android 手机拍照流程

来源：互联网发布：全景拍照软件编辑：程序博客网时间：2024/04/27 23:17

1. 在布局文件中添加一个 surfaceView (摄影平面)

2.根据 SurfaceView 获得 Holder (固定器)

3.给固定器设置 SurfaceHolder.Callback ; 这个 Callback 有一系列的周期方法,

比如:surfaceCreated,surfaceChanged,surfaceDestroyed等方法.

①.在surfaceDestroyed 中打开相机,设置预览效果 ;

②.在surfaceChanged中可以初始化相机( Camera );比如相机的参数: 像素, 大小,格式,开始预览,等等

③.在surfaceDestroyed可以可以停止相机拍摄;释放相机资源

4. 相机自动对焦的回调处理

Camera.autoFocus( AutoFocusCallback )

AutoFocusCallback 有个接口方法 public void onAutoFocus(boolean focused, Camera camera) {                    /* 对到焦点拍照 */                    if (focused) {                            takePicture();//见第5步                    }            }

5.Camera.takePicture(ShutterCallback shutter/*摄像*/, PictureCallback raw/*拍照*/, PictureCallback jpeg/*照片*/)

查看API或者源码,可以发现,这些callback里面都有包含摄像,或者被拍照时的byte[]数据,而这些数据可以根据BitmapFactory变成Bitmap图片.

见源代码如下：

public class ScanBarZBarActivity extends Activity implements SurfaceHolder.Callback{private static String TAG = "ScanBarZBarActivity"; private Camera mCamera;    private Button mButton, mButton1, mButton2;    private SurfaceView mSurfaceView;    private SurfaceHolder holder;    private AutoFocusCallback mAutoFocusCallback = new AutoFocusCallback();    private String path = "WXJSMyPhoto";    private String path1;    private Bitmap bmp;    private int cnt = 1;    private Calendar c;    public native String getISBN(Bitmap bmp);    private int flag=5;    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {            super.onCreate(savedInstanceState);            /* 隐藏状态栏 */            this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,                            WindowManager.LayoutParams.FLAG_FULLSCREEN);            /* 隐藏标题栏 */            requestWindowFeature(Window.FEATURE_NO_TITLE);            /* 设定屏幕显示为横向 */            this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);            setContentView(R.layout.camera);            /* SurfaceHolder设定 */            mSurfaceView = (SurfaceView) findViewById(R.id.mSurfaceView);            holder = mSurfaceView.getHolder();            holder.addCallback(ScanBarZBarActivity.this);            holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);            c = Calendar.getInstance();            /* Button初始化 */            mButton = (Button) findViewById(R.id.myButton);            mButton1 = (Button) findViewById(R.id.myButton1);            mButton2 = (Button) findViewById(R.id.myButton2);            /* 拍照Button的事件处理 */            mButton.setOnClickListener(new Button.OnClickListener() {                    @Override                    public void onClick(View arg0) {                            /* 告动对焦后拍照 */                            mCamera.autoFocus(mAutoFocusCallback);                    }            });            /* Button的事件处理 */            mButton1.setOnClickListener(new Button.OnClickListener() {                    @Override                    public void onClick(View arg0) {                            /* 保存文件 */                    Log.i(TAG,"click button2");                            if (bmp != null) {                                    /* 检查SDCard是否存在 */                                    if (!Environment.MEDIA_MOUNTED.equals(Environment                                                    .getExternalStorageState())) {                                            /* SD卡不存在，显示Toast信息 */                                            Toast.makeText(ScanBarZBarActivity.this,                                                            "SD卡不存在!无法保存相片,请插入SD卡。", Toast.LENGTH_LONG)                                                            .show();                                    } else {                                            try {                                                    /* 文件不存在就创建 */                                                    File f = new File(Environment                                                                    .getExternalStorageDirectory(), path);                                                    Log.i(TAG,"click button2:" + f.getAbsolutePath());                                                    if (!f.exists()) {                                                            f.mkdir();                                                    }                                                    /* 保存相片文件 */                                                    path1 = String.valueOf(c.get(Calendar.MILLISECOND))                                                                    + "camera.jpg";                                                    File n = new File(f, path1);                                                    FileOutputStream bos = new FileOutputStream(n                                                                    .getAbsolutePath());                                                    /* 文件转换 */                                                    bmp.compress(Bitmap.CompressFormat.JPEG, 100, bos);                                                    /* 调用flush()方法，更新BufferStream */                                                    bos.flush();                                                    /* 结束OutputStream */                                                    bos.close();                                                    Toast.makeText(ScanBarZBarActivity.this,                                                                    path1 + "保存成功!", Toast.LENGTH_LONG).show();                                                    cnt++;                                            } catch (Exception e) {                                                    e.printStackTrace();                                            }                                    }                            }                            mButton.setVisibility(View.VISIBLE);                            mButton1.setVisibility(View.VISIBLE);                            mButton2.setVisibility(View.VISIBLE);                            /* 重新设定Camera */                            stopCamera();                            initCamera();                    }            });            /* 放弃Button的事件处理 */            mButton2.setOnClickListener(new Button.OnClickListener() {                    @Override                    public void onClick(View arg0) {                            mButton.setVisibility(View.VISIBLE);                            mButton1.setVisibility(View.VISIBLE);                            mButton2.setVisibility(View.VISIBLE);                            /* 重新设定Camera */                            stopCamera();                            initCamera();                    }            });    }    @Override    public void surfaceCreated(SurfaceHolder surfaceholder) {            try {                    /* 打开相机， */                    mCamera = Camera.open();                    mCamera.setPreviewDisplay(holder);            } catch (IOException exception) {                    mCamera.release();                    mCamera = null;            }    }    @Override    public void surfaceChanged(SurfaceHolder surfaceholder, int format, int w,                    int h) {            /* 相机初始化 */    Log.i(TAG,"init camera");            initCamera();    }    @Override    public void surfaceDestroyed(SurfaceHolder surfaceholder) {    Log.i(TAG,"destoryed camera");            stopCamera();            mCamera.release();            mCamera = null;    }    /* 拍照的method */    private void takePicture() {            if (mCamera != null) {            Log.i(TAG,"takePicture");                    mCamera.takePicture(shutterCallback, rawCallback, jpegCallback);            }    }    private ShutterCallback shutterCallback = new ShutterCallback() {            public void onShutter() {            }    };    private PictureCallback rawCallback = new PictureCallback() {            public void onPictureTaken(byte[] _data, Camera _camera) {            }    };    private PictureCallback jpegCallback = new PictureCallback() {            public void onPictureTaken(byte[] _data, Camera _camera) {                    /* 取得相仞 */                    try {                            /* 设定Button?视性 */                            mButton.setVisibility(View.GONE);                            mButton1.setVisibility(View.VISIBLE);                            mButton2.setVisibility(View.VISIBLE);                            /* 取得相仞Bitmap对象 */                            bmp = BitmapFactory.decodeByteArray(_data, 0, _data.length);                            //发送给isbn分析                           // String isbn = getISBN(bmp);获得图片解析后的信息                          //  Log.i(TAG, "isbn:" + flag + isbn);                            flag--;                            if(flag>0){                            mCamera.autoFocus(mAutoFocusCallback);                            }                                               } catch (Exception e) {                            e.printStackTrace();                    }            }    };    /* 告定义class AutoFocusCallback */    public final class AutoFocusCallback implements                    android.hardware.Camera.AutoFocusCallback {            public void onAutoFocus(boolean focused, Camera camera) {                    /* 对到焦点拍照 */                    if (focused) {                            takePicture();                    }            }    };    /* 相机初始化的method */    private void initCamera() {            if (mCamera != null) {                    try {                            Camera.Parameters parameters = mCamera.getParameters();                            /*                             * 设定相片大小为1024*768， 格式为JPG                             */                            parameters.setPictureFormat(PixelFormat.JPEG);                            parameters.setPictureSize(1024, 768);                            mCamera.setParameters(parameters);                            /* 开启预览画面 */                            mCamera.startPreview();                    } catch (Exception e) {                            e.printStackTrace();                    }            }    }    /* 停止相机的method */    private void stopCamera() {            if (mCamera != null) {                    try {                            /* 停止预览 */                            mCamera.stopPreview();                    } catch (Exception e) {                            e.printStackTrace();                    }            }    }}

xml布局文件如下：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <SurfaceView        android:id="@+id/mSurfaceView"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_weight="1" />    <LinearLayout        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:orientation="horizontal" >        <Button            android:id="@+id/myButton"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="拍照" />        <Button            android:id="@+id/myButton1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="保存" />        <Button            android:id="@+id/myButton2"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="退出" />    </LinearLayout> </LinearLayout>