Android调用系统相机以及自定义相机
2016-02-19 12:45
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0.综述
自定义相机,此处展示简单的相机功能,官方文档中还有相应关于视频拍摄的内容,此处不提1.添加权限
<!--相机权限,数据存储--> <uses-permission android:name="android.permission.CAMERA" /> <uses-feature android:name="android.hardware.camera" /> <uses-feature android:name="android.hardware.camera.autofocus" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
2.通过Intent调用自带相机应用拍摄
2.1启动相机private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100; private Uri fileUri; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // create Intent to take a picture and return control to the calling application Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); // create a file to save the image,之后在存储时会提到 intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name // start the image capture Intent startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE); }
2.2处理结果
private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100; private static final int CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE = 200; @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) { if (resultCode == RESULT_OK) { // Image captured and saved to fileUri specified in the Intent Toast.makeText(this, "Image saved to:\n" + data.getData(), Toast.LENGTH_LONG).show(); } else if (resultCode == RESULT_CANCELED) { // User cancelled the image capture } else { // Image capture failed, advise user } } }
3.获取相机
3.1 检测是否有相机硬件/** Check if this device has a camera */ private boolean checkCameraHardware(Context context) { if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){ // this device has a camera return true; } else { // no camera on this device return false; } }
3.2 打开相机
有多个相机时可使用Camera.open(int)
获取更过相机相关信息可使用Camera.getCameraInfo()
/** A safe way to get an instance of the Camera object. */ public static Camera getCameraInstance(){ Camera c = null; try { c = Camera.open(); // attempt to get a Camera instance } catch (Exception e){ // Camera is not available (in use or does not exist) } return c; // returns null if camera is unavailable }
4.创建预览界面
4.1 自定义一个SurfaceView用于展示图片/** A basic Camera preview class */ public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback { private SurfaceHolder mHolder; private Camera mCamera; public CameraPreview(Context context, Camera camera) { super(context); mCamera = camera; // 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 { mCamera.setPreviewDisplay(holder); mCamera.setDisplayOrientation(90); mCamera.startPreview(); } catch (IOException e) { Log.d(TAG, "Error setting camera preview: " + e.getMessage()); } } public void surfaceDestroyed(SurfaceHolder holder) { // empty. Take care of releasing the Camera preview in your activity. } 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 { mCamera.setPreviewDisplay(mHolder); mCamera.startPreview(); } catch (Exception e){ Log.d(TAG, "Error starting camera preview: " + e.getMessage()); } } }
4.2创建容纳布局文件
<?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"> <FrameLayout android:id="@+id/fl_preview" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="1" /> <Button android:id="@+id/bt_capture" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:text="Capture" /> </LinearLayout>
4.3 在Activity中CameraPreview添加控件
mPreview = new CameraPreview(this, mCamera); FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview); preview.addView(mPreview);
4.4注册Activity
<activity android:name=".CameraActivity" android:screenOrientation="portrait"> <!-- configure this activity to use landscape orientation --> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity>
5.拍摄照片
5.1 照片拍摄回调private Camera.PictureCallback mPicture = new Camera.PictureCallback() { @Override public void onPictureTaken(byte[] data, Camera camera) { File pictureFile = null; try { pictureFile = SaveUtils.getOutputMediaFile(SaveUtils.MEDIA_TYPE_IMAGE); } catch (Exception e) { Log.d(TAG, "Error creating media file, check storage permissions: " + e.getMessage()); return; } try { FileOutputStream fos = new FileOutputStream(pictureFile); fos.write(data); fos.close(); } catch (FileNotFoundException e) { Log.d(TAG, "File not found: " + e.getMessage()); } catch (IOException e) { Log.d(TAG, "Error accessing file: " + e.getMessage()); } Log.i(TAG, "拍摄存储完成"); camera.startPreview(); } };
5.2 监听事件
// Add a listener to the Capture button Button captureButton = (Button) findViewById(id.button_capture); captureButton.setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { // get an image from the camera mCamera.takePicture(null, null, mPicture); } } );
5.3 注销相机
@Override protected void onPause() { super.onPause(); releaseCamera(); } /** * 释放相机 */ private void releaseCamera() { if (mCamera != null) { mCamera.release(); // release the camera for other applications mCamera = null; } }
6.存储照片
public static final int MEDIA_TYPE_IMAGE = 1; public static final int MEDIA_TYPE_VIDEO = 2; /** Create a file Uri for saving an image or video */ private static Uri getOutputMediaFileUri(int type){ return Uri.fromFile(getOutputMediaFile(type)); } /** Create a File for saving an image or video */ private static File getOutputMediaFile(int type){ // To be safe, you should check that the SDCard is mounted // using Environment.getExternalStorageState() before doing this. File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory( Environment.DIRECTORY_PICTURES), "MyCameraApp"); // This location works best if you want the created images to be shared // between applications and persist after your app has been uninstalled. // Create the storage directory if it does not exist if (! mediaStorageDir.exists()){ if (! mediaStorageDir.mkdirs()){ Log.d("MyCameraApp", "failed to create directory"); return null; } } // Create a media file name String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()); File mediaFile; if (type == MEDIA_TYPE_IMAGE){ mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_"+ timeStamp + ".jpg"); } else if(type == MEDIA_TYPE_VIDEO) { mediaFile = new File(mediaStorageDir.getPath() + File.separator + "VID_"+ timeStamp + ".mp4"); } else { return null; } return mediaFile; }
7.高级功能
Android提供了更多功能可以通过以下方式修改,还有人脸识别等// get Camera parameters Camera.Parameters params = mCamera.getParameters(); // set the focus mode params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO); // set Camera parameters mCamera.setParameters(params);
8.其他
8.1 参考文章Camera | Android Developers
8.2 代码地址
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