我正在尝试使用AsyncTask编写代码,从摄像头拍摄照片并通过UDP协议将其发送到服务器100次。然而,PictureCallback没有被调用。请有人帮助我吗?以下是我的尝试内容:
public class MainAsyncTask extends AsyncTask<Void, String, Void> {
protected static final String TAG = null;
public MainActivity mainAct;
public MainAsyncTask(MainActivity mainActivity)
{
super();
this.mainAct = mainActivity;
}
@Override
protected Void doInBackground(Void... params) {
DatagramSocket clientSocket = null;
InetAddress IPAddress = null;
try {
clientSocket = new DatagramSocket();
IPAddress = InetAddress.getByName("192.168.1.15");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
byte [] data;
DatagramPacket sendPacket;
try {
for (int i=0; i < 100; i++)
{
publishProgress("");
File file = new File(Environment.getExternalStorageDirectory()+ File.separator +"img.jpg");
while (!file.exists() || file.length() == 0);
Bitmap screen = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory()+ File.separator +"img.jpg");
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
screen.compress(Bitmap.CompressFormat.JPEG, 15, bytes);
data = bytes.toByteArray();
sendPacket = new DatagramPacket(data, data.length, IPAddress, 3107);
clientSocket.send(sendPacket);
file.delete();
}
clientSocket.close();
} catch (Exception e) {
// TODO Auto-generated catch block
publishProgress(e.getMessage());
}
return null;
}
public static void takeSnapShots(MainActivity mainAct)
{
PictureCallback jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera)
{
FileOutputStream outStream = null;
try {
outStream = new FileOutputStream(Environment.getExternalStorageDirectory()+File.separator+"img"+".jpg");
outStream.write(data);
outStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally
{
camera.stopPreview();
camera.release();
camera = null;
}
Log.d(TAG, "onPictureTaken - jpeg");
}
};
SurfaceView surface = new SurfaceView(mainAct.getApplicationContext());
Camera camera = Camera.open();
try {
camera.setPreviewDisplay(surface.getHolder());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
camera.startPreview();
camera.takePicture(null,null,jpegCallback);
}
protected void onProgressUpdate(String... progress) {
takeSnapShots(mainAct);
}
@Override
protected void onPostExecute(Void result)
{
}
}