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Assuming you aren't using a using statement the object will not be destructed immediately when going out of scope. The garbage collector will take care of the unreferenced Attachment objects from time to time.
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Hello,
I need to create a desktop application using C# as frontend and postgresql/postgis for the database.
I have google maps V3 embedded into web browser control.
My question is, is there any way to visualize geometry column of postgis into google maps using C#.
Thanks in advance
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tashee wrote: I have google maps V3 embedded into web browser control.
My question is, is there any way to visualize geometry column of postgis into google maps using C#.
The WebBrowser will simply display a webpage. So, yes, if your app displays the Google Map correctly, it should be visible.
Specifics (setting options and the likes) won't be done in C# but in JavaScript. See the Google documentation for details.
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Dear All,
Request your help/Suggestion.
I have created a windows application which will get data from centaralized SQL server having image datatype as well.
And am using simple ado.net to connect to the SQL server and the connection will be made via internet.
Now my problem is when i try to connect the SQL Server via internet am getting perfomance issue that it is taking much time to connect and get the data back from the SQL server.
Now I need help from you experts that,
1) How to handle this data transfer from Centralized SQL Server to my Windows application effectively.
2) Will webservice work for me? if i convert the SQL Server connections through web services then the data transfers will be good? and also the image will come fast?
Or please suggest me what is the effective way to get data from Centralized SQL server via internet.
Thanks in advance
Hema Bairavan
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Hema Bairavan wrote: Now my problem is when i try to connect the SQL Server via internet
Your second problem is security; check out if there are a lot of foreigners trying to log in, that might kill performance a bit. It'd be better to have the Sql server expose it's data over a webservice.
Hema Bairavan wrote: am getting perfomance issue that it is taking much time to connect and get the data back from the SQL server.
Again, are you sure? Isn't it just a query that's taking a lot of time? Did you ask for the "statistics" in Sql management Studio?
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Dear Eddy,
First of all thanks for your time to replying to me.. Regarding to the security i am using the encrypted password for the sql server, and only my application from various places going to access the DB with same user id and password so i hope security wont be an issue.
And Its just a query only i hope, because when i put a select statement ignoring the image column am getting records bit faster (even though its late only when compared to query executed in normal LAN server) but when i query with image data type am even getting more.
So getting into webservices will solve my problem? but how about images through web services?
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Ultimately, an image is just an array of bytes. There's a huge hint.
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Hema Bairavan wrote: Regarding to the security i am using the encrypted password for the sql server, and only my application from various places going to access the DB with same user id and password so i hope security wont be an issue.
So.. I could simply try "sa" and password-combinations over the internet? Can I has the IP? 
Hema Bairavan wrote: And Its just a query only i hope, because when i put a select statement ignoring the image column am getting records bit faster (even though its late only when compared to query executed in normal LAN server) but when i query with image data type am even getting more.
"A bit faster" isn't very encouraging; it means that the image's size probably isn't the bottleneck. Your LAN is a few MB wide, at least - one usually does not have that bandwidth on the internet.
Hema Bairavan wrote: So getting into webservices will solve my problem? but how about images through web services?
Webservices would not make it go faster, on the contrary, it's an extra layer. OTOH, it'd be a bit safer.
You're describing a desktop-application. How long does it take to download a megabyte, using your code? I assume you download the images only once, and cache them locally?
Otherwise, consider hosting them on a webserver (not a database) and use the WebBrowser control to display them; that way IE will determine whether or not it needs to download a new version, or use the cached one in a temp-folder.
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The first thing you might look at is the size of the images. Depending on it's usage you might want to save a copy with less quality (tuned for webapplications eg). If quality is needed I would look into saving the images on disc and providing the link and/or caching.
From a speed point of view, the webservice will probably slow you down, but you might find it easier managable to go through a web service.
As long as the application is running on the inside, you can get away with the security, but if someone external wants to use it you better use a webservice.
If all that doesn't help to improve performance you need to have a look at the database and/or the application.
Is the database tuned and indexed correctly (does it need to be re-indexed?). Is your application not doing things unnecessary like fetching/loading the image multiple times during copies from memory objects eg.
hope this helps.
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Dear V,
First of all thanks for your time to replying to me.
I have restricted the application to store the image size only less than 50kb, and even there also am getting problem. And i hope i could go for the option you said saving in the disk but once again as an windows application accessing image from a shared drive???
and regarding the security none other than me or my application is going to log in to the application none other foreigners.
And i have only 5 records in my table.. Is there indexing will apply in this case? am getting the time delay on just putting a select statement of 5 records...
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Hema Bairavan wrote: size only less than 50kb
That´s not much, so no problem there
Hema Bairavan wrote: but once again as an windows application accessing image from a shared drive???
Why should this be a problem?
Hema Bairavan wrote: Is there indexing will apply in this case?
No , five records doens´t need indexing.
In this case you have to culprits left, your code or the network, debug your application and check what method or statement takes a long time.
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You must localize the problem.
However per your other comment it is probably a network problem.
Your other comment suggest that a query without the image data is a "bit" faster.
A query without the image data would be smaller than one with it. And a network problem would have more problems with more data. Thus that fits.
A database problem with the size that you suggested in another comment seems very unlikely unless you did something very odd with the database. And I can't image how you could have messed up the client side that would cause a slow down.
There are various ways to test network performance which you can google for.
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Ok Guys,
Thanks for all your help and suggestions and your time for replying.
With your suggestions and replies now am planning to change my application to take the image from shared disk using web browser control in my application and database connection would be using web services.
So is this ok?
Thanks again for all your help.
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Hello, Can i get step by step tutorial on how to program fingerprint recognition using c#.
I don't know how to start fingerprint system with c#.
I want to know following.
1. what database is suitable used for fingerprint data saving? (mysql, access or ...)?
2. how to save image in database?
please help me.
thank u so much.
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This depends on how much data you need to store in the database.
If its just a few users and you can store your database on a file server go for Access.
MySql provides you with a free option while you may need to pay for other databases.
Sql Server or Oracle would provide you with many powerful options for enterprise level applications.
The way you store images will be vary slightly from database to database.
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Perhaps you will find this very useful:
A Framework in C# for Fingerprint Verification[^]
Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore, Dream. Discover.
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Search for digitalPersona in google. They are one of the leader in finger print recognition. You can purchase the devices and also you can get their SDK that make your life easy.
The SDK process has two important steps.
1) Registration: Forming single Registration template by taking the same finger input for at-least 4 times (This will be stored in the database as binary object. Kind of gray scale image formed from the registration templates). The template should be registered for a user of the application
2) Verification: Takes the finger input of the user, walk through the registration template in the in database (Actually you should read the template one by one and ask the sdk that verification succeeded) and a match occurs, you know who the user is..
Note: The finger prints are unique, if a match occurs between verification and already registered template, then you know who the user is.
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I'm trying to change the background image of a diferent form, both forms that I'm using aren't the parent form, what I'm trying to achieve is that by the click of a button the background image of the other form is changed.
Thanks.
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How you solve this really depends on how the second form was created. If it was created from the first form, a simple solution would be to have a public method on that does what you want, and call it from the first form. If you have a reference to the first form in your second form, add an event to the first form that signifies that the image should change, and subscribe to it from the second form.
Alternatively, you could go all pattern based and use a Mediator, so the message would be raised by the first form and the mediator would notify all interested parties that this was ready to be handled.
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The simplest answer is to provide a reference to Form2 to Form1 (in its constructor or via a property). Then, in an event handler on Form1 you can simply do
form2.BackgroundImage = whatever;
However, providing this sort of direct link to other UI elements quickly results in a horrible mess of dependencies and global state, so if it's not a trivial UI I don't recommend it. Instead, I would guess that the change in image actually represents some state that should be stored in a data model, not the UI (although the UI will reflect it). What does the image mean? That meaning should be a property on a data object and the UI for the second form should be data bound to it.
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I don't have currently my computer on hand, and I didn't try it yet, what I want to do is have the form constantly opened in a background behind 2 forms, and while I transit between the forms there won't be a flash of the desktop by navigating between the forms, the solution I thought of was placing a background that is the same as the two forms.
I tried using once a public event, but always had a error I couldn't fix, so I would thank a lot if someone would paste the code to do so from another form.
Here is a resume of my application:
The main form is started and hidden instantly, it's just a container for my global variables.
The only thing it does is start another form where the user can do a login, to which the user can liberaly change his background during the application, and while doing so the background of the "background form" is changed aswell. That way while I navigate between the fullscreen-forms I won't see the desktop. (a slight flash of it).
If there is some way to solve this in a better way I'll be grateful of any feedback I can get.
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Yeah using the background image is a big hack here and it should be avoidable.
I don't actually see why you want multiple forms at all here. If they are designed to be full screen then you can only see one at a time, so why not use Panels on a single form, and switch visibility when you change state?
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