android 圆形相机预览拍照_Android Camera2 Api 实现预览和拍照

camera2的结构如下，主要是通过相机管理器（CameraManager）获得相机设备（CameraDevice），然后再开启一个控制相机的会话，最后发送拍照、预览、录像等请求。

0 准备

1 新建工程，在一个Activity上

设置一个TextureView 用于预览图片；

设置一个ImageView 用于显示拍照结果；

设置一个 Button 用于触发拍照功能；

2 设置AndroidManifest.xml文件配置相机权限

<uses-permission android:name="android.permission.CAMERA" /><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /><uses-feature android:name="android.hardware.camera2.full" />

I 实现预览功能

1.先创建好一个预览的容器textureView

textureView=findViewById(R.id.texture_view_camera2);

监听这个容器的状态，如果容器准备好了，就开启相机：

// 先准备一个监听器surfaceTextureListener=new TextureView.SurfaceTextureListener() {@Overridepublic void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {texture_surface=new Surface(textureView.getSurfaceTexture());openCamera();}/.../};//绑定监听器textureView.setSurfaceTextureListener(surfaceTextureListener);

启动相机时，要创建一系列的回调函数，所以应该从后向前写代码：

private void openCamera() {// 1 创建相机管理器，调用系统相机cameraManager= (CameraManager) getSystemService(Context.CAMERA_SERVICE); // 2 准备 相机状态回调对象为后面用cam_stateCallback=new CameraDevice.StateCallback() {@Overridepublic void onOpened(@NonNull CameraDevice camera) {// 2.1 保存已开启的相机对象opened_camera=camera;try {// 2.2 构建请求对象（设置预览参数，和输出对象） requestBuilder = opened_camera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW); // 设置参数：预览requestBuilder.addTarget(texture_surface); // 设置参数：目标容器request = requestBuilder.build();//2.3 创建会话的回调函数，后面用cam_capture_session_stateCallback=new CameraCaptureSession.StateCallback() {@Override  //2.3.1  会话准备好了，在里面创建 预览或拍照请求public void onConfigured(@NonNull CameraCaptureSession session) {cameraCaptureSession=session;try {// 2.3.2 预览请求session.setRepeatingRequest(request,null,null);} catch (CameraAccessException e) {e.printStackTrace();}}};// 2.3 创建会话opened_camera.createCaptureSession( Arrays.asList(texture_surface), cam_capture_session_stateCallback,null);} catch (CameraAccessException e) {e.printStackTrace();}}/..../};// 4 检查相机权限 checkPermission();// 5 开启相机（传入：要开启的相机ID，和状态回调对象）try {cameraManager.openCamera(cameraManager.getCameraIdList()[0],cam_stateCallback,null);} catch (CameraAccessException e) {e.printStackTrace();}}

4 申请相机权限

private void checkPermission() {// 检查是否申请了权限if(ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)!= PackageManager.PERMISSION_GRANTED){if(ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.CAMERA)){}else{ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.CAMERA},1);}}}

II 实现拍照功能

这段代码都是在 Activity的onCreate里面写的。

准备ImageReader用于监听并接收相机拍摄的图片

//B1. 准备工作：初始化ImageReaderimageReader = ImageReader.newInstance(1000  ,1000, ImageFormat.JPEG,2);

设置ImageReader的监听函数

//B2. 准备工作：设置ImageReader收到图片后的回调函数imageReader.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() {@Overridepublic void onImageAvailable(ImageReader reader) {//B2.1 接收图片：从ImageReader中读取最近的一张，转成BitmapImage image= reader.acquireLatestImage();ByteBuffer buffer= image.getPlanes()[0].getBuffer();int length= buffer.remaining();byte[] bytes= new byte[length];buffer.get(bytes);image.close();bitmap = BitmapFactory.decodeByteArray(bytes,0,length);//B2.2 显示图片takephoto_imageView.setImageBitmap(bitmap);}},null);

保存ImageReader的Surface

//B3 配置：获取ImageReader的SurfaceimageReaderSurface = imageReader.getSurface();

