GridView排序加上下箭头

ASPX:

          <table width="778" border="0" align="center" cellpadding="0" cellspacing="0">
            <tr>
               <td align="center">
                    <asp:GridView  ID="myGridView" runat="server" AllowPaging="True" DataKeyNames="id"
                        AutoGenerateColumns="False" Width="100%" PageSize="25" OnRowDataBound="myGridView_RowDataBound" AllowSorting="True" OnSorting="myGridView_Sorting" OnPageIndexChanging="myGridView_PageIndexChanging" EmptyDataText="沒有記錄" OnRowCreated="myGridView_RowCreated">
                        <Columns>
                            <asp:BoundField HeaderText="序號" />
                            <asp:BoundField DataField="empno" SortExpression="empno" HeaderText="工號" />
                            <asp:BoundField DataField="cname" SortExpression="cname" HeaderText="姓名" />
                            <asp:BoundField DataField="sex" SortExpression="sex" HeaderText="性別" />
                            <asp:BoundField DataField="age" SortExpression="age" HeaderText="年齡" />
                            <asp:BoundField DataField="linecode" SortExpression="linecode" HeaderText="拉名"  />
                            <asp:BoundField DataField="hold_date" DataFormatString="{0:MM月dd日yyyy年}"  HeaderText="入廠日期"  HtmlEncode="False" SortExpression="hold_date"/>
                            <asp:BoundField DataField="g_time" DataFormatString="{0:MM月dd日yyyy年}"  HeaderText="體檢日期"  HtmlEncode="False" SortExpression="g_time"/>
                            <asp:CommandField HeaderText="操作" ShowEditButton="True" />
                            <asp:TemplateField>
                                <HeaderTemplate>
                                    <input id="CheckAll" type="checkbox" onclick="selectAll(this)" />
                                </HeaderTemplate>
                                <ItemTemplate>
                                    <input id="chkID" name="chkID" type="checkbox" value='<%# Eval("empno")%>' onclick="selectOne(this)" />
                                </ItemTemplate>
                            </asp:TemplateField>
                        </Columns>
                        <HeaderStyle BackColor="Gainsboro" />
                        <PagerSettings PageButtonCount="15" Visible="False" />
                    </asp:GridView >
              </td>
            </tr>
        </table>
       <table width="778" height="25" border="0" align="center" cellpadding="0" cellspacing="0">
        <tr>
          <td>
            <asp:Label ID="labRecordCount" runat="server"></asp:Label>&nbsp;
            <asp:Label ID="labPageCount" runat="server"></asp:Label>&nbsp;
            <asp:Label ID="labPageRecord" runat="server"></asp:Label>&nbsp;
            </td>
          <td align="right">
          <asp:LinkButton ID="btnFirst" CommandArgument="first" OnClick="PagerButtonClick" runat="server">首 页</asp:LinkButton>&nbsp;
            <asp:LinkButton ID="btnPrev" CommandArgument="prev" OnClick="PagerButtonClick" runat="server">上一页</asp:LinkButton>&nbsp;
            <asp:LinkButton ID="btnNext" CommandArgument="next" OnClick="PagerButtonClick" runat="server">下一页</asp:LinkButton>&nbsp;
          <asp:LinkButton ID="btnLast" CommandArgument="last" OnClick="PagerButtonClick" runat="server">尾 页</asp:LinkButton>
          </td>
        </tr>
      </table>

CS:

  1using System;
  2using System.Data;
  3using System.Configuration;
  4using System.Collections;
  5using System.Web;
  6using System.Web.Security;
  7using System.Web.UI;
  8using System.Web.UI.WebControls;
  9using System.Web.UI.WebControls.WebParts;
 10using System.Web.UI.HtmlControls;
 11
 12
 13public partial class ComEmployee : System.Web.UI.Page
 14{
 15    protected void Page_Load(object sender, EventArgs e)
 16    {
 17        if (!IsPostBack)
 18        {
 19            this.txtDate.Text = DateTime.Now.ToString("MM/dd/yyyy");
 20            this.btnGetEmp.Attributes["onclick"] = "changeStatus();";
 21            GridViewBind();
 22        }
 23    }
 24    private void GridViewBind()
 25    {
 26        WebClass.NewEmpClass tmp = new WebClass.NewEmpClass();
 27        DataTable dt = tmp.ComEmployyeeList();
 28        DataView dv = dt.DefaultView;
 29        if (ViewState["SortExpression"] != null)
 30        {
 31            dv.Sort = ViewState["SortExpression"].ToString() + " " + ViewState["SortDirection"].ToString();
 32        }
 33        myGridView.DataSource = dv;
 34        myGridView.DataBind();
 35        labRecordCount.Text = "共<font color='red'>" + dt.Rows.Count.ToString() + "</font>筆記錄";
 36        labPageCount.Text = "頁次<font color='blue'>" + (myGridView.PageIndex + 1).ToString() + "</font>/<font color='red'>" + myGridView.PageCount.ToString() + "</font>頁";
 37        labPageRecord.Text = "<font color='red'>" + myGridView.PageSize.ToString() + "</font>筆記錄/頁";
 38
 39        if (dt.Rows.Count == 0)
 40        {
 41            btnFirst.Visible = false;
 42            btnPrev.Visible = false;
 43            btnNext.Visible = false;
 44            btnLast.Visible = false;
 45
 46            labRecordCount.Visible = false;
 47            labPageCount.Visible = false;
 48            labPageRecord.Visible = false;
 49        }
 50        else if (myGridView.PageCount == 1)
 51        {
 52            btnFirst.Visible = false;
 53            btnPrev.Visible = false;
 54            btnNext.Visible = false;
 55            btnLast.Visible = false;
 56        }
 57
 58        btnFirst.CommandName = "1";
 59        btnPrev.CommandName = (myGridView.PageIndex == 0 ? "1" : myGridView.PageIndex.ToString());
 60        btnNext.CommandName = (myGridView.PageCount == 1 ? myGridView.PageCount.ToString() : (myGridView.PageIndex + 2).ToString());
 61        btnLast.CommandName = myGridView.PageCount.ToString();
 62        BtnValidate();
 63    }
 64    private void BtnValidate()
 65    {
 66        if (myGridView.PageIndex + 1 >= myGridView.PageCount)
 67        {
 68            btnNext.Enabled = false;
 69            btnLast.Enabled = false;
 70        }
 71        else
 72        {
 73            btnNext.Enabled = true;
 74            btnLast.Enabled = true;
 75        }
 76        if (myGridView.PageIndex + 1 <= 1)
 77        {
 78            btnPrev.Enabled = false;
 79            btnFirst.Enabled = false;
 80        }
 81        else
 82        {
 83            btnPrev.Enabled = true;
 84            btnFirst.Enabled = true;
 85        }
 86    }
 87    protected void PagerButtonClick(object sender, EventArgs e)
 88    {
 89        myGridView.PageIndex = Convert.ToInt32(((LinkButton)sender).CommandName) - 1;
 90        GridViewBind();
 91    }
 92    protected void myGridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
 93    {
 94        myGridView.PageIndex = e.NewPageIndex;
 95        GridViewBind();
 96    }
 97    protected void myGridView_RowDataBound(object sender, GridViewRowEventArgs e)
 98    {
 99        if (e.Row.RowIndex != -1)
100        {
101            int orderID = this.myGridView.PageIndex * this.myGridView.PageSize + e.Row.RowIndex + 1;
102            e.Row.Cells[0].Text = orderID.ToString();
103        }
104    }
105    protected void myGridView_Sorting(object sender, GridViewSortEventArgs e)
106    {
107        ViewState["SortExpression"] = e.SortExpression;
108        if (ViewState["SortDirection"] == null)
109        {
110            ViewState["SortDirection"] = "asc";
111        }
112        else
113        {
114            if (ViewState["SortDirection"].ToString() == "asc")
115            {
116                ViewState["SortDirection"] = "desc";
117            }
118            else
119            {
120                ViewState["SortDirection"] = "asc";
121            }
122        }
123        GridViewBind();
124    }
125    protected void imgbtnUpdate_Click(object sender, ImageClickEventArgs e)
126    {
127        GridViewBind();
128    }
129    protected void btnGetEmp_Click(object sender, EventArgs e)
130    {
131        string strEmpno = Request.Form.Get("chkID");
132        WebClass.NewEmpClass tmp = new WebClass.NewEmpClass();
133        tmp.CheckNewEmployyee(strEmpno);
134    }
135    protected void myGridView_RowCreated(object sender, GridViewRowEventArgs e)
136    {
137        if (e.Row != null && e.Row.RowType == DataControlRowType.Header)
138        {
139            string strSortBy = (string)ViewState["SortExpression"];
140            string strSortAscending = (string)ViewState["SortAscending"];
141            string strOrder = (strSortAscending == "yes" ? "5" : "6");
142
143            for (int i = 0; i < myGridView.Columns.Count; i++)
144            {
145                if (strSortBy == myGridView.Columns[i].SortExpression)
146                {
147                    TableCell cell = e.Row.Cells[i];
148                    Label lblSorted = new Label();
149                    lblSorted.Font.Name = "webdings";
150                    lblSorted.Font.Size = FontUnit.XSmall;
151                    lblSorted.Text = strOrder;
152                    cell.Controls.Add(lblSorted);
153                }
154            }
155        }
156    }
157}
158

有点郁闷,在DataGrid中,页面加载的时候默认排序字段会有箭头.
GridView同样的原理就没有.只有点击的时候才有,这样的话在页面加载时就不知道按照什么排序.