更新使用说明和移动代码

app/src/main/ets/pages/media/PhotoPage.ets

@@ -0,0 +1,63 @@
+import { TitleBar } from '@devwiki/common_ui/Index';
+import picker from '@ohos.file.picker';
+import { BusinessError } from '@kit.BasicServicesKit';
+import fs, { ReadOptions } from '@ohos.file.fs';
+import buffer from '@ohos.buffer';
+
+@Entry
+@Component
+struct PhotoPage {
+
+  build() {
+    Column() {
+      TitleBar({
+        title: "PhotoPage",
+        onLeftClicked: ()=> {
+          this.getUIContext().getRouter().back();
+      }}).width('100%')
+      Divider();
+      Button("Open").onClick(() =>{
+
+      }).margin(5);
+
+    }.width('100%').height('100%')
+  }
+
+  openPhotoSelector() {
+    let selectOptions = new picker.PhotoSelectOptions();
+    selectOptions.maxSelectNumber = 1;
+    let viewPicker = new picker.PhotoViewPicker()
+    viewPicker.select(selectOptions).then((result) => {
+      let uri = result.photoUris;
+      let file = fs.openSync(uri[0], fs.OpenMode.READ_ONLY);
+      // 打开文件流
+      let inputStream = fs.createStreamSync(uri[0], 'r+');
+      let outputStream = buffer.alloc(fs.statSync(uri[0]).size);
+      // 以流的形式读取源文件内容并写入目的文件
+      let bufSize = 4096;
+      let readSize = 0;
+      let buf = new ArrayBuffer(bufSize);
+      let readOptions: ReadOptions = {
+        offset: readSize,
+        length: bufSize
+      };
+      new String(buf);
+      let readLen = inputStream.readSync(buf, readOptions);
+      readSize += readLen;
+      while (readLen > 0) {
+        for (let index = 0; index < readSize; index++) {
+          outputStream[readSize] = buf.slice(index);
+        }
+        readOptions.offset = readSize;
+        readLen = inputStream.readSync(buf, readOptions);
+        readSize += readLen;
+      }
+      // 关闭文件流
+      inputStream.closeSync();
+
+      console.info('PhotoViewPicker.select to file succeed and uri is:' + uri);
+    }).catch((err: BusinessError) => {
+      console.error(`Invoke documentViewPicker.select failed, code is ${err.code}, message is ${err.message}`);
+    })
+  }
+}