工模-Camera测试

该模块的主要功能要求是实现自动循环开启摄像头并拍照。
主要实现代码如下：

package com.dw.cameratest2;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Toast;

/**
 * 
 * @author  dw
 * 
 */
public class CameraTestActivity extends Activity {
    private static final String TAG="com.dw.cameratest2.CameraTestActivity";
    private SurfaceView mySurfaceView;
    private SurfaceHolder myHolder;
    private Camera myCamera;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 无title
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        // 全屏
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        // 设置布局
        setContentView(R.layout.activity_camera_test);
        // 初始化surface
        initSurface();
        // 这里得开线程进行拍照，因为Activity还未完全显示的时候，是无法进行拍照的，SurfaceView必须先显示
        new Thread(new Runnable() {
            @Override
            public void run() {
                // 初始化camera并对焦拍照
                initCamera();
            }
        }).start();

    }

    // 初始化surface
    @SuppressWarnings("deprecation")
    private void initSurface() {
        // 初始化surfaceview
        mySurfaceView = (SurfaceView) findViewById(R.id.camera_surfaceview);

        // 初始化surfaceholder
        myHolder = mySurfaceView.getHolder();
        myHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    }
    // 初始化摄像头
    private void initCamera() {
        // 如果存在摄像头
        if (checkCameraHardware(getApplicationContext())) {
            // 获取摄像头（首选前置，无前置选后置）
            if (openFacingFrontCamera()) {
                // 进行对焦
                autoFocus();
            } else {
                Log.d("Demo", "openCameraFailed");
            }

        }
    }

    // 对焦并拍照
    private void autoFocus() {
        try {
            // 因为开启摄像头需要时间，这里让线程延迟2s
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        Timer timer = new Timer();
        TimerTask task = new TimerTask() {
            @Override
            public void run() {
                // TODO Auto-generated method stub
                // 自动对焦
                myCamera.autoFocus(myAutoFocus);
                // 对焦后拍照
                myCamera.takePicture(null, null, myPicCallback);
            }
        };
        timer.schedule(task, 1000, 10000);


    }

    // 判断是否存在摄像头
    private boolean checkCameraHardware(Context context) {

        if (context.getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA)) {
            // 设备存在摄像头
            return true;
        } else {
            // 设备不存在摄像头
            Log.e(TAG, "未检测到摄像头");
            return false;
        }
    }

    // 获取摄像头
    @SuppressLint("NewApi")
    private boolean openFacingFrontCamera() {

        // 尝试开启后置摄像头
        Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
        for (int camIdx = 0, cameraCount = Camera.getNumberOfCameras(); camIdx < cameraCount; camIdx++) {
            Camera.getCameraInfo(camIdx, cameraInfo);
            if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                try {
                    Log.d("Demo", "tryToOpenCamera");
                    myCamera = Camera.open(camIdx);
                } catch (RuntimeException e) {
                    e.printStackTrace();
                    return false;
                }
            }
        }
        // 如果开启后置失败（或无后置）则开启前置
        if (myCamera == null) {
            for (int camIdx = 0, cameraCount = Camera.getNumberOfCameras(); camIdx < cameraCount; camIdx++) {
                Camera.getCameraInfo(camIdx, cameraInfo);
                if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
                    try {
                        myCamera = Camera.open(camIdx);
                    } catch (RuntimeException e) {
                        return false;
                    }
                }
            }
        }
        try {
            // 这里的myCamera为已经初始化的Camera对象
            myCamera.setPreviewDisplay(myHolder);
        } catch (IOException e) {
            e.printStackTrace();
            myCamera.stopPreview();
            myCamera.release();
            myCamera = null;
        }
        myCamera.startPreview();
        return true;
    }
    // 自动对焦回调函数(空实现)
    private AutoFocusCallback myAutoFocus = new AutoFocusCallback() {
        @Override
        public void onAutoFocus(boolean success, Camera camera) {
        }
    };
    // 拍照成功回调函数
    private PictureCallback myPicCallback = new PictureCallback() {
        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            // 完成拍照后关闭Activity
            //CameraTestActivity.this.finish();
            // 将得到的照片进行270°旋转，使其竖直
            Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
            Matrix matrix = new Matrix();
            matrix.preRotate(270);
            bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),
                    bitmap.getHeight(), matrix, true);
            // 创建并保存图片文件,每拍一次会覆盖上一次拍的照片以节省空间
            File pictureFile = new File(getDir(), "camera_test.jpeg");
            try {
                FileOutputStream fos = new FileOutputStream(pictureFile);
                bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
                fos.close();
            } catch (Exception error) {
                Toast.makeText(CameraTestActivity.this, "拍照失败",
                        Toast.LENGTH_SHORT).show();
                ;
                Log.d("Demo", "保存照片失败" + error.toString());
                error.printStackTrace();
                myCamera.stopPreview();
                myCamera.release();
                myCamera = null;
            }
            myCamera.startPreview();
            Log.d("Demo", "获取照片成功");
            Toast.makeText(CameraTestActivity.this, "获取照片成功",
                    Toast.LENGTH_SHORT).show();
            /*myCamera.stopPreview();
            myCamera.release();
            myCamera = null;*/
        }
    };
    // 获取文件夹
    private File getDir() {
        // 得到SD卡根目录
        File dir = Environment.getExternalStorageDirectory();
        if (dir.exists()) {
            return dir;
        } else {
            dir.mkdirs();
            return dir;
        }
    }


    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        if(myCamera != null)
        {
            myCamera.stopPreview();
        myCamera.release();
        myCamera = null;
        }

    }

}