Android 4.4以上获取图片URI格式不同导致getContentResolver返回null

今天在实现用户头像选择裁剪功能时，虚拟机裁剪没问题，实机却调用不了系统的裁剪，百度了一下以为是网上说的miui的裁剪的图片过大，或对return data分配的资源不够，可是我这连裁剪Activity都没有启动，所以可能性不大，试着Log输出一下，果然是因为getContentResolver()没有获得数据，这种情况大多都是Android系统版本问题，所以我又试着打印了uri的字符串，果然不同版本通过
intent.setAction(Intent.ACTION_PICK); intent.setData(MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
返回的uri格式不同
Android4.4以前获取的uri的字符串是“content://media/external/image/media”格式的，而4.4以后变成"file:///sdcard/mysong.mp3"格式，会导致
Cursor c = getContentResolver().query(uri,MediaStore.Images.Media.DATA, null, null, null);
获取的c里面并没有图片信息。而裁剪图片所需要获取图片的真实路径path可以使用由android_Y网友提供的根据Uri获取图片绝对路径，解决Android4.4以上版本Uri转换

     * 根据Uri获取图片绝对路径，解决Android4.4以上版本Uri转换
     * @param activity
     * @param imageUri
     * @author yaoxing
     * @date 2014-10-12
     */
    @TargetApi(19)
    public static String getImageAbsolutePath(Activity context, Uri imageUri) {
        if (context == null || imageUri == null)
            return null;
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT && DocumentsContract.isDocumentUri(context, imageUri)) {
            if (isExternalStorageDocument(imageUri)) {
                String docId = DocumentsContract.getDocumentId(imageUri);
                String[] split = docId.split(":");
                String type = split[0];
                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }
            } else if (isDownloadsDocument(imageUri)) {
                String id = DocumentsContract.getDocumentId(imageUri);
                Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
                return getDataColumn(context, contentUri, null, null);
            } else if (isMediaDocument(imageUri)) {
                String docId = DocumentsContract.getDocumentId(imageUri);
                String[] split = docId.split(":");
                String type = split[0];
                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }
                String selection = MediaStore.Images.Media._ID + "=?";
                String[] selectionArgs = new String[] { split[1] };
                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        } // MediaStore (and general)
        else if ("content".equalsIgnoreCase(imageUri.getScheme())) {
            // Return the remote address
            if (isGooglePhotosUri(imageUri))
                return imageUri.getLastPathSegment();
            return getDataColumn(context, imageUri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(imageUri.getScheme())) {
            return imageUri.getPath();
        }
        return null;
    }

    public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
        Cursor cursor = null;
        String column = MediaStore.Images.Media.DATA;
        String[] projection = { column };
        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
            if (cursor != null && cursor.moveToFirst()) {
                int index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is ExternalStorageProvider.
     */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is Google Photos.
     */
    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getAuthority());
    }````