ASP.Net2.0GridView多列排序，显示排序图标，分页

    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。

  1    public class WebGridView:GridView
  2    &＃123;
  3        属性#region 属性
  4        /**////

  5        /// 是否启用或者禁止多列排序
  6        ///

  7        [
  8        Description("是否启用多列排序功能"),
  9        Category("排序"),
 10        DefaultValue("false"),
 11        ]
 12        public bool AllowMultiColumnSorting
 13        &＃123;
 14            get
 15            &＃123;
 16                object o = ViewState["EnableMultiColumnSorting"];
 17                return (o != null ? (bool)o : false);
 18            &＃125;
 19            set
 20            &＃123;
 21                AllowSorting = true;
 22                ViewState["EnableMultiColumnSorting"] = value;
 23            &＃125;
 24        &＃125;
 25        /**////

 26        /// 升序时显示图标
 27        ///

 28        [
 29        Description("升序时显示图标"),
 30        Category("排序"),
 31        Editor("System.Web.UI.Design.UrlEditor", typeof(System.Drawing.Design.UITypeEditor)),
 32        DefaultValue(""),
 33
 34        ]
 35        public string SortAscImageUrl
 36        &＃123;
 37            get
 38            &＃123;
 39                object o = ViewState["SortImageAsc"];
 40                return (o != null ? o.ToString() : "");
 41            &＃125;
 42            set
 43            &＃123;
 44                ViewState["SortImageAsc"] = value;
 45            &＃125;
 46        &＃125;
 47        /**////

 48        /// 降序时显示图标
 49        ///

 50        [
 51        Description("降序时显示图标"),
 52        Category("排序"),
 53        Editor("System.Web.UI.Design.UrlEditor", typeof(System.Drawing.Design.UITypeEditor)),
 54        DefaultValue(""),
 55        ]
 56        public string SortDescImageUrl
 57        &＃123;
 58            get
 59            &＃123;
 60                object o = ViewState["SortImageDesc"];
 61                return (o != null ? o.ToString() : "");
 62            &＃125;
 63            set
 64            &＃123;
 65                ViewState["SortImageDesc"] = value;
 66            &＃125;
 67        &＃125;
 68        #endregion
 69        重写方法#region 重写方法
 70        protected override void OnSorting(GridViewSortEventArgs e)
 71        &＃123;
 72            if (AllowMultiColumnSorting)
 73            &＃123;
 74                e.SortExpression = GetSortExpression(e);
 75            &＃125;
 76
 77            base.OnSorting(e);
 78        &＃125;
 79        protected override void OnRowCreated(GridViewRowEventArgs e)
 80        &＃123;
 81            if (e.Row.RowType == DataControlRowType.Header)
 82            &＃123;
 83                if (SortExpression != String.Empty)
 84                &＃123;
 85                    DisplaySortOrderImages(SortExpression, e.Row);
 86                    this.CreateRow(0, 0, DataControlRowType.EmptyDataRow, DataControlRowState.Normal);
 87                &＃125;
 88            &＃125;
 89            base.OnRowCreated(e);
 90        &＃125;
 91        #endregion
 92        受保护的方法#region 受保护的方法
 93        /**////

 94        ///  获取排序表达式
 95        ///

 96        protected string GetSortExpression(GridViewSortEventArgs e)
 97        &＃123;
 98            string[] sortColumns = null;
 99            string sortAttribute = SortExpression;
100
101            if (sortAttribute != String.Empty)
102            &＃123;
103                sortColumns = sortAttribute.Split(",".ToCharArray());
104            &＃125;
105            if (sortAttribute.IndexOf(e.SortExpression) > 0 || sortAttribute.StartsWith(e.SortExpression))
106            &＃123;
107                sortAttribute = ModifySortExpression(sortColumns, e.SortExpression);
108            &＃125;
109            else
110            &＃123;
111                sortAttribute += String.Concat(",", e.SortExpression, " ASC ");
112            &＃125;
113            return sortAttribute.TrimStart(",".ToCharArray()).TrimEnd(",".ToCharArray());
114
115        &＃125;
116        /**////

