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ASP.Net2.0 GridView 多列排序，顯示排序圖標，分頁

作者：Eve Cole 更新時間：2009-06-30 16:48:57

最近在使用ASP.net 2.0的GridView 控制項時，發現排序與分頁功能Microsoft實現的都很簡單，例如排序，在點擊列名的時候來觸發整頁的PostBack，然後排序，但是在列頭上沒有一個顯示升序降序的圖標，這會讓最終用戶使用時很迷惑，因為不知道是升序了還是降序了，所以今天首先解決的第一問題就是升序降序在列上顯示圖標，第二要解決的問題是預設GridView按列排序只能排一列的，也就是不能進行多列排序，而在實際應用中僅按照一列來排序是不能滿足業務需求的，第三是GridView 分頁問題，GridView預定義的分頁頁碼顯示，比較簡單，而實際應用中，分頁可能不是只顯示首頁，上一頁，下一頁，末頁，或者是數字的頁碼那麼簡單，應該更需要，跳轉，當前的頁碼，總頁數等，更詳盡的資訊。

第一：GridView 多列排序與排序圖示顯示

首先我們可以新建一個類別庫程序，主要需要引用System.Web.Dll檔案然後新建一個類，這個類別繼承與GridView控件，我們只需要對部分方法進行重新即可。
我的示範的例子，採用了單列排序，如果啟用多列排序，把控制項的AllowMultiColumnSorting設定為True就是多列排序。


1 public class WebGridView:GridView
2 {
3 屬性#region 屬性
4 /**//// <summary>
5 /// 是否啟用或禁止多列排序
6 /// </summary>
7 [
8 Description("是否啟用多列排序功能"),
9 Category("排序"),
10 DefaultValue("false"),
11 ]
12 public bool AllowMultiColumnSorting
13 {
14 get
15 {
16 object o = ViewState["EnableMultiColumnSorting"];
17 return (o != null ? (bool)o : false);
18 }
19 set
20 {
21 AllowSorting = true;
22 ViewState["EnableMultiColumnSorting"] = value;
23 }
24 }
25 /**//// <summary>
26 /// 升序時顯示圖示
27 /// </summary>
28 [
29 Description("升序時顯示圖示"),
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 {
37 get
38 {
39 object o = ViewState["SortImageAsc"];
40 return (o != null ? o.ToString() : "");
41 }
42 set
43 {
44 ViewState["SortImageAsc"] = value;
45 }
46 }
47 /**//// <summary>
48 /// 降序時顯示圖示
49 /// </summary>
50 [
51 Description("降序時顯示圖示"),
52 Category("排序"),
53 Editor("System.Web.UI.Design.UrlEditor", typeof(System.Drawing.Design.UITypeEditor)),
54 DefaultValue(""),
55 ]
56 public string SortDescImageUrl
57 {
58 get
59 {
60 object o = ViewState["SortImageDesc"];
61 return (o != null ? o.ToString() : "");
62 }
63 set
64 {
65 ViewState["SortImageDesc"] = value;
66 }
67 }
68 #endregion
69 重寫方法#region 重寫方法
70 protected override void OnSorting(GridViewSortEventArgs e)
71 {
72 if (AllowMultiColumnSorting)
73 {
74 e.SortExpression = GetSortExpression(e);
75 }
76
77 base.OnSorting(e);
78 }
79 protected override void OnRowCreated(GridViewRowEventArgs e)
80 {
81 if (e.Row.RowType == DataControlRowType.Header)
82 {
83 if (SortExpression != String.Empty)
84 {
85 DisplaySortOrderImages(SortExpression, e.Row);
86 this.CreateRow(0, 0, DataControlRowType.EmptyDataRow, DataControlRowState.Normal);
87 }
88 }
89 base.OnRowCreated(e);
90 }
91 #endregion
92 受保護的方法#region 受保護的方法
93 /**//// <summary>
94 /// 取得排序表達式
95 /// </summary>
96 protected string GetSortExpression(GridViewSortEventArgs e)
97 {
98 string[] sortColumns = null;
99 string sortAttribute = SortExpression;
100
101 if (sortAttribute != String.Empty)
102 {
103 sortColumns = sortAttribute.Split(",".ToCharArray());
104 }
105 if (sortAttribute.IndexOf(e.SortExpression) > 0 || sortAttribute.StartsWith(e.SortExpression))
106 {
107 sortAttribute = ModifySortExpression(sortColumns, e.SortExpression);
108 }
109 else
110 {
111 sortAttribute += String.Concat(",", e.SortExpression, " ASC ");
112 }
113 return sortAttribute.TrimStart(",".ToCharArray()).TrimEnd(",".ToCharArray());
114
115 }
116 /**//// <summary>
117 /// 修改排序順序
118 /// </summary>
119 protected string ModifySortExpression(string[] sortColumns, string sortExpression)
120 {
121 string ascSortExpression = String.Concat(sortExpression, " ASC ");
122 string descSortExpression = String.Concat(sortExpression, " DