Javascript 为什么componentdidmount调用了两次
我已在componentDidMount中使用React组件从服务器获取数据。问题是componentDidMount被调用了两次,API也被调用了两次。我有一个视图增量API,比如youtube视频视图,由于两次API调用,数据库中的视图增量为两次Javascript 为什么componentdidmount调用了两次,javascript,reactjs,react-redux,react-dom,Javascript,Reactjs,React Redux,React Dom,我已在componentDidMount中使用React组件从服务器获取数据。问题是componentDidMount被调用了两次,API也被调用了两次。我有一个视图增量API,比如youtube视频视图,由于两次API调用,数据库中的视图增量为两次 class SingleVideoPlay extends React.Component { constructor(props) { super(props); this.player = React.c
class SingleVideoPlay extends React.Component {
constructor(props) {
super(props);
this.player = React.createRef();
}
state = {
autoPlay: true,
relatedVideos: [],
video: null,
user: null,
comments: [],
commentInput: {
value: '',
touch: false,
error: false
},
following: false,
tab: 'comments'
};
_Mounted = false;
componentDidMount() {
this._Mounted = true;
if (this._Mounted) {
const videoId = this.props.match.params.id;
this.getVideoDetails(videoId);
}
}
componentWillUnmount() {
this._Mounted = false;
try {
clearInterval(this.state.videoInterval);
this.props.videoEditUrl('');
} catch (error) {}
}
captureVideoTime = async () => {
const { video } = this.state;
const result = await updateWatchTime({
id: video._id,
time: 1
});
if (result.status === 200) {
const updateVideo = {
...video,
secondsWatched: video.secondsWatched + 1
};
this.setState({ video: updateVideo });
}
};
videoEnded = () => {
clearInterval(this.state.videoInterval);
};
videoPause = () => {
clearInterval(this.state.videoInterval);
};
loadVideo = () => {
clearInterval(this.state.videoInterval);
};
playingVideo = () => {
const interval = setInterval(this.captureVideoTime, 1000);
this.setState({ videoInterval: interval });
};
getVideoDetails = async (videoId) => {
const video = await getVideo(videoId);
if (video.status === 200) {
let response = video.data;
if (this.props.userId)
if (response.user._id === this.props.userId._id)
this.props.videoEditUrl(`/video/edit/${response.media._id}`);
this.setState({
relatedVideos: response.videos.docs,
video: response.media,
user: response.user
});
this.checkIsFollowing();
this.updateVideoStat(response.media._id);
}
};
updateVideoStat = async (id) => videoView(id);
checkIsFollowing = async () => {
const { userId } = this.props;
const { video } = this.state;
if (userId && video) {
const response = await isFollow({
follower: userId._id,
following: video._id
});
if (response) {
this.setState({ following: response.following });
}
}
};
addOrRemoveFollowing = async () => {
this.checkIsFollowing();
const { following, video } = this.state;
const { userId } = this.props;
if (userId) {
if (following) {
const response = await removeFollow({
follower: userId._id,
following: video._id
});
this.setState({ following: false });
} else {
const response = await addFollow({
follower: userId._id,
following: video._id
});
this.setState({ following: true });
}
}
};
submitCommentHandler = async (event) => {
const { userId } = this.props;
event.preventDefault();
if (userId) {
const result = await saveComment({
mediaId: this.state.video._id,
parentId: '0',
userID: userId._id,
userName: userId.username,
comment: this.state.commentInput.value
});
console.log(result);
if (result.status === 200) {
this.getVideoComments();
this.setState({ commentInput: { value: '', touch: false, error: false } });
}
}
};
render() {
const { autoPlay, relatedVideos, video, user, comments, commentInput, following, tab } = this.state;
const { userId } = this.props;
