数据库操作

 

从URI获得文件路径

string  myImageUrl = "content://media/external/images/media/***";
    Uri uri = Uri.parse(myImageUrl);
    

    String[] proj = { MediaStore.Images.Media.DATA };   
    Cursor actualimagecursor = this.ctx.managedQuery(uri,proj,null,null,null);  
    int actual_image_column_index = actualimagecursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);   
    actualimagecursor.moveToFirst();   
    

    String img_path = actualimagecursor.getString(actual_image_column_index);  
    File file = new File(img_path);
    Uri fileUri = Uri.fromFile(file);

 

 

由文件路径得到URI

Uri mUri = Uri.parse("content://media/external/images/media"); 
            Uri mImageUri = null;

            Cursor cursor = managedQuery(
                    MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null, null,
                    null, MediaStore.Images.Media.DEFAULT_SORT_ORDER);
            cursor.moveToFirst();

            while (!cursor.isAfterLast()) {
                String data = cursor.getString(cursor
                        .getColumnIndex(MediaStore.MediaColumns.DATA));
                if (picPath.equals(data)) {
                    int ringtoneID = cursor.getInt(cursor
                            .getColumnIndex(MediaStore.MediaColumns._ID));
                    mImageUri = Uri.withAppendedPath(mUri, ""
                            + ringtoneID);
                    break;
                }
                cursor.moveToNext();
            }