How to change color of textbox in C# GUI?

Question

Hi  I have 5 or 6 textboxes and all of them are required ( have required field validators ) .. I want to change their background color to yellow when they are left blank and when the box is filled the backgorund color to white ..Is it possible??? to do in c# And can I apply same method for login page too!!

Satyapriya Nayak · Answer

Hi Nits Iam attaching the source code please look into it. Thanks

Nits · Answer

I have yet to check the code mam busy with something else:-)

Satyapriya Nayak · Answer

Hi Nits If this post helps you mark it as answer Thanks

Satyapriya Nayak · Answer

Hi Nits Here is your desired 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 change_color_of_textbox { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void textBox1_Leave(object sender EventArgs e) { if (textBox1.Text == ) { textBox1.BackColor = Color.Red; } else { textBox1.BackColor = Color.White; } } private void textBox1_KeyDown(object sender KeyEventArgs e) { if (e.KeyCode == Keys.Space) { e.SuppressKeyPress = true; } } private void textBox2_Leave(object sender EventArgs e) { if (textBox2.Text == ) { textBox2.BackColor = Color.Red; } else { textBox2.BackColor = Color.White; } } private void textBox2_KeyDown(object sender KeyEventArgs e) { if (e.KeyCode == Keys.Space) { e.SuppressKeyPress = true; } } private void textBox3_Leave(object sender EventArgs e) { if (textBox3.Text == ) { textBox3.BackColor = Color.Red; } else { textBox3.BackColor = Color.White; } } private void textBox3_KeyDown(object sender KeyEventArgs e) { if (e.KeyCode == Keys.Space) { e.SuppressKeyPress = true; } } } } Thanks If this post helps you mark it as answer

Sam Hobbs · Answer

Vulpes's code will work if it is used as instructed unless you have other code that is interfering with it. The field validation code might be the interference.

Vulpes · Answer

I think you'll have to post some code so we can see what it is you're doing.

Nits · Answer

hi vulpes sir again it only changes after I backspace character & does not change when I tabbed to another textbox??

Vulpes · Answer

It sounds like you're putting the code in the wrong place - possibly in the TextChanged eventhandler. If you put it say in the Leave eventhandler then it should work: private void textBox1_Leave(object sender EventArgs e) { string text = textBox1.Text.Trim(); if (text == ) textBox1.BackColor = Color.Yellow; else textBox1.BackColor = Color.White; }

Nits · Answer

it only changes when I backspace the character but it does not change when I use tab to go on another textbox????

Priya Linge · Answer

Hi Try this string a = textBox1.Text; if (a != String.Empty) { textBox1.BackColor = Color.Red; } else if (a == String.Empty) { textBox1.BackColor = Color.White; } else { textBox1.BackColor = Color.Black; } Hope this will help you. Thanks.