如何使用自定义相机拍摄并保存图像，并在下一个活动的屏幕上显示保存的图像。 （使用PostTask）
这是我试过的...... 1.相机活动
public static final int CAMERA_REQUEST = 1000;
private FrameLayout cameraPreview;
private Camera mCamera;
private CameraPreview mCameraPreview;
private Camera_Activity screen;
private final Context context = this;
capture_snap.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mCamera.takePicture(null, null, mPicture);
PostTask pt = new PostTask();
pt.execute(screen);
pdialog = new ProgressDialog(Camera_Activity.this);
pdialog.setCancelable(false);
pdialog.setMessage("Please Wait...");
pdialog.show();*/
}
});
private Camera getCameraInstance() {
Camera camera = null;
try {
camera = Camera.open();
} catch (Exception e) {
// cannot get camera or does not exist
}
return camera;
}
PictureCallback mPicture = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile();
if (pictureFile == null) {
System.out.println("picture file is null");
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
} catch (IOException e) {
}
}
};
private static File getOutputMediaFile() {
File mediaStorageDir = new File(
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
"MyCameraApp");
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;
mediaFile = new File(mediaStorageDir.getPath() + File.separator
+ "IMG_" + timeStamp + ".jpeg");
return mediaFile;
}
private class PostTask extends AsyncTask<Activity, String, String>
{
@Override
protected String doInBackground(Activity... params) {
return "";
}
protected void onPostExecute(String result) {
if(pdialog != null)
{
pdialog.setCancelable(true);
pdialog.dismiss();
Intent i=new Intent(getApplicationContext(),Camera_view.class);
//i.putExtra(mediaFile, mediaFile);
startActivity(i);
}
else{
pdialog.setCancelable(true);
pdialog.dismiss();
MessageDialog.showMessage("Alert",
"Incorrect Path", Camera_Activity.screen);
}
}
}
private void releaseCamera(){
if (mCamera != null){
mCameraPreview.getHolder().removeCallback(mCameraPreview);
mCamera.release(); // release the camera for other applications
}
}
2.Camera Preivew
public class CameraPreview extends SurfaceView implements
SurfaceHolder.Callback {
private SurfaceHolder mSurfaceHolder;
private Camera mCamera;
// Constructor that obtains context and camera
@SuppressWarnings("deprecation")
public CameraPreview(Context context, Camera camera) {
super(context);
this.mCamera = camera;
this.mSurfaceHolder = this.getHolder();
this.mSurfaceHolder.addCallback(this);
this.mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
try {
mCamera.setPreviewDisplay(surfaceHolder);
mCamera.startPreview();
} catch (IOException e) {
// left blank for now
}
}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
//mCamera.stopPreview();
//mCamera.release();
if(mCamera != null){
mCamera.stopPreview();
mCamera.setPreviewCallback(null);
mCamera.release();
}
}
public void onPause() {
mCamera.stopPreview();
//mCamera = null;
}
@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int format,
int width, int height) {
// start preview with new settings
try {
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(surfaceHolder);
mCamera.startPreview();
} catch (Exception e) {
// intentionally left blank for a test
}
}
}
3.Camera View //这里我正在尝试显示捕获的图像...