Android之使用Camera拍照

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback, Camera.AutoFocusCallback {
private SurfaceHolder mHolder;
private Camera mCamera;
private Context context;
private static final String TAG = CameraPreview.class.getSimpleName();

public CameraPreview(Context context) {
super(context);
this.context = context;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
// 0: 启动后置摄像头,1:启动前置摄像头
mCamera = Camera.open(0);

setCameraParameters(mCamera);
setCameraDisplayOrientation((Activity) context, 0, mCamera);
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}

/**
*销毁视图时,释放内存
*/
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}

Log.d("Dennis", "surfaceDestroyed() is called");
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.

if (mHolder.getSurface() == null) {
// preview surface does not exist
return;
}

// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e) {
// ignore: tried to stop a non-existent preview
}

// set preview size and make any resize, rotate or
// reformatting changes here

// start preview with new settings
try {
setCameraParameters(mCamera);
requestLayout();
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();

} catch (Exception e) {
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}

public void setCameraParameters(Camera camera) {
Camera.Parameters mCameraParameters = mCamera.getParameters();
// 通常会默认在50Hz 如果设置60Hz会有水波纹
mCameraParameters.setAntibanding(Camera.Parameters.ANTIBANDING_AUTO);
boolean autoExposureLockSupported = mCameraParameters.isAutoExposureLockSupported();
if (autoExposureLockSupported) {
mCameraParameters.setAutoExposureLock(true);
}
// 设置闪光灯
mCameraParameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
// 设置颜色效果
mCameraParameters.setColorEffect(Camera.Parameters.EFFECT_NONE);
// 设置自动白平衡锁定状态
mCameraParameters.setAutoWhiteBalanceLock(mCameraParameters.getAutoWhiteBalanceLock());
// 设置曝光补偿指数
// mCameraParameters.setExposureCompensation(1);
mCameraParameters.setPreviewSize(1920, 1080);
mCamera.setParameters(mCameraParameters);
}

public void takePicture(Camera.PictureCallback imageCallback) {
mCamera.takePicture(null, null, imageCallback);
}

/**
* 设置预览视图的方向 如果不设置的话,拍的照片方向不是我们看到的方向,通过这个方法,我们在旋转手机是,预览视图的方向也跟着旋转.
*
* @param activity
* @param cameraId
* @param camera
*/
public void setCameraDisplayOrientation(Activity activity,
int cameraId, android.hardware.Camera camera) {
android.hardware.Camera.CameraInfo info =
new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(cameraId, info);
int rotation = activity.getWindowManager().getDefaultDisplay()
.getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0;
break;
case Surface.ROTATION_90:
degrees = 90;
break;
case Surface.ROTATION_180:
degrees = 180;
break;
case Surface.ROTATION_270:
degrees = 270;
break;
}

int result;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360;  // compensate the mirror
} else {  // back-facing
result = (info.orientation - degrees + 360) % 360;
}
camera.setDisplayOrientation(result);
}

@Override
public void onAutoFocus(boolean success, Camera camera) {

}
}

public class FileUtils {
/**
* 判断内存卡是否存在
* @return
*/
public static boolean SDCardIsAvailable() {
String state = Environment.getExternalStorageState();
return state.equals(Environment.MEDIA_MOUNTED);
}
/**
* 获取图片存储路径
* @return
*/
public static File getFilePath() {
if (!SDCardIsAvailable()) {
throw new RuntimeException("the sdcard is error,please check sdcard and try again");
}
//get the mobile Pictures directory
File picDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
//get the current time
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
Log.i("picPath", picDir.getPath() + File.separator + timeStamp);
return new File(picDir.getPath() + File.separator + "IMAGE_" + timeStamp + ".jpg");
}
/**
* 将数据一.jpg格式保存到指定的路径中
* @param data
* @param file
*/
public static void saveData2Pic(byte data[], File file) {
if (null == file || data == null) {
Log.d("sava picture is failed", "FileUtil.class--saveData2Pic");
return;
}
FileOutputStream fos = null;
try {
fos = new FileOutputStream(file);
fos.write(data);
fos.flush();
Log.i("save pic is successful", file.getAbsolutePath());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (null == fos) {
return;
}
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

public class MainActivity extends Activity implements View.OnClickListener, Camera.PictureCallback {

private Button btOk;
private FrameLayout frameLayout;
private CameraPreview cameraPreview;

private static final String TAG = MainActivity.class.getSimpleName();

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

btOk = (Button) findViewById(R.id.take_picture);
frameLayout = (FrameLayout) findViewById(R.id.camera_content);
cameraPreview = new CameraPreview(this);
frameLayout.addView(cameraPreview);
btOk.setOnClickListener(this);
}

@Override
public void onClick(View v) {
btOk.setEnabled(false);

// get an image from the camera
cameraPreview.takePicture(this);
}

@Override
public void onPictureTaken(byte[] data, Camera camera) {
File picFile = FileUtils.getFilePath();
if (picFile == null) {
Log.d(TAG, "Error creating media file, check storage permissions: ");
return;
}
FileUtils.saveData2Pic(data, picFile);
// Restart the preview and re-enable the shutter button so that we can take another picture
camera.startPreview();
//See if need to enable or not
btOk.setEnabled(true);
}

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<FrameLayout
android:id="@+id/camera_content"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"></FrameLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp">

<Button
android:id="@+id/take_picture"
android:layout_width="80dip"
android:layout_height="match_parent" />
</LinearLayout>
</LinearLayout>