Android开发笔记（五十六）摄像头拍照

import com.example.exmcamera.util.BitmapUtil;
import com.example.exmcamera.util.MetricsUtil;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.ImageFormat;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.ShutterCallback;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class CameraView extends SurfaceView implements SurfaceHolder.Callback {
	private static final String TAG = "CameraView";
	private Context mContext;
	private Camera mCamera;
    private Bitmap mBitmap = null;
	private SurfaceHolder mHolder = null;
	private boolean isPreviewing = false;
	private Point mCameraSize;
	private int mCameraType = CAMERA_BEHIND;
	public static int CAMERA_BEHIND = 0;
	public static int CAMERA_FRONT = 1;

	public CameraView(Context context, AttributeSet attrs) {
		super(context, attrs);
		mContext = context;
		mHolder = getHolder();
		mHolder.setFormat(PixelFormat.TRANSPARENT);//translucent半透明 transparent透明
		//mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
		mHolder.addCallback(this);
	}

	public CameraView(Context context) {
		this(context, null);
	}

	public int getCameraType() {
		return mCameraType;
	}
	
	public void setCameraType(int CameraType) {
		mCameraType = CameraType;
	}

	public Bitmap getPhoto() {
		if (mBitmap != null) {
			Log.d(TAG, "mBitmap.size="+(mBitmap.getByteCount()/1024)+"K");
		} else {
			Log.d(TAG, "mBitmap is null.");
		}
		return mBitmap;
	}

	public void doTakePicture() {
		if(isPreviewing && (mCamera != null)) {
			mCamera.takePicture(mShutterCallback, null, mPictureCallback);
		}
	}

	//快门按下的回调，在这里我们可以设置类似播放“咔嚓”声之类的操作。默认的就是咔嚓。
	ShutterCallback mShutterCallback = new ShutterCallback() {
		public void onShutter() {
			Log.d(TAG, "myShutterCallback:onShutter...");
		}
	};
	
	PictureCallback mPictureCallback = new PictureCallback() {
		public void onPictureTaken(byte[] data, Camera camera) {
			Log.d(TAG, "mPictureCallback:onPictureTaken...");
			Bitmap b = null;
			if(null != data) {
				b = BitmapFactory.decodeByteArray(data, 0, data.length);//data是字节数据，将其解析成位图
				mCamera.stopPreview();
				isPreviewing = false;
			}
			if (mCameraType == CameraView.CAMERA_BEHIND) {
				mBitmap = BitmapUtil.getRotateBitmap(b, 90);
			} else {
				mBitmap = BitmapUtil.getRotateBitmap(b, -90);
			}
			Log.d(TAG, "mBitmap.size="+(mBitmap.getByteCount()/1024)+"K");
			try {
				Thread.sleep(1000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			//再次进入预览
			mCamera.startPreview();
			isPreviewing = true;
		}
	};

	@Override
	public void surfaceCreated(SurfaceHolder mHolder) {
		// 当预览视图创建的时候开启相机
		mCamera = Camera.open(mCameraType);
		try {
			// 设置预览
			mCamera.setPreviewDisplay(mHolder);
			mCameraSize = MetricsUtil.getCameraSize(mCamera.getParameters(), MetricsUtil.getSize(mContext));
			Log.d(TAG, "width="+mCameraSize.x+", height="+mCameraSize.y);
		    Camera.Parameters parameters = mCamera.getParameters();
			// 设置预览大小
		    parameters.setPreviewSize(mCameraSize.x, mCameraSize.y);
			// 设置图片保存时的分辨率大小
			parameters.setPictureSize(mCameraSize.x, mCameraSize.y);
			// 设置格式
			parameters.setPictureFormat(ImageFormat.JPEG);
			// 设置自动对焦。前置摄像头似乎无法自动对焦
			if (mCameraType == CameraView.CAMERA_BEHIND) {
				parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
			}
		    mCamera.setParameters(parameters);
		} catch (Exception e) {
			Log.d(TAG, "setPreviewDisplay error: "+e.getMessage());
			// 释放相机资源并置空
			mCamera.release();
			mCamera = null;
		}
		return;
	}

	@Override
	public void surfaceChanged(SurfaceHolder mHolder, int format, int width, int height) {
		Log.d(TAG, "surfaceChanged");
		mCamera.setDisplayOrientation(90);
		// 开始预览
		mCamera.startPreview();
		isPreviewing = true;
		mCamera.autoFocus(null);
	}

	@Override
	public void surfaceDestroyed(SurfaceHolder mHolder) {
		Log.d(TAG, "surfaceDestroyed");
		mCamera.stopPreview();
		mCamera.release();
		mCamera = null;
	}

}

import java.text.SimpleDateFormat;
import java.util.Date;

import com.example.exmcamera.R;
import com.example.exmcamera.util.BitmapUtil;
import com.example.exmcamera.util.MetricsUtil;
import com.example.exmcamera.widget.CameraView;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Point;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageButton;

public class CameraActivity extends Activity implements OnClickListener {
	private static final String TAG = "CameraActivity";
	private CameraView cameraView;
	private ImageButton shutterBtn;
	private int mCameraType;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
		setContentView(R.layout.item_camera);
		mCameraType = getIntent().getIntExtra("type", CameraView.CAMERA_BEHIND);
		cameraView = (CameraView)findViewById(R.id.camera_view);
		cameraView.setCameraType(mCameraType);
		shutterBtn = (ImageButton)findViewById(R.id.btn_shutter);
		shutterBtn.setOnClickListener(this);
		initViewParams();
	}

	private void initViewParams(){
		LayoutParams paramsLayout = cameraView.getLayoutParams();
		Point size = MetricsUtil.getSize(this);
		paramsLayout.width = size.x;
		paramsLayout.height = size.y;
		cameraView.setLayoutParams(paramsLayout);

		LayoutParams paramsButton = shutterBtn.getLayoutParams();
		paramsButton.width = MetricsUtil.dip2px(this, 60);
		paramsButton.height = MetricsUtil.dip2px(this, 60);
		shutterBtn.setLayoutParams(paramsButton);
	}

	@Override
	public void onBackPressed() {
        Intent intent = new Intent();
		Bundle bundle = new Bundle();
		Bitmap bitmap = cameraView.getPhoto();
		if (bitmap == null) {
			bundle.putString("is_null", "yes");
		} else {
			bundle.putString("is_null", "no");
			String path = String.format("%s%s.jpg", BitmapUtil.getCachePath(this),getNowDateTime());
			BitmapUtil.saveFile(cameraView.getPhoto(), path);
			bundle.putString("path", path);
		}
		intent.putExtras(bundle);
        setResult(Activity.RESULT_OK, intent);
        finish();
	}

	private String getNowDateTime() {
		SimpleDateFormat s_format = new SimpleDateFormat("yyyyMMddHHmmss");
		Date d_date = new Date();
		String s_date = "";
		s_date = s_format.format(d_date);
		return s_date;
	}

	@Override
	public void onClick(View v) {
		if (v.getId() == R.id.btn_shutter) {
			cameraView.doTakePicture();
		}
	}

}