拍照实现方案
开发流程
在获取到相机支持的输出流能力后，开始创建拍照流，开发流程如下。
完整示例
import camera from '@ohos.multimedia.camera';
import image from '@ohos.multimedia.image';
import { BusinessError } from '@ohos.base';
import common from '@ohos.app.ability.common';
import fs from '@ohos.file.fs';
import PhotoAccessHelper from '@ohos.file.photoAccessHelper';
let context = getContext(this);
function getImageReceiver(width: number, height: number, format: number, capacity: number): image.ImageReceiver {
//获取ImageReceiver
let imageReceiver: image.ImageReceiver = image.createImageReceiver(width, height, format, capacity);
return imageReceiver;
}
async function savePicture(buffer: ArrayBuffer, img: image.Image) {
let photoAccessHelper = PhotoAccessHelper.getPhotoAccessHelper(context);
let testFileName = 'testFile' + Date.now() + '.jpg';
let photoAsset = await photoAccessHelper.createAsset(testFileName);
//createAsset的调用需要ohos.permission.READ_IMAGEVIDEO和ohos.permission.WRITE_IMAGEVIDEO的权限
const fd = await photoAsset.open('rw');
fs.write(fd, buffer);
await photoAsset.close(fd);
img.release();
}
function setImageArrivalCb(receiver: image.ImageReceiver) {
//设置回调之后，调用photoOutput的capture方法，就会将拍照的buffer回传到回调中
receiver.on('imageArrival', (): void => {
receiver.readNextImage((errCode: BusinessError, imageObj: image.Image): void => {
if (errCode || imageObj === undefined) {
return;
}
imageObj.getComponent(image.ComponentType.JPEG, (errCode: BusinessError, component: image.Component): void => {
if (errCode || component === undefined) {
return;
}
let buffer: ArrayBuffer;
if (component.byteBuffer) {
buffer = component.byteBuffer;
} else {
return;
}
savePicture(buffer, imageObj);
});
});
});
}
async function cameraShootingCase(baseContext: common.BaseContext, surfaceId: string): Promise<void> {
// 创建CameraManager对象
let cameraManager: camera.CameraManager = camera.getCameraManager(baseContext);
if (!cameraManager) {
console.error("camera.getCameraManager error");
return;
}
// 监听相机状态变化
cameraManager.on('cameraStatus', (err: BusinessError, cameraStatusInfo: camera.CameraStatusInfo) => {
console.info(`camera : ${cameraStatusInfo.camera.cameraId}`);
console.info(`status: ${cameraStatusInfo.status}`);
});
// 获取相机列表
let cameraArray: Array<camera.CameraDevice> = 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); // 获取相机ID
console.info('cameraPosition : ' + cameraArray[index].cameraPosition); // 获取相机位置
console.info('cameraType : ' + cameraArray[index].cameraType); // 获取相机类型
console.info('connectionType : ' + cameraArray[index].connectionType); // 获取相机连接类型
}
// 创建相机输入流
let cameraInput: camera.CameraInput | undefined = undefined;
try {
cameraInput = cameraManager.createCameraInput(cameraArray[0]);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to createCameraInput errorCode = ' + err.code);
}
if (cameraInput === undefined) {
return;
}
// 监听cameraInput错误信息
let cameraDevice: camera.CameraDevice = cameraArray[0];
cameraInput.on('error', cameraDevice, (error: BusinessError) => {
console.info(`Camera input error code: ${error.code}`);
})
// 打开相机
await cameraInput.open();
// 获取相机设备支持的输出流能力
let cameraOutputCap: camera.CameraOutputCapability = cameraManager.getSupportedOutputCapability(cameraArray[0]);
if (!cameraOutputCap) {
console.error("cameraManager.getSupportedOutputCapability error");
return;
}
console.info("outputCapability: " + JSON.stringify(cameraOutputCap));
let previewProfilesArray: Array<camera.Profile> = cameraOutputCap.previewProfiles;
if (!previewProfilesArray) {
console.error("createOutput previewProfilesArray == null || undefined");
}
let photoProfilesArray: Array<camera.Profile> = cameraOutputCap.photoProfiles;
if (!photoProfilesArray) {
console.error("createOutput photoProfilesArray == null || undefined");
}
// 创建预览输出流,其中参数 surfaceId 参考上文 XComponent 组件，预览流为XComponent组件提供的surface
let previewOutput: camera.PreviewOutput | undefined = undefined;
try {
previewOutput = cameraManager.createPreviewOutput(previewProfilesArray[0], surfaceId);
} catch (error) {
let err = error as BusinessError;
console.error(`Failed to create the PreviewOutput instance. error code: ${err.code}`);
}
if (previewOutput === undefined) {
return;
}
// 监听预览输出错误信息
previewOutput.on('error', (error: BusinessError) => {
console.info(`Preview output error code: ${error.code}`);
});
// 创建ImageReceiver对象，并设置照片参数：分辨率大小是根据前面 photoProfilesArray 获取的当前设备所支持的拍照分辨率大小去设置
let imageReceiver: image.ImageReceiver = getImageReceiver(1920, 1080, 4, 8);
//调用上面的回调函数来保存图片
setImageArrivalCb(imageReceiver);
// 获取照片显示SurfaceId
let photoSurfaceId: string = await imageReceiver.getReceivingSurfaceId();
// 创建拍照输出流
let photoOutput: camera.PhotoOutput | undefined = undefined;
try {
photoOutput = cameraManager.createPhotoOutput(photoProfilesArray[0], photoSurfaceId);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to createPhotoOutput errorCode = ' + err.code);
}
if (photoOutput === undefined) {
return;
}
//创建会话
let captureSession: camera.CaptureSession | undefined = undefined;
try {
captureSession = cameraManager.createCaptureSession();
} catch (error) {
let err = error as BusinessError;
console.error('Failed to create the CaptureSession instance. errorCode = ' + err.code);
}
if (captureSession === undefined) {
return;
}
// 监听session错误信息
captureSession.on('error', (error: BusinessError) => {
console.info(`Capture session error code: ${error.code}`);
});
// 开始配置会话
try {
captureSession.beginConfig();
} catch (error) {
let err = error as BusinessError;
console.error('Failed to beginConfig. errorCode = ' + err.code);
}
// 向会话中添加相机输入流
try {
captureSession.addInput(cameraInput);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to addInput. errorCode = ' + err.code);
}
// 向会话中添加预览输出流
try {
captureSession.addOutput(previewOutput);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to addOutput(previewOutput). errorCode = ' + err.code);
}
// 向会话中添加拍照输出流
try {
captureSession.addOutput(photoOutput);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to addOutput(photoOutput). errorCode = ' + err.code);
}
// 提交会话配置
await captureSession.commitConfig();
// 启动会话
await captureSession.start().then(() => {
console.info('Promise returned to indicate the session start success.');
});
// 判断设备是否支持闪光灯
let flashStatus: boolean = false;
try {
flashStatus = captureSession.hasFlash();
} catch (error) {
let err = error as BusinessError;
console.error('Failed to hasFlash. errorCode = ' + err.code);
}
console.info('Promise returned with the flash light support status:' + flashStatus);
if (flashStatus) {
// 判断是否支持自动闪光灯模式
let flashModeStatus: boolean = false;
try {
let status: boolean = captureSession.isFlashModeSupported(camera.FlashMode.FLASH_MODE_AUTO);
flashModeStatus = status;
} catch (error) {
let err = error as BusinessError;
console.error('Failed to check whether the flash mode is supported. errorCode = ' + err.code);
}
if(flashModeStatus) {
// 设置自动闪光灯模式
try {
captureSession.setFlashMode(camera.FlashMode.FLASH_MODE_AUTO);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to set the flash mode. errorCode = ' + err.code);
}
}
}
// 判断是否支持连续自动变焦模式
let focusModeStatus: boolean = false;
try {
let status: boolean = captureSession.isFocusModeSupported(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO);
focusModeStatus = status;
} catch (error) {
let err = error as BusinessError;
console.error('Failed to check whether the focus mode is supported. errorCode = ' + err.code);
}
if (focusModeStatus) {
// 设置连续自动变焦模式
try {
captureSession.setFocusMode(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to set the focus mode. errorCode = ' + err.code);
}
}
// 获取相机支持的可变焦距比范围
let zoomRatioRange: Array<number> = [];
try {
zoomRatioRange = captureSession.getZoomRatioRange();
} catch (error) {
let err = error as BusinessError;
console.error('Failed to get the zoom ratio range. errorCode = ' + err.code);
}
if (zoomRatioRange.length <= 0) {
return;
}
// 设置可变焦距比
try {
captureSession.setZoomRatio(zoomRatioRange[0]);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to set the zoom ratio value. errorCode = ' + err.code);
}
let photoCaptureSetting: camera.PhotoCaptureSetting = {
quality: camera.QualityLevel.QUALITY_LEVEL_HIGH, // 设置图片质量高
rotation: camera.ImageRotation.ROTATION_0 // 设置图片旋转角度0
}
// 使用当前拍照设置进行拍照
photoOutput.capture(photoCaptureSetting, (err: BusinessError) => {
if (err) {
console.error('Failed to capture the photo ${err.message}');
return;
}
console.info('Callback invoked to indicate the photo capture request success.');
});
// 停止当前会话
captureSession.stop();
// 释放相机输入流
cameraInput.close();
// 释放预览输出流
previewOutput.release();
// 释放拍照输出流
photoOutput.release();
// 释放会话
captureSession.release();
// 会话置空
captureSession = undefined;
}