设置相机的点击事件

//B4. 相机点击事件takephoto_btn.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//B4.1 配置request的参数 拍照模式(这行代码要调用已启动的相机 opened_camera，所以不能放在外面try {requestBuilder_image_reader = opened_camera.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);} catch (CameraAccessException e) {e.printStackTrace();}requestBuilder_image_reader.set(CaptureRequest.JPEG_ORIENTATION,90);requestBuilder_image_reader.set(CaptureRequest.CONTROL_AF_TRIGGER, CameraMetadata.CONTROL_AF_TRIGGER_START);//B4.2 配置request的参数 的目标对象requestBuilder_image_reader.addTarget(imageReaderSurface );try {//B4.3 触发拍照cameraCaptureSession.capture(requestBuilder_image_reader.build(),null,null);} catch (CameraAccessException e) {e.printStackTrace();}}});

最后要记得在之前配置的session会话里面绑定，当前这个输出对象imageReaderSurface：

private void openCamera() {/.../cam_stateCallback=new CameraDevice.StateCallback() {@Overridepublic void onOpened(@NonNull CameraDevice camera) {/.../opened_camera.createCaptureSession( Arrays.asList(texture_surface,imageReaderSurface), cam_capture_session_stateCallback,null);}

这段功能的整体代码为：

@Overrideprotected void onCreate(Bundle savedInstanceState) {/......///B1. 准备工作：初始化ImageReaderimageReader = ImageReader.newInstance(1000  ,1000, ImageFormat.JPEG,2);//B2. 准备工作：设置ImageReader收到图片后的回调函数imageReader.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() {@Overridepublic void onImageAvailable(ImageReader reader) {//B2.1 接收图片：从ImageReader中读取最近的一张，转成BitmapImage image= reader.acquireLatestImage();ByteBuffer buffer= image.getPlanes()[0].getBuffer();int length= buffer.remaining();byte[] bytes= new byte[length];buffer.get(bytes);image.close();bitmap = BitmapFactory.decodeByteArray(bytes,0,length);//B2.2 显示图片takephoto_imageView.setImageBitmap(bitmap);}},null);//B3 配置：获取ImageReader的SurfaceimageReaderSurface = imageReader.getSurface();//B4. 相机点击事件takephoto_btn.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//B4.1 配置request的参数 拍照模式(这行代码要调用已启动的相机 opened_camera，所以不能放在外面try {requestBuilder_image_reader = opened_camera.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);} catch (CameraAccessException e) {e.printStackTrace();}requestBuilder_image_reader.set(CaptureRequest.JPEG_ORIENTATION,90);requestBuilder_image_reader.set(CaptureRequest.CONTROL_AF_TRIGGER, CameraMetadata.CONTROL_AF_TRIGGER_START);//B4.2 配置request的参数 的目标对象requestBuilder_image_reader.addTarget(imageReaderSurface );try {//B4.3 触发拍照cameraCaptureSession.capture(requestBuilder_image_reader.build(),null,null);} catch (CameraAccessException e) {e.printStackTrace();}}});}

III 相机的声明周期管理

1. 当activity不处于交互状态时释放相机

@Overrideprotected void onPause() {// 先把相机的session关掉if(cameraCaptureSession!=null){cameraCaptureSession.close();}// 再关闭相机if(null!=opened_camera){opened_camera.close();}// 最后关闭ImageReaderif(null!=imageReader){imageReader.close();}// 最后交给父View去处理super.onPause();}

2 当活动再次可以交互时开启相机

@Overrideprotected void onResume() {super.onResume();// 如果 textureView可用，就直接打开相机if(textureView.isAvailable()){openCamera();}else{// 否则，就开启它的可用时监听。textureView.setSurfaceTextureListener(surfaceTextureListener);}}

