如何修复Ionic List组件闪烁？ （反应）

Question

我是离子/反应编程的新手。我目前正在构建一个连接到Google Firebase的应用程序，并自动调用我在那里的Cloud Firestore。

我有一个页面呈现一个带有两个自定义离子列表组件的离子组件。列表中包含一些项目，单击这些项目可显示提示用户的警报。

我注意到，每当我单击列表并打开警报时，当离子页面刷新以显示警报时，“离子列表”组件都会闪烁。当我关闭警报时，该组件也会闪烁。

Rulesets.tsx

  const Rulesets: React.FC = () => {
  const [loading, setLoading] = useState(true)
  const [rulesList, setRulesList] = useState([])
  const [userRulesList, setUserRulesList] = useState([])
  const [downloadRules, setDownloadRules] = useState(false)
  const [deleteRules, setDeleteRules] = useState(false)
  const [focusedRulesetName, setFocusRulesetName] = useState("")
  const [focusedRulesetId, setFocusRulesetId] = useState("")
  const [focusedRulesetVersion, setFocusRulesetVer] = useState("")

  useEffect(() => {
    getUserRulesets().then((rulesets: any) => {
      if(rulesets){
        setUserRulesList(rulesets)
        console.log("Use effect setting user rules list.")
      }
      else{
        console.log("Use effect found no rulesets found for user.")
      }
    }).finally(() => setLoading(false))
  }, [])

  useEffect(() => {
    getRulesets().then((rulesets: any) => {
      if(rulesets){
        setRulesList(rulesets.map((rule: {rule: []}) => rule))
        console.log("Use effect setting available rules list.")
      }
    }).finally(() => setLoading(false))
  }, [])

  function updateUserRulesList(){
    getUserRulesets().then((rulesets: any) => {
      if(rulesets){
        console.log("Current user rules list: ",userRulesList)
        console.log("New user rules list: ", rulesets)
        if(rulesets === userRulesList){
          console.log("Rules unchanged.")
        }
        setUserRulesList(rulesets)
      }
      else{
        console.log("No rulesets found for user.")
        setUserRulesList([])
      }
    })
  }

  function openAlert(check: boolean, alertName: string, rulesetId: string, rulesetName: string, rulesetVer: string){
    setFocusRulesetName(rulesetName)
    setFocusRulesetId(rulesetId)
    setFocusRulesetVer(rulesetVer)
    
    if(alertName === "download"){
      setDownloadRules(check)
    }
    else{
      setDeleteRules(check)
    }
  }

  const RulesetItem = (prop: {id: string, name: string, version: string}) => {
    var installed = false
    var rule: {id: string}

    for(rule of userRulesList){
        if(rule.id === prop.id){
          installed = true
        }
      }
    
    if(installed){
      return (
        <IonItem key={prop.id+ "-available"}>
        <IonLabel>
          <h2>{prop.name}</h2>
          <h3>Version: {prop.version}</h3>
          <p>Installed</p>
        </IonLabel>
      </IonItem>
      )
    }
    return (
      <IonItem key={prop.id+ "-available"} button={true} onClick={() => openAlert(true, "download", prop.id, prop.name, prop.version)}>
      <IonLabel>
        <h2>{prop.name}</h2>
        <h3>Version: {prop.version}</h3>
      </IonLabel>
    </IonItem>
    )    
  }

  const DownloadAlert = () => {
    return (
      <IonAlert
        isOpen={downloadRules}
        onDidDismiss={() => setDownloadRules(false)}
        header={'Download Ruleset?'}
        subHeader={focusedRulesetName}
        message={'This will install this ruleset.'}
        buttons={[
          {
            text: 'Yes',
            handler: async () => {
              setDownloadRules(false)
              console.log("Downloading rules.")
              setLoading(true)
              await addRulesetToUser(focusedRulesetId, 
                focusedRulesetName,
                focusedRulesetVersion
              ).then(updateUserRulesList).finally(() => setLoading(false))
            }
          }, 
          {
            text: 'No'
          }
        ]}
      />
    )
  }

  const DeleteAlert = () => {
    return (
      <IonAlert
        isOpen={deleteRules}
        onDidDismiss={() => setDeleteRules(false)}
        header={'Delete Ruleset?'}
        subHeader={focusedRulesetName}
        message={'This will uninstall this ruleset.'}
        buttons={[
          {
            text: 'Yes',
            handler: async () => {
              setDeleteRules(false)
              console.log("Deleting rules.")
              console.log("Setting loading to true")
              setLoading(true)
              console.log("Loading set to true.")
              await removeRulesetFromUser(focusedRulesetId, 
                focusedRulesetName,
                focusedRulesetVersion
              ).then(updateUserRulesList).finally(() => setLoading(false))
            }
          }, 
          {
            text: 'No'
          }
        ]}
      />
    )
  }

  const InstalledRulesList = () => {
    if(userRulesList.length !== 0){
      return (
        <IonList lines="full" inset={true}>
        <IonListHeader lines="full">Installed Rules</IonListHeader>
        {userRulesList.map((rule: {id: string, name: string, version: string}) => (
          <IonItem key={rule.id + "-installed"}>
            <IonLabel>
              <h2>{rule.name}</h2>
              <h3>Version: {rule.version}</h3>
              <IonButton slot="end" onClick={() => openAlert(true, "delete", rule.id, rule.name, rule.version)}> 
                Delete
              </IonButton>
            </IonLabel>
          </IonItem>
        ))}
      </IonList>
      )
    }
    return null
  }

  const AvailableRulesList = () => { //Component that flickers
    console.log("Returning available rules.")
    console.log("Ruleslist: ",rulesList)
    return(
      <IonList lines="full" inset={true}>
        <IonListHeader lines="full">Available Rules</IonListHeader>
        {rulesList.map((rule: {id: string, data: {name: string, version: string}}) => (
          <RulesetItem key={rule.id + "ruleset-item"} id={rule.id} name={rule.data.name} version={rule.data.version}/>
        ))}
      </IonList>
    )
  }

  return (
    <IonPage>
      <MainHeader/>
      <IonContent className="ion-content-rulesets ion-padding" fullscreen>
        <InstalledRulesList/> {/*Custom list component*/}
        <AvailableRulesList/> {/*Custom list component*/}
        <DownloadAlert/>
        <DeleteAlert/> 
        <IonLoading duration={0} isOpen={loading}/>
      </IonContent>
    </IonPage>
  )
}

export default Rulesets

希望这是足够的信息。如果需要，我可以添加更多。预先感谢。

编辑：另一个问题是，除非状态改变，我是否可以阻止重新加载特定组件？