图片下载模块

+import { abilityAccessCtrl, common, Permissions } from '@kit.AbilityKit';
+import { http } from '@kit.NetworkKit';
+import { BusinessError } from '@kit.BasicServicesKit';
+import { promptAction } from '@kit.ArkUI';
+import { image } from '@kit.ImageKit';
+import { photoAccessHelper } from '@kit.MediaLibraryKit';
+import fs from '@ohos.file.fs';
+
+const PERMISSIONS: Array<Permissions> = [
+  'ohos.permission.READ_MEDIA',
+  'ohos.permission.WRITE_MEDIA'
+];
+
+@Component
+export struct ImageDownloadComponent {
+  @State image: PixelMap | undefined = undefined;
+  @State photoAccessHelper: photoAccessHelper.PhotoAccessHelper | undefined = undefined; // 相册模块管理实例
+  @State imageBuffer: ArrayBuffer | undefined = undefined; // 图片ArrayBuffer
+  url: string = ''
+
+  build() {
+    Column() {
+      Image($r('app.media.icon_arrow_left_white'))
+        .width(24)
+        .height(24)
+        .aspectRatio(1)
+        .interpolation(ImageInterpolation.High)
+        .rotate({ angle: -90 })
+        .onClick(async () => {
+          console.info(`cj2024 onClick ${this.imageBuffer}`)
+          if (this.imageBuffer !== undefined) {
+            await this.saveImage(this.imageBuffer);
+            promptAction.showToast({
+              message: $r('app.string.image_request_success'),
+              duration: 2000
+            })
+          }
+        })
+    }
+
+  }
+
+  async aboutToAppear(): Promise<void> {
+    console.info(`cj2024 图片下载 ${this.url}`)
+    const context = getContext(this) as common.UIAbilityContext;
+    const atManager = abilityAccessCtrl.createAtManager();
+    await atManager.requestPermissionsFromUser(context, PERMISSIONS);
+    this.getPicture();
+  }
+
+  /**
+   * 通过http的request方法从网络下载图片资源
+   */
+  async getPicture() {
+    console.info(`cj2024 getPicture`)
+    http.createHttp()
+      .request(this.url,
+        (error: BusinessError, data: http.HttpResponse) => {
+          if (error) {
+            // 下载失败时弹窗提示检查网络，不执行后续逻辑
+            promptAction.showToast({
+              message: $r('app.string.image_request_fail'),
+              duration: 2000
+            })
+            return;
+          }
+          this.transcodePixelMap(data);
+          // 判断网络获取到的资源是否为ArrayBuffer类型
+          console.info(`cj2024 getPicture ${data.result}`)
+          if (data.result instanceof ArrayBuffer) {
+            console.info(`cj2024 getPicture 222`)
+            this.imageBuffer = data.result as ArrayBuffer;
+          }
+        }
+      )
+  }
+
+  /**
+   * 使用createPixelMap将ArrayBuffer类型的图片装换为PixelMap类型
+   * @param data：网络获取到的资源
+   */
+  transcodePixelMap(data: http.HttpResponse) {
+    console.info(`cj2024 transcodePixelMap ${data.responseCode}`)
+    if (http.ResponseCode.OK === data.responseCode) {
+      const imageData: ArrayBuffer = data.result as ArrayBuffer;
+      // 通过ArrayBuffer创建图片源实例。
+      const imageSource: image.ImageSource = image.createImageSource(imageData);
+      const options: image.InitializationOptions = {
+        'alphaType': 0, // 透明度
+        'editable': false, // 是否可编辑
+        'pixelFormat': 3, // 像素格式
+        'scaleMode': 1, // 缩略值
+        'size': { height: 100, width: 100 }
+      }; // 创建图片大小
+
+      // 通过属性创建PixelMap
+      imageSource.createPixelMap(options).then((pixelMap: PixelMap) => {
+        this.image = pixelMap;
+      });
+    }
+  }
+
+  /**
+   * 保存ArrayBuffer到图库
+   * @param buffer：图片ArrayBuffer
+   * @returns
+   */
+  async saveImage(buffer: ArrayBuffer | string): Promise<void> {
+    console.info(`cj2024 saveImage buffer ${buffer}`)
+    const context = getContext(this) as common.UIAbilityContext; // 获取getPhotoAccessHelper需要的context
+    const helper = photoAccessHelper.getPhotoAccessHelper(context); // 获取相册管理模块的实例
+    const uri = await helper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'jpg'); // 指定待创建的文件类型、后缀和创建选项，创建图片或视频资源
+    console.info(`cj2024 saveImage uri ${uri}`)
+    const file = await fs.open(uri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
+    await fs.write(file.fd, buffer);
+    await fs.close(file.fd);
+  }
+}

 import { PhotoListBean } from 'wdBean/Index';
 import { PhotoListBean } from 'wdBean/Index';
 import { Logger } from 'wdKit/Index';
 import { Logger } from 'wdKit/Index';
 import { MultiPictureDetailItemComponent } from './MultiPictureDetailItemComponent';
 import { MultiPictureDetailItemComponent } from './MultiPictureDetailItemComponent';
-import { display } from '@kit.ArkUI';
+import { display, router } from '@kit.ArkUI';
+import { ImageDownloadComponent } from './ImageDownloadComponent';
 
 
 const TAG = 'ImageSwiperComponent';
 const TAG = 'ImageSwiperComponent';
 
 
@@ -35,6 +36,20 @@ export struct ImageSwiperComponent {
 
 
   build() {
   build() {
     RelativeContainer() {
     RelativeContainer() {
+      Image($r('app.media.icon_arrow_left_white'))
+        .width(24)
+        .height(24)
+        .aspectRatio(1)
+        .interpolation(ImageInterpolation.High)
+        .alignRules({
+          top: { anchor: "__container__", align: VerticalAlign.Top },
+          left: { anchor: "__container__", align: HorizontalAlign.Start }
+        })
+        .onClick(() => {
+          router.back();
+        })
+        .id("backImg")
+
       if (this.photoList && this.photoList?.length > 0) {
       if (this.photoList && this.photoList?.length > 0) {
         Swiper(this.swiperController) {
         Swiper(this.swiperController) {
           ForEach(this.photoList, (item: PhotoListBean) => {
           ForEach(this.photoList, (item: PhotoListBean) => {
@@ -96,6 +111,19 @@ export struct ImageSwiperComponent {
           middle: { anchor: "__container__", align: HorizontalAlign.Center }
           middle: { anchor: "__container__", align: HorizontalAlign.Center }
         })
         })
       }
       }
+
+      ImageDownloadComponent({ url: this.photoList[this.swiperIndex].picPath })
+        .alignRules({
+          bottom: { anchor: "__container__", align: VerticalAlign.Bottom },
+          right: { anchor: "__container__", align: HorizontalAlign.End }
+        })
+        .margin({
+          top: 8,
+          left: 18,
+          bottom: 24,
+          right: 18
+        })
+        .id("downloadImg")
     }
     }
     .width('100%')
     .width('100%')
     .height('100%')
     .height('100%')