ASP.Net2.0 GridView 多列排序，显示排序图标，分页(转)

最近在使用ASP.net 2.0的GridView 控件时，发现排序与分页功能Microsoft实现的都很简单，比如排序，在点击列名的时候来触发整页的PostBack，然后排序，但是在列头上没有一个显示升序降序的图标，这会让最终用户使用时很迷惑，因为不知道是升序了还是降序了，所以今天首先解决的第一问题就是升序降序在列上显示图标，第二要解决的问题是默认GridView按列排序只能排一列的，也就是不能进行多列排序，而在实际应用中仅仅按照一列来排序是不能满足业务需求的，第三是GridView 分页问题，GridView预定义的分页页码显示，比较简单，而实际应用中，分页可能不是只显示首页，上一页，下一页，末页，或者是数字的页码那么简单，应该更需要，跳转，当前的页码，总页数等，更详尽的信息。

第一：GridView 多列排序与排序图标显示

首先我们可以新建一个类库程序，主要需要引用System.Web.Dll文件
然后新建一个类，这个类继承与GridView控件，我们只需要对部分方法进行重新即可。
我的演示的例子，采用了单列排序，如果启用多列排序，把控件的AllowMultiColumnSorting设置为True就是
多列排序。

 public class WebGridView:GridView
    ...{
        属性属性#region 属性
        /**//**//**//// <summary>
        /// 是否启用或者禁止多列排序
       /// </summary>
        [
        Description("是否启用多列排序功能"),
        Category("排序"),
        DefaultValue("false"),
        ]
        public bool AllowMultiColumnSorting
        ...{
            get
            ...{
                object o = ViewState["EnableMultiColumnSorting"];
                return (o != null ? (bool)o : false);
            }
            set
            ...{
                AllowSorting = true;
                ViewState["EnableMultiColumnSorting"] = value;
            }
        }
        /**//**//**//// <summary>
        /// 升序时显示图标
        /// </summary>
        [
        Description("升序时显示图标"),
        Category("排序"),
        Editor("System.Web.UI.Design.UrlEditor", typeof(System.Drawing.Design.UITypeEditor)),
        DefaultValue(""),

        ]
        public string SortAscImageUrl
        ...{
            get
            ...{
                object o = ViewState["SortImageAsc"];
                return (o != null ? o.ToString() : "");
            }
            set
            ...{
                ViewState["SortImageAsc"] = value;
            }
        }
        /**//**//**//// <summary>
        /// 降序时显示图标
        /// </summary>
        [
        Description("降序时显示图标"),
        Category("排序"),
        Editor("System.Web.UI.Design.UrlEditor", typeof(System.Drawing.Design.UITypeEditor)),
        DefaultValue(""),
        ]
        public string SortDescImageUrl
        ...{
            get
            ...{
                object o = ViewState["SortImageDesc"];
                return (o != null ? o.ToString() : "");
            }
            set
            ...{
                ViewState["SortImageDesc"] = value;
            }
        }
        #endregion
        重写方法重写方法#region 重写方法
        protected override void OnSorting(GridViewSortEventArgs e)
        ...{
            if (AllowMultiColumnSorting)
            ...{
                e.SortExpression = GetSortExpression(e);
            }

            base.OnSorting(e);
        }
        protected override void OnRowCreated(GridViewRowEventArgs e)
        ...{
            if (e.Row.RowType == DataControlRowType.Header)
            ...{
                if (SortExpression != String.Empty)
                ...{
                    DisplaySortOrderImages(SortExpression, e.Row);
                    this.CreateRow(0, 0, DataControlRowType.EmptyDataRow, DataControlRowState.Normal);
                }
            }
            base.OnRowCreated(e);
        }
        #endregion
        受保护的方法受保护的方法#region 受保护的方法
        /**//**//**//// <summary>
        ///  获取排序表达式
        /// </summary>
        protected string GetSortExpression(GridViewSortEventArgs e)
        ...{
            string[] sortColumns = null;
            string sortAttribute = SortExpression;

            if (sortAttribute != String.Empty)
            ...{
                sortColumns = sortAttribute.Split(",".ToCharArray());
            }
            if (sortAttribute.IndexOf(e.SortExpression) > 0 || sortAttribute.StartsWith(e.SortExpression))
            ...{
                sortAttribute = ModifySortExpression(sortColumns, e.SortExpression);
            }
            else
            ...{
                sortAttribute += String.Concat(",", e.SortExpression, " ASC ");
            }
            return sortAttribute.TrimStart(",".ToCharArray()).TrimEnd(",".ToCharArray());

