Skype Profile Image Downloader in Visual Basic

[A61a]

Introduction:
In this tutorial we are going to be making a simple program in Visual Basic to download someones Skype profile picture.

How It Works:
We are going to use the Skype API to act as a link to get the profile picture, from that we can use a simple download function within Visual Basic .NET to download the returned image through the link.

Design:
This program will take two components;
Button, named 'skypeButton', text set as 'Download Profile Image'
Textbox, named 'skypeText', where the user will enter the skype profile username.

Verifying:
Once the button has been clicked, we first want to check that the text falls within the Skype username requirements (greater than 5 characters but less than 33) and only contains letters/numbers.

First we check the character length...

1. Private
   
   Sub
   
   skypeButton_Click(sender As
   
   Object
   
   , e As
   
   EventArgs) Handles skypeButton.Click
   
2. Dim
   
   username As
   
   String
   
   = skypeText.Text
   
3. Dim
   
   runDownload As
   
   Boolean
   
   = True
   
4. If
   
   (username.Length >= 6 And
   
   username.Length <= 32) Then
   
5. 'Next code goes in here.
   
6. Else
   
   : MsgBox("Username is not the right length!"
   
   )
   
7. End
   
   If
   
8. End
   
   Sub
   

Then we iterate through each character and ensure that it is allowed (contained within our allowed characters list), if any of them is not there, we set the boolean value of our earlier defined 'runDownload' variable to false...

1. Dim
   
   allowed As
   
   Char() = "abcdefghijklmnopqrstuvwxyz0123456789"
   
2. username = username.ToLower() 'Easier to check against the allowed characters, case insensitive.
   
3. For
   
   Each
   
   character As
   
   String
   
   In
   
   username
   
4. Dim
   
   isFound As
   
   Boolean
   
   = False
   
5. For
   
   Each
   
   c As
   
   Char In
   
   allowed
   
6. If
   
   c = character Then
   
   isFound = True
   
7. Next
   
8. If
   
   Not
   
   (isFound) Then
   
9. MsgBox(character)
   
10. runDownload = False
    
11. End
    
    If
    
12. Next
    

Then if the 'runDownload' variable is True/y/yes/ok/1 then no error occured, the username is ok, and we try to download the image...

1. If
   
   (runDownload) Then
   
2. Dim
   
   link As
   
   String
   
   = "http://api.skype.com/users/"
   
   + username + "/profile/avatar"
   
3. Dim
   
   fs As
   
   New
   
   SaveFileDialog
   
4. fs.Filter = "JPEG Files | .jpg | PNG Files | *.png"
   
5. fs.FilterIndex = 1
   
6. fs.ShowDialog()
   
7. If
   
   (My.Computer.FileSystem.FileExists(fs.FileName)) Then
   
8. Dim
   
   result As
   
   MsgBoxResult = MsgBox("File already exists, overwrite it?"
   
   , MsgBoxStyle.YesNo, "File Exists"
   
   )
   
9. If
   
   (result = MsgBoxResult.Yes) Then
   
10. Dim
    
    wc As
    
    New
    
    WebClient
    
11. wc.DownloadFile(link, fs.FileName)
    
12. End
    
    If
    
13. Else
    
14. Dim
    
    wc As
    
    New
    
    WebClient
    
15. wc.DownloadFile(link, fs.FileName)
    
16. End
    
    If
    
17. Else
    
    : MsgBox("Not all the characters meet the Skype requirements for a username. Please try again with a different username"
    
    )
    
18. End
    
    If
    

We let the user choose a save location, file name and file type out of .jpg or .png.