新增preload预加载和cancel取消加载接口，添加prefetch配合preload接口样例

Signed-off-by: zgf <zenggaofeng2@h-partners.com>

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 3.0.2
+- 新增图片重新加载接口reload
+- 新增返回请求request预加载接口preload
+- 新增取消请求接口cancel
+
 ## 3.0.2-rc.2
 - ImageKnifeAnimatorComponent新增开始、结束、暂停的回调事件
 - 文件缓存数量负数和超过INT最大值时默认为INT最大值

README_zh.md

@@ -316,6 +316,8 @@ ImageKnifeAnimatorComponent({
 | initMemoryCache   | newMemoryCache: IMemoryCache                                                                          | 自定义内存缓存策略        |
 | initFileCache     | context: Context, size: number, memory: number                                                        | 初始化文件缓存数量和大小     |
 | reload            | request: ImageKnifeRequest                                                                            | 图片重新加载           |
+| preLoad           | loadSrc: string I ImageKnifeOption                                                                    | 预加载返回图片请求request |
+| cancel            | request: ImageKnifeRequest                                                                    | 取消图片请求           |
 | preLoadCache      | loadSrc: string I ImageKnifeOption                                                                            | 预加载并返回文件缓存路径     |
 | getCacheImage     | loadSrc: string, cacheType: CacheStrategy = CacheStrategy.Default, signature?: string)                | 从内存或文件缓存中获取资源    |
 | addHeader         | key: string, value: Object                                                                            | 全局添加http请求头      |

entry/src/main/ets/pages/Index.ets

@@ -40,6 +40,11 @@ struct Index {
             uri: 'pages/ImageKnifeReload',
           });
         })
+        Button("动态预加载prefetch").margin({top:10}).onClick(()=>{
+          router.push({
+            uri: 'pages/PrefetchAndCacheCount',
+          });
+        })
         Button($r('app.string.Test_multiple_images')).margin({top:10}).onClick(()=>{
           router.push({
             uri: 'pages/TestCommonImage',

entry/src/main/ets/pages/LazyForEachCache.ets

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { InfoItem } from './model/DataSourcePrefetching';
+import { PageViewModel } from './model/PageViewModel';
+import { ImageKnifeComponent, ImageKnifeOption } from '@ohos/libraryimageknife';
+import { CommonDataSource } from './model/CommonDataSource';
+
+@Entry
+@Component
+export struct LazyForEachCache {
+  @State hotCommendList:CommonDataSource<InfoItem> = new CommonDataSource<InfoItem>([])
+  aboutToAppear(): void {
+    this.hotCommendList.addData(this.hotCommendList.totalCount(),PageViewModel.getItems())
+  }
+  build() {
+    Column() {
+      List({ space: 16 }) {
+        LazyForEach(this.hotCommendList, (item: InfoItem,index) => {
+          ListItem() {
+            Column({ space: 12 }) {
+              ImageKnifeComponent({
+                imageKnifeOption:{
+                  loadSrc: item.albumUrl,
+                  placeholderSrc:$r('app.media.loading')
+                }
+              }).width(100).height(100)
+              Text(`${index}`)
+            }.border({ width: 5 , color: "#000000"})
+          }
+        })
+      }
+      .cachedCount(5)
+      .width("100%")
+      .height("100%")
+      .margin({ left: 10, right: 10 })
+      .layoutWeight(1)
+    }
+  }
+}

entry/src/main/ets/pages/LazyForEachCount.ets

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { InfoItem } from './model/DataSourcePrefetching';
+import { PageViewModel } from './model/PageViewModel';
+import { ImageKnifeComponent, ImageKnifeOption } from '@ohos/libraryimageknife';
+import { CommonDataSource } from './model/CommonDataSource';
+
+@Entry
+@Component
+export struct LazyForEachCount {
+  @State hotCommendList:CommonDataSource<InfoItem> = new CommonDataSource<InfoItem>([])
+  aboutToAppear(): void {
+    this.hotCommendList.addData(this.hotCommendList.totalCount(),PageViewModel.getItems())
+  }
+  build() {
+    Column() {
+      List({ space: 16 }) {
+        LazyForEach(this.hotCommendList, (item: InfoItem,index) => {
+          ListItem() {
+            Column({ space: 12 }) {
+              ImageKnifeComponent({
+                imageKnifeOption:{
+                  loadSrc: item.albumUrl,
+                  placeholderSrc:$r('app.media.loading')
+                }
+              }).width(100).height(100)
+              Text(`${index}`)
+            }.border({ width: 5 , color: "#000000"})
+          }
+        })
+      }
+      .cachedCount(30)
+      .width("100%")
+      .height("100%")
+      .margin({ left: 10, right: 10 })
+      .layoutWeight(1)
+    }
+  }
+}

entry/src/main/ets/pages/PrefetchAndCacheCount.ets

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { router } from '@kit.ArkUI'
+
+@Entry
+@Component
+struct PrefetchAndCacheCount {
+  build() {
+    Column() {
+      Button("cacheCount == 5")
+        .onClick(()=>{
+          router.pushUrl({url:"pages/LazyForEachCache"})
+        })
+      Button("cacheCount == 30")
+        .margin({top:10})
+        .onClick(()=>{
+          router.pushUrl({url:"pages/LazyForEachCount"})
+        })
+      Button("prefetch + preload")
+        .margin({top:10})
+        .onClick(()=>{
+          router.pushUrl({url:"pages/PrefetchAndPreload"})
+        })
+    }.width("100%")
+    .height("100%")
+  }
+}

entry/src/main/ets/pages/PrefetchAndPreload.ets

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { BasicPrefetcher } from '@kit.ArkUI';
+import DataSourcePrefetchingImageKnife, { InfoItem } from './model/DataSourcePrefetching';
+import { PageViewModel } from './model/PageViewModel';
+import { ImageKnifeComponent, ImageKnifeOption } from '@ohos/libraryimageknife';
+@Entry
+@Component
+export struct PrefetchAndPreload {
+  // 创建DataSourcePrefetchingImageKnife对象，具备任务预取、取消能力的数据源
+  private readonly dataSource = new DataSourcePrefetchingImageKnife(PageViewModel.getItems());
+  // 创建BasicPrefetcher对象，默认的动态预取算法实现
+  private readonly prefetcher = new BasicPrefetcher(this.dataSource);
+
+  build() {
+    Column() {
+      List({ space: 16 }) {
+        LazyForEach(this.dataSource, (item: InfoItem,index:number) => {
+          ListItem() {
+            Column({ space: 12 }) {
+              ImageKnifeComponent({
+                imageKnifeOption:{
+                  loadSrc: item.albumUrl,
+                  placeholderSrc:$r('app.media.loading')
+                }
+              }).width(100).height(100)
+              Text(`${index}`)
+            }.border({ width: 5 , color: "#000000"})
+          }
+          .reuseId('imageKnife')
+        })
+      }
+      .cachedCount(5)
+      .onScrollIndex((start: number, end: number) => {
+        // 列表滚动触发visibleAreaChanged，实时更新预取范围，触发调用prefetch、cancel接口
+        this.prefetcher.visibleAreaChanged(start, end)
+      })
+      .width("100%")
+      .height("100%")
+      .margin({ left: 10, right: 10 })
+      .layoutWeight(1)
+    }
+  }
+}

entry/src/main/ets/pages/UserPage.ets

@@ -12,48 +12,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+import { CommonDataSource } from './model/CommonDataSource'
 import { UserAvatar } from './User'
 
-class CommonDataSource <T> implements IDataSource {
-  private dataArray: T[] = []
-  private listeners: DataChangeListener[] = []
-
-  constructor(element: []) {
-    this.dataArray = element
-  }
-
-  public getData(index: number) {
-    return this.dataArray[index]
-  }
-
-  public totalCount(): number {
-    return this.dataArray.length
-  }
-
-  public addData(index: number, data: T[]): void {
-    this.dataArray = this.dataArray.concat(data)
-    this.notifyDataAdd(index)
-  }
-
-  unregisterDataChangeListener(listener: DataChangeListener): void {
-    const pos = this.listeners.indexOf(listener);
-    if (pos >= 0) {
-      this.listeners.splice(pos, 1);
-    }
-  }
-
-  registerDataChangeListener(listener: DataChangeListener): void {
-    if (this.listeners.indexOf(listener) < 0) {
-      this.listeners.push(listener)
-    }
-  }
-
-  notifyDataAdd(index: number): void {
-    this.listeners.forEach((listener: DataChangeListener) => {
-      listener.onDataAdd(index)
-    })
-  }
-}
 @Entry
 @Component
 struct Index {