        }
        /**//**//**//// <summary>
        ///  修改排序顺序
        /// </summary>
        protected string ModifySortExpression(string[] sortColumns, string sortExpression)
        ...{
            string ascSortExpression = String.Concat(sortExpression, " ASC ");
            string descSortExpression = String.Concat(sortExpression, " DESC ");

            for (int i = 0; i < sortColumns.Length; i++)
            ...{

                if (ascSortExpression.Equals(sortColumns[i]))
                ...{
                    sortColumns[i] = descSortExpression;
                }

                else if (descSortExpression.Equals(sortColumns[i]))
                ...{
                    Array.Clear(sortColumns, i, 1);
                }
            }

            return String.Join(",", sortColumns).Replace(",,", ",").TrimStart(",".ToCharArray());

        }
        /**//**//**//// <summary>
        ///  获取当前的表达式对所选列进行排序
        /// </summary>
        protected void SearchSortExpression(string[] sortColumns, string sortColumn, out string sortOrder, out int sortOrderNo)
        ...{
            sortOrder = "";
            sortOrderNo = -1;
            for (int i = 0; i < sortColumns.Length; i++)
            ...{
                if (sortColumns[i].StartsWith(sortColumn))
                ...{
                    sortOrderNo = i + 1;
                    if (AllowMultiColumnSorting)
                    ...{
                        sortOrder = sortColumns[i].Substring(sortColumn.Length).Trim();
                    }
                    else
                    ...{
                        sortOrder = ((SortDirection == SortDirection.Ascending) ? "ASC" : "DESC");
                    }
                }
            }
        }
        /**//**//**//// <summary>
        ///  绘制升序降序的图片
        /// </summary>
        protected void DisplaySortOrderImages(string sortExpression, GridViewRow dgItem)
        ...{
            string[] sortColumns = sortExpression.Split(",".ToCharArray());

            for (int i = 0; i < dgItem.Cells.Count; i++)
            ...{
                if (dgItem.Cells[i].Controls.Count > 0 && dgItem.Cells[i].Controls[0] is LinkButton)
                ...{
                    string sortOrder;
                    int sortOrderNo;
                    string column = ((LinkButton)dgItem.Cells[i].Controls[0]).CommandArgument;
                    SearchSortExpression(sortColumns, column, out sortOrder, out sortOrderNo);
                    if (sortOrderNo > 0)
                    ...{
                        string sortImgLoc = (sortOrder.Equals("ASC") ? SortAscImageUrl : SortDescImageUrl);

                        if (sortImgLoc != String.Empty)
                        ...{
                            Image imgSortDirection = new Image();
                            imgSortDirection.ImageUrl = sortImgLoc;
                            dgItem.Cells[i].Controls.Add(imgSortDirection);

                        }
                        else
                        ...{

                            if (AllowMultiColumnSorting)
                            ...{
                                Literal litSortSeq = new Literal();
                                litSortSeq.Text = sortOrderNo.ToString();
                                dgItem.Cells[i].Controls.Add(litSortSeq);

                            }
                       }
                    }
                }
            }

        }
        #endregion
    }

第二：详尽的分页信息显示，此功能没有封装成控件形式，直接在GridView_DataBound事件中对尾页操作即可。
下面是多列排序与分页显示代码的演示

<script runat="server">
    void PageDropDownList_SelectedIndexChanged(Object sender, EventArgs e)
    ...{
        GridViewRow pagerRow = CustomersGridView.BottomPagerRow;
        DropDownList pageList = (DropDownList)pagerRow.Cells[0].FindControl("PageDropDownList");
        CustomersGridView.PageIndex = pageList.SelectedIndex;
    }
    void CustomersGridView_DataBound(Object sender, EventArgs e)
    ...{
        GridViewRow pagerRow = CustomersGridView.BottomPagerRow;

