~楓花雪岳~: [C#] WebForm 之間傳遞參數

星期二, 9月 09, 2014

[C#] WebForm 之間傳遞參數

論壇問題

在 WebForm 之間傳遞參數

利用 QueryString 和 Session 來練習傳遞參數

using System.Data;

namespace PassPara
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                DataTable dt = new DataTable("Demo");
                dt.Columns.Add("ProdNO", typeof(int));
                dt.Columns.Add("ProdName", typeof(string));
                dt.Rows.Add(1, "Visial Studio 2013");
                dt.Rows.Add(2, "SQL Server 2014");
                dt.Rows.Add(3, "Windows Server 2012 R2");
                dt.Rows.Add(4, "Office 365");
                dt.Rows.Add(5, "Windows Azure");
                gvData.DataSource = dt;
                gvData.DataBind();
            }
        }

        protected void btnShowData_Click(object sender, EventArgs e)
        {
            // 避免重覆選取，要先把 Text 內容清空
            lblResult.Text = "";
            // 利用 foreach 方式來搜尋使用者勾選資料
            foreach (GridViewRow row in gvData.Rows)
            {
                // 確認 RowType 是 DataRow
                if (row.RowType != DataControlRowType.DataRow) continue;
                // 利用 FindControl 來找到 CheckBox 控件
                CheckBox cb = row.FindControl("cbChecked") as CheckBox;
                if (cb == null || !cb.Checked) continue;
                lblResult.Text += row.Cells[2].Text + "＜br＞";
            }
        }

        private List<string> getCheck(GridView gvData)
        {
            // 利用 LINQ 方式找出使用者勾選資料
            List<string> checkresult = (from GridViewRow r in gvData.Rows
                                        where (r.FindControl("cbChecked") as CheckBox).Checked == true
                                        select gvData.Rows[r.RowIndex].Cells[2].Text.ToString()).ToList<string>();

            return checkresult;
        }

        protected void btnQueryString_Click(object sender, EventArgs e)
        {
            Response.Redirect("QueryStringPage.aspx?Data=" + Server.UrlEncode(string.Join(",", getCheck(gvData))));
        }

        protected void btnSession_Click(object sender, EventArgs e)
        {
            Session["Data"] = getCheck(gvData);
            Response.Redirect("SessionPage.aspx");
        }
    }
}

QuerString 作法

// SessionPage.aspx.cs 內容
namespace PassPara
{
    public partial class SessionPage : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            gvResult.DataSource = Session["Data"] as List<string>;
            gvResult.DataBind();
            gvResult.HeaderRow.Cells[0].Text = "勾選選項";
        }
    }
}

// SessionPage.aspx 內容
<body>
    <form id="form1" runat="server">
        <div>
            <h1>利用 QueryString 傳遞參數</h1>
            QueryString 參數內容: <%=Server.UrlDecode(Request.QueryString["Data"]) %>＜br/＞
            ＜br/＞
        </div>
        <asp:GridView ID="gvResult" runat="server">
        </asp:GridView>
        ＜br/＞
        <asp:HyperLink ID="Hyperlink1" runat="server" NavigateUrl="~/Default.aspx">回首頁</asp:HyperLink>
    </form>
</body>

Session 作法

// SessionPage.aspx.cs
namespace PassPara
{
    public partial class SessionPage : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            gvResult.DataSource = Session["Data"] as List<string>;
            gvResult.DataBind();
            gvResult.HeaderRow.Cells[0].Text = "勾選選項";
        }
    }
}

// SessionPage.aspx
<body>
    <form id="form1" runat="server">
        <div>
            <h1>利用 session 傳遞參數</h1>
            session 參數內容: <%= string.Join(",",Session["Data"] as List<string>) %>＜br /＞
            ＜br /＞
        </div>
        <asp:GridView ID="gvResult" runat="server">
        </asp:GridView>
        ＜br /＞
        <asp:HyperLink ID="Hyperlink1" runat="server" NavigateUrl="~/Default.aspx">回首頁</asp:HyperLink>
    </form>
</body>