[C#] Form 傳值

論壇問題：要在 Form 之間傳值，拿來練習

Project 內容

frmMain layout

frmCustSearch layout

Customer Class

namespace WindowsFormsApplication1
{
    public class Customer
    {
        public int CustID { get; set; }
        public string CustName { get; set; }
        public string Address { get; set; }
    }
}

frmMain C# Code

namespace WindowsFormsApplication1
{
    public partial class frmMain : Form
    {
        public frmMain()
        {
            InitializeComponent();
        }

        private void frmMain_Load(object sender, EventArgs e)
        {

        }

        private void btnCustSearch_Click(object sender, EventArgs e)
        {

            ClearControlValue();

            frmCustSearch CustSearch = new frmCustSearch();
            if (CustSearch.ShowDialog() != DialogResult.OK)
                return;

            var customer = CustSearch.RetValue;
            txtCustID.Text = customer.CustID.ToString();
            txtCustName.Text = customer.CustName;
            txtAddress.Text = customer.Address;
        }

        void ClearControlValue()
        {
            foreach (Control ctl in Controls.OfType<TextBox>())
            {
                if ((ctl is TextBox txt) == false)
                    continue;

                txt.Text = string.Empty;
            }
        }
    }
}

frmCustSearch C# Code

namespace WindowsFormsApplication1
{
    public partial class frmCustSearch : Form
    {
        public frmCustSearch()
        {
            InitializeComponent();
        }

        // 紀錄使用者點選的是哪一筆資料
        public Customer RetValue { get; set; }

        private void frmCustSearch_Load(object sender, EventArgs e)
        {
            dgvCustomer.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
            btnOK.Click += btn_Click;
            btnCancel.Click += btn_Click;
            dgvCustomer.DataSource = DataGridViewSource();
            dgvCustomer.ClearSelection();
        }

        List<Customer> DataGridViewSource()
        {
            return
                new List<Customer>()
                    {
                        new Customer() { CustID = 1, CustName = "客戶1", Address = "台北" },
                        new Customer() { CustID = 2, CustName = "客戶2", Address = "台中" },
                        new Customer() { CustID = 3, CustName = "客戶3", Address = "高雄" }
                    };
        }

        void btn_Click(object sender, EventArgs e)
        {
            Button btn = sender as Button;
            if (btn == null) 
                return;

            DialogResult result = DialogResult.OK;

            if (RetValue == null || 
                btn.Name == btnCancel.Name)
                result = DialogResult.Cancel;

            DialogResult = result;

            Close();
        }

        private void dgvCustomer_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            RetValue = new Customer()
            {
                CustID = (int)dgvCustomer.CurrentRow.Cells[ColCustID.Name].Value,
                CustName = (string)dgvCustomer.CurrentRow.Cells[ColCustName.Name].Value,
                Address = (string)dgvCustomer.CurrentRow.Cells[ColAddress.Name].Value
            };
        }
    }
}

結果

• 參考資料
• 論壇討論 => 有用到 Pattern 的作法