        LinkButton linkBtnFirst = (LinkButton)pagerRow.Cells[0].FindControl("linkBtnFirst");
        LinkButton linkBtnPrev = (LinkButton)pagerRow.Cells[0].FindControl("linkBtnPrev");
        LinkButton linkBtnNext = (LinkButton)pagerRow.Cells[0].FindControl("linkBtnNext");
        LinkButton linkBtnLast = (LinkButton)pagerRow.Cells[0].FindControl("linkBtnLast");

        if (CustomersGridView.PageIndex == 0)
        ...{
            linkBtnFirst.Enabled = false;
            linkBtnPrev.Enabled = false;
        }
        else if (CustomersGridView.PageIndex == CustomersGridView.PageCount-1)
        ...{
            linkBtnLast.Enabled  = false;
            linkBtnNext.Enabled = false;
        }
        else if (CustomersGridView.PageCount<=0)
        ...{
            linkBtnFirst.Enabled = false;
            linkBtnPrev.Enabled = false;
            linkBtnNext.Enabled = false;
            linkBtnLast.Enabled = false;
        }
        DropDownList pageList = (DropDownList)pagerRow.Cells[0].FindControl("PageDropDownList");
        Label pageLabel = (Label)pagerRow.Cells[0].FindControl("CurrentPageLabel");

        if (pageList != null)
        ...{
            for (int i = 0; i < CustomersGridView.PageCount; i++)
            ...{
                int pageNumber = i + 1;
                ListItem item = new ListItem(pageNumber.ToString() + "/" + CustomersGridView.PageCount.ToString(), pageNumber.ToString());
                if (i == CustomersGridView.PageIndex)
                ...{
                    item.Selected = true;
                }
                pageList.Items.Add(item);

            }

        }
        if (pageLabel != null)
        ...{
            int currentPage = CustomersGridView.PageIndex + 1;
            pageLabel.Text = "当前页： " + currentPage.ToString() +
              " / " + CustomersGridView.PageCount.ToString();
        }
    }

</script>

<html>
<body>
    <form id="Form1" runat="server">
        <h3>
            GridView PagerTemplate Example</h3>
        <asp:WebGridView ID="CustomersGridView" DataSourceID="CustomersSqlDataSource" AutoGenerateColumns="true"
            AllowPaging="true" OnDataBound="CustomersGridView_DataBound" SortAscImageUrl="~imagesarrow-up.gif" SortDescImageUrl="~imagesarrow-down.gif" runat="server" AllowSorting="True" Width="723px">
            <PagerStyle ForeColor="Blue" BackColor="LightBlue" />
            <PagerTemplate>
                <table width="100%">
                    <tr>
                        <td width="70%">
                            <asp:Label ID="MessageLabel" ForeColor="Blue" Text="页码:" runat="server" />
                            <asp:DropDownList ID="PageDropDownList" AutoPostBack="true" OnSelectedIndexChanged="PageDropDownList_SelectedIndexChanged"
                                runat="server" />
                            <asp:LinkButton CommandName="Page" CommandArgument="First" ID="linkBtnFirst" runat="server">首页</asp:LinkButton>
                            <asp:LinkButton CommandName="Page" CommandArgument="Prev" ID="linkBtnPrev" runat="server">上一页</asp:LinkButton>
                            <asp:LinkButton CommandName="Page" CommandArgument="Next" ID="linkBtnNext" runat="server">下一页</asp:LinkButton>
                            <asp:LinkButton CommandName="Page" CommandArgument="Last" ID="linkBtnLast" runat="server">末页</asp:LinkButton>
                        </td>
                        <td width="70%" align="right">
                            <asp:Label ID="CurrentPageLabel" ForeColor="Blue" runat="server" />
                        </td>
                    </tr>
                </table>
            </PagerTemplate>
       </asp:WebGridView>
        <asp:SqlDataSource ID="CustomersSqlDataSource" SelectCommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
            ConnectionString="<%$ ConnectionStrings:NorthWindConnectionString%>" runat="server">
        </asp:SqlDataSource>

    </form>
</body>
</html>

效果：