隐藏密码文字

时间:2012-05-02 06:46:25

标签: c# winforms password-protection

我有一个使用UseSystemPasswordChar的文本框,因此它不会显示用户输入的密码。问题是密码仍然可以被类似Spy ++的东西读取。我正在寻找一种方法来隐藏它,就像他们在Services.msc>中的密码字段中那样。登录选项卡。

3 个答案:

答案 0 :(得分:2)

这是我到目前为止所做的。

你可以通过一些独特的事件来表明是否已经接受了按下的键,是否已经改变了InputFilter或RealText等来改善这一点......

另一个需要改进的好处是InputFilter的默认用法,因为使用char和Keys并不适用于许多特殊键。例如 - 目前,如果你在密码框处于焦点时按Alt + F4,它将输入's'...所以有一堆错误需要修复。

最后,处理大写和非大写字母输入的方式可能比我在那里做的更优雅。

所以这是:

public class PasswordBox : TextBox
{
    private string _realText;

    public string RealText
    {
        get { return this._realText; }
        set
        {
            var i = this.SelectionStart;

            this._realText = value ?? "";

            this.Text = "";
            this.Text = new string('*', this._realText.Length);

            this.SelectionStart = i > this.Text.Length ? this.Text.Length : i;
        }
    }

    private Func<KeyEventArgs, bool> _inputFilter;

    public Func<KeyEventArgs, bool> InputFilter
    {
        get { return this._inputFilter; }
        set { this._inputFilter = value ?? (e => true); }
    }

    public PasswordBox()
    {
        this.RealText = "";
        this.InputFilter = e => "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".Any(c => c == e.KeyValue);
    }

    protected override void OnKeyDown(KeyEventArgs e)
    {
        e.SuppressKeyPress = true;

        switch (e.KeyCode)
        {
            case Keys.Back:
                if (this.SelectionStart > 0 || this.SelectionLength > 0)
                {
                    this.RealText = this.SelectionLength == 0
                                        ? this.RealText.Remove(--this.SelectionStart, 1)
                                        : this.RealText.Remove(this.SelectionStart, this.SelectionLength);
                }
                break;
            case Keys.Delete:
                if (this.SelectionStart == this.TextLength)
                {
                    return;
                }

                this.RealText = this.RealText.Remove(this.SelectionStart, this.SelectionLength == 0 ? 1 : this.SelectionLength);
                break;
            case Keys.X:
            case Keys.C:
            case Keys.V:
                if (e.Control)
                {
                    return;
                }
                goto default;
            case Keys.Right:
            case Keys.Left:
            case Keys.Up:
            case Keys.Down:
            case Keys.Shift:
            case Keys.Home:
            case Keys.End:
                e.SuppressKeyPress = false;
                base.OnKeyDown(e);
                break;
            default:
                if (e.Control)
                {
                    e.SuppressKeyPress = false;
                    base.OnKeyDown(e);
                    break;
                }

                if (this.InputFilter(e))
                {
                    var c = (char)e.KeyValue;

                    if (e.Shift == IsKeyLocked(Keys.CapsLock))
                    {
                        c = char.ToLower(c);
                    }

                    this.RealText = this.RealText.Remove(this.SelectionStart, this.SelectionLength)
                        .Insert(this.SelectionStart, c.ToString());

                    this.SelectionStart++;
                }
                break;
        }
    }
}

答案 1 :(得分:1)

所以尝试这样的事情

        private string realpass = "";
        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == (Char) Keys.Back)
                realpass += realpass.Substring(0, realpass.Length - 2);
            realpass += e.KeyChar.ToString();
            textBox1.Text = "";
            for (int i = 0; i < realpass.Length; i++)
                textBox1.Text += "*";
        }

答案 2 :(得分:1)

如果您打算收集Windows /域用户凭据,则不应使用自己的对话框。您应该使用Windows通过PInvoke提供的内容,或者只使用这样的包装器,

http://weblogs.asp.net/hernandl/archive/2005/11/21/usercredentialsdialog.aspx

这个,

http://credentials.codeplex.com/