如何从Android中的另一个活动调用takePicture（）方法？

Question

I have main activity class where i have written takePicturefromCamera() method like this:

public void takePicturefromCamera() {
             Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                try {

                    String state = Environment.getExternalStorageState();
                    if (Environment.MEDIA_MOUNTED.equals(state)) {
                        mImageCaptureUri = Uri.fromFile(mFileTemp);
                    }
                    else {
                    //  The solution is taken from here: http://stackoverflow.com/questions/10042695/how-to-get-camera-result-as-a-uri-in-data-folder

                        mImageCaptureUri = InternalStorageContentProvider.CONTENT_URI;
                    }   
                    intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, mImageCaptureUri);
                    intent.putExtra("return-data", true);
                    startActivityForResult(intent, REQUEST_CODE_TAKE_PICTURE);
                } catch (ActivityNotFoundException e) {

                    Log.d("TAG", "cannot take picture", e);
                }

        }

Now I have another class where i am doing some cropping part and my requirement is if while cropping user feels that he want to take some another picture instead of previous there i want to call above takePicturefromCamera() method of main activity class on some button click. Can anyone help me how can I do like this. I have tried by doing like this:

retake_button.setOnClickListener(
                     new View.OnClickListener() {
                         public void onClick(View v) {
                            // setResult(RESULT_CANCELED);
                           main m = new main();
                           m.takePicturefromCamera();
                         }
                     });

But it gives me error NullPointerException at mImageCaptureUri = Uri.fromFile(mFileTemp);

Please help me.

Answer 1

I would suggest you to keep takePicturefromCamera() in separate class, and then call this method passing the activitycontext and data required to it.

Or else you can make Activity2 extend Activity1 and use takePicturefromCamera() .

Answer 2

Make that method as static so you can use it anywhere in your application.

Also add one more parameter "File" to your function. By this, you also have flexibility to use the same function for different file object in your application.

Hope this will help you.