A simple Silverlight verification code example

On the Silverlight login page, it is often used to enter the verification code. How to generate the verification code is similar to that generated by. net. The following is a brief introduction:
1. Create an indentifycodeclass. CS file under the Silverlight Project
1) First, pay attention to adding references. Using system. Windows. Media. imaging;
2) Add a method to generate a verification code
Public String Createindentifycode (INT count)
{
String allchar = "1, 2, 3, 4, 5, 6, 7, 8, 9, 0, a, a, B, B, C, C, D, D, E, E, F, F," +
"G, G, H, H, I, I, J, J, K, k, l, l, m, M, N, N, O, O, P, p, Q, Q, R, R, S, S, "+
"T, t, u, u, v, V, W, W, X, X, Y, Y, Z ";
String [] allchararray = allchar. Split (',');
String randomcode = "";
Int temp =-1;
Random Rand = new random ();
For (INT I = 0; I <count; I ++)
{
If (temp! =-1)
{
Rand = new random (I * temp * (INT) datetime. Now. ticks ));
}
Int T = Rand. Next (61 );
If (temp = T)
{
Return createindentifycode (count );
}
Temp = T;
Randomcode + = allchararray [T];
}
Return randomcode;
}
3) Add a method to generate the background noise image of the verification code.
Random r = new random (datetime. Now. millisecond );
Public void Creatimage (String text, image imgsource, int IW, int IH)
{
Grid GX = new grid ();
Canvas cv1 = new canvas ();
For (INT I = 0; I <6; I ++)
{
Polyline P = new polyline ();
For (int ix = 0; ix <R. Next (3, 6); ix ++)
{
P. Points. Add (new point (R. nextdouble () * IW,
R. nextdouble () * IH ));
}
Byte [] buffer = new byte [3];
R. nextbytes (buffer );
Solidcolorbrush SC = new solidcolorbrush (color. fromargb (255,
Buffer [0], buffer [1], buffer [2]);
P. Stroke = SC;
P. strokethickness = 0.5;
Cv1.children. Add (P );
}
Canvas cv2 = new canvas ();
Int y = 0;
Int LW = 6;
Double W = (IW-LW)/text. length;
Int H = (INT) IH;
Foreach (char X in text)
{
Byte [] buffer = new byte [3];
R. nextbytes (buffer );
Solidcolorbrush SC = new solidcolorbrush (color. fromargb (255,
Buffer [0], buffer [1], buffer [2]);
Textblock T = new textblock ();
T. textalignment = textalignment. Center;
T. fontsize = R. Next (H-3, H );
T. Foreground = SC;
T. Text = x. tostring ();
T. Projection = new planeprojection ()
{
Rotationx = R. Next (-30, 30 ),
Rotationy = R. Next (-30, 30 ),
Rotationz = R. Next (-10, 10)
};
Cv2.children. Add (t );
Canvas. setleft (T, LW/2 + y * w );
Canvas. settop (T, 0 );
Y ++;
}
GX. Children. Add (cv1 );
GX. Children. Add (cv2 );
Writeablebitmap W = new writeablebitmap (GX, new transformgroup ());
W. Render (GX, new transformgroup ());
Imgsource. Source = W;
}
2. Add the following to the usercontrol_loaded event on the logon page: Code You can:
Indentifycodeclass code = new indentifycodeclass ();
String generatedcode = code. createindentifycode (6 );
Code. creatimage (generatedcode, checkcodeimage, 150, 30 );
3. Obtain the verification code entered by the user in the text box and compare it with the generated verification code.
....
String indentifycode = This. tbindentifycode. Text. Trim ();
If (generatedcode! = Indentifycode)
{
MessageBox. Show ("Incorrect verification code! ");
This. tbindentifycode. Focus (); // input focus
}
4. implement verification results. Just try it!