android camera 根据加速器的变化实现自动对焦

实现的效果是当加速器的变化在设定范围外时，相机会自动对焦。

public class MainActivity extends AppCompatActivity implements SurfaceHolder.Callback {

private SurfaceView surfaceview;
private SurfaceHolder surfaceholder;
private Camera camera = null;
private ImageView imageView;
private Button startPre;
private Button stopPre;
private Button getPicture;
private SensorManager sensorManager;
private MyListener myListener;
private Sensor mySensor;

private float mLastX;
private float mLastY;
private float mLastZ;
private boolean initBool = false;
private boolean myAutoFocus = true;
private Camera.AutoFocusCallback autoFocusCallback;
private Camera.Parameters parameters;
private WindowManager wm;
private int screenWidth;
private int screenHeight;

/* 通过Camera方式来实现拍照
通过Camera方式 会比通过Intent方式获得更为丰富的功能。通常创建一个定制化的Camera需要如下步骤：
(1) 通过Camera.open()来获取Camera实例。
(2) 创建Preview类，需要继承SurfaceView类并实现SurfaceHolder.Callback接口。
(3) 为相机设置Preview
(4) 构建一个Preview的Layout来 预览相机；
(5) 为拍照建立Listener以获取拍照后的回调;
(6) 拍照并保存文件;
(7) 释放Camera。*/

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

initSensor();
initView();
initEvent();

}

//初始化加速传感器
private void initSensor() {
sensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
mySensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
myListener = new MyListener();
List<Sensor> list = sensorManager.getSensorList(Sensor.TYPE_ALL);
//全部传感器
for(Sensor sensor:list){
Log.i("----->",""+sensor.getName());
}
}

private void initView() {
surfaceview = (SurfaceView) findViewById(R.id.surfaceview);
startPre = (Button) this.findViewById(R.id.beginPrievw);
stopPre = (Button) this.findViewById(R.id.stopPrievw);
getPicture = (Button) this.findViewById(R.id.getPicture);
imageView = (ImageView) this.findViewById(R.id.imageView);
}

private void initEvent() {

surfaceholder = surfaceview.getHolder();
surfaceholder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
surfaceholder.addCallback(this);

stopPre.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
camera.stopPreview();
}
});

getPicture.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
camera.takePicture(null, null, pictureCallback);
}
});

//初始化自动对焦回掉
autoFocusCallback = new Camera.AutoFocusCallback() {
@Override
public void onAutoFocus(boolean b, Camera camera) {
myAutoFocus = true;
if (b) {
camera.cancelAutoFocus();
Log.i("=========>", "对焦成功！");
} else {
Log.i("=========>", "对焦失败！");
}
}
};

//获取屏幕的宽和高
wm = (WindowManager)this
.getSystemService(Context.WINDOW_SERVICE);
screenWidth = wm.getDefaultDisplay().getWidth();
screenHeight = wm.getDefaultDisplay().getHeight();
}

@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
Log.i("------->", "surfaceCreated");
System.out.println("surfacecreated");
//获取camera对象
if (camera == null) {
camera = Camera.open();
Log.i("------->", "Camera open");
}
try {
//设置预览监听
camera.setPreviewDisplay(surfaceHolder);
parameters = camera.getParameters();
List<Camera.Size> sizeList = parameters.getSupportedPreviewSizes();
// parameters.setPictureFormat(PixelFormat.JPEG);
// parameters.setJpegQuality(CameraProfile.QUALITY_HIGH);

Log.i("pictureFromat",""+parameters.getPictureFormat());

parameters.setPictureSize(3840, 2160);

//获得相机的对焦模式有哪些
// List<String> focusModes = parameters.getSupportedFocusModes();
// for (String mode:focusModes){
// // Log.i("==-------->",""+mode);
// }
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);

// List<String> focusModes = parameters.getSupportedFocusModes();
// //得到摄像头支持的分辨率
// if (sizeList.size() > 1){
// Iterator<Camera.Size> itor = sizeList.iterator();
// while(itor.hasNext()){
// Camera.Size cur = itor.next();
// Log.i("------->","width:"+cur.width+" "+cur.height);
// }
// }

