Silverlight Password Box

Download source - 488.8 KB

Introduction

While digging into Silverlight 2 Beta 2, I have noticed that there is no Password Box available. It will be in the final version, but till then we have to figure out some other way to do it. This solution is quick and maybe even a little bit dirty but it works and that's what makes it valuable enough to be posted. :)

Using the Code

Just attach the tbPassword_TextChanged method (from the attached example) to your password text box (simple Silverlight Text Box).

string _currentText = "";
void tbPassword_TextChanged(object sender, TextChangedEventArgs e)
{
    TextBox __textBox = sender as TextBox;
    if (__textBox != null)
    {
        string __currentText = __textBox.Text;
        if (__currentText.Length < _currentText.Length)
            _currentText = _currentText.Substring(0, __currentText.Length);
        if (__currentText != "")
        {
            for (int i = 0; i < __currentText.Length; i++)
            {
                if (__currentText[i] != '\u25CF')
                {           
                    string __temp = __currentText.Remove(i, 1);
                    __textBox.Text = __temp.Insert(i, "\u25CF");
                    _currentText = _currentText.Insert
			(_currentText.Length, __currentText[i].ToString());
                }
            }
        }
    }
}

In the _currentText, you will find text from the password box.

Points of Interest

I am working on quite a big RIA Silverlight application. Lacking this basic password box made my stomach ache. Hopefully, in the final release of Silverlight, we won't have such issues anymore.

History

While creating this small sample, I was inspired by Michael Sync's post. Unfortunately, Silverlight 2 beta 2 sample source code did not work properly and that is why I decided to write a simpler solution (IMHO).

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

Maciej Gren

Team Leader
GOYELLO

Poland

Member

I started work with .Net in year 2005. During my studies I was a team leader of project which scored 4th place on Polish Imagine Cup Finals where we delivered WPF application with https WCF services. Meanwhile I have worked on Windows Mobile Applications with Windows CE 5.0. I have learned how to create Windows CE Images using Platform Builder and I gained high skills in Compact Framework 2.0. After one year of developing using this framework I have switched to ASP.Net. Currently I am using Monorail Framework together with Active Record and Extjs library (for presentation layer). I am a Team Leader in GOYELLO where we delivered quite successful projects. My aim is to develop good quality applications but not forgetting about reality. Always there are some drawbacks on each solution. The case is to find the proper balance Smile | :)

Article Top

Poor

Excellent

Add a reason or comment to your vote: x
Votes of 3 or less require a comment

Comments and Discussions

You must Sign In to use this message board. (secure sign-in)

Search this forum
	Profile popups Noise Layout Per page

[My vote of 2] What about the cursor????

Sike Mullivan

8:02 27 May '10

The following is actually a better implementation. It will handle cases where the user places the cursor into the middle of existing text.

 
public class WatermarkedPasswordBox : WatermarkedTextBox
    {
        private char _lastKey;
        private int _prevSelectionLength;
        private int _prevSelectionStart;
        private int _currPosition;
 
        public WatermarkedPasswordBox()
        {
           
            this.TextChanged += new TextChangedEventHandler(WatermarkedPasswordBox_TextChanged);
            this.CurrentPassword = string.Empty;
        }
 
        public string CurrentPassword
        {
            get;
            set;
        }
 
        private void WatermarkedPasswordBox_TextChanged(object sender, TextChangedEventArgs e)
        {
            string currText = this.Text;
            int currPosition = this.SelectionStart;
            int startPosition = 0;
 
            List<char> chars = GetNonPassChars(currText);
 
            if (currText.Length == this.CurrentPassword.Length && chars.Count == 0)
                return;
 
            int removeCharCount = this.CurrentPassword.Length - (currText.Length - chars.Count);
 
            startPosition = currPosition - chars.Count;
 
            if (removeCharCount > 0)
                this.CurrentPassword = this.CurrentPassword.Remove(startPosition, removeCharCount);
 
            for (int i = 0; i < chars.Count; i++)
            {
                this.CurrentPassword = this.CurrentPassword.Insert(i + startPosition, chars[i].ToString());
            }
 
            currText = string.Empty;
            for (int i = 0; i < this.CurrentPassword.Length; i++)
                currText += '\u25CF';
 
            this.Text = currText;
            this.SelectionStart = currPosition;
        }
 
        private List<char> GetNonPassChars(string currText)
        {
            List<char> chars = new List<char>();
            foreach (char c in currText)
            {
                if (c != '\u25CF')
                    chars.Add(c);
            }
            return chars;
        }
    }

PasswordBox Control

Jinal Desai - LIVE

1:36 10 May '10

Some changes for given code [modified]

introsas

8:24 19 Sep '08

Here is my updated code

public class PasswordBox : TextBox
{
    #region Private Member Variables
 
    private string _text = string.Empty;
    private char _passwordChar = '\u25CF';
 
    #endregion
 
    #region Constructor
 
    /// <summary>
    /// Default Class Constructor
    /// </summary>
    public PasswordBox()
    {
        this.TextChanged += new TextChangedEventHandler(TextBox_TextChanged);
    }
<br>
    #endregion
<br>
    #region Private Methods
<br>
    private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
    {
        TextBox myTxtBox = sender as TextBox;
 
        if (myTxtBox != null)
        {
            string currentText = myTxtBox.Text;
            int selStart = myTxtBox.SelectionStart;
 
            if (currentText.Length < _text.Length)
            {
                <font color="blue">// Remove deleted chars
                _text = _text.Remove(selStart, _text.Length - currentText.Length);</font>
            }
            if (currentText != "")
            {
                for (int i = 0; i < currentText.Length; i++)
                {
                    if (currentText[i] != _passwordChar)
                    {
                        // Unattach event handler
                        <font color="blue">myTxtBox.TextChanged -= new TextChangedEventHandler(TextBox_TextChanged);
                        myTxtBox.Text = myTxtBox.Text.Remove(i, 1).Insert(i, _passwordChar.ToString());
                        myTxtBox.TextChanged += new TextChangedEventHandler(TextBox_TextChanged);</font>
                        // Replace or insert char
                        <font color="blue">_text = myTxtBox.Text.Length == _text.Length ?
                                _text.Remove(i, 1).Insert(i, currentText[i].ToString()) :
                                _text.Insert(i, currentText[i].ToString());</font>
                    }
                }
            }
            <font color="blue">myTxtBox.SelectionStart = selStart;</font>
        }
    }
 
    #endregion
    #region Properties
 
    public new string Text
    {
        get { return _text; }
    }
 
    #endregion
}</br></br></br>

modified on Sunday, September 21, 2008 6:36 AM

Connection with the server?

sydaze

4:23 10 Sep '08

Hi, there's something I still don't understand with silverlight: When I created this login box, what are the solutions to send the data (login/password) to the servers and receive an answer to know if it's correct or not. I read about web services but is it the only solution for silverlight to communicate with the server?
Sign In·View Thread·Permalink	3.50/5 (2 votes)