HarmonyOS 页面返回会把上个页面已经打开的弹窗关闭掉

@Entry
@Component
struct MainPage {
    private isDialogOpen: boolean = false;

    // 当页面初始化时检查是否需要显示弹窗
    onInit() {
        this.isDialogOpen = AppStorage.get('isDialogOpen', false);
    }

    build() {
        Column({ space: 20 }) {
            Button("Show Dialog")
                .onClick(() => {
                    this.isDialogOpen = true;
                    AppStorage.set('isDialogOpen', true);
                })

            // 根据状态显示弹窗
            if (this.isDialogOpen) {
                AlertDialog({
                    message: "This is a dialog",
                    confirm: {
                        value: "OK",
                        action: () => {
                            this.isDialogOpen = false;
                            AppStorage.set('isDialogOpen', false);
                        }
                    }
                })
            }
        }.padding(20)
    }

    // 页面离开时保存弹窗状态
    onBackPress() {
        AppStorage.set('isDialogOpen', this.isDialogOpen);
        return false; // 返回false以允许页面正常退出
    }
}

@Entry
@Component
struct MainPage {
    private currentIndex: number = 0;

    build() {
        Column({ space: 20 }) {
            Button("Go to Page 1")
                .onClick(() => {
                    this.currentIndex = 0;
                })
            
            Button("Go to Page 2")
                .onClick(() => {
                    this.currentIndex = 1;
                })

            // 使用索引来切换页面内容
            if (this.currentIndex === 0) {
                PageOne()
            } else {
                PageTwo()
            }
        }.padding(20)
    }
}

@Component
struct PageOne {
    build() {
        Column({ space: 20 }) {
            Text("This is Page One")
        }
    }
}

@Component
struct PageTwo {
    build() {
        Column({ space: 20 }) {
            Text("This is Page Two")
            AlertDialog({
                message: "This is a dialog in Page Two",
                confirm: {
                    value: "OK",
                    action: () => {}
                }
            })
        }
    }
}

import router from '@ohos.router';  
  
@Entry  
@Component  
struct First {  
  @State textValue: string  = 'Hello World'  
  // 显隐控制设置为不占用  
  @State visible: Visibility = Visibility.None  
  build() {  
    // 使用stack可以实现假的dialog覆盖原页面上面  
    Stack() {  
      Row() {  
        // 初始页面  
        Column() {  
          Text('Hello World')  
            .fontSize(50)  
            .fontWeight(FontWeight.Bold)  
          // 触发dialog的地方  
          Button('click')  
            .onClick(() => {  
              //用于检测点击事件是否透传到原来的页面，我测了一下是没有透传的，符合dialog规范  
              console.log("hit me!")  
              if (this.visible == Visibility.Visible) {  
                this.visible = Visibility.None  
              } else {  
                this.visible = Visibility.Visible  
              }  
            })  
            .backgroundColor(0x777474)  
            .fontColor(0x000000)  
        }  
        .width('100%')  
      }  
      .height('100%')  
      .backgroundColor(0x885555)  
      //这里开始是构造弹窗效果主要需要修改的地方，首先是加了一个半透明灰色的蒙层效果  
      Text('')  
        .onClick(() => {  
          if (this.visible == Visibility.Visible) {  
            this.visible = Visibility.None  
          } else {  
            this.visible = Visibility.Visible  
          }  
        })  
        .width('100%')  
        .height('100%')  
          // 透明度可以自己调节一下  
        .opacity(0.16)  
        .backgroundColor(0x000000)  
        .visibility(this.visible)  
  
      Column() {  
        // 这个可以调节对话框效果，栅格布局，xs，sm，md，lg分别为四种规格  
        // 下面的breakpoints是用来区别当前属于哪个类型的断点  
        // gridRow里的栅格数量为总数，gridCol里的就是偏移和假Dialog所占据的栅格数  
        GridRow({  
          columns:{xs:1 ,sm: 4, md: 8, lg: 12},  
          breakpoints: { value: ["400vp", "600vp", "800vp"],  
            reference: BreakpointsReference.WindowSize },  
        })  
        {  
          GridCol({  
            span:{xs:1 ,sm: 2, md: 4, lg: 8},  
            offset:{xs:0 ,sm: 1, md: 2, lg: 2}  
          }){  
  
            // 这里放的就是原Dialog里的column里的东西  
            Column() {  
              Text('Change text').fontSize(20).margin({ top: 10, bottom: 10 })  
              TextInput({ placeholder: '', text: this.textValue }).height(60).width('90%')  
                .onChange((value: string) => {  
                  this.textValue = value  
                })  
              Text('Whether to change a text?').fontSize(16).margin({ bottom: 10 })  
              Flex({ justifyContent: FlexAlign.SpaceAround }) {  
                Button('cancel')  
                  .onClick(() => {  
                    if (this.visible == Visibility.Visible) {  
                      this.visible = Visibility.None  
                    } else {  
                      this.visible = Visibility.Visible  
                    }  
  
                  }).backgroundColor(0xffffff).fontColor(Color.Black)  
                Button('jump')  
                  .onClick(() => {  
                    router.pushUrl({  
                      url: 'pages/Index'  
                    })  
                  }).backgroundColor(0xffffff).fontColor(Color.Red)  
              }.margin({ bottom: 10 })  
            }  
            .backgroundColor(0xffffff)  
            .visibility(this.visible)  
            .clip(true)  
            .borderRadius(20)  
          }  
        }  
      }.width('95%')//设置弹窗宽度  
    }  
  }  
}