return (
<div className="container-fluid">
some coponents
</div>
);
}
}
const mapStateToProps = (state) => ({
userId: state.auth.user
});
export default connect(mapStateToProps, { videoEditUrl })(SingleVideoPlay);
class SingleVideoPlay扩展了React.Component{
建造师(道具){
超级(道具);
this.player=React.createRef();
}
状态={
自动播放:对,
相关视频:[],
视频:空,
用户:null,
评论:[],
评论输入:{
值:“”,
触摸:错,
错误:false
},
以下是:假,
选项卡:“评论”
};
_安装=错误;
componentDidMount(){
这是真的;
如果(本安装){
const videoId=this.props.match.params.id;
这个.getVideoDetails(videoId);
}
}
组件将卸载(){
这是错误的;
试一试{
clearInterval(this.state.videoInterval);
this.props.videoEditUrl(“”);
}捕获(错误){}
}
captureVideoTime=async()=>{
const{video}=this.state;
const result=await updateWatchTime({
id:video.\u id,
时间:1
});
如果(result.status==200){
常数updateVideo={
视频
secondsWatched:video.secondsWatched+1
};
this.setState({video:updateVideo});
}
};
视频结束=()=>{
clearInterval(this.state.videoInterval);
};
视频暂停=()=>{
clearInterval(this.state.videoInterval);
};
loadVideo=()=>{
clearInterval(this.state.videoInterval);
};
播放视频=()=>{
const interval=setInterval(this.captureVideoTime,1000);
this.setState({videoInterval:interval});
};
getVideoDetails=async(videoId)=>{
const video=等待获取视频(videoId);
如果(video.status==200){
让响应=video.data;
if(this.props.userId)
if(response.user.\u id==this.props.userId.\u id)
this.props.videoEditUrl(`/video/edit/${response.media.\u id}`);
这是我的国家({
相关视频:response.videos.docs,
视频:response.media,
用户:response.user
});
this.checkIsFollowing();
this.updateVideoStat(response.media.\u id);
}
};
updateVideoStat=async(id)=>videoView(id);
checkIsFollowing=async()=>{
const{userId}=this.props;
const{video}=this.state;
if(用户标识和视频){
const response=wait isFollow({
follower:userId.\u id,
以下:视频
});
如果(答复){
this.setState({following:response.following});
}
}
};
addOrRemoveFollowing=async()=>{
this.checkIsFollowing();
const{following,video}=this.state;
const{userId}=this.props;
如果(用户ID){
如果(以下){
const response=等待移除跟随({
follower:userId.\u id,
以下:视频
});
this.setState({following:false});
}否则{
const response=wait addFollow({
follower:userId.\u id,
以下:视频
});
this.setState({following:true});
}
}
};
SubmitCommonHandler=异步(事件)=>{
const{userId}=this.props;
event.preventDefault();
如果(用户ID){
const result=等待saveComment({
mediaId:this.state.video.\u id,
父ID:“0”,
userID:userID.\u id,
用户名:userId.userName,
注释:this.state.commentInput.value
});
控制台日志(结果);
如果(result.status==200){
这个.getVideoComments();
this.setState({commentInput:{value:'',touch:false,error:false});
}
}
};
render(){
const{autoPlay,relatedVideos,video,user,comments,commentInput,following,tab}=this.state;
const{userId}=this.props;
返回(
某些成分
);
}
}
常量mapStateToProps=(状态)=>({
userId:state.auth.user
});
导出默认连接(MapStateTops,{videoEditUrl})(SingleVideoPlay);
我不知道为什么componentDidMount打了两次电话,因为它显示了memmory lecage问题
如何修复。我认为问题存在于使用SingleVideoPlay组件的父组件上。可能是父组件导致SingleVideoPlay组件多次渲染。 此外,您的代码中也存在一个问题
componentDidMount() {
this._Mounted = true;
if (this._Mounted) {
const videoId = this.props.match.params.id;
this.getVideoDetails(videoId);
}
}
在这里,不需要检查是否安装了。因为它总是正确的。我认为问题存在于使用SingleVideoPlay组件的父组件上。可能是父组件导致SingleVideoPlay组件多次渲染。 此外,您的代码中也存在一个问题
componentDidMount() {
this._Mounted = true;
if (this._Mounted) {
const videoId = this.props.match.params.id;
this.getVideoDetails(videoId);
}
}
在这里,不需要检查是否安装了。_,因为它总是正确的。我建议您将组件状态放在构造函数中,如下所示:
this.state={…}
我建议您将组件状态放在构造函数中,如下所示:this.state={…}
为什么在第一个渲染组件后调用componentWillUnmount?这意味着父组件将卸载SingleVideoPlay组件并再次装载。我正在使用metronic主题,但我不能