Csharp/C Sharp/GUI Windows Form/Data Validation

Error Provider Validation

/*
User Interfaces in C#: Windows Forms and Custom Controls
by Matthew MacDonald
Publisher: Apress
ISBN: 1590590457
*/
using System;
using System.Drawing;
using System.Collections;
using System.ruponentModel;
using System.Windows.Forms;
namespace Validation
{
    /// <summary>
    /// Summary description for ErrorProviderValidation.
    /// </summary>
    public class ErrorProviderValidation : System.Windows.Forms.Form
    {
        internal System.Windows.Forms.Label Label3;
        internal System.Windows.Forms.TextBox txtEmail;
        internal System.Windows.Forms.Label Label2;
        internal System.Windows.Forms.Label Label1;
        internal System.Windows.Forms.TextBox txtFirstName;
        internal System.Windows.Forms.TextBox txtLastName;
        internal System.Windows.Forms.Button Button1;
        internal System.Windows.Forms.ErrorProvider errProvider;
        internal System.Windows.Forms.GroupBox grpValidation;
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ruponentModel.Container components = null;
        public ErrorProviderValidation()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
            //
            // TODO: Add any constructor code after InitializeComponent call
            //
        }
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if(components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }
        #region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.grpValidation = new System.Windows.Forms.GroupBox();
            this.Label3 = new System.Windows.Forms.Label();
            this.txtEmail = new System.Windows.Forms.TextBox();
            this.Label2 = new System.Windows.Forms.Label();
            this.Label1 = new System.Windows.Forms.Label();
            this.txtFirstName = new System.Windows.Forms.TextBox();
            this.txtLastName = new System.Windows.Forms.TextBox();
            this.Button1 = new System.Windows.Forms.Button();
            this.errProvider = new System.Windows.Forms.ErrorProvider();
            this.grpValidation.SuspendLayout();
            this.SuspendLayout();
            // 
            // grpValidation
            // 
            this.grpValidation.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                                        this.Label3,
                                                                                        this.txtEmail,
                                                                                        this.Label2,
                                                                                        this.Label1,
                                                                                        this.txtFirstName,
                                                                                        this.txtLastName});
            this.grpValidation.Location = new System.Drawing.Point(8, 8);
            this.grpValidation.Name = "grpValidation";
            this.grpValidation.Size = new System.Drawing.Size(368, 124);
            this.grpValidation.TabIndex = 13;
            this.grpValidation.TabStop = false;
            // 
            // Label3
            // 
            this.Label3.Location = new System.Drawing.Point(16, 88);
            this.Label3.Name = "Label3";
            this.Label3.Size = new System.Drawing.Size(64, 16);
            this.Label3.TabIndex = 10;
            this.Label3.Text = "Email:";
            // 
            // txtEmail
            // 
            this.txtEmail.Location = new System.Drawing.Point(84, 84);
            this.txtEmail.Name = "txtEmail";
            this.txtEmail.Size = new System.Drawing.Size(152, 21);
            this.txtEmail.TabIndex = 9;
            this.txtEmail.Text = "";
            this.txtEmail.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.txtEmail_KeyPress);
            // 
            // Label2
            // 
            this.Label2.Location = new System.Drawing.Point(16, 52);
            this.Label2.Name = "Label2";
            this.Label2.Size = new System.Drawing.Size(64, 16);
            this.Label2.TabIndex = 8;
            this.Label2.Text = "Last Name:";
            // 
            // Label1
            // 
            this.Label1.Location = new System.Drawing.Point(16, 28);
            this.Label1.Name = "Label1";
            this.Label1.Size = new System.Drawing.Size(64, 16);
            this.Label1.TabIndex = 7;
            this.Label1.Text = "First Name:";
            // 
            // txtFirstName
            // 
            this.txtFirstName.Location = new System.Drawing.Point(84, 24);
            this.txtFirstName.Name = "txtFirstName";
            this.txtFirstName.Size = new System.Drawing.Size(152, 21);
            this.txtFirstName.TabIndex = 4;
            this.txtFirstName.Text = "";
            this.txtFirstName.Validating += new System.ruponentModel.CancelEventHandler(this.txtName_Validating);
            // 
            // txtLastName
            // 
            this.txtLastName.Location = new System.Drawing.Point(84, 48);
            this.txtLastName.Name = "txtLastName";
            this.txtLastName.Size = new System.Drawing.Size(152, 21);
            this.txtLastName.TabIndex = 5;
            this.txtLastName.Text = "";
            this.txtLastName.Validating += new System.ruponentModel.CancelEventHandler(this.txtName_Validating);
            // 
            // Button1
            // 
            this.Button1.Location = new System.Drawing.Point(152, 204);
            this.Button1.Name = "Button1";
            this.Button1.Size = new System.Drawing.Size(76, 24);
            this.Button1.TabIndex = 12;
            this.Button1.Text = "OK";
            this.Button1.Click += new System.EventHandler(this.Button1_Click);
            // 
            // errProvider
            // 
            this.errProvider.DataMember = null;
            // 
            // ErrorProviderValidation
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 14);
            this.ClientSize = new System.Drawing.Size(388, 242);
            this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                          this.grpValidation,
                                                                          this.Button1});
            this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
            this.Name = "ErrorProviderValidation";
            this.Text = "ErrorProviderValidation";
            this.grpValidation.ResumeLayout(false);
            this.ResumeLayout(false);
        }
        #endregion
        [STAThread]
        static void Main() 
        {
            Application.Run(new ErrorProviderValidation());
        }
        private void Button1_Click(object sender, System.EventArgs e)
        {
            bool invalidInput = false;
            
            foreach (Control ctrl in this.grpValidation.Controls)
            {
                if (errProvider.GetError(ctrl) != "")
                {
                    invalidInput = true;
                    break;
                }
            }
            
            if (invalidInput)
            {
                MessageBox.Show("You still have invalid input.", "Invalid Input", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
            else
            {
                this.Close();
            }
        
