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">  <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()); } } }

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