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 = "";
}
}
}