IV 预览和功能的完整代码为：

文件名 Camera2ApiActivity.java

package com.example.myapplication;import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.camera.camera2.impl.Camera2CaptureRequestBuilder;
import androidx.camera.core.CameraCaptureResult;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.ImageFormat;
import android.graphics.SurfaceTexture;
import android.hardware.biometrics.BiometricManager;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraCaptureSession;
import android.hardware.camera2.CameraDevice;
import android.hardware.camera2.CameraManager;
import android.hardware.camera2.CameraMetadata;
import android.hardware.camera2.CaptureFailure;
import android.hardware.camera2.CaptureRequest;
import android.hardware.camera2.CaptureResult;
import android.hardware.camera2.TotalCaptureResult;
import android.media.Image;
import android.media.ImageReader;
import android.os.Bundle;
import android.util.Size;
import android.view.Surface;
import android.view.TextureView;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;import java.io.ByteArrayInputStream;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;public class Camera2apiActivity extends AppCompatActivity {TextureView textureView;TextureView.SurfaceTextureListener surfaceTextureListener;CameraManager cameraManager;CameraDevice.StateCallback cam_stateCallback;CameraDevice opened_camera;Surface texture_surface;CameraCaptureSession.StateCallback cam_capture_session_stateCallback;CameraCaptureSession.CaptureCallback still_capture_callback;CameraCaptureSession cameraCaptureSession;CaptureRequest.Builder requestBuilder;CaptureRequest.Builder requestBuilder_image_reader;ImageReader imageReader;Surface imageReaderSurface;Bitmap bitmap;CaptureRequest request;CaptureRequest takephoto_request;Button takephoto_btn;ImageView takephoto_imageView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_camera2api);textureView=findViewById(R.id.texture_view_camera2);takephoto_btn=findViewById(R.id.btn_camera2_takephoto);takephoto_imageView= findViewById(R.id.image_view_preview_image);surfaceTextureListener=new TextureView.SurfaceTextureListener() {@Overridepublic void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {texture_surface=new Surface(textureView.getSurfaceTexture());openCamera();}@Overridepublic void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {}@Overridepublic boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {return false;}@Overridepublic void onSurfaceTextureUpdated(SurfaceTexture surface) {}};textureView.setSurfaceTextureListener(surfaceTextureListener);//B1. 准备工作：初始化ImageReaderimageReader = ImageReader.newInstance(1000  ,1000, ImageFormat.JPEG,2);//B2. 准备工作：设置ImageReader收到图片后的回调函数imageReader.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() {@Overridepublic void onImageAvailable(ImageReader reader) {//B2.1 接收图片：从ImageReader中读取最近的一张，转成BitmapImage image= reader.acquireLatestImage();ByteBuffer buffer= image.getPlanes()[0].getBuffer();int length= buffer.remaining();byte[] bytes= new byte[length];buffer.get(bytes);image.close();bitmap = BitmapFactory.decodeByteArray(bytes,0,length);//B2.2 显示图片takephoto_imageView.setImageBitmap(bitmap);}},null);//B3 配置：获取ImageReader的SurfaceimageReaderSurface = imageReader.getSurface();//B4. 相机点击事件takephoto_btn.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//B4.1 配置request的参数 拍照模式(这行代码要调用已启动的相机 opened_camera，所以不能放在外面try {requestBuilder_image_reader = opened_camera.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);} catch (CameraAccessException e) {e.printStackTrace();}requestBuilder_image_reader.set(CaptureRequest.JPEG_ORIENTATION,90);requestBuilder_image_reader.set(CaptureRequest.CONTROL_AF_TRIGGER, CameraMetadata.CONTROL_AF_TRIGGER_START);//B4.2 配置request的参数 的目标对象requestBuilder_image_reader.addTarget(imageReaderSurface );try {//B4.3 触发拍照cameraCaptureSession.capture(requestBuilder_image_reader.build(),null,null);} catch (CameraAccessException e) {e.printStackTrace();}}});}private void openCamera() {cameraManager= (CameraManager) getSystemService(Context.CAMERA_SERVICE);  // 初始化cam_stateCallback=new CameraDevice.StateCallback() {@Overridepublic void onOpened(@NonNull CameraDevice camera) {opened_camera=camera;try {requestBuilder = opened_camera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);requestBuilder.addTarget(texture_surface);request = requestBuilder.build();cam_capture_session_stateCallback=new CameraCaptureSession.StateCallback() {@Overridepublic void onConfigured(@NonNull CameraCaptureSession session) {cameraCaptureSession=session;try {session.setRepeatingRequest(request,null,null);} catch (CameraAccessException e) {e.printStackTrace();}}@Overridepublic void onConfigureFailed(@NonNull CameraCaptureSession session) {}};opened_camera.createCaptureSession( Arrays.asList(texture_surface,imageReaderSurface), cam_capture_session_stateCallback,null);} catch (CameraAccessException e) {e.printStackTrace();}}@Overridepublic void onDisconnected(@NonNull CameraDevice camera) {}@Overridepublic void onError(@NonNull CameraDevice camera, int error) {}};checkPermission();try {cameraManager.openCamera(cameraManager.getCameraIdList()[0],cam_stateCallback,null);} catch (CameraAccessException e) {e.printStackTrace();}}private void checkPermission() {// 检查是否申请了权限if(ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)!= PackageManager.PERMISSION_GRANTED){if(ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.CAMERA)){}else{ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.CAMERA},1);}}}@Overrideprotected void onResume() {super.onResume();// 如果 textureView可用，就直接打开相机if(textureView.isAvailable()){openCamera();}else{// 否则，就开启它的可用时监听。textureView.setSurfaceTextureListener(surfaceTextureListener);}}@Overrideprotected void onPause() {// 先把相机的session关掉if(cameraCaptureSession!=null){cameraCaptureSession.close();}// 再关闭相机if(null!=opened_camera){opened_camera.close();}// 最后关闭ImageReaderif(null!=imageReader){imageReader.close();}// 最后交给父View去处理super.onPause();}}

