uni-app提交表单成功之后跳转首页

sub() {
                uni.showToast({
                    title: '上传成功',
                    icon: 'success',
                    duration: 1000
                })
                setTimeout(() => {
                    uni.switchTab({
                        url: "../main",
                    });
                }, 600);
            },

<template>
    <view>
        <form>
            <view class="cu-form-group margin-top">
                <view class="title">补卡原因</view>
                <picker @change="PickerChange" :value="index" :range="picker">
                    <view class="picker">
                        {{index>-1?picker[index]:'出差'}}
                    </view>
                </picker>
            </view>
            <!-- #endif -->
            <view class="cu-form-group">
                <view class="title">时间选择</view>
                <picker mode="time" :value="time" start="09:01" end="21:01" @change="TimeChange">
                    <view class="picker">
                        {{time}}
                    </view>
                </picker>
            </view>
            <view class="cu-form-group">
                <view class="title">日期选择</view>
                <picker mode="date" :value="date" start="2015-09-01" end="2020-09-01" @change="DateChange">
                    <view class="picker">
                        {{date}}
                    </view>
                </picker>
            </view>
            <view class="cu-form-group align-start">
                <view class="title">补卡事由</view>
                <textarea maxlength="-1" :disabled="modalName!=null" @input="textareaBInput" placeholder="多行文本输入框"></textarea>
            </view>
            <view class="uni-btn-v uni-common-mt">
                <button class="btn-submit" formType="submit" type="primary" @click="sub">提交审批</button>
            </view>
        </form>
    </view>
</template>
<script>
    export default {
        data() {
            return {
                index: -1,
                picker: ['出差', '年休', '忘记打卡', '病假', '事假', '外勤'],
                // multiIndex: [0, 0, 0],
                time: '12:01',
                date: '2018-12-25',
                modalName: null,
                textareaBValue: ''
            };
        },
        methods: {
            PickerChange(e) {
                this.index = e.detail.value
            },
            sub() {
                uni.showToast({
                    title: '上传成功',
                    icon: 'success',
                    duration: 1000
                })
                setTimeout(() => {
                    uni.switchTab({
                        url: "../main",
                    });
                }, 600);
            },
            TimeChange(e) {
                this.time = e.detail.value
            },
            DateChange(e) {
                this.date = e.detail.value
            },
            textareaBInput(e) {
                this.textareaBValue = e.detail.value
            }
        }
    }
</script>
<style>
    .cu-form-group .title {
        min-width: calc(4em + 15px);
    }
    .btn-submit {
        background-color: #1C2A86;
        margin: 100upx 20upx;
        color: #fff;
    }
</style>