如何在C＃中向我的文本框添加键盘快捷键（输入）？

Question

So I'm still very new to programming and I'm trying to create a program in which you'll enter a number (from 1-9 only) in a textbox and then clicking Enter instead of having to click on a button to have the number that I wrote on the textbox displayed on my second label. I keep getting two errors, the first throws off a

No overload for 'textBox1_TextChanged' matches delegate 'EventHandler'

when I add Key to EventArgs (because EventArgs does not contain Keycode ). The second is flags here:

this.label2.Click += new System.EventHandler(this.label2_Click);    

"CS1061 'Form1' does not contain a definition for 'label2_Click' and no extension method 'label2_Click' accepting a first argument of type 'Form1' could be found (are you missing a using directive or an assembly reference?)"

My code:

using System;
using System.Windows.Forms;

namespace Tarea7
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                label2.Text = textBox1.ToString();
            }
            if (System.Text.RegularExpressions.Regex.IsMatch(textBox1.Text, "[^0-9]"))
            {
                MessageBox.Show("Debes de escribir un numero de 1-9");
                textBox1.Text.Remove(textBox1.Text.Length - 1);
            }   
        }

        private void label2_TextChanged(object sender, EventArgs e)
        {

        }
    }
}

Answer 1

Add textBox1_KeyDown event to your textBox1.KeyDown event at visual designer or at the file Form1.designer.cs:

this.textBox1.KeyDown += 
    new System.Windows.Forms.KeyEventHandler(this.textBox1_KeyDown);

Then add following function to your code. When user type a number from 1 - 9 and press Enter, it will be copied to label2 .

    private void textBox1_KeyDown(object sender, KeyEventArgs e)
    {
        Text = DateTime.Now.ToString();
        switch (e.KeyCode)
        {
            case Keys.Enter:
                if (textBox1.Text.Length == 1)
                {
                    char tbChar = textBox1.Text[0];
                    if (tbChar >= '1' && tbChar <= '9')
                    {
                        MessageBox.Show("Correct");
                        label2.Text = tbChar.ToString();

                        // Clear textbox
                        textBox1.Text = "";
                        return;
                    }
                }
                MessageBox.Show("Your input is not a number from 1 - 9");
                break;
        }
    }

Also, you don't need this line, remove it:

this.label2.Click += new System.EventHandler(this.label2_Click);