请具体描述问题出现的流程，并提供能复现问题的简单代码片段（https://developers.weixin.qq.com/miniprogram/dev/devtools/minicode.html）。

<template>
    <view>
        <view class="uni-padding-wrap uni-common-mt">
            <view>
                <video id="myVideo" src="https://img.cdn.aliyun.dcloud.net.cn/guide/uniapp/%E7%AC%AC1%E8%AE%B2%EF%BC%88uni-app%E4%BA%A7%E5%93%81%E4%BB%8B%E7%BB%8D%EF%BC%89-%20DCloud%E5%AE%98%E6%96%B9%E8%A7%86%E9%A2%91%E6%95%99%E7%A8%8B@20200317.mp4"
                    @error="videoErrorCallback" :danmu-list="danmuList" enable-danmu danmu-btn controls></video>
            </view>
            <!-- #ifndef MP-ALIPAY -->
            <view class="uni-list uni-common-mt">
                <view class="uni-list-cell">
                    <view>
                        <view class="uni-label">弹幕内容</view>
                    </view>
                    <view class="uni-list-cell-db">
                        <input v-model="danmuValue" class="uni-input" type="text" placeholder="在此处输入弹幕内容" />
                    </view>
                </view>
            </view>
            <view class="uni-btn-v">
                <button @click="sendDanmu" class="page-body-button">发送弹幕</button>
            </view>
            <!-- #endif -->
        </view>
    </view>
</template>
<script>
export default {
    data() {
        return {
            src: '',
            danmuList: [{
                    text: '第 1s 出现的弹幕',
                    color: '#ff0000',
                    time: 1
                },
                {
                    text: '第 3s 出现的弹幕',
                    color: '#ff00ff',
                    time: 3
                }
            ],
            danmuValue: ''
        }
    },
    onReady: function(res) {
        // #ifndef MP-ALIPAY
        this.videoContext = uni.createVideoContext('myVideo')
        // #endif
    },
    methods: {
        sendDanmu: function() {
            this.videoContext.sendDanmu({
                text: this.danmuValue,
                color: this.getRandomColor()
            });
            this.danmuValue = '';
        },
        videoErrorCallback: function(e) {
            uni.showModal({
                content: e.target.errMsg,
                showCancel: false
            })
        },
        getRandomColor: function() {
            const rgb = []
            for (let i = 0; i < 3; ++i) {
                let color = Math.floor(Math.random() * 256).toString(16)
                color = color.length == 1 ? '0' + color : color
                rgb.push(color)
            }
            return '#' + rgb.join('')
        }
    }
}
</script>

官方估计希望你提供代码片段，然后再去看看是啥问题