Question

我正在尝试创建一个应用，允许用户拍摄照片，然后在应用中显示并保存。

我正在使用以下代码拍摄照片（来自Google）

Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(takePictureIntent, 1);

如何判断用户何时按下后退按钮并返回我的应用程序，以便显示图像???

Answer 1

使用此代码拍照...

File pictureFileDir = getDir();
                                if (!pictureFileDir.exists() && !pictureFileDir.mkdirs()) {

                                    Log.d("Photo Take", "Can't create directory to save image.");
                                    Toast.makeText(PhotoTake.this , "Can't create directory to save image.",
                                            Toast.LENGTH_LONG).show();
                                    return;
                                }

                                SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
                                String date = dateFormat.format(new Date());
                                String photoFile = "Picture_" + date + ".jpg";
                                String filepath = pictureFileDir.getPath() + File.separator;
                                File imageFile = new File(filepath , photoFile);

                                ContentValues image = new ContentValues();

                                image.put(Images.Media.TITLE, photoFile);
                                image.put(Images.Media.DISPLAY_NAME, photoFile);
                                image.put(Images.Media.DESCRIPTION, "Accident data Accachment " + date);
                                image.put(Images.Media.DATE_ADDED, date);
                                image.put(Images.Media.DATE_TAKEN, date);
                                image.put(Images.Media.DATE_MODIFIED, date);
                                image.put(Images.Media.MIME_TYPE, "image/jpeg");
                                image.put(Images.Media.ORIENTATION, 0);

                                 File parent = imageFile.getParentFile();
                                 String path = parent.toString().toLowerCase();
                                 String name = parent.getName().toLowerCase();
                                 image.put(Images.ImageColumns.BUCKET_ID, path.hashCode());
                                 image.put(Images.ImageColumns.BUCKET_DISPLAY_NAME, name);
                                 image.put(Images.Media.SIZE, imageFile.length());

                                 image.put(Images.Media.DATA, imageFile.getAbsolutePath());

                                 mCapturedImageURI = PhotoTake.this.getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, image);


                                Intent intent = new Intent(
                                        MediaStore.ACTION_IMAGE_CAPTURE);
                                intent.putExtra(MediaStore.EXTRA_OUTPUT,
                                        mCapturedImageURI);

                                startActivityForResult(intent, req);

现在在onActivityResult中检索它......

if (requestCode == 100 && resultCode == Activity.RESULT_OK) {
            if (mCapturedImageURI != null) {
                img1.setImageBitmap(getScaledBitmap(mCapturedImageURI));;

                System.out.println("Onactivity Result uri = " + mCapturedImageURI.toString());
            } else {
                Toast.makeText(PhotoTake.this, "Error getting Image",
                        Toast.LENGTH_SHORT).show();
            }

        }

您需要此方法来避免OutOfMemory Exception

private Bitmap getScaledBitmap(Uri uri){
        Bitmap thumb = null ;
        try {
            ContentResolver cr = getContentResolver();
            InputStream in = cr.openInputStream(uri);
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inSampleSize=8;
            thumb = BitmapFactory.decodeStream(in,null,options);
        } catch (FileNotFoundException e) {
            Toast.makeText(PhotoTake.this , "File not found" , Toast.LENGTH_SHORT).show();
        }
        return thumb ; 
    }

希望它有所帮助。

Answer 2

你在同一个活动中做了startActivityForResult

you need to call 
onActivityResult(int requestcode, int resultCode, Intent data){
if(resultCode==RESULT_OK){

if(requestCode==1){

    // get your data from the intent
   }
  }

}

试图在我的应用程序中显示刚刚使用内置相机应用程序拍摄的照片

2 个答案: