Develop Reference

How save a part of a map with Mapsui?

For a project, i'd like to save a part of a map and use it when i'm offline.
I'd like to know if it is possible to save a part of map using Mapsui ?
I already search but I didn't found something good..

If it is just the image of the map you could look at the test file 'MapRendererTests.cs'. It shows how you can save a map extent as an image.
var bitmap = new MapRenderer().RenderToBitmapStream(viewport, map.Layers, map.BackColor);
There is no support for saving the geometries themselves.

Get Facebook user's details and big profile picture in one call

I can get in one call /me details including picture, email, name.
But URL returned is of an extremely small picture (50px*50px).
I know I can make additional call to get bigger image with something like:
.../me/picture?width=999
But is it possible to combine it with:
https://graph.facebook.com/v2.5/me?fields=id,relationship_status,picture,email,gender,first_name,last_name,significant_other
to receive all this information in one request-response instead of two?

Here you go:
https://graph.facebook.com/v2.6/me?fields=id,relationship_status,picture.width(999),email,gender,first_name,last_name,significant_other
You can make nested requests by following this:
https://developers.facebook.com/docs/graph-api/using-graph-api#fieldexpansion

Retrieve random DB record

What is the best way to retrieve a "X" number of random records using Entity Framework (EF5 if it's relevant). The value of "X" will be set based on where this will be used.
Is there a method for doing this built into EF or is best to pull down a result set and then use a C# random number function to pull the records. Or is there a method that I'm not thinking of?
On the off chance that it's relevant I have a table that stores images that I use for different usages (there is a FK to an image type table). The images that I use in my carousel on the homepage is what I'm wanting to add some variety to...consequently how "random" it is doesn't matter to me much. I'm just trying to get away from the same six or so pictures always being displayed. (Also, I'm not really interested in debating/discussing storing images in a table vs local storage.)
The solution needs to be one using EF via a LINQ statement. If this isn't directly possibly I may end up doing something SIMILAR to what #cmd has recommended in the comments. This would most likely be a matter of retrieving a record count...testing the PK to make sure the resulting object wasn't null and building a LIST of the X number of object's PKs to pass to front end. The carousel lazy loads the images so I don't actually need the image when I'm building the list that will be used by the carousel.

Can you just add an ORDER BY RAND() clause to your query?
See this related question: MySQL: Alternatives to ORDER BY RAND()

Retrieving image stored in long datatype

I have one web application, having one table in oracle10g having following structure:
Column Name DataType
UserImage long
My problem is that how should I display the IMAGE on my aspx page which is stored in long format?
If data type is BLOB or CLOB then it could be easier one, but it's stored in long.
I could not change the datatype since this is third party DB.
Please suggest me how could I achieve this. The solution could be either using Oracle or C#, I'm fine with both.
Thanks in advance.

You can't store an image in a 'long' datatype.
Instead - hold a static list of key-value pairs, each pair defines an index (say, from 1 to n) of an image
and the value holds the Image's file name.
For instance, the following pseudo code demonstrates a similar approach (should be implemented on the client/server side of your application, not in the DB
SWITCH (USERIMAGE)
CASE 1:
SETIMAGE("IMAGES/IMAGE_NUMBER_ONE.JPG");
BREAK:
CASE 2:
SETIMAGE("IMAGES/IMAGE_NUMBER_TWO.JPG");
BREAK:
and so on.
Another solution:
Assume your 1st table is called "Table1". create a new table in your database called my_images
Column name Column type Comments
UserImage LONG Foreign key to Table1.UserImage
ImageData BLOB
And,
SELECT t1.ImageData FROM Table1 t1, my_images mi
WHERE t1.UserImage == mi.UserImage;

The "chunk" characters you have posted seem to be a TIFF image. That gives an idea how the images are stored. In fact, the binary image data seems to be stored as character data. That's certainly completely unsupported and very fragile. I'd recommend converting it as soon as possible.
In the mean time, I can propose two ways of retrieving the data so I cannot guarantee that either one works.
But approaches are susceptible to characters sets: If two or more character sets are involved, your data will be converted and thereby destroyed. And both are susceptible to the maximum length of certain data types.
Approach 1:
Try to go via the RAW data type and retrieve it as a byte array. It's certainly limited to 32'000 characters, maybe even less.
SELECT UTL_RAW.CAST_TO_RAW(UserImage) FROM UNNAMED_TABLE WHERE ...
On the C# side, you should get an OracleBinary or byte[] instance.
Approach 2:
Try to retrieve it as a string. Then convert the string into a byte array using the original encoding (Encoding.GetBytes. With enough luck, the original data can be restored.

ASP.NET MVC / C# - String to valid URL characters?

I don't know how to ask this, and I don't know what it is called either so I'll just describe what I want to achieve.
In the database, some articles' title originaly has spaces:
my title with spaces
But in the url, spaces are replaced by other characters such as plus sign (+) or underscore (_)
http://www.mydomain.com/mycontroller/myaction/my_title_with_spaces
or
http://www.mydomain.com/mycontroller/myaction/my+title+with+spaces
Now, how do you do that in C#? Or is there any helper in ASP.NET MVC that can do something like that?
Let say we achieved the said URL, is there any risk that two unique titles become the same in the URL? Please consider these titles:
Title's
Titles
after parsing, they became the same
Titles
Titles
This will be a problem when retrieving the article from the database since I'll get two results, one for "Title" and one for "Title's".

I would implement that functionality like this:
1. When creating a new article, generate the URL representation based on the title.
Use a function that converts the title for a suitable representation.
For example, the title "This is an example" might generate something like "This_is_an_example".
This is up to you. You can create a function that parses the title with rules you define, or use an existing one if it suits better your problem.
2. Ensure the URL representation is unique
If it's going to be an ID, it must be unique. So, when creating new articles you must query your database for the resulting URL representation. If you get a result from the database, it means the newly created article generated the same representation as one of the already created articles. Add something to it so it remains unique.
This could be something like "This_is_an_example_2". In this case, we added the "_2" to the end of the generated representation so it differs from the already existing one. Once more, with each change you have to ensure this representation remains unique.
3. Save the created ID in the database, along with the article data
In the database be sure to save the "This_is_an_example" ID and relate it to the article. Maybe even as the table primary key?
4. Query the database for the correct article
Now, about showing a site visitor the correct article:
When a visitor asks for the following resource, for example:
http://www.mydomain.com/mycontroller/myaction/this_is_an_example_2
Extract the URL part that identifies the article, in this case "this_is_an_example_2".
When you have that, you have the identifier of the article in the database. So, you can query the database for the article with the "this_is_an_example_2" ID and show the article's content to the user.
This might involve some URL rewriting. Unfortunately I'm unable to help you with that in asp.NET. Some search on the subject will surely help you.