//设置预览的方向
if (this.getResources().getConfiguration().orientation
!= Configuration.ORIENTATION_LANDSCAPE) {
parameters.set("orientation", "portrait");
camera.setDisplayOrientation(90);
parameters.setRotation(90);
} else {
parameters.set("orientation", "landscape");
camera.setDisplayOrientation(0);
parameters.setRotation(0);
}
camera.setParameters(parameters);
camera.startPreview();
//camera.cancelAutoFocus();
} catch (IOException e) {
e.printStackTrace();
camera.release();
Log.e("---->","摄像头创建失败");
}
}

@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
Log.i("------->", "surfaceChanged");
myAutoFocus();
}

//对焦
private void myAutoFocus() {
try {
camera.autoFocus(autoFocusCallback);
} catch (Exception e) {
Log.d("---->", "" + e.getMessage());
}
}

@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
Log.i("------->", "surfaceDestroyed");

System.out.println("surfaceDestroyed");
if (camera != null) {
camera.stopPreview();
camera.release();
camera = null;
}
}

/* camera.takePicture(shutterCallback,rawcallback,pictureCallback);*/

private Camera.ShutterCallback shutterCallback = new Camera.ShutterCallback() {
@Override
public void onShutter() {
//按下快门瞬间的处理事件处
}
};

private Camera.PictureCallback rawcallback = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] bytes, Camera camera) {
//处理raw代码
}
};

private Camera.PictureCallback pictureCallback = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] bytes, Camera camera) {

File pictureFile = getOutputMediafile();

if (pictureFile == null) {
Log.e("--------->", "获取文件路径失败！");
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(bytes);
fos.close();
Log.i("--------->", "照片保存文件成功！");
} catch (FileNotFoundException e) {
Log.d("-------->", "row");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Bitmap bitmap = BitmapFactory.decodeByteArray(bytes,0,bytes.length);
imageView.setImageBitmap(bitmap);
camera.startPreview();
}
};

//加速传感器监听

public class MyListener implements SensorEventListener{
@Override
public void onSensorChanged(SensorEvent sensorEvent) {
//values[0]:X轴，values[1]：Y轴，values[2]：Z轴
float[] values = sensorEvent.values;
float x = values[0];
float y = values[1];
float z = values[2];
if (!initBool){
mLastX = x;
mLastY = y;
mLastZ = z;
initBool = !initBool;
}
float deltaX = Math.abs(mLastX - x);
float deltaY = Math.abs(mLastY - y);
float deltaZ = Math.abs(mLastZ - z);

if (deltaX > .5 && myAutoFocus){
myAutoFocus = false;
myAutoFocus();
}
if (deltaY > .5 && myAutoFocus){
myAutoFocus = false;
Log.i("---====---->","");
myAutoFocus();
}
if (deltaZ > .5 && myAutoFocus){
myAutoFocus = false;
Log.i("---====---->","");
myAutoFocus();
}
mLastX = x;
mLastY = y;
mLastZ = z;
}

@Override
public void onAccuracyChanged(Sensor sensor, int i) {
//传感器精度变化时使用
}
}

private File getOutputMediafile() {
File picDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String path = picDir.getPath() + File.separator + "IMAGE_" + timeStamp + ".jpg";
Log.i("------------>", "文件保存路径是：" + path);
return new File("/sdcard/Pictures/Test" + "IMAGE_" + timeStamp + ".jpg");
}

@Override
protected void onPause() {
super.onPause();
camera.stopPreview();
//注销传感器监听事件，若不，后台仍继续运行
sensorManager.unregisterListener(myListener);
}

@Override
protected void onResume() {
super.onResume();
camera.startPreview();

//注册传感器监听事件
boolean result = sensorManager.registerListener(myListener,mySensor,SensorManager.SENSOR_DELAY_NORMAL);
Log.i("----->",""+result);
}

}

布局文件

<pre name="code" class="html"><?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.myapplication.MainActivity">

<SurfaceView
android:id="@+id/surfaceview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true"/>
<ImageView
android:id="@+id/imageView"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"/>

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/stopPrievw"
android:layout_marginBottom="10dp"
android:text="拍摄照片"
android:id="@+id/getPicture"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="停止预览"
android:layout_alignParentBottom="true"
android:id="@+id/stopPrievw"/>
</RelativeLayout>