Hi , i have crated a textbox which shows current date . i want that user cannot enter special characters inside that except - or / . can you please suggest how to do it .

USe a MaskedTextBox Class , you can define the valid/allowed entry format.

If you use TextBox, input only numbers. Edit when focus leaves the control. If 20230922 is entered, edit it to 2023/09/22. Completion functions are also nice. 22 → Complete year and month → 2023/09/22 922 → Complement year → 2023/09/22 In that case, the six months before and after the system date will be used as the reference point. For example, if you enter December in January, it will be December of the previous year. Conversely, if you enter January in December, it will be set as January of the next year. It is also interesting to paste a Button control inside a TextBox and give it a function like DateTimePicker.

Special characters in a textbox

Accepted answer

Brian Zarb 1,650

Here’s an example of how you can set up a MaskedTextBox to allow date input in the format yyyy-MM-dd or yyyy/MM/dd:

using System;
using System.Windows.Forms;
namespace WindowsFormsApp
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
            // Create a MaskedTextBox
            MaskedTextBox maskedTextBox = new MaskedTextBox
            {
                // Set the mask to accept date in yyyy-MM-dd or yyyy/MM/dd format
                Mask = "0000-00-00",
                // Set the prompt character to a space
                PromptChar = ' ',
                // Set the valid input to digits and the date separator characters
                ValidChars = "0123456789-/",
                // Set the location and size of the MaskedTextBox
                Location = new System.Drawing.Point(50, 50),
                Size = new System.Drawing.Size(100, 20)
            };
            // Add the MaskedTextBox to the form
            Controls.Add(maskedTextBox);
        }
    }
}

In this example, we've set the mask to "0000-00-00" to allow input in the yyyy-MM-dd format. We've also set the ValidChars property to "0123456789-/", which means the user can only enter digits and the '-' or '/' characters. The PromptChar is set to a space, which will be displayed in place of the mask characters until the user enters something.

You can also use the TypeValidationCompleted event to perform additional validation on the input and provide feedback to the user.

Shaifali jain 420 Reputation points

2023-09-22T09:56:56.9533333+00:00

@Brian Zarb , please suggest using normal textbox

Brian Zarb 1,650

If you prefer to use a normal TextBox control instead of a MaskedTextBox, you can handle the KeyPress event of the TextBox to restrict the user input.

Here's an example:

using System;
using System.Windows.Forms;
namespace WindowsFormsApp
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
            // Create a TextBox
            TextBox textBox = new TextBox
            {
                // Set the location and size of the TextBox
                Location = new System.Drawing.Point(50, 50),
                Size = new System.Drawing.Size(100, 20)
            };
            // Handle the KeyPress event of the TextBox
            textBox.KeyPress += TextBox_KeyPress;
            // Set the Text of the TextBox to the current date
            textBox.Text = DateTime.Now.ToString("yyyy-MM-dd");
            // Add the TextBox to the form
            Controls.Add(textBox);
        }
        private void TextBox_KeyPress(object sender, KeyPressEventArgs e)
        {
            // Check if the pressed key is a digit, '-' or '/'
            if (!char.IsDigit(e.KeyChar) && e.KeyChar != '-' && e.KeyChar != '/' && !char.IsControl(e.KeyChar))
            {
                // If not, suppress the key press
                e.Handled = true;
            }
        }
    }
}

In this example, we've created a TextBox and handled its KeyPress event. In the event handler TextBox_KeyPress, we check whether the pressed key is a digit, '-' or '/', or a control character (like backspace). If the pressed key is not one of these, we suppress the key press by setting e.Handled = true, thus preventing the user from entering any other characters.

Shaifali jain 420 Reputation points

2023-09-22T10:35:54.8166667+00:00

@Brian Zarb , not working

Brian Zarb 1,650

hmm works for me:

User's image

Change the public form to:

public Form1()
        {
            InitializeComponent();
            // Create a TextBox
            textBox1.KeyPress += TextBox1_KeyPress;

            // Set the Text of the TextBox to the current date
            textBox1.Text = DateTime.Now.ToString("yyyy-MM-dd");
        }

Brian Zarb 1,650

May i recommend using DateTimePicker instead, its way easier, The DateTimePicker control allows users to easily select a date (and optionally time) from a visual calendar, eliminating the potential for formatting errors and ensuring that the input is always a valid date.

User's image

This removes so many possible areas for Bad inserts or user mistakes:

using System;
using System.Windows.Forms;

namespace WinFormsApp1
{
    public partial class Form1 : Form
    {
        // Declare a DateTimePicker control
        private DateTimePicker dateTimePicker;

        public Form1()
        {
            InitializeComponent();
            InitializeDateTimePicker();
        }

        private void InitializeDateTimePicker()
        {
            // Initialize the DateTimePicker control
            dateTimePicker = new DateTimePicker
            {
                // Set the location and size of the DateTimePicker
                Location = new System.Drawing.Point(50, 50),
                Size = new System.Drawing.Size(200, 20),
                // Set the format to display only date
                Format = DateTimePickerFormat.Short
            };

            // Add the DateTimePicker to the form
            Controls.Add(dateTimePicker);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // Your form load logic here
        }

        private void btnGetDate_Click(object sender, EventArgs e)
        {
            // Get the selected date from the DateTimePicker
            DateTime selectedDate = dateTimePicker.Value;
            MessageBox.Show($"Selected Date: {selectedDate.ToShortDateString()}");
        }
    }
}

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Special characters in a textbox

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