li>
                    <img src="img/0-1.png" alt="">
                    <div class="center ">
                        <h2 >圆珠笔1</h2>
 
                    </div>
                    <div class="center">
                        <span class="colors">红色</span>
 
                    </div>
 
                    <div class="center">
                        <h3>总价：21.00元</h3>
                    </div>
                    <div class="center">
                        x1 <button class="cars">删除</button>
                    </div>
 
                </li>
                <h2>总价120元</h2>
            </div> -->
        <h2> 总价：{{allprice}}元</h2>
        </div>
 
 
        <template id="shopall">
            <ul class="carall">
                <li v-for="(item,shopindex) in all" :key="item.id">
                    <img :src="item.img" alt="">
                    <div class="center aa">
                        <h2>{{item.name}}</h2>
                        <span :class="{active: colorindex==item.cn}" @click="selectcolor(item,colorindex,color,shopindex)"
                            class="colors" v-for="(color,colorindex) in item.colors">
                            {{color}}</span>
 
                    </div>
                    <div class="center">
                        <h1>{{item.price}}.00元</h1>
                    </div>
                    <div class="center">
                        <button @click="add(item,-1)">-</button>
                        <span class="num">{{item.selectNum}}</span>
                        <button @click="add(item,1)">+</button>
                    </div>
                    <div class="center">
                        <button class="cars" @click="buycars(item)">加入购物车</button>
                    </div>
                </li>
            </ul>
        </template>
        <template id="selectall">
            <div class="carsel">
                <h1>已选中商品</h1>
                <br>
 
                <li v-for="(sel,selindex) in selectalls">
                    <img :src="sel.img" alt="">
                    <div class="center ">
                        <h2>{{sel.name}}</h2>
 
                    </div>
                    <div class="center">
                        <span class="colors">
                            {{sel.selectColor}}
                        </span>
 
                    </div>
 
                    <div class="center">
                        <h3>总价： {{sel.totalPrice }}.00元</h3>
                    </div>
                    <div class="center">
                        x{{sel.selectNum }}<button class="cars" @click="del(sel.id)">删除</button>
                    </div>
 
                </li>
                 
            </div>
 
        </template>
        <script>
            vm = new Vue({
                el: "#app",
                methods:{
                    addlist(item){
                        console.log(item+"执行了addlist")
                        this.selectall=item
                    },
                    cute(item){
                         
                        let index = this.selectall.findIndex(obj => obj.id === item);  
                        console.log(index)
                        if (index !== -1) {  
                          this.selectall.splice(index, 1);  
                        }
                    }
                },
                computed:{
                    allprice(){
                    nums=0;
                    // this.selectall.forEach(item=>{
                    //  nums+=item.totalPrice
                    // })
                     this.selectall.forEach(function(item){
                         nums+=item.totalPrice
                     })
                    return  nums;
                    }
                },
                 watch:{
                     // selectall(o,p){
                        //  console.log("变了"+o+p)
                     // }
                 },
                data() {
                    return {
                        all: [{
                            id: 0,
                            name: '华晨钢笔',
                            price: 20,
                            img: 'img/0-1.png',
                            colors: ['红', '绿', '白']
                        }, {
                            id: 1,
                            name: '保温水杯',
                            price: 120,
                            img: 'img/1-1.png',
                            colors: ['保温', '不保温']
                        }],
                        selectall: []
                    }
                },
                components: {
                    shopalls: {
                        template: "#shopall",
                        props: {
                            all: {
                                type: Array,
                            }
                        },
                        data() {
                            return {
                                currcolor: '',
                                select:[],
                            }
                        },
                        methods: {
                            add(item, num) {
 
                                let newmum = item.selectNum;
                                newmum = newmum + num
                                if (newmum <= 0) {
                                    newmum = 0
                                }
                                item.selectNum = newmum
                                    item.totalPrice = newmum*item.price
                                // item.selectNum=item.selectNum+num
                                console.log("执行了加减函数"+num)
                            },
                            selectcolor(item, colorindex, color,shopindex) {
                                this.$set(item, 'cn', colorindex)
                                colorindex = colorindex + 1
                                item.img = 'img/' + shopindex + '-' + colorindex + '.png'
                                item.selectColor = color
                                console.log(shopindex+"执行了选颜色"+colorindex)
                                console.log(vm.selectall[0].selectColor+'xx')
                                // console.log(item)
                                // console.log()
                            },
                            buycars(items){
                                // this.select.push(items)
                                // console.log(this.select)
                                let newselect=this.select;
                                 
                                let data =this.select.find(item => item.id == items.id);
                                     
                                    data ? items : this.select.push(items); //传过来的数据在select里找到了，就替换掉。没找到的话再push
                     
                                 
                                this.$emit('adds',newselect)
                                 
                         
                                 
                                console.log(data+"123")
                            }
 
                        },
                    },
                    selectall: {
                        template: "#selectall",
                        props: {
                            selectalls: {
                                type: Array,
                            }
                        },
                        methods:{
                            del(i){
                                this.$emit('cute',i)
                                // console.log(i)
                            }
                        }
                    }
                }
            })
 
            vm.$data.all.map(item => {
                vm.$set(item, 'selectNum', 0)
                vm.$set(item, 'selectColor', item.colors[0])
                vm.$set(item, 'totalPrice', 0)
            })
            // console.log(vm.$data.all)
        </script>
 
    </body>
</html>