Blank validation on textbox in windows application

In this blog we will know blank validation on textbox in windows.

 

Method-1

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 Validation_on_textbox

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            if (textBox1.Text == "")

            {

                MessageBox.Show("Name Field cannnot be blank");

                textBox1.Focus();

            }

            else

            {

                MessageBox.Show("Correct");

            }

            clear();

        }

        private void clear()

        {

            textBox1.Text = "";

        }

    }

}

 

Method-2

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 Validation_on_textbox

{

    public partial class Form2 : Form

    {

        public Form2()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            foreach (Control c1 in this.Controls)

            {

                if (c1 is TextBox)

                {

                    if (c1.Text == "")

                    {

                        MessageBox.Show("Name Field cannnot be blank");

                        c1.BackColor = Color.Orange;

                        textBox1.Focus();

                    }

                    else

                    {

                        MessageBox.Show("Correct");

                        c1.BackColor = Color.White;

                    }

                }

            }

            clear();

        }

        private void clear()

        {

            textBox1.Text = "";

        }

    }

}

 

Method-3

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 Validation_on_textbox

{

    public partial class Form3 : Form

    {

        public Form3()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            if (textBox1.Text.Trim() == "")

            {

                errorProvider1.SetError(textBox1, "Name Field cannnot be blank");

                textBox1.Focus();

            }

            else

            {

                errorProvider1.Clear();

                MessageBox.Show("Correct");

            }

            clear();

        }

        private void clear()

        {

            textBox1.Text = "";

        }

    }

}