Uri 和 File 相互转。兼容各个版本

Uri 转 File

 public static File uriToFile(Uri uri,Context context) {
        String path = null;
        if ("file".equals(uri.getScheme())) {
            path = uri.getEncodedPath();
            if (path != null) {
                path = Uri.decode(path);
                ContentResolver cr = context.getContentResolver();
                StringBuffer buff = new StringBuffer();
                buff.append("(").append(MediaStore.Images.ImageColumns.DATA).append("=").append("'" + path + "'").append(")");
                Cursor cur = cr.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[] { MediaStore.Images.ImageColumns._ID, MediaStore.Images.ImageColumns.DATA }, buff.toString(), null, null);
                int index = 0;
                int dataIdx = 0;
                for (cur.moveToFirst(); !cur.isAfterLast(); cur.moveToNext()) {
                    index = cur.getColumnIndex(MediaStore.Images.ImageColumns._ID);
                    index = cur.getInt(index);
                    dataIdx = cur.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
                    path = cur.getString(dataIdx);
                }
                cur.close();
                if (index == 0) {
                } else {
                    Uri u = Uri.parse("content://media/external/images/media/" + index);
                    System.out.println("temp uri is :" + u);
                }
            }
            if (path != null) {
                return new File(path);
            }
        } else if ("content".equals(uri.getScheme())) {
            // 4.2.2以后
            String[] proj = { MediaStore.Images.Media.DATA };
            Cursor cursor = context.getContentResolver().query(uri, proj, null, null, null);
            if (cursor.moveToFirst()) {
                int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                path = cursor.getString(columnIndex);
            }
            cursor.close();

            return new File(path);
        } else {
            //Log.i(TAG, "Uri Scheme:" + uri.getScheme());
        }
        return null;
    }

File 转 Uri

public static Uri getImageContentUri(Context context,File imageFile) {
    String filePath = imageFile.getAbsolutePath();
    Cursor cursor = context.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
            new String[] { MediaStore.Images.Media._ID }, MediaStore.Images.Media.DATA + "=? ",
            new String[] { filePath }, null);
    if (cursor != null && cursor.moveToFirst()) {
        int id = cursor.getInt(cursor.getColumnIndex(MediaStore.MediaColumns._ID));
        Uri baseUri = Uri.parse("content://media/external/images/media");
        return Uri.withAppendedPath(baseUri, "" + id);
    } else {
        if (imageFile.exists()) {
            ContentValues values = new ContentValues();
            values.put(MediaStore.Images.Media.DATA, filePath);
            return context.getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
        } else {
            return null;
        }
    }
}