android 圆形相机预览拍照_Android Camera2 Api 实现预览和拍照相关推荐

android 圆形相机预览拍照_Android多种方式实现相机圆形预览
最终效果图如下: 一.为预览控件设置圆角 public RoundTextureView(Context context, AttributeSet attrs) { super(context, a ...
android 圆形相机预览拍照_Android多种方式实现相机圆形预览的示例代码
效果图如下: 一.为预览控件设置圆角 public RoundTextureView(Context context, AttributeSet attrs) { super(context, att ...
android 读取mysql中的图片_Android 通过API获取数据库中的图片文件方式
Overview 今天复习了一下Android 如何将我们数据库中图片获取出来,并且将其转换为bitmap进行显示. 开发环境以及技术使用Visual Studio 2019 Android Stu ...
Android Camera API/Camera2 API 相机预览及滤镜、贴纸等处理
Android Lollipop 增加了Camera2 API,并将原来的Camera API标记为废弃了.相对原来的Camera API来说,Camera2是重新定义的相机 API,也重构了相机 A ...
android高仿微信拍照、多选、预览、删除(去除相片)相冊功能
先声明授人与鱼不如授人与渔,仅仅能提供一个思路,当然须要源代码的同学能够私下有偿问我要源代码:QQ:508181017 工作了将近三年时间了,一直没正儿八经的研究系统自带的相冊和拍照,这回来个高仿微信 ...
android surfaceview 大小_Android 使用Camera2 API采集视频数据
Android 视频数据采集系列的最后一篇出炉了,和前两篇文章想比,这篇文章从系统API层面进行一些探索,涉及到的细节更多.初次接触 Camera2 API 会觉得它的使用有些繁琐,涉及到的类有些多, ...
Android camera相机开发拍照功能
在Android 5.0(SDK 21)中,Google使用Camera2替代了Camera接口.Camera2在接口和架构上做了巨大的变动,但是基于众所周知的原因,我们还必须基于 Android 4 ...
详记Android打开相机拍照流程
写在前面本文并不是基于Camera2的,所以想要了解Camera2的同学可以先散了.文题加了详记二字,因为相机整个打开的流程的确是比较复杂的,稍有疏忽可能就会引发一系列问题.我也是看了一下Andro ...
Android Camera2 API和拍照与录像过程
简介: Android 5.0开始出现了新的相机Camera 2 API,用来替代以前的camera api. Camera2 API不仅提高了android系统的拍照性能,还支持RAW照片输出,还可 ...
Android最新相机(Camera)拍照、拍视频全面总结
介绍利用系统相机调用系统相机拍照获取小图标获取全尺寸图片添加到相册系统相机拍视频自定义相机自定义相机拍照监测设备是否有相机可使用利用SurfaceView创建拍照时预览界面拍照并 ...