基本框架:
antD upLoad組件上傳視頻 +視頻消息推送+ canvas截取視頻首幀圖片
- 上傳視頻
<Upload
name="myfile"
data={ {
_token: getConfig()._token,
}}
listType="picture-card"
className="avatar-uploader"
showUploadList={false}
action="/admin/api/upload_file"
beforeUpload={this.handleFileBeforeUpload.bind(this, 'video')}
onChange={this.handleFileUpload.bind(this)}
>
<div className={`${classNamePrefix}-im-chat-footer-video`}></div>
</Upload>
- 截取的首幀圖預覽
<div className='title'>視頻預覽</div>
<div id='preview' style={{border: '1px solid red'}}>
<div className='scrllo_bg'>
<div id='scrllo_val'></div>
</div>
</div>
// push發消息
handleCommonCorePushMessage(messageItem) {
if (messageItem.data === '') {
message.warn('不能發送空白消息');
return;
}
// 視頻類型
if (messageItem.content_type === 3) {
this.captureImage(messageItem);
} else {
this.handleRealPush(messageItem, '');
}
}
- 首幀圖片截取方法
// 自動截取視頻第一幀作爲封面
captureImage(messageItem) {
const video = document.getElementById('video');
video.src = messageItem.data;
const preview = document.getElementById('preview');
const canvas = document.createElement('canvas');//創建一個canvas
const img = new Image();
video.onloadeddata = evt => { // 此處特別注意下,監聽的是onloadeddata事件,而不是loadedmetadata
// 防止查看視頻時再次觸發截取首幀和消息的push操作
if (this.state.isShowMedaiModal) {
return;
}
canvas.width = video.videoWidth;
canvas.height = video.videoHeight;
canvas.getContext('2d').drawImage(video, 0, 0, canvas.width, canvas.height);//繪製圖像
img.src = canvas.toDataURL('image/png');
uploadFileBase({
data_base64: img.src,
_token: getConfig()._token,
}).then((json) => {
if (json.status) {
this.handleRealPush(messageItem, json.data);
}
});
preview.appendChild(img);
};
}
video的監聽事件:
video.addEventListener(‘loadeddata’, xxxxx) // 當前幀加載完畢
video.addEventListener(‘loadedmetadata’, xxxxx) // 視頻元數據加載完畢
注意:
點擊查看視頻時,同樣會觸發video.onloadeddata,因此,需在video.onloadeddata的回調方法中添加截取首幀和消息push操作的條件判斷。