Android：没有用户界面拍照

时间：2013-11-24 08:00:30

标签： java android android-camera

我有兴趣为Android编写应用程序，在应用程序中的某个事件后，使用Android上的相机自动拍摄照片。

我需要的东西：

  • 无预览照片

  • 没有按钮供用户按下拍照

  • 只需运行操作即可拍照并将其存储到相册中。

这是我在线教程尝试的一些代码：

public void snap(){
       mCamera = Camera.open();
       SurfaceView sv = new SurfaceView(getApplicationContext());


       try {
                  mCamera.setPreviewDisplay(sv.getHolder());
                  parameters = mCamera.getParameters();

                   //set camera parameters
                 mCamera.setParameters(parameters);
                 mCamera.startPreview();
                 mCamera.takePicture(null, null, mCall);

            } catch (IOException e) {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
            }


       //Get a surface
         sHolder = sv.getHolder();

}
 Camera.PictureCallback mCall = new Camera.PictureCallback()
    {

       public void onPictureTaken(byte[] data, Camera camera)
       {
             //decode the data obtained by the camera into a Bitmap

             FileOutputStream outStream = null;
                  try{
                      outStream = new FileOutputStream("/sdcard/Image.jpg");
                      outStream.write(data);
                      outStream.close();
                  } catch (FileNotFoundException e){
                      Log.d("CAMERA", e.getMessage());
                  } catch (IOException e){
                      Log.d("CAMERA", e.getMessage());
                  }

       }
    };


      public IBinder onBind(Intent intent) {
            // TODO Auto-generated method stub
            return null;
      }

以及它所做的logcat 

    11-24 01:54:37.738: E/AndroidRuntime(6971): FATAL EXCEPTION: main                                                                                                                  
    11-24 01:54:37.738: E/AndroidRuntime(6971): java.lang.RuntimeException: Unable to start activity   ComponentInfo{com.example.udptest/com.example.udptest.Main}: java.lang.RuntimeException: takePicture failed
    11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2308)
    11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2358)
    11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.app.ActivityThread.access$600(ActivityThread.java:153)
    11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
    11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.os.Handler.dispatchMessage(Handler.java:99)
    11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.os.Looper.loop(Looper.java:137)
    11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.app.ActivityThread.main(ActivityThread.java:5227)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at java.lang.reflect.Method.invokeNative(Native Method)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at java.lang.reflect.Method.invoke(Method.java:511)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at dalvik.system.NativeStart.main(Native Method)
11-24 01:54:37.738: E/AndroidRuntime(6971): Caused by: java.lang.RuntimeException: takePicture failed
11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.hardware.Camera.native_takePicture(Native Method)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.hardware.Camera.takePicture(Camera.java:1101)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.hardware.Camera.takePicture(Camera.java:1046)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at com.example.udptest.Main.snap(Main.java:129)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at com.example.udptest.Main.onCreate(Main.java:84)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.app.Activity.performCreate(Activity.java:5104)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
11-24 01:54:37.738: E/AndroidRuntime(6971):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2262)
11-24 01:54:37.738: E/AndroidRuntime(6971):     ... 11 more

任何想法可能会在这里发生什么，或者更好的方法来完成这项任务？

4 个答案:

答案 0 :(得分：3)

这是服务来捕捉背景中的照片，希望它有所帮助：

public class CapPhoto extends Service
{
    private SurfaceHolder sHolder;    
    private Camera mCamera;
    private Parameters parameters;


  @Override
    public void onCreate()
    {
      super.onCreate();
      Log.d("CAM", "start");

      if (android.os.Build.VERSION.SDK_INT > 9) {
          StrictMode.ThreadPolicy policy = 
               new StrictMode.ThreadPolicy.Builder().permitAll().build();
          StrictMode.setThreadPolicy(policy);}
          Thread myThread = null;


  }
  @Override
  public void onStart(Intent intent, int startId) {

    super.onStart(intent, startId);

 if (Camera.getNumberOfCameras() >= 2) { 

    mCamera = Camera.open(CameraInfo.CAMERA_FACING_FRONT); }

 if (Camera.getNumberOfCameras() < 2) { 

    mCamera = Camera.open(); }
    SurfaceView sv = new SurfaceView(getApplicationContext());


     try {
               mCamera.setPreviewDisplay(sv.getHolder());
               parameters = mCamera.getParameters();
               mCamera.setParameters(parameters);
               mCamera.startPreview();

               mCamera.takePicture(null, null, mCall);
         } catch (IOException e) { e.printStackTrace(); }

        sHolder = sv.getHolder();
        sHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
  }

  Camera.PictureCallback mCall = new Camera.PictureCallback()
  {

     public void onPictureTaken(final byte[] data, Camera camera)
     {

        FileOutputStream outStream = null;
                try{

                    File sd = new File(Environment.getExternalStorageDirectory(), "A");
                    if(!sd.exists()) {                                 
                      sd.mkdirs();
                      Log.i("FO", "folder" + Environment.getExternalStorageDirectory());
                    } 

                        Calendar cal = Calendar.getInstance();
                        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd_HHmmss");
                        String tar = (sdf.format(cal.getTime()));

                        outStream = new FileOutputStream(sd+tar+".jpg");
                        outStream.write(data);  outStream.close();

                        Log.i("CAM", data.length + " byte written to:"+sd+tar+".jpg");
                        camkapa(sHolder);               


                 } catch (FileNotFoundException e){
                    Log.d("CAM", e.getMessage());
                } catch (IOException e){
                    Log.d("CAM", e.getMessage());
                }}
  };


    @Override
    public IBinder onBind(Intent intent) {
          return null;
    }

    public void camkapa(SurfaceHolder sHolder) {

        if (null == mCamera)
            return;
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
        Log.i("CAM", " closed");
        }

    }

<强>的AndroidManifest.xml 

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-feature android:name="android.hardware.camera" />

<service android:name=".CapPhoto" android:enabled="true">
             <intent-filter>

            </intent-filter>
        </service>

在 MainActivity 中调用此方法来呼叫服务：

    Intent service;

    ....

    Calendar cal = Calendar.getInstance();

    service = new Intent(getBaseContext(), CapPhoto.class);
    cal.add(Calendar.SECOND, 15);
    //TAKE PHOTO EVERY 15 SECONDS
    PendingIntent pintent = PendingIntent.getService(this, 0, service, 0);
    AlarmManager alarm = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

    alarm.setRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(),
                 60*60*1000, pintent);
    startService(service);

答案 1 :(得分：1)

几点提示：

  • 首先，不要硬编码文件路径。您的/ SD卡可能根本不存在，因此您的outStream将为null，并且当您从outStream调用任何方法时它将崩溃。相反，请使用 Environment.getExternalStoragePublicDirectory 或 Environment.getExternalStorageDirectory （适用于Android版本＆lt; 2.2的设备）。请参阅here

  • 没有照片预览 - 您可以预览1像素x像素1像素，因此几乎看不见

  • 您需要在AndroidManifest中声明权限：

      

    “android.permission.CAMERA”和“android.permission.WRITE_EXTERNAL_STORAGE”（如果你想保存图片）

我建议您通过example形式完成文档和实验。

答案 2 :(得分：0)

本指南告诉您如何构建相机应用程序。我希望这可以帮助您。 http://developer.android.com/guide/topics/media/camera.html#custom-camera

答案 3 :(得分：0)

也许你可以获得服务吗？

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