WinForms Text Editor - Display password strength indicator

This example creates a custom text editor that displays the strength of the entered password.

Note

In v22.2+, the WinForms Subscription includes pre-designed UI controls (templates) designed to jump start the form development process. UI templates include the Password Box control that integrates the password strength indicator. It also displays a warning hint when the Caps Lock key is on, or when the password is weak. Read the following help topic for additional information: Password Editor.

Files to look at:

Form1.cs (VB: Form1.vb)
RepositoryItemTextEditPwdStrength.cs (VB: RepositoryItemTextEditPwdStrength.vb)
TextEditPwdStrength.cs (VB: TextEditPwdStrengthViewInfo.vb)
TextEditPwdStrengthPainter.cs (VB: TextEditPwdStrengthPainter.vb)
TextEditPwdStrengthViewInfo.cs (VB: TextEditPwdStrengthViewInfo.vb)

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Example Code

TextEditPasswordStrengthBar/Form1.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace TextEditPasswordStrengthBar
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        void textEditPwdStrength_Leave(object sender, EventArgs e)
        {
            TextEditPwdStrength te = sender as TextEditPwdStrength;
            te.Properties.PasswordChar = '*';
        }

        void textEditPwdStrength_Enter(object sender, EventArgs e)
        {
            TextEditPwdStrength te = sender as TextEditPwdStrength;
            te.Properties.PasswordChar = '\0';
        }
    }
}

Visual Basic
Imports System
Imports System.ComponentModel
Imports System.Drawing
Imports System.Windows.Forms

Namespace TextEditPasswordStrengthBar

    Public Partial Class Form1
        Inherits Form

        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub textEditPwdStrength_Leave(ByVal sender As Object, ByVal e As EventArgs)
            Dim te As TextEditPwdStrength = TryCast(sender, TextEditPwdStrength)
            te.Properties.PasswordChar = "*"c
        End Sub

        Private Sub textEditPwdStrength_Enter(ByVal sender As Object, ByVal e As EventArgs)
            Dim te As TextEditPwdStrength = TryCast(sender, TextEditPwdStrength)
            te.Properties.PasswordChar = Microsoft.VisualBasic.Strings.ChrW(0)
        End Sub
    End Class
End Namespace

TextEditPasswordStrengthBar/TextEditPwdStrength/RepositoryItemTextEditPwdStrength.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using DevExpress.XtraEditors.Repository;
using DevExpress.XtraEditors.Registrator;
using DevExpress.XtraEditors.ViewInfo;
using DevExpress.XtraEditors.Drawing;
using DevExpress.XtraEditors.Controls;

namespace TextEditPasswordStrengthBar
{
    //The attribute that points to the registration method 
    [UserRepositoryItem("RegisterTextEditPwdStrength")]
    class RepositoryItemTextEditPwdStrength : RepositoryItemTextEdit
    {
        private static readonly object editValueChanging = new object();

        // Static constructor should call registration method
        static RepositoryItemTextEditPwdStrength() { RegisterTextEditPwdStrength(); }

        public const string TextEditPwdStrengthName = "TextEditPwdStrength";
        public override string EditorTypeName { get { return TextEditPwdStrengthName; } }

        public static void RegisterTextEditPwdStrength()
        {
            EditorRegistrationInfo.Default.Editors.Add(new EditorClassInfo(
                TextEditPwdStrengthName, typeof(TextEditPwdStrength), typeof(RepositoryItemTextEditPwdStrength),
                typeof(TextEditPwdStrengthViewInfo), new TextEditPwdStrengthPainter(), true));
        }
    }
}

Visual Basic
Imports DevExpress.XtraEditors.Repository
Imports DevExpress.XtraEditors.Registrator
Imports DevExpress.XtraEditors.Drawing
Imports DevExpress.XtraEditors.Controls

Namespace TextEditPasswordStrengthBar

    'The attribute that points to the registration method 
    <UserRepositoryItem("RegisterTextEditPwdStrength")>
    Friend Class RepositoryItemTextEditPwdStrength
        Inherits RepositoryItemTextEdit

        Private Shared ReadOnly editValueChanging As Object = New Object()

        ' Static constructor should call registration method
        Shared Sub New()
            Call RegisterTextEditPwdStrength()
        End Sub

        Public Const TextEditPwdStrengthName As String = "TextEditPwdStrength"

        Public Overrides ReadOnly Property EditorTypeName As String
            Get
                Return TextEditPwdStrengthName
            End Get
        End Property

        Public Shared Sub RegisterTextEditPwdStrength()
            Call EditorRegistrationInfo.Default.Editors.Add(New EditorClassInfo(TextEditPwdStrengthName, GetType(TextEditPwdStrength), GetType(RepositoryItemTextEditPwdStrength), GetType(TextEditPwdStrengthViewInfo), New TextEditPwdStrengthPainter(), True))
        End Sub
    End Class
End Namespace

TextEditPasswordStrengthBar/TextEditPwdStrength/TextEditPwdStrength.cs

C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;
using DevExpress.XtraEditors;

namespace TextEditPasswordStrengthBar
{
    class TextEditPwdStrength : TextEdit
    {
        static TextEditPwdStrength() { RepositoryItemTextEditPwdStrength.RegisterTextEditPwdStrength(); }
        public TextEditPwdStrength() : base() { }

        public override string EditorTypeName { get { return RepositoryItemTextEditPwdStrength.TextEditPwdStrengthName; } }

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public new RepositoryItemTextEditPwdStrength Properties
        { get { return base.Properties as RepositoryItemTextEditPwdStrength; } }

        protected override void OnEditValueChanged()
        {
            this.RefreshVisualLayout();
            base.OnEditValueChanged();
        }
    }
}

TextEditPasswordStrengthBar/TextEditPwdStrength/TextEditPwdStrengthViewInfo.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using DevExpress.XtraEditors.ViewInfo;
using DevExpress.XtraEditors.Repository;

namespace TextEditPasswordStrengthBar
{
    class TextEditPwdStrengthViewInfo : TextEditViewInfo
    {
        public TextEditPwdStrengthViewInfo(RepositoryItem item) : base(item) { }

        public RepositoryItemTextEditPwdStrength RepositoryItem
        {
            get { return this.Item as RepositoryItemTextEditPwdStrength; }
        }

        protected override System.Drawing.Rectangle CalcMaskBoxRect(System.Drawing.Rectangle content, ref Rectangle contextImageBounds)
        {
            Rectangle r = base.CalcMaskBoxRect(content, ref contextImageBounds);
            r.Height -= 1;
            r.Y = 1;
            return r;
        }
    }
}

Visual Basic
Imports System.Drawing
Imports DevExpress.XtraEditors.ViewInfo
Imports DevExpress.XtraEditors.Repository

Namespace TextEditPasswordStrengthBar

    Friend Class TextEditPwdStrengthViewInfo
        Inherits TextEditViewInfo

        Public Sub New(ByVal item As RepositoryItem)
            MyBase.New(item)
        End Sub

        Public ReadOnly Property RepositoryItem As RepositoryItemTextEditPwdStrength
            Get
                Return TryCast(Item, RepositoryItemTextEditPwdStrength)
            End Get
        End Property

        Protected Overrides Function CalcMaskBoxRect(ByVal content As System.Drawing.Rectangle, ByRef contextImageBounds As Rectangle) As System.Drawing.Rectangle
            Dim r As Rectangle = MyBase.CalcMaskBoxRect(content, contextImageBounds)
            r.Height -= 1
            r.Y = 1
            Return r
        End Function
    End Class
End Namespace

TextEditPasswordStrengthBar/TextEditPwdStrength/TextEditPwdStrengthPainter.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Windows.Forms;
using System.Text.RegularExpressions;
using DevExpress.XtraEditors.Drawing;
using DevExpress.XtraEditors.ViewInfo;

namespace TextEditPasswordStrengthBar
{
    class TextEditPwdStrengthPainter : TextEditPainter
    {
        public TextEditPwdStrengthPainter() : base() { }
        
        protected override void DrawContent(ControlGraphicsInfoArgs info) {
            base.DrawContent(info);
            this.DrawLine(info);
        }

        void DrawLine(ControlGraphicsInfoArgs info)
        {
            TextEditViewInfo vi = info.ViewInfo as TextEditViewInfo;
            Rectangle r = vi.ClientRect;
            r.Height = 3;

            r.Y = vi.ClientRect.Height - r.Height;
            Brush brush = Brushes.Green;

            switch (this.GetPasswordStrength(vi.EditValue, vi.ClientRect))
            {
                case 0:
                    if (vi.EditValue == null || vi.EditValue.ToString().Length == 0)
                        r.Width = 0;
                    else
                        r.Width = r.Width / 3;
                    brush = Brushes.Red;
                    break;
                case 1:
                    r.Width = r.Width * 2 / 3;
                    brush = Brushes.Orange;
                    break;
            }
            info.Paint.FillRectangle(info.Graphics, brush, r);
        }

        int GetPasswordStrength(object pwd, Rectangle contentRectangle)
        {
            int passwordStrength = 0, passwordPoints = 0;
            if (pwd == null) return passwordStrength;

            string password = pwd.ToString();

