Question

我在tabs1上有一张地图。

我单击标记并发送localstorage标记标题并发送到tab2。多数民众赞成运作良好

that.passingData(dogwalkMarker.valueOf().parkid);

passingData(something: string) {
localStorage.setItem('passingData', JSON.stringify(something));
console.log(something);

但是当我第一次加载tab2后返回出错的地方。在我加载应用程序上的任何页面并加载选项卡2后，它工作并返回好！

我不明白我在哪里做错了。感谢。

我在标签2上有以下代码。

scanOtopark() {
this.selectedOtopark = {};
let x = JSON.parse(localStorage.getItem('passingData'));

this.selectedOtopark = this.otoparks.find(otopark => otopark.parkqr === x);
if (this.selectedOtopark !== undefined) {
  this.otoparkFound = true;

  const toast = this.toastCtrl.create({
    message: "good",
    duration: 3000,
    position: 'top'
  });
  toast.present();
  console.log(this.selectedOtopark);
} else {
  this.otoparkFound = false;
  const toast = this.toastCtrl.create({
    message: 'something goes wrong',
    duration: 3000,
    position: 'top'
  });
  toast.present();
  this.selectedOtopark = {};
}

Answer 1

您的本地存储似乎存在async问题。所以我强烈建议您使用native storage module。由于它支持开箱即用的承诺，因此您可以在async情况下轻松使用它。如果您也安装了SQLite，它可以在所有平台上正常工作（尤其需要iOS设备。）

来自doc：

的示例

 // set a key/value
  storage.set('name', 'Max');

  // Or to get a key/value pair
  storage.get('age').then((val) => {
    console.log('Your age is', val);
  });

<强>更新

在first time load上你需要使用：

 this.platform.ready().then(() => {

    });

更新2：

x: any;

scanOtopark() {
this.selectedOtopark = {};


this.platformCtrl.ready().then(() => {
  this.storageCtrl.get('passingData').then((data) => {
    this.x= data;

  this.selectedOtopark = this.otoparks.find(otopark => otopark.parkqr === this.x);
  if (this.selectedOtopark !== undefined) {
    this.otoparkFound = true;

    const toast = this.toastCtrl.create({
      message: "good",
      duration: 3000,
      position: 'top'
    });
    toast.present();
    console.log(this.selectedOtopark);
  } else {
    this.otoparkFound = false;
    const toast = this.toastCtrl.create({
      message: 'something goes wrong',
      duration: 3000,
      position: 'top'
    });
    toast.present();
    this.selectedOtopark = {};
  }
 });
});

Answer 2

<强>解

这是我的错，因为我定义了我在构造函数中获取数据库代码。因为该页面需要加载以获取数据。

忘记了代码部分

constructor(private navCtrl: NavController,
          ...
          ...
          ...
          ...
          private storageCtrl: Storage,
          private platformCtrl: Platform,
          ) {

this.firebaseProvider.getOtoparks().subscribe((response) => {
  this.otoparks = response;
  console.log(this.otoparks);
});}

所以我在函数中导入该代码并且它有效！

<强> TAB1

passingData(something: string) {
this.platformCtrl.ready().then(() => {
  this.storageCtrl.set('passingData', something);
  console.log(something);
});

<强> TAB2

passingData: any;
scanOtopark() {
this.platformCtrl.ready().then(() => {
  this.storageCtrl.get('passingData').then((data) => {
    this.passingData = data;
    this.firebaseProvider.getOtoparks().subscribe((response) => {
      this.otoparks = response;
      this.selectedOtopark = this.otoparks.find(otopark => otopark.parkqr === this.passingData);

      if (this.selectedOtopark !== undefined) {
        this.otoparkFound = true;
        console.log(this.selectedOtopark);


        const toast = this.toastCtrl.create({
          message: "good",
          duration: 3000,
          position: 'top'
        });
        toast.present();
      } else {
        this.otoparkFound = false;
        const toast = this.toastCtrl.create({
          message: 'something goes wrong',
          duration: 3000,
          position: 'top'
        });
        toast.present();
      }
    });
  });
});}

离子3上的locastorage和标签菜单

2 个答案: