跳过网络，从内存中取图片，接口说明文档

Signed-off-by: ‘面条侠’ <‘wangxinxin51@h-partners.com’>

entry/src/main/ets/pages/testImageKnifeCache.ets

@@ -54,12 +54,7 @@ struct testImageKnifeCache {
       placeholderSrc: $r('app.media.icon_loading'),
       errorholderSrc: $r('app.media.icon_failed')
     };
-
-  hasUrlCache(url: string, cacheType: CacheType = CacheType.Default, size: Size = {
-    width: 0,
-    height: 0
-  }) {
-    imageKnife?.isUrlExist(url, cacheType, size).then((data: ImageKnifeData) => {
+  loadSuccess = (data: ImageKnifeData) => {
     clearTimeout(this.timeId);
     if (data.isPixelMap()) {
       if (data.drawPixelMap) {
@@ -101,10 +96,8 @@ struct testImageKnifeCache {
         }
       }
     }
-    }).catch((err: BusinessError) => {
-
-    });
-
+  }
+  loadError = (err: BusinessError) => {
   }
 
   build() {
@@ -192,20 +185,19 @@ struct testImageKnifeCache {
           Button('缓存图片')
             .onClick(() => {
               this.index_ = 1;
-              this.hasUrlCache(this.url, CacheType.Cache, this.comSize);
-
+              imageKnife?.isUrlExist(this.url, CacheType.Cache, this.comSize);
             })
 
           Button('磁盘图片')
             .onClick(() => {
               this.index_ = 2;
-              this.hasUrlCache(this.url, CacheType.Disk, this.comSize);
+              imageKnife?.isUrlExist(this.url, CacheType.Disk, this.comSize);
             })
 
           Button('默认')
             .onClick(() => {
               this.index_ = 2;
-              this.hasUrlCache(this.url);
+              imageKnife?.isUrlExist(this.url);
             })
         }