            // Simple algorithm of password strength calculation
            Regex rx;
            // If password is longer than 6 symbols than add 1 point
            if (password.Length > 6)
                passwordPoints++;
            // If password has both lower and upper case characters than add 1 point
            rx = new Regex(@"(?=.*[a-z])(?=.*[A-Z])");
            if (rx.Match(password).Success)
                passwordPoints++;
            // Add 1 point if password contains at least one digit
            rx = new Regex(@"[0-9]");
            if (rx.Match(password).Success)
                passwordPoints++;
            // Add 1 point in case if password contains at least one special char
            rx = new Regex(@"\~|\@|\#|\$|\%|\^|\&|\*|\:|\;");
            if (rx.Match(password).Success)
                passwordPoints++;
            // Add 1 point if password is longer than 12 symbols
            if (password.Length > 12)
                passwordPoints++;

            if (passwordPoints > 3)
                passwordStrength = 2;
            else if (passwordPoints >= 2 && passwordPoints <= 3)
                passwordStrength = 1;

            return passwordStrength;
        }
    }
}

Visual Basic
Imports System.Drawing
Imports System.Text.RegularExpressions
Imports DevExpress.XtraEditors.Drawing
Imports DevExpress.XtraEditors.ViewInfo

Namespace TextEditPasswordStrengthBar

    Friend Class TextEditPwdStrengthPainter
        Inherits TextEditPainter

        Public Sub New()
            MyBase.New()
        End Sub

        Protected Overrides Sub DrawContent(ByVal info As ControlGraphicsInfoArgs)
            MyBase.DrawContent(info)
            DrawLine(info)
        End Sub

        Private Sub DrawLine(ByVal info As ControlGraphicsInfoArgs)
            Dim vi As TextEditViewInfo = TryCast(info.ViewInfo, TextEditViewInfo)
            Dim r As Rectangle = vi.ClientRect
            r.Height = 3
            r.Y = vi.ClientRect.Height - r.Height
            Dim brush As Brush = Brushes.Green
            Select Case GetPasswordStrength(vi.EditValue, vi.ClientRect)
                Case 0
                    If vi.EditValue Is Nothing OrElse vi.EditValue.ToString().Length = 0 Then
                        r.Width = 0
                    Else
                        r.Width = r.Width \ 3
                    End If

                    brush = Brushes.Red
                Case 1
                    r.Width = r.Width * 2 \ 3
                    brush = Brushes.Orange
            End Select

            info.Paint.FillRectangle(info.Graphics, brush, r)
        End Sub

        Private Function GetPasswordStrength(ByVal pwd As Object, ByVal contentRectangle As Rectangle) As Integer
            Dim passwordStrength As Integer = 0, passwordPoints As Integer = 0
            If pwd Is Nothing Then Return passwordStrength
            Dim password As String = pwd.ToString()
            ' Simple algorithm of password strength calculation
            Dim rx As Regex
            ' If password is longer than 6 symbols than add 1 point
            If password.Length > 6 Then passwordPoints += 1
            ' If password has both lower and upper case characters than add 1 point
            rx = New Regex("(?=.*[a-z])(?=.*[A-Z])")
            If rx.Match(password).Success Then passwordPoints += 1
            ' Add 1 point if password contains at least one digit
            rx = New Regex("[0-9]")
            If rx.Match(password).Success Then passwordPoints += 1
            ' Add 1 point in case if password contains at least one special char
            rx = New Regex("\~|\@|\#|\$|\%|\^|\&|\*|\:|\;")
            If rx.Match(password).Success Then passwordPoints += 1
            ' Add 1 point if password is longer than 12 symbols
            If password.Length > 12 Then passwordPoints += 1
            If passwordPoints > 3 Then
                passwordStrength = 2
            ElseIf passwordPoints >= 2 AndAlso passwordPoints <= 3 Then
                passwordStrength = 1
            End If

            Return passwordStrength
        End Function
    End Class
End Namespace

DevExpress Support Team

last modified 2 years ago

Modified: September 22, 2023 11:33 AM

Platform: WinForms

Product: XtraEditors Library

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WinForms Text Editor - Display password strength indicator

See Also

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Example Code

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