图片缩放及下载

@@ -3,15 +3,15 @@
     {
       "name": "shared_desc",
       "value": "全局工具包"
-    } ,
+    },
     {
       "name": "net_core_no_network",
       "value": "当前无网络，请重试"
-    } ,
+    },
     {
       "name": "net_core_weak_network",
       "value": "当前无网络，请重试"
-    } ,
+    },
     {
       "name": "net_core_page_error_network",
       "value": "网络出小差了，请检查下网络"
@@ -47,6 +47,10 @@
     {
       "name": "auditing_core_error",
       "value": "内容已下线"
+    },
+    {
+      "name": "image_request_fail",
+      "value": "图片加载失败，请检查网络"
     }
   ]
 }
\ No newline at end of file

 import { PhotoListBean } from 'wdBean/Index';
 import { Logger } from 'wdKit/Index';
-import { MultiPictureDetailItemComponent } from './MultiPictureDetailItemComponent';
 import { display, router } from '@kit.ArkUI';
 import { ImageDownloadComponent } from './ImageDownloadComponent';
+import { ImageItemView } from './view/ImageItemView';
 
 const TAG = 'ImageSwiperComponent';
 
@@ -17,6 +17,9 @@ export struct ImageSwiperComponent {
   private screenWidth: number = 0
   private picWidth: number = 0
   @State picHeight: number = 0
+  @State isEnableSwipe: boolean = true;
+
+  // @Provide bgc: Color = Color.White;
 
   //watch监听页码回调
   onCurrentPageNumUpdated(): void {
@@ -53,7 +56,8 @@ export struct ImageSwiperComponent {
       if (this.photoList && this.photoList?.length > 0) {
         Swiper(this.swiperController) {
           ForEach(this.photoList, (item: PhotoListBean) => {
-            MultiPictureDetailItemComponent({ MultiPictureDetailItem: item })
+            // MultiPictureDetailItemComponent({ MultiPictureDetailItem: item })
+            ImageItemView({ MultiPictureDetailItem: item, isEnableSwipe: this.isEnableSwipe })
           })
         }
         .index(this.swiperIndex)

