# 通过系统相机拍照和录像(CameraPicker)
<!--Kit: Camera Kit-->
<!--Subsystem: Multimedia-->
<!--Owner: @qano-->
<!--Designer: @leo_ysl-->
<!--Tester: @xchaosioda-->
<!--Adviser: @zengyawen-->

应用可调用CameraPicker拍摄照片或录制视频，无需申请相机权限。
CameraPicker的相机交互界面由系统提供，在用户点击拍摄和确认按钮后，调用CameraPicker的应用获取对应的照片或者视频。

应用开发者如果只是需要获取即时拍摄的照片或者视频，则可以使用CameraPicker能力来轻松实现。

由于照片的拍摄和确认都是由用户进行主动确认，因此应用开发者可以不用申请操作相机的相关权限。

## 开发步骤

详细的API说明请参考[CameraPicker API参考](../../reference/apis-camera-kit/js-apis-cameraPicker.md)。

1. 导入相关接口，导入方法如下。
   ```ts
   import { camera, cameraPicker as picker } from '@kit.CameraKit';
   import { fileIo, fileUri } from '@kit.CoreFileKit';
   ```

2. 配置[PickerProfile](../../reference/apis-camera-kit/js-apis-cameraPicker.md#pickerprofile)。

   > **说明：**
   >
   > PickerProfile的saveUri为可选参数，如果未配置该项，拍摄的照片和视频默认存入媒体库中。
   >
   > 如果不想将照片和视频存入媒体库，请自行配置应用沙箱内的文件路径。
   > 应用沙箱内的这个文件必须是一个存在的、可写的文件。这个文件的uri传入picker接口之后，相当于应用给系统相机授权该文件的读写权限。系统相机在拍摄结束之后，会对此文件进行覆盖写入。

   ```ts
   function createPickerProfile(context: Context): picker.PickerProfile {
     let pathDir = context.filesDir;
     let fileName = `${new Date().getTime()}`;
     let filePath = pathDir + `/${fileName}.tmp`;
     try {
       fileIo.createRandomAccessFileSync(filePath, fileIo.OpenMode.CREATE);
     } catch (error) {
       let err = error as BusinessError;
       console.error(`create picker profile failed. error code: ${err.code}`);
     }
     
     let uri = fileUri.getUriFromPath(filePath);
     let pickerProfile: picker.PickerProfile = {
       cameraPosition: camera.CameraPosition.CAMERA_POSITION_BACK,
       saveUri: uri
     };
     return pickerProfile;
   }
   ```
   fileIo接口调用方法请参考：[createRandomAccessFileSync](../../reference/apis-core-file-kit/js-apis-file-fs.md#fscreaterandomaccessfilesync10)和[getUriFromPath](../../reference/apis-core-file-kit/js-apis-file-fileuri.md#fileurigeturifrompath)。
   

3. 调用picker拍摄接口获取拍摄的结果。
   ```ts
   async function getPickerResult(context: Context, pickerProfile: picker.PickerProfile): Promise<picker.PickerResult> {
     let result: picker.PickerResult =
       // 调用picker方法拉起系统相机，获取拍摄的图片或视频。
       await picker.pick(context, [picker.PickerMediaType.PHOTO, picker.PickerMediaType.VIDEO],
         pickerProfile);
     console.info(`picker resultCode: ${result.resultCode},resultUri: ${result.resultUri},mediaType: ${result.mediaType}`);
     return result;
   }
   ```

## 完整示例
   ```ts 
   import { camera, cameraPicker as picker } from '@kit.CameraKit';
   import { fileIo, fileUri } from '@kit.CoreFileKit';

   @Entry
   @Component
   struct Index {
     @State imgSrc: string = '';
     @State videoSrc: string = '';
     createPickerProfile(context: Context): picker.PickerProfile {
       let pathDir = context.filesDir;
       let fileName = `${new Date().getTime()}`;
       let filePath = pathDir + `/${fileName}.tmp`;
       fileIo.createRandomAccessFileSync(filePath, fileIo.OpenMode.CREATE);
       
       let uri = fileUri.getUriFromPath(filePath);
       let pickerProfile: picker.PickerProfile = {
         cameraPosition: camera.CameraPosition.CAMERA_POSITION_BACK,
         saveUri: uri
       };
       return pickerProfile;
     }

     async getPickerResult(context: Context, pickerProfile: picker.PickerProfile): Promise<picker.PickerResult> {
       let result: picker.PickerResult =
         await picker.pick(context, [picker.PickerMediaType.PHOTO, picker.PickerMediaType.VIDEO],
           pickerProfile);
       console.info(`picker resultCode: ${result.resultCode},resultUri: ${result.resultUri},mediaType: ${result.mediaType}`);
       return result;
     }

     getContext(): Context | undefined {
       let uiContext: UIContext = this.getUIContext();
       let context: Context | undefined = uiContext.getHostContext();
       return context;
     }

     build() {
       RelativeContainer() {
         Column() {
           Image(this.imgSrc).width(200).height(200).backgroundColor(Color.Black).margin(5);
           Video({ src: this.videoSrc}).width(200).height(200).autoPlay(true);
           Button("Test Picker Photo&Video").fontSize(20)
             .fontWeight(FontWeight.Bold)
             .onClick(async () => {
               let context = this.getContext();
               if (context === undefined) {
                 return;
               }
               let pickerProfile = this.createPickerProfile(context);
               let result = await this.getPickerResult(context, pickerProfile);
               if (result.resultCode == 0) {
                 if (result.mediaType === picker.PickerMediaType.PHOTO) {
                   this.imgSrc = result.resultUri;
                 } else {
                   this.videoSrc = result.resultUri;
                 }
               }
             }).margin(5);
   
         }.alignRules({
           center: { anchor: '__container__', align: VerticalAlign.Center },
           middle: { anchor: '__container__', align: HorizontalAlign.Center }
         });
       }
       .height('100%')
       .width('100%')
     }
   }
   ```