Android 打开相册，选择一张图片并返回

Intent albumIntent = new Intent(Intent.ACTION_PICK, null);
			albumIntent.setDataAndType(
					MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");
			startActivityForResult(albumIntent, ALBUM_OK);

	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		if (ALBUM_OK == requestCode) {
			Toast.makeText(this, "OK now", Toast.LENGTH_SHORT).show();
			Bitmap bitmap;
			Log.e("MainActivity ", " onActivityResult ");
			ContentResolver cr = this.getContentResolver();
			Uri uri = data.getData();

			try {
				bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri));
				Log.e("MainActivity ", " onActivityResult "
						+ data.getData().toString());//此处用Log.e，仅是为了查看红色Log方便
				imageview.setImageBitmap(bitmap);
				readExifInfo(getImagePath(uri));//这是用来读取图片的exif
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			}
			catch (IOException e) {
				e.printStackTrace();
			}
		}
}

	private String getImagePath(Uri uri) {
		if (null == uri) {
			Log.e("getImagePath", "uri return null");
			return null;
		}

		Log.e("getImagePath", uri.toString());
		String path = null;
		final String scheme = uri.getScheme();
		if (null == scheme) {
			path = uri.getPath();
		} else if (ContentResolver.SCHEME_FILE.equals(scheme)) {
			path = uri.getPath();
		} else if (ContentResolver.SCHEME_CONTENT.equals(scheme)) {
			String[] proj = { MediaStore.Images.Media.DATA };
			Cursor cursor = getContentResolver().query(uri, proj, null, null,
					null);
			int nPhotoColumn = cursor
					.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
			if (null != cursor) {
				cursor.moveToFirst();
				path = cursor.getString(nPhotoColumn);
			}
			cursor.close();
		}

		return path;
	}

	private void readExifInfo(String path) throws IOException {
		ExifInterface exif = new ExifInterface(path);
		String iso = exif.getAttribute(ExifInterface.TAG_ISO);
		String make = exif.getAttribute(ExifInterface.TAG_MAKE);
		String model = exif.getAttribute(ExifInterface.TAG_MODEL);
		String flash = exif.getAttribute(ExifInterface.TAG_FLASH);
		String time = exif.getAttribute(ExifInterface.TAG_DATETIME);
		String wb = exif.getAttribute(ExifInterface.TAG_WHITE_BALANCE);
		String aperture = exif.getAttribute(ExifInterface.TAG_APERTURE);
		String width = exif.getAttribute(ExifInterface.TAG_IMAGE_WIDTH);
		String height = exif.getAttribute(ExifInterface.TAG_IMAGE_LENGTH);
		String focal_len = exif.getAttribute(ExifInterface.TAG_FOCAL_LENGTH);
		String exposure_time = exif.getAttribute(ExifInterface.TAG_EXPOSURE_TIME);
		String msg = "时间: "+ time + "\n机型: "  + model + "\n厂商: " + make 
				+ "\n光感: " + iso   + "\n曝光: "  + exposure_time + "\n光圈: " + aperture 
				+ "\n闪光: " + flash + "\n焦距: "  + focal_len+ "\n高度: " + height 
				+ "\n宽度: " + width + "\n白平衡: "+  wb;
		Log.e("readExifInfo", msg);

		AlertDialog.Builder builder = new Builder(MainActivity.this);
		builder.setTitle("Exif");
		builder.setMessage(msg);
		builder.create().show();
	}