Android实现调用摄像头进行拍照功能

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.fukaimei.camerav2test"> <!-- 授予该程序使用摄像头的权限 --> <uses-permission android:name="android.permission.CAMERA" /> <application  android:allowBackup="true"  android:icon="@mipmap/ic_launcher"  android:label="@string/app_name"  android:roundIcon="@mipmap/ic_launcher_round"  android:supportsRtl="true"  android:theme="@style/AppTheme">   <activity android:name=".MainActivity">   <intent-filter>    <action android:name="android.intent.action.MAIN" />    <category android:name="android.intent.category.LAUNCHER" />   </intent-filter>  </activity> </application></manifest>

package com.fukaimei.camerav2test;import android.content.Context;import android.util.AttributeSet;import android.view.TextureView;/** * Created by FuKaimei on 2017/9/29. */public class AutoFitTextureView extends TextureView { private int mRatioWidth = 0; private int mRatioHeight = 0; public AutoFitTextureView(Context context, AttributeSet attrs) {  super(context, attrs); } public void setAspectRatio(int width, int height) {  mRatioWidth = width;  mRatioHeight = height;  requestLayout(); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {  super.onMeasure(widthMeasureSpec, heightMeasureSpec);  int width = MeasureSpec.getSize(widthMeasureSpec);  int height = MeasureSpec.getSize(heightMeasureSpec);  if (0 == mRatioWidth || 0 == mRatioHeight) {   setMeasuredDimension(width, height);  } else {   if (width < height * mRatioWidth / mRatioHeight) {    setMeasuredDimension(width, width * mRatioHeight / mRatioWidth);   } else {    setMeasuredDimension(height * mRatioWidth / mRatioHeight, height);   }  } }}

package com.fukaimei.camerav2test;import android.Manifest;import android.app.Activity;import android.content.Context;import android.content.pm.PackageManager;import android.content.res.Configuration;import android.graphics.ImageFormat;import android.graphics.SurfaceTexture;import android.hardware.camera2.CameraAccessException;import android.hardware.camera2.CameraCaptureSession;import android.hardware.camera2.CameraCharacteristics;import android.hardware.camera2.CameraDevice;import android.hardware.camera2.CameraManager;import android.hardware.camera2.CameraMetadata;import android.hardware.camera2.CaptureRequest;import android.hardware.camera2.TotalCaptureResult;import android.hardware.camera2.params.StreamConfigurationMap;import android.media.Image;import android.media.ImageReader;import android.os.Build;import android.os.Bundle;import android.support.annotation.RequiresApi;import android.support.v4.app.ActivityCompat;import android.util.Log;import android.util.Size;import android.util.SparseIntArray;import android.view.Surface;import android.view.TextureView;import android.view.View;import android.widget.Toast;import java.io.File;import java.io.FileOutputStream;import java.nio.ByteBuffer;import java.util.ArrayList;import java.util.Arrays;import java.util.Collections;import java.util.Comparator;import java.util.List;@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)public class MainActivity extends Activity implements View.OnClickListener { private static final SparseIntArray ORIENTATIONS = new SparseIntArray(); private static final String TAG = "MainActivity"; static {  ORIENTATIONS.append(Surface.ROTATION_0, 90);  ORIENTATIONS.append(Surface.ROTATION_90, 0);  ORIENTATIONS.append(Surface.ROTATION_180, 270);  ORIENTATIONS.append(Surface.ROTATION_270, 180); } private AutoFitTextureView textureView; // 摄像头ID（通常0代表后置摄像头，1代表前置摄像头） private String mCameraId = "0"; // 定义代表摄像头的成员变量 private CameraDevice cameraDevice; // 预览尺寸 private Size previewSize; private CaptureRequest.Builder previewRequestBuilder; // 定义用于预览照片的捕获请求 private CaptureRequest previewRequest; // 定义CameraCaptureSession成员变量 private CameraCaptureSession captureSession; private ImageReader imageReader; private final TextureView.SurfaceTextureListener mSurfaceTextureListener   = new TextureView.SurfaceTextureListener() {  @Override  public void onSurfaceTextureAvailable(SurfaceTexture texture    , int width, int height) {   // 当TextureView可用时，打开摄像头   openCamera(width, height);  }  @Override  public void onSurfaceTextureSizeChanged(SurfaceTexture texture    , int width, int height) {  }  @Override  public boolean onSurfaceTextureDestroyed(SurfaceTexture texture) {   return true;  }  @Override  public void onSurfaceTextureUpdated(SurfaceTexture texture) {  } }; private final CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {  // 摄像头被打开时激发该方法  @Override  public void onOpened(CameraDevice cameraDevice) {   MainActivity.this.cameraDevice = cameraDevice;   // 开始预览   createCameraPreviewSession(); // ②  }  // 摄像头断开连接时激发该方法  @Override  public void onDisconnected(CameraDevice cameraDevice) {   cameraDevice.close();   MainActivity.this.cameraDevice = null;  }  // 打开摄像头出现错误时激发该方法  @Override  public void onError(CameraDevice cameraDevice, int error) {   cameraDevice.close();   MainActivity.this.cameraDevice = null;   MainActivity.this.finish();  } }; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  textureView = (AutoFitTextureView) findViewById(R.id.texture);  // 为该组件设置监听器  textureView.setSurfaceTextureListener(mSurfaceTextureListener);  findViewById(R.id.capture).setOnClickListener(this); } @Override public void onClick(View view) {  captureStillPicture(); } private void captureStillPicture() {  try {   if (cameraDevice == null) {    return;   }   // 创建作为拍照的CaptureRequest.Builder   final CaptureRequest.Builder captureRequestBuilder =     cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);   // 将imageReader的surface作为CaptureRequest.Builder的目标   captureRequestBuilder.addTarget(imageReader.getSurface());   // 设置自动对焦模式   captureRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,     CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);   // 设置自动曝光模式   captureRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE,     CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);   // 获取设备方向   int rotation = getWindowManager().getDefaultDisplay().getRotation();   // 根据设备方向计算设置照片的方向   captureRequestBuilder.set(CaptureRequest.JPEG_ORIENTATION     , ORIENTATIONS.get(rotation));   // 停止连续取景   captureSession.stopRepeating();   // 捕获静态图像   captureSession.capture(captureRequestBuilder.build()     , new CameraCaptureSession.CaptureCallback() // ⑤     {      // 拍照完成时激发该方法      @Override      public void onCaptureCompleted(CameraCaptureSession session        , CaptureRequest request, TotalCaptureResult result) {       try {        // 重设自动对焦模式        previewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER,          CameraMetadata.CONTROL_AF_TRIGGER_CANCEL);        // 设置自动曝光模式        previewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE,          CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);        // 打开连续取景模式        captureSession.setRepeatingRequest(previewRequest, null,          null);       } catch (CameraAccessException e) {        e.printStackTrace();       }      }     }, null);  } catch (CameraAccessException e) {   e.printStackTrace();  } } // 打开摄像头 private void openCamera(int width, int height) {  setUpCameraOutputs(width, height);  CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);  try {   // 打开摄像头   if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {    // TODO: Consider calling    // ActivityCompat#requestPermissions    // here to request the missing permissions, and then overriding    // public void onRequestPermissionsResult(int requestCode, String[] permissions,    //           int[] grantResults)    // to handle the case where the user grants the permission. See the documentation    // for ActivityCompat#requestPermissions for more details.    return;   }   manager.openCamera(mCameraId, stateCallback, null); // ①  } catch (CameraAccessException e) {   e.printStackTrace();  } } private void createCameraPreviewSession() {  try {   SurfaceTexture texture = textureView.getSurfaceTexture();   texture.setDefaultBufferSize(previewSize.getWidth(), previewSize.getHeight());   Surface surface = new Surface(texture);   // 创建作为预览的CaptureRequest.Builder   previewRequestBuilder = cameraDevice     .createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);   // 将textureView的surface作为CaptureRequest.Builder的目标   previewRequestBuilder.addTarget(new Surface(texture));   // 创建CameraCaptureSession，该对象负责管理处理预览请求和拍照请求   cameraDevice.createCaptureSession(Arrays.asList(surface     , imageReader.getSurface()), new CameraCaptureSession.StateCallback() // ③     {      @Override      public void onConfigured(CameraCaptureSession cameraCaptureSession) {       // 如果摄像头为null，直接结束方法       if (null == cameraDevice) {        return;       }       // 当摄像头已经准备好时，开始显示预览       captureSession = cameraCaptureSession;       try {        // 设置自动对焦模式        previewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,          CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);        // 设置自动曝光模式        previewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE,          CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);        // 开始显示相机预览        previewRequest = previewRequestBuilder.build();        // 设置预览时连续捕获图像数据        captureSession.setRepeatingRequest(previewRequest,          null, null); // ④       } catch (CameraAccessException e) {        e.printStackTrace();       }      }      @Override      public void onConfigureFailed(CameraCaptureSession cameraCaptureSession) {       Toast.makeText(MainActivity.this, "配置失败！"         , Toast.LENGTH_SHORT).show();      }     }, null   );  } catch (CameraAccessException e) {   e.printStackTrace();  } } private void setUpCameraOutputs(int width, int height) {  CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);  try {   // 获取指定摄像头的特性   CameraCharacteristics characteristics     = manager.getCameraCharacteristics(mCameraId);   // 获取摄像头支持的配置属性   StreamConfigurationMap map = characteristics.get(     CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);   // 获取摄像头支持的最大尺寸   Size largest = Collections.max(     Arrays.asList(map.getOutputSizes(ImageFormat.JPEG)),     new CompareSizesByArea());   // 创建一个ImageReader对象，用于获取摄像头的图像数据   imageReader = ImageReader.newInstance(largest.getWidth(), largest.getHeight(),     ImageFormat.JPEG, 2);   imageReader.setOnImageAvailableListener(     new ImageReader.OnImageAvailableListener() {      // 当照片数据可用时激发该方法      @Override      public void onImageAvailable(ImageReader reader) {       // 获取捕获的照片数据       Image image = reader.acquireNextImage();       ByteBuffer buffer = image.getPlanes()[0].getBuffer();       byte[] bytes = new byte[buffer.remaining()];       // 使用IO流将照片写入指定文件       File file = new File(getExternalFilesDir(null), "pic.jpg");       buffer.get(bytes);       try (         FileOutputStream output = new FileOutputStream(file)) {        output.write(bytes);        Toast.makeText(MainActivity.this, "保存: " + file, Toast.LENGTH_LONG).show();       } catch (Exception e) {        e.printStackTrace();       } finally {        image.close();       }      }     }, null);   // 获取最佳的预览尺寸   previewSize = chooseOptimalSize(map.getOutputSizes(     SurfaceTexture.class), width, height, largest);   // 根据选中的预览尺寸来调整预览组件（TextureView的）的长宽比   int orientation = getResources().getConfiguration().orientation;   if (orientation == Configuration.ORIENTATION_LANDSCAPE) {    textureView.setAspectRatio(      previewSize.getWidth(), previewSize.getHeight());   } else {    textureView.setAspectRatio(      previewSize.getHeight(), previewSize.getWidth());   }  } catch (CameraAccessException e) {   e.printStackTrace();  } catch (NullPointerException e) {   Log.d(TAG, "出现错误");  } } private static Size chooseOptimalSize(Size[] choices   , int width, int height, Size aspectRatio) {  // 收集摄像头支持的打过预览Surface的分辨率  List<Size> bigEnough = new ArrayList<>();  int w = aspectRatio.getWidth();  int h = aspectRatio.getHeight();  for (Size option : choices) {   if (option.getHeight() == option.getWidth() * h / w &&     option.getWidth() >= width && option.getHeight() >= height) {    bigEnough.add(option);   }  }  // 如果找到多个预览尺寸，获取其中面积最小的。  if (bigEnough.size() > 0) {   return Collections.min(bigEnough, new CompareSizesByArea());  } else {   System.out.println("找不到合适的预览尺寸！！！");   return choices[0];  } } // 为Size定义一个比较器Comparator static class CompareSizesByArea implements Comparator<Size> {  @Override  public int compare(Size lhs, Size rhs) {   // 强转为long保证不会发生溢出   return Long.signum((long) lhs.getWidth() * lhs.getHeight() -     (long) rhs.getWidth() * rhs.getHeight());  } }}

<!-- 授予该程序使用摄像头的权限 --> <uses-permission android:name="android.permission.CAMERA" />