# Camera Photographing Sample

## Development Process

After obtaining the output stream capabilities supported by the camera, create a photo stream. The development process is as follows:

![Photographing Development Process](figures/photographing-development-process.png)

## Sample Code

```ts
import camera from '@ohos.multimedia.camera'
import image from '@ohos.multimedia.image'
import media from '@ohos.multimedia.media'

// Create a CameraManager instance.
context: any = getContext(this)
let cameraManager = camera.getCameraManager(this.context)
if (!cameraManager) {
    console.error("camera.getCameraManager error")
    return;
} 
// Listen for camera status changes.
cameraManager.on('cameraStatus', (cameraStatusInfo) => {
    console.info(`camera : ${cameraStatusInfo.camera.cameraId}`);
    console.info(`status: ${cameraStatusInfo.status}`);
})

// Obtain the camera list.
let cameraArray = cameraManager.getSupportedCameras();
if (cameraArray.length <= 0) {
    console.error("cameraManager.getSupportedCameras error")
    return;
} 

for (let index = 0; index < cameraArray.length; index++) {
    console.info('cameraId : ' + cameraArray[index].cameraId);                          // Obtain the camera ID.
    console.info('cameraPosition : ' + cameraArray[index].cameraPosition);              // Obtain the camera position.
    console.info('cameraType : ' + cameraArray[index].cameraType);                      // Obtain the camera type.
    console.info('connectionType : ' + cameraArray[index].connectionType);              // Obtain the camera connection type.
}

// Create a camera input stream.
let cameraInput
try {
    cameraInput = cameraManager.createCameraInput(cameraArray[0]);
} catch (error) {
   console.error('Failed to createCameraInput errorCode = ' + error.code);
}

// Listen for camera input errors.
let cameraDevice = cameraArray[0];
cameraInput.on('error', cameraDevice, (error) => {
    console.info(`Camera input error code: ${error.code}`);
})

// Open the camera.
await cameraInput.open();

// Obtain the output stream capabilities supported by the camera.
let cameraOutputCap = cameraManager.getSupportedOutputCapability(cameraArray[0]);
if (!cameraOutputCap) {
    console.error("cameraManager.getSupportedOutputCapability error")
    return;
}
console.info("outputCapability: " + JSON.stringify(cameraOutputCap));

let previewProfilesArray = cameraOutputCap.previewProfiles;
if (!previewProfilesArray) {
    console.error("createOutput previewProfilesArray == null || undefined")
} 

let photoProfilesArray = cameraOutputCap.photoProfiles;
if (!photoProfilesArray) {
    console.error("createOutput photoProfilesArray == null || undefined")
} 

// Create a preview output stream. For details about the surfaceId parameter, see the XComponent. The preview stream is the surface provided by the XComponent.
let previewOutput
try {
    previewOutput = cameraManager.createPreviewOutput(previewProfilesArray[0], surfaceId)
} catch (error) {
    console.error("Failed to create the PreviewOutput instance.")
}

// Listen for preview output errors.
previewOutput.on('error', (error) => {
    console.info(`Preview output error code: ${error.code}`);
})

// Create an ImageReceiver instance and set photographing parameters. Wherein, the resolution must be one of the photographing resolutions supported by the current device, which are obtained by photoProfilesArray.
let imageReceiver = await image.createImageReceiver(1920, 1080, 4, 8)
// Obtain the surface ID for displaying the photos.
let photoSurfaceId = await imageReceiver.getReceivingSurfaceId()
// Create a photo output stream.
let photoOutput
try {
    photoOutput = cameraManager.createPhotoOutput(photoProfilesArray[0], photoSurfaceId)
} catch (error) {
   console.error('Failed to createPhotoOutput errorCode = ' + error.code);
}
// Create a session.
let captureSession
try {
    captureSession = cameraManager.createCaptureSession()
} catch (error) {
    console.error('Failed to create the CaptureSession instance. errorCode = ' + error.code);
}

// Listen for session errors.
captureSession.on('error', (error) => {
    console.info(`Capture session error code: ${error.code}`);
})

// Start configuration for the session.
try {
    captureSession.beginConfig()
} catch (error) {
    console.error('Failed to beginConfig. errorCode = ' + error.code);
}

// Add the camera input stream to the session.
try {
    captureSession.addInput(cameraInput)
} catch (error) {
    console.error('Failed to addInput. errorCode = ' + error.code);
}

// Add the preview output stream to the session.
try {
    captureSession.addOutput(previewOutput)
} catch (error) {
    console.error('Failed to addOutput(previewOutput). errorCode = ' + error.code);
}

// Add the photo output stream to the session.
try {
    captureSession.addOutput(photoOutput)
} catch (error) {
    console.error('Failed to addOutput(photoOutput). errorCode = ' + error.code);
}

// Commit the session configuration.
await captureSession.commitConfig()

// Start the session.
await captureSession.start().then(() => {
    console.info('Promise returned to indicate the session start success.');
})
// Check whether the camera has flash.
let flashStatus
try {
    flashStatus = captureSession.hasFlash()
} catch (error) {
    console.error('Failed to hasFlash. errorCode = ' + error.code);
}
console.info('Promise returned with the flash light support status:' + flashStatus);

if (flashStatus) {
    // Check whether the auto flash mode is supported.
    let flashModeStatus
    try {
        let status = captureSession.isFlashModeSupported(camera.FlashMode.FLASH_MODE_AUTO)
        flashModeStatus = status
    } catch (error) {
        console.error('Failed to check whether the flash mode is supported. errorCode = ' + error.code);
    }
    if(flashModeStatus) {
        // Set the flash mode to auto.
        try {
            captureSession.setFlashMode(camera.FlashMode.FLASH_MODE_AUTO)
        } catch (error) {
            console.error('Failed to set the flash mode. errorCode = ' + error.code);
        }
    }
}

// Check whether the continuous auto focus is supported.
let focusModeStatus
try {
    let status = captureSession.isFocusModeSupported(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO)
    focusModeStatus = status
} catch (error) {
    console.error('Failed to check whether the focus mode is supported. errorCode = ' + error.code);
}

if (focusModeStatus) {
    // Set the focus mode to continuous auto focus.
    try {
        captureSession.setFocusMode(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO)
    } catch (error) {
        console.error('Failed to set the focus mode. errorCode = ' + error.code);
    }
}

// Obtain the zoom ratio range supported by the camera.
let zoomRatioRange
try {
    zoomRatioRange = captureSession.getZoomRatioRange()
} catch (error) {
    console.error('Failed to get the zoom ratio range. errorCode = ' + error.code);
}

// Set a zoom ratio.
try {
    captureSession.setZoomRatio(zoomRatioRange[0])
} catch (error) {
    console.error('Failed to set the zoom ratio value. errorCode = ' + error.code);
}
let settings = {
    quality: camera.QualityLevel.QUALITY_LEVEL_HIGH,                                     // Set the photo quality to high.
    rotation: camera.ImageRotation.ROTATION_0                                            // Set the rotation angle of the photo to 0.
}
// Use the current photographing settings to take photos.
photoOutput.capture(settings, async (err) => {
    if (err) {
        console.error('Failed to capture the photo ${err.message}');
        return;
    }
    console.info('Callback invoked to indicate the photo capture request success.');
});
// Stop the session.
captureSession.stop()

// Release the camera input stream.
cameraInput.close()

// Release the preview output stream.
previewOutput.release()

// Release the photo output stream.
photoOutput.release()

// Release the session.
captureSession.release()

// Set the session to null.
captureSession = null
```