+import { image } from '@kit.ImageKit';
+import { matrix4, promptAction, window } from '@kit.ArkUI';
+import { BusinessError } from '@kit.BasicServicesKit';
+import { ScaleModel } from '../../model/ScaleModel';
+import { OffsetModel } from '../../model/OffsetModel';
+import { windowSizeManager } from '../../utils/Managers';
+import { runWithAnimation } from '../../utils/FuncUtils';
+import { PhotoListBean } from 'wdBean/Index';
+import { http } from '@kit.NetworkKit';
+
+// TODO：知识点：组件复用
+@Reusable
+@Component
+export struct ImageItemView {
+  @Consume private bgc: Color;
+  @Link isEnableSwipe: boolean; // TODO：需求：多图切换
+  @State isEnableOffset: boolean = false;
+  @State imageScaleInfo: ScaleModel = new ScaleModel(1.0, 1.0, 1.5, 0.3);
+  @State imageOffsetInfo: OffsetModel = new OffsetModel(0, 0);
+  @State matrix: matrix4.Matrix4Transit = matrix4.identity().copy();
+  @State imagePixelMap: image.PixelMap | null = null; // 当前图片pixelMap，用于Image组件显示
+  @State fitWH: "width" | "height" | undefined = undefined; // 表示当前图片是根据宽度适配还是高度适配
+  @State imageDefaultSize: image.Size = { width: 0, height: 0 }; // 图片默认大小，即，与屏幕大小最适配的显示大小
+  imageUri: string = ""; // 当前图片uri
+  imageWHRatio: number = 0; // 图片原始宽高比
+  private MultiPictureDetailItem: PhotoListBean = {} as PhotoListBean
+  @State imageBuffer: ArrayBuffer | undefined = undefined; // 图片ArrayBuffer
+
+  aboutToAppear(): void {
+    this.imageUri = this.MultiPictureDetailItem.picPath
+    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.imageUri,
+        (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);
+      this.initCurrentImageInfo(imageSource);
+    }
+  }
+
+  /**
+   * 根据图片宽高比及窗口大小计算图片的默认宽高，即，图片最适配屏幕的大小
+   * @param imageWHRatio：图片原始宽高比
+   * @param size：窗口大小{with:number,height:number}
+   * @returns image.Size
+   */
+  calcImageDefaultSize(imageWHRatio: number, size: window.Size): image.Size {
+    let width = 0
+    let height = 0;
+    if (imageWHRatio > size.width / size.height) {
+      // 图片宽高比大于屏幕宽高比，图片默认以屏幕宽度进行显示
+      width = size.width;
+      height = size.width / imageWHRatio;
+    } else {
+      height = size.height;
+      width = size.height * imageWHRatio;
+    }
+    return { width: width, height: height };
+  }
+
+  /**
+   * TODO：知识点：根据图片大小（宽高<=屏幕宽高）和屏幕大小计算图片放大适配屏幕进行显示的缩放倍率
+   * @param imageSize：图片当前大小
+   * @param windowSize：窗口大小
+   * @returns：缩放倍率
+   */
+  calcFitScaleRatio(imageSize: image.Size, windowSize: window.Size): number {
+    let ratio: number = 1.0;
+    if (windowSize.width > imageSize.width) {
+      ratio = windowSize.width / imageSize.width;
+    } else {
+      ratio = windowSize.height / imageSize.height;
+    }
+    return ratio;
+  }
+
+  /**
+   * 设置当前图片的相关信息：uri、whRatio、pixelMap、fitWH、defaultSize、maxScaleValue
+   * TODO：知识点：提前获取图片的信息，以进行Image组件的尺寸设置及后续的相关计算
+   */
+  initCurrentImageInfo(imageSource: image.ImageSource): void {
+    this.matrix = matrix4.identity().copy();
+    // const imageSource: image.ImageSource = image.createImageSource(this.imageUri);
+    imageSource.getImageInfo(0).then((data: image.ImageInfo) => {
+      this.imageWHRatio = data.size.width / data.size.height;
+      this.imageDefaultSize = this.calcImageDefaultSize(this.imageWHRatio, windowSizeManager.get());
+      if (this.imageDefaultSize.width === windowSizeManager.get().width) {
+        this.fitWH = "width";
+      } else {
+        this.fitWH = "height";
+      }
+      this.imageScaleInfo.maxScaleValue += this.fitWH === "width" ?
+        (windowSizeManager.get().height / this.imageDefaultSize.height) :
+        (windowSizeManager.get().width / this.imageDefaultSize.width);
+    }).catch((err: BusinessError) => {
+      console.error(`[error][getImageInfo]${err.message}`);
+    });
+    imageSource.createPixelMap().then((data: image.PixelMap) => {
+      this.imagePixelMap = data;
+    }).catch((err: BusinessError) => {
+      console.error(`[error][createPixelMap]${err.message}`);
+    });
+    this.isEnableOffset = false;
+    this.imageScaleInfo.reset();
+    this.imageOffsetInfo.reset();
+  }
+
+  /**
+   * 在图片消失时，将当前图片的信息设置为默认值
+   */
+  resetCurrentImageInfo(): void {
+    this.imageScaleInfo.reset();
+    this.imageOffsetInfo.reset();
+    this.matrix = matrix4.identity().copy();
+  }
+
+  /**
+   * TODO：需求：在偏移时评估是否到达边界，以便进行位移限制与图片的切换
+   * @returns：长度为4的boolean数组，表示上下左右是否到达边界
+   */
+  evaluateBound(): boolean[] {
+    return [false, false, false, false];
+  }
+
+  build() {
+    Stack() {
+      Image(this.imagePixelMap)// TODO：知识点：宽高只根据其尺寸设置一个，通过保持宽高比来设置另一个属性
+        .width(this.fitWH === "width" ? "100%" : undefined)
+        .height(this.fitWH === "height" ? "100%" : undefined)
+        .aspectRatio(this.imageWHRatio)
+        .objectFit(ImageFit.Cover)// TODO：知识点：保持宽高比进行缩放，可以超出父组件，以便实现多图切换的增强功能
+        .autoResize(false)
+        .transform(this.matrix)// TODO：知识点：通过matrix控制图片的缩放
