أرجو المساعدة في ال C#

السلام عليكــم ورحمـة الله وبركاتــه ،،

// Boolean flag used to determine when a character other than a number is entered.
private bool nonNumberEntered = false;

// Handle the KeyDown event to determine the type of character entered into the control.
private void textBox1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
	// Initialize the flag to false.
	nonNumberEntered = false;

	// Determine whether the keystroke is a number from the top of the keyboard.
	if (e.KeyCode < Keys.D0 || e.KeyCode > Keys.D9)
	{
		// Determine whether the keystroke is a number from the keypad.
		if (e.KeyCode < Keys.NumPad0 || e.KeyCode > Keys.NumPad9)
		{
			// Determine whether the keystroke is a backspace.
			if(e.KeyCode != Keys.Back)
			{
				// A non-numerical keystroke was pressed.
				// Set the flag to true and evaluate in KeyPress event.
				nonNumberEntered = true;
			}
		}
	}
}

// This event occurs after the KeyDown event and can be used to prevent
// characters from entering the control.
private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
	// Check for the flag being set in the KeyDown event.
	if (nonNumberEntered == true)
	{
		// Stop the character from being entered into the control since it is non-numerical.
		e.Handled = true;
	}
}

هذا الكود من msdn

ممكن الكود دا يفيدك

http://www.csharphelp.com/archives/files/a...64/NumberBox.cs