117        ///  修改排序顺序
118        ///

119        protected string ModifySortExpression(string[] sortColumns, string sortExpression)
120        &＃123;
121            string ascSortExpression = String.Concat(sortExpression, " ASC ");
122            string descSortExpression = String.Concat(sortExpression, " DESC ");
123
124            for (int i = 0; i 125            &＃123;
126
127                if (ascSortExpression.Equals(sortColumns[i]))
128                &＃123;
129                    sortColumns[i] = descSortExpression;
130                &＃125;
131
132                else if (descSortExpression.Equals(sortColumns[i]))
133                &＃123;
134                    Array.Clear(sortColumns, i, 1);
135                &＃125;
136            &＃125;
137
138            return String.Join(",", sortColumns).Replace(",,", ",").TrimStart(",".ToCharArray());
139
140        &＃125;
141        /**////

142        ///  获取当前的表达式对所选列进行排序
143        ///

144        protected void SearchSortExpression(string[] sortColumns, string sortColumn, out string sortOrder, out int sortOrderNo)
145        &＃123;
146            sortOrder = "";
147            sortOrderNo = -1;
148            for (int i = 0; i 149            &＃123;
150                if (sortColumns[i].StartsWith(sortColumn))
151                &＃123;
152                    sortOrderNo = i + 1;
153                    if (AllowMultiColumnSorting)
154                    &＃123;
155                        sortOrder = sortColumns[i].Substring(sortColumn.Length).Trim();
156                    &＃125;
157                    else
158                    &＃123;
159                        sortOrder = ((SortDirection == SortDirection.Ascending) ? "ASC" : "DESC");
160                    &＃125;
161                &＃125;
162            &＃125;
163        &＃125;
164        /**////

165        ///  绘制升序降序的图片
166        ///

167        protected void DisplaySortOrderImages(string sortExpression, GridViewRow dgItem)
168        &＃123;
169            string[] sortColumns = sortExpression.Split(",".ToCharArray());
170
171            for (int i = 0; i 172            &＃123;
173                if (dgItem.Cells[i].Controls.Count > 0 && dgItem.Cells[i].Controls[0] is LinkButton)
174                &＃123;
175                    string sortOrder;
176                    int sortOrderNo;
177                    string column = ((LinkButton)dgItem.Cells[i].Controls[0]).CommandArgument;
178                    SearchSortExpression(sortColumns, column, out sortOrder, out sortOrderNo);
179                    if (sortOrderNo > 0)
180                    &＃123;
181                        string sortImgLoc = (sortOrder.Equals("ASC") ? SortAscImageUrl : SortDescImageUrl);
182
183                        if (sortImgLoc != String.Empty)
184                        &＃123;
185                            Image imgSortDirection = new Image();
186                            imgSortDirection.ImageUrl = sortImgLoc;
187                            dgItem.Cells[i].Controls.Add(imgSortDirection);
188
189                        &＃125;
190                        else
191                        &＃123;
192
193                            if (AllowMultiColumnSorting)
194                            &＃123;
195                                Literal litSortSeq = new Literal();
196                                litSortSeq.Text = sortOrderNo.ToString();
197                                dgItem.Cells[i].Controls.Add(litSortSeq);
198
199                            &＃125;
200                        &＃125;
201                    &＃125;
202                &＃125;
203            &＃125;
204
205        &＃125;
206        #endregion
207    &＃125;

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

   
       

            GridView PagerTemplate Example

                    AllowPaging="true" OnDataBound="CustomersGridView_DataBound" SortAscImageUrl="~\images\arrow-up.gif" SortDescImageUrl="~\images\arrow-down.gif" runat="server" AllowSorting="True" >
           
           
               
                   
                       
                       
                   
               

runat="server" />                             首页                             上一页                             下一页                             末页

           
      
                    COnnectionString="<%&＃36; ConnectionStrings:NorthWindConnectionString%>" runat="server">