        }
        private void txtName_Validating(object sender, System.ruponentModel.CancelEventArgs e)
        {
            Control ctrl = (Control)sender;
            if (ctrl.Text == "")
            {
                errProvider.SetError(ctrl, "You must enter a first and last name.");
            }
            else
            {
                errProvider.SetError(ctrl, "");
            }
        }
        private void txtEmail_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
        {
            System.Text.RegularExpressions.Regex regex;
            regex = new System.Text.RegularExpressions.Regex(@"\S+@\S+\.\S+");
            Control ctrl = (Control)sender;
            if (regex.IsMatch(ctrl.Text))
            {
                errProvider.SetError(ctrl, "");
            }
            else
            {
                errProvider.SetError(ctrl, "Not a valid email.");
            }
        }
    
    }
}

Simple Form Validation

/*
User Interfaces in C#: Windows Forms and Custom Controls
by Matthew MacDonald
Publisher: Apress
ISBN: 1590590457
*/
using System;
using System.Drawing;
using System.Collections;
using System.ruponentModel;
using System.Windows.Forms;
namespace Validation
{
    /// <summary>
    /// Summary description for SimpleValidation.
    /// </summary>
    public class SimpleValidation : System.Windows.Forms.Form
    {
        internal System.Windows.Forms.GroupBox GroupBox1;
        internal System.Windows.Forms.Label Label2;
        internal System.Windows.Forms.Label Label1;
        internal System.Windows.Forms.TextBox txtFirstName;
        internal System.Windows.Forms.TextBox txtLastName;
        internal System.Windows.Forms.Button Button1;
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ruponentModel.Container components = null;
        public SimpleValidation()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
            //
            // TODO: Add any constructor code after InitializeComponent call
            //
        }
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if(components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }
        #region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.GroupBox1 = new System.Windows.Forms.GroupBox();
            this.Label2 = new System.Windows.Forms.Label();
            this.Label1 = new System.Windows.Forms.Label();
            this.txtFirstName = new System.Windows.Forms.TextBox();
            this.txtLastName = new System.Windows.Forms.TextBox();
            this.Button1 = new System.Windows.Forms.Button();
            this.GroupBox1.SuspendLayout();
            this.SuspendLayout();
            // 
            // GroupBox1
            // 
            this.GroupBox1.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                                    this.Label2,
                                                                                    this.Label1,
                                                                                    this.txtFirstName,
                                                                                    this.txtLastName});
            this.GroupBox1.Location = new System.Drawing.Point(8, 12);
            this.GroupBox1.Name = "GroupBox1";
            this.GroupBox1.Size = new System.Drawing.Size(368, 88);
            this.GroupBox1.TabIndex = 11;
            this.GroupBox1.TabStop = false;
            // 
            // Label2
            // 
            this.Label2.Location = new System.Drawing.Point(16, 52);
            this.Label2.Name = "Label2";
            this.Label2.Size = new System.Drawing.Size(64, 16);
            this.Label2.TabIndex = 8;
            this.Label2.Text = "Last Name:";
            // 
            // Label1
            // 
            this.Label1.Location = new System.Drawing.Point(16, 28);
            this.Label1.Name = "Label1";
            this.Label1.Size = new System.Drawing.Size(64, 16);
            this.Label1.TabIndex = 7;
            this.Label1.Text = "First Name:";
            // 
            // txtFirstName
            // 
            this.txtFirstName.Location = new System.Drawing.Point(84, 24);
            this.txtFirstName.Name = "txtFirstName";
            this.txtFirstName.Size = new System.Drawing.Size(152, 21);
            this.txtFirstName.TabIndex = 4;
            this.txtFirstName.Text = "";
            this.txtFirstName.Validating += new System.ruponentModel.CancelEventHandler(this.txtName_Validating);
            // 
            // txtLastName
            // 
            this.txtLastName.Location = new System.Drawing.Point(84, 48);
            this.txtLastName.Name = "txtLastName";
            this.txtLastName.Size = new System.Drawing.Size(152, 21);
            this.txtLastName.TabIndex = 5;
            this.txtLastName.Text = "";
            this.txtLastName.Validating += new System.ruponentModel.CancelEventHandler(this.txtName_Validating);
            // 
            // Button1
            // 
            this.Button1.Location = new System.Drawing.Point(152, 208);
            this.Button1.Name = "Button1";
            this.Button1.Size = new System.Drawing.Size(76, 24);
            this.Button1.TabIndex = 10;
            this.Button1.Text = "OK";
            this.Button1.Click += new System.EventHandler(this.Button1_Click);
            // 
            // SimpleValidation
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 14);
            this.ClientSize = new System.Drawing.Size(384, 242);
            this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                          this.GroupBox1,
                                                                          this.Button1});
            this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
            this.Name = "SimpleValidation";
            this.Text = "SimpleValidation";
            this.GroupBox1.ResumeLayout(false);
            this.ResumeLayout(false);
        }
        #endregion
        private void Button1_Click(object sender, System.EventArgs e)
        {
            this.Close();
        }
        [STAThread]
        static void Main() 
        {
            Application.Run(new SimpleValidation());
        }
        private void txtName_Validating(object sender, System.ruponentModel.CancelEventArgs e)
        {
            if (((TextBox)sender).Text == "")
            {
                MessageBox.Show("You must enter a first and last name.", "Invalid Input", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                e.Cancel = true;
            }
        }
    }
}