C# Text Box'a buton ile değer verme

 public Form1()
        {
            InitializeComponent();
            textBox1.Text = "0";
        }

        private void btn_arttir_Click(object sender, EventArgs e)
        {
            try
            {
                textBox1.Text = (Convert.ToInt32(textBox1.Text) + 5).ToString();
            }
            catch (Exception EX)
            {
                MessageBox.Show(EX.Message);
            }
        }

        private void btn_azalt_Click(object sender, EventArgs e)
        {
            try
            {
                textBox1.Text = (Convert.ToInt32(textBox1.Text) - 5).ToString();
            }
            catch (Exception EX)
            {
                MessageBox.Show(EX.Message);
            }
        }