+        .defaultFocus(true)
+        .expandSafeArea([SafeAreaType.SYSTEM], [SafeAreaEdge.TOP, SafeAreaEdge.BOTTOM])
+        .offset({
+          // TODO：知识点：通过offset控制图片的偏移
+          x: this.imageOffsetInfo.currentX,
+          y: this.imageOffsetInfo.currentY
+        })
+    }
+    .onBlur(() => {
+      this.resetCurrentImageInfo();
+    })
+    // .backgroundColor(this.bgc)
+    .alignContent(Alignment.Center)
+    .expandSafeArea([SafeAreaType.SYSTEM], [SafeAreaEdge.TOP, SafeAreaEdge.BOTTOM])
+    .width("100%")
+    .height("100%")
+    .gesture(
+      GestureGroup(
+        GestureMode.Exclusive,
+        // TODO：知识点：双击切换图片大小
+        TapGesture({ count: 2 })
+          .onAction(() => {
+            let fn: Function;
+            // 已经是放大状态下，双击缩小
+            if (this.imageScaleInfo.scaleValue > this.imageScaleInfo.defaultScaleValue) {
+              fn = () => {
+                this.isEnableSwipe = true;
+                this.imageScaleInfo.reset();
+                this.imageOffsetInfo.reset();
+                this.matrix = matrix4.identity().copy();
+              };
+            } else {
+              // 已经是缩小状态，双击放大
+              fn = () => {
+                this.isEnableSwipe = false;
+                const ratio: number = this.calcFitScaleRatio(this.imageDefaultSize, windowSizeManager.get());
+                this.imageScaleInfo.scaleValue = ratio;
+                this.imageOffsetInfo.reset();
+                this.matrix = matrix4.identity().scale({
+                  x: ratio,
+                  y: ratio,
+                }).copy();
+                this.imageScaleInfo.stash();
+              }
+            }
+            runWithAnimation(fn);
+          }),
+        // 单击切换背景色
+        // TapGesture({ count: 1 }).onAction(() => {
+        //   runWithAnimation(() => {
+        //     this.bgc = this.bgc === Color.White ? Color.Black : Color.White;
+        //   });
+        // }),
+        // TODO：知识点：双指捏合缩放图片
+        PinchGesture({ fingers: 2, distance: 1 })
+          .onActionUpdate((event: GestureEvent) => {
+            this.imageScaleInfo.scaleValue = this.imageScaleInfo.lastValue * event.scale;
+            // TODO：知识点：缩放时不允许大于最大缩放因子+额外缩放因子，不允许小于默认大小-额外缩放因子，额外缩放因子用于提升用户体验
+            if (this.imageScaleInfo.scaleValue > this.imageScaleInfo.maxScaleValue *
+              (1 + this.imageScaleInfo.extraScaleValue)
+            ) {
+              this.imageScaleInfo.scaleValue = this.imageScaleInfo.maxScaleValue *
+                (1 + this.imageScaleInfo.extraScaleValue);
+            }
+            if (this.imageScaleInfo.scaleValue < this.imageScaleInfo.defaultScaleValue *
+              (1 - this.imageScaleInfo.extraScaleValue)) {
+              this.imageScaleInfo.scaleValue = this.imageScaleInfo.defaultScaleValue *
+                (1 - this.imageScaleInfo.extraScaleValue);
+            }
+            // TODO：知识点：matrix默认缩放中心为组件中心
+            this.matrix = matrix4.identity().scale({
+              x: this.imageScaleInfo.scaleValue,
+              y: this.imageScaleInfo.scaleValue,
+            }).copy();
+            console.debug(this.imageScaleInfo.toString());
+          })
+          .onActionEnd((event: GestureEvent) => {
+            /**
+             * TODO：知识点：当小于默认大小时，恢复为默认大小
+             */
+            if (this.imageScaleInfo.scaleValue < this.imageScaleInfo.defaultScaleValue) {
+              runWithAnimation(() => {
+                this.imageScaleInfo.reset();
+                this.imageOffsetInfo.reset();
+                this.matrix = matrix4.identity().copy();
+              })
+            }
+            // TODO：知识点：当大于最大缩放因子时，恢复到最大
+            if (this.imageScaleInfo.scaleValue > this.imageScaleInfo.maxScaleValue) {
+              runWithAnimation(() => {
+                this.imageScaleInfo.scaleValue = this.imageScaleInfo.maxScaleValue;
+                this.matrix = matrix4.identity()
+                  .scale({
+                    x: this.imageScaleInfo.maxScaleValue,
+                    y: this.imageScaleInfo.maxScaleValue
+                  });
+              })
+            }
+            this.imageScaleInfo.stash();
+          }),
+        // // TODO：知识点：滑动图片
+        // PanGesture({ fingers: 1 })// TODO：需求：默认大小下左右滑动应当是切换图片
+        //   .onActionUpdate((event: GestureEvent) => {
+        //     if (this.imageScaleInfo.scaleValue === this.imageScaleInfo.defaultScaleValue) {
+        //       // 默认大小下不允许移动
+        //       return;
+        //     }
+        //     this.imageOffsetInfo.currentX = this.imageOffsetInfo.lastX + event.offsetX;
+        //     this.imageOffsetInfo.currentY = this.imageOffsetInfo.lastY + event.offsetY;
+        //   })
+        //   .onActionEnd((event: GestureEvent) => {
+        //     this.imageOffsetInfo.stash();
+        //   })
+      ),
+    )
+  }
+}
\ No newline at end of file

+export class ImageViewerConstants {
+  // 缩放动画的持续时间
+  static readonly ANIMATE_DURATION: number = 300;
+  // swiper中缓存图片的数量
+  static readonly SWIPER_CACHE_COUNT: number = 2;
+}

+@Observed
+export class OffsetModel {
+  public currentX: number;
+  public currentY: number;
+  public lastX: number = 0;
+  public lastY: number = 0;
+
+  constructor(currentX: number = 0, currentY: number = 0) {
+    this.currentX = currentX;
+    this.currentY = currentY;
+  }
+
+  reset(): void {
+    this.currentX = 0;
+    this.currentY = 0;
+    this.lastX = 0;
+    this.lastY = 0;
+  }
+
+  stash(): void {
+    this.lastX = this.currentX;
+    this.lastY = this.currentY;
+  }
+
+  toString(): string {
+    return `[currentX: ${this.currentX} currentY: ${this.currentY} lastX: ${this.lastX} lastY: ${this.lastY}]`;
+  }
+}
\ No newline at end of file

+@Observed
+export class ScaleModel {
+  /**
+   * scaleValue: 本次缩放因子，用于控制图片的大小显示
+   * lastValue：记录上次缩放完后的缩放因子
+   * defaultMaxScaleValue：默认的最大放大值
+   * defaultScaleValue：默认缩放值，1
+   */
+  public scaleValue: number;
+  public lastValue: number;
+  public maxScaleValue: number;
+  public extraScaleValue: number;
+  public readonly defaultScaleValue: number = 1;
+
+  constructor(scaleValue: number = 1.0, lastValue: number = 1.0,
+              maxScaleValue: number = 1.5, extraScaleValue: number = 0.2) {
+    this.scaleValue = scaleValue;
+    this.lastValue = lastValue;
+    this.maxScaleValue = maxScaleValue;
+    this.extraScaleValue = extraScaleValue;
+  }
+
+  reset(): void {
+    this.scaleValue = this.defaultScaleValue;
+    this.lastValue = this.scaleValue;
+  }
+
+  stash(): void {
+    this.lastValue = this.scaleValue;
+  }
+
+  toString(): string {
+    return `[scaleValue: ${this.scaleValue} lastValue: ${this.lastValue}]`;
+  }
+}
\ No newline at end of file

+/**
+ * 给函数的执行加上动画
+ * @param fn：要在动画内执行的回调函数，通常fn里面会改变状态变量
+ * @param duration：动画持续时长
+ * @param curve：动画区线
+ */
+import { ImageViewerConstants } from '../constants/ImageViewerConstants';
+
+export function runWithAnimation(
+  fn: Function,
+  duration: number = ImageViewerConstants.ANIMATE_DURATION,
+  curve: Curve = Curve.Smooth): void {
+  animateTo({ duration: duration, curve: curve }, () => {
+    fn();
+  })
+}
\ No newline at end of file

+import { window } from '@kit.ArkUI';
+
+class WindowSizeManager {
+  private size: window.Size = { width: 0, height: 0 };
+
+  constructor() {
+    window.getLastWindow(getContext()).then((value: window.Window) => {
+      const rect: window.Rect = value.getWindowProperties().windowRect;
+      this.size.width = px2vp(rect.width);
+      this.size.height = px2vp(rect.height);
+      console.log(`[windowWidth]${this.size.width} [windowHeight]${this.size.height}`);
+    })
+  }
+
+  get(): window.Size {
+    return this.size;
+  }
+}
+
+export const windowSizeManager: WindowSizeManager = new WindowSizeManager();
\ No newline at end of file

@@ -39,6 +39,14 @@
     {
       "name": "image_request_fail",
       "value": "图片加载失败，请检查网络"
+    },
+    {
+      "name": "EntryAbility_desc",
+      "value": "$string:app_desc"
+    },
+    {
+      "name": "reason_read_write_media",
+      "value": "user_grant"
     }
   ]
 }
\ No newline at end of file

@@ -31,6 +31,10 @@
     {
       "name": "refresh_fail_text",
       "value": "刷新失败"
+    },
+    {
+      "name": "reason_read_write_media",
+      "value": "user_grant"
     }
   ]
 }
\ No newline at end of file

@@ -43,7 +43,10 @@
     {
       "name": "privacy_text_title_protocol",
       "value": "《用户协议》"
+    },
+    {
+      "name": "reason_read_write_media",
+      "value": "user_grant"
     }
-
   ]
 }
\ No newline at end of file