Text box validation using Error Provider control in C#

Error provider control improves the better user experience, The Error provider control provides a user interface for indicating that a control on a form has an error associated with it. In the Following example we will use the to validate the enter text into the textbox control.

textbox validation through Error Provider control

We have a textbox control on the windows form that enable user to enter the correct PIN Code up to six characters. If user enter the PIN code less than six characters, an red error icon appears next to the control with the specified tool tip text.

See the following example:

 private void Validatefivedigits(TextBox Text_Box)
        {
            if (Text_Box.Text.Length !=6 )
            {
                // Invalid. Set An Error.
                errorProvider1.SetError(Text_Box,"Pincode must be six digits");
            }
            else
            {
                // Valid. Clear The Error.
                errorProvider1.SetError(Text_Box, "");
            }
        }

private void textBox1_Validating(object sender, CancelEventArgs e)
        {
            Validatefivedigits(textBox1);
        }

Full Code:

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 WindowsApplication1
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        private void textBox1_Validating(object sender, CancelEventArgs e)
        {
            Validatefivedigits(textBox1);
        }
        private void Validatefivedigits(TextBox Text_Box)
        {
            if (Text_Box.Text.Length != 6)
            {
                // Invalid. Set An Error.
                errorProvider1.SetError(Text_Box, "Pincode must be six digits");
            }
            else
            {
                // Valid. Clear The Error.
                errorProvider1.SetError(Text_Box, "");
            }
        }
        private System.ComponentModel.IContainer components = null;
 
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (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.components = new System.ComponentModel.Container();
            this.textBox1 = new System.Windows.Forms.TextBox();
            this.btnOk = new System.Windows.Forms.Button();
            this.errorProvider1 = new System.Windows.Forms.ErrorProvider(this.components);
            this.label1 = new System.Windows.Forms.Label();
            ((System.ComponentModel.ISupportInitialize)(this.errorProvider1)).BeginInit();
            this.SuspendLayout();
            // 
            // textBox1
            // 
            this.textBox1.Location = new System.Drawing.Point(118, 24);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(151, 20);
            this.textBox1.TabIndex = 0;
            this.textBox1.Validating += new System.ComponentModel.CancelEventHandler(this.textBox1_Validating);
            // 
            // btnOk
            // 
            this.btnOk.Location = new System.Drawing.Point(101, 75);
            this.btnOk.Name = "btnOk";
            this.btnOk.Size = new System.Drawing.Size(75, 23);
            this.btnOk.TabIndex = 1;
            this.btnOk.Text = "Ok";
            this.btnOk.UseVisualStyleBackColor = true;
            // 
            // errorProvider1
            // 
            this.errorProvider1.ContainerControl = this;
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.Location = new System.Drawing.Point(13, 27);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(99, 13);
            this.label1.TabIndex = 2;
            this.label1.Text = "Enter the Pin Code:";
            // 
            // Form2
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(317, 121);
            this.Controls.Add(this.label1);
            this.Controls.Add(this.btnOk);
            this.Controls.Add(this.textBox1);
            this.Name = "Form2";
            this.Text = "Form2";
            ((System.ComponentModel.ISupportInitialize)(this.errorProvider1)).EndInit();
            this.ResumeLayout(false);
            this.PerformLayout();
 
        }
 
        #endregion
 
        private System.Windows.Forms.TextBox textBox1;
        private System.Windows.Forms.Button btnOk;
        private System.Windows.Forms.ErrorProvider errorProvider1;
        private System.Windows.Forms.Label label1;
 
 
    }
 
}