entry/src/main/ets/pages/model/CommonDataSource.ets

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+export class CommonDataSource <T> implements IDataSource {
+  private dataArray: T[] = []
+  private listeners: DataChangeListener[] = []
+
+  constructor(element: []) {
+    this.dataArray = element
+  }
+
+  public getData(index: number) {
+    return this.dataArray[index]
+  }
+
+  public totalCount(): number {
+    return this.dataArray.length
+  }
+
+  public addData(index: number, data: T[]): void {
+    this.dataArray = this.dataArray.concat(data)
+    this.notifyDataAdd(index)
+  }
+
+  unregisterDataChangeListener(listener: DataChangeListener): void {
+    const pos = this.listeners.indexOf(listener);
+    if (pos >= 0) {
+      this.listeners.splice(pos, 1);
+    }
+  }
+
+  registerDataChangeListener(listener: DataChangeListener): void {
+    if (this.listeners.indexOf(listener) < 0) {
+      this.listeners.push(listener)
+    }
+  }
+
+  notifyDataAdd(index: number): void {
+    this.listeners.forEach((listener: DataChangeListener) => {
+      listener.onDataAdd(index)
+    })
+  }
+}

entry/src/main/ets/pages/model/DataSourcePrefetching.ets

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import {ImageKnife, ImageKnifeRequest} from "@ohos/libraryimageknife"
+import { IDataSourcePrefetching } from '@kit.ArkUI';
+import { HashMap } from '@kit.ArkTS';
+
+const IMADE_UNAVAILABLE = $r('app.media.failed')
+export interface InfoItem {
+  albumUrl: string | Resource
+}
+export default class DataSourcePrefetchingImageKnife implements IDataSourcePrefetching {
+  private dataArray: Array<InfoItem>
+  private readonly  requestList: HashMap<number,ImageKnifeRequest> = new HashMap()
+  private listeners: DataChangeListener[] = [];
+
+  constructor(dataArray: Array<InfoItem>) {
+    this.dataArray = dataArray;
+  }
+  public getData(index: number) {
+    return this.dataArray[index]
+  }
+
+  public totalCount(): number {
+    return this.dataArray.length
+  }
+
+  public addData(index: number, data: InfoItem[]): void {
+    this.dataArray = this.dataArray.concat(data)
+    this.notifyDataAdd(index)
+  }
+
+  unregisterDataChangeListener(listener: DataChangeListener): void {
+    const pos = this.listeners.indexOf(listener);
+    if (pos >= 0) {
+      this.listeners.splice(pos, 1);
+    }
+  }
+
+  registerDataChangeListener(listener: DataChangeListener): void {
+    if (this.listeners.indexOf(listener) < 0) {
+      this.listeners.push(listener)
+    }
+  }
+
+  notifyDataAdd(index: number): void {
+    this.listeners.forEach((listener: DataChangeListener) => {
+      listener.onDataAdd(index)
+    })
+  }
+  async prefetch(index: number): Promise<void> {
+    let item = this.dataArray[index]
+    if (typeof item.albumUrl == "string") {
+      // 图片预加载
+      let request = ImageKnife.getInstance().preload({
+        loadSrc:item.albumUrl,
+        onLoadListener:{
+          onLoadSuccess:()=>{
+            // 预加载成功，删除成功请求
+            this.requestList.remove(index)
+          },
+          onLoadFailed:()=>{
+            // 移除失败请求
+            this.requestList.remove(index)
+          }
+        }
+      })
+      this.requestList.set(index,request)
+    }
+  }
+  // 取消请求处理
+  cancel(index: number) {
+    if(this.requestList.hasKey(index)) {
+      // 返回MAP对象指定元素
+      const request = this.requestList.get(index)
+      // 取消请求
+      ImageKnife.getInstance().cancel(request)
+      // 移除被取消的请求对象
+      this.requestList.remove(index)
+    }
+  }
+}

entry/src/main/ets/pages/model/PageViewModel.ets

@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { InfoItem } from './DataSourcePrefetching'
+
+export class PageViewModel {
+  private static dataArray: Array<InfoItem> = [
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/56/v3/8MdhfSsCSMKj4sA6okUWrg/5uBx56tLTUO3RYQl-E5JiQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/e2/v3/4zI1Xm_3STmV30aZXWRrKw/6aN7WodDRUiBApgffiLPCg.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/42/v3/2dSQCqERTP2TTPyssOMEbQ/zL1ebnKKQ_ilqTDcwCAkOw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/78/v3/qQJpAtRGQe2e_VhbGHDgIw/b3zlit99S6GybD3XdNwqJw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/55/v3/5DZ2LLqYSsK85-shqgLveQ/7ZXcyCWNTvOzQP5FFLBGkg.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/3e/v3/LqRoLI-PRSu9Nqa8KdJ-pQ/dSqskBpSR9eraAMn7NBdqA.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/25/v3/jgB2ekkTRX-3yTYZalnANQ/xff_x9cbSPqb7fbNwgJa7A.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/fb/v3/alXwXLHKSyCAIWt_ydgD2g/BCCuu25TREOitQxM7eYOEw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/63/v3/qbe6NZkCQyGcITvdWoZBgg/Y-5U1z3GT_yaK8CBD3jkwg.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/16/v3/fm2tO4TsRH6mv_D_nSSd5w/FscLpLwQQ-KuV7oaprFK2Q.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/89/v3/UAUvtPHqRD-GWWANsEC57Q/zcRJCQebQ322Aby4jzmwmQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/30/v3/tUUzzx73R4yp8G--lMhuWQ/EBbcu_dLTT-Jj68XAh6mtA.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/76/v3/EyF6z4FISpCHhae38eEexw/OtyAiu-zSSevNQYvUdtVmA.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/37/v3/12rH1yiEQmK9wlOOcy5avQ/RzBXiEBRRqOC7LRkwNj6VA.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/9a/v3/TpRN4AIzRoyUXIqWdKoE0g/ShOnD_tfS46HDbpSWhbCkQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/03/v3/H3X17s8eTdS2w56JgbB5jQ/a45sT-j8Sbe8sSQXTzeYvQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/10/v3/qaEzwkU0QeKb1yehnP2Xig/q7fxAlgMQKup-HUBayRLGQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/96/v3/rMJJoAflTDSWa1z2pHs2wg/8dOqD0GlQBOCL5AvQok9FQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/ed/v3/KMO4D6D2QGuVOCLX4AhOFA/ef51xAaLQuK7BsnuD9abog.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/d9/v3/FSZH0aTdSqWxeAaxoPvi0g/RqxPxUCXQFiTMBfKTF9kkw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/bf/v3/lSjrRwFcS-ez6jp1ALSQFg/0n7R7XinSPyrYLqDu_1dfw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/8a/v3/ZKzYV5BJTuCk5hCE0y_xNA/8JT95OQnSZSd6_xQQUONhQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/1/v3/sTXb_I7URBKjdMyLDYa19w/qpcwa_FNQmi3-EzjbGsJ8A.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/e5/v3/m7wFvw_eQIuDV0Mk0IKi8g/gJU4migzTHKYk5KrgdZbBw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/3f/v3/k_UWbB5_RGW7JemQZ0OQdw/_DUdmaZRQyG-Oyvkb663Bw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/39/v3/rFRN7G_VSo-p4mBjTZtkRw/gBwTI-ieSIqSsSmLNBEcgw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/04/v3/6K8BPYKVQFOr7KCuAG9nog/qKd3pZlrQy2M-feB3ycVPA.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/7d/v3/f0GQFzm1T6eduVeMUhO3Wg/-4cvzIJiRCegjIno3ofIbQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/e4/v3/C0xxsSeySxW-2iYR5OEbpQ/f1GlaD3zTeKPX8Vd-M1oVQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/c2/v3/32LCyXN4TuWKWcdf9gAwWw/ej14_BCJQNCaWOKoI9aZAw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/fd/v3/LyYJMdMmQNaC5GyBYEZ5Pw/uFLiovypRSagKyIS-UJPVw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/15/v3/MHM9KaWGTgubn6M8-B_6nw/1YO9JyYhTHSBWsoiqYkGZw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/4c/v3/UdYfbv1_QYqn_ulDHp89OA/VkjexMluTqGO3yt3gPK1DA.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/e8/v3/N8blT_7qSK-tRtahIyov7g/M_kjGEEmSzOlTc47Zrfozg.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/28/v3/VS_h3m4YRrSgbgxnqE3vtQ/h-2Q1Qy2SSGEuXM36-Rq_w.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/2e/v3/R-BaM5ToRNGq5rwtNTcnww/Q2e01VHiR2y9KtFaZmpmNQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/88/v3/3djkAJKKTdC539XqMdstSg/wHO7DxvXQS2xbt2Y_-4BNg.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/fb/v3/guw4eiggR3uWjscFTxITYg/TzRB35iPTdCztrZUUaNuFg.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/93/v3/UvSh_f1LT66i0-3hvsYN_A/eYnE3Z8YT5Sk7F-vS2ZmCQ.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/5/v3/tv8Vqf9hQrKpozGeZWg2mw/VEICB-bmQYi0Iv6TGADbhw.jpg"
+    },
+    {
+      albumUrl: "https://contentcenter-drcn.dbankcdn.cn/pub_1/DevEcoSpace_1_900_9/30/v3/4v1Ot5BRR6OFVQ9MGn9Xxg/xrPgRn0LS1ep-r7ewIuwiw.jpg"
+    },
+  ]
+  static getItems() {
+    return PageViewModel.dataArray
+  }
+}

entry/src/main/resources/base/profile/main_pages.json

@@ -24,6 +24,10 @@
     "pages/TestSetCustomImagePage",
     "pages/TestErrorHolderPage",
     "pages/TestTaskResourcePage",
-    "pages/ImageKnifeReload"
+    "pages/ImageKnifeReload",
+    "pages/LazyForEachCount",
+    "pages/LazyForEachCache",
+    "pages/PrefetchAndCacheCount",
+    "pages/PrefetchAndPreload"
   ]
 }

library/oh-package.json5

@@ -14,7 +14,7 @@
   "main": "index.ets",
   "repository": "https://gitee.com/openharmony-tpc/ImageKnife",
   "type": "module",
-  "version": "3.0.2-rc.2",
+  "version": "3.0.2",
   "dependencies": {
     "@ohos/gpu_transform": "^1.0.2"
   },

library/src/main/ets/ImageKnife.ets

@@ -145,8 +145,39 @@ export class ImageKnife {
     let key = this.getEngineKeyImpl().generateMemoryKey(imageKnifeOption.loadSrc, ImageKnifeRequestSource.SRC, imageKnifeOption);
     this.memoryCache.remove(key);
   }
-
+  /**
-
+   * 预加载
+   * @param loadSrc 图片地址url
+   * @returns 图片请求request
+   */
+  preload(loadSrc:string | ImageKnifeOption):ImageKnifeRequest{
+    let imageKnifeOption = new ImageKnifeOption()
+    if (typeof loadSrc == "string") {
+      imageKnifeOption.loadSrc = loadSrc
+    } else {
+      imageKnifeOption = loadSrc;
+    }
+    let request = new ImageKnifeRequest(
+      imageKnifeOption,
+      imageKnifeOption.context !== undefined ? imageKnifeOption.context : getContext(this) as common.UIAbilityContext,
+      0,
+      0,
+      0,
+      {
+        showPixelMap(version: number, pixelMap: PixelMap | string) {
+        }
+      }
+    )
+    this.execute(request)
+    return request
+  }
+  /**
+   * 取消图片请求
+   * @param request 图片请求request
+   */
+  cancel(request:ImageKnifeRequest) {
+    request.requestState = ImageKnifeRequestState.DESTROY
+  }
   /**
    * 预加载图片到文件缓存
    * @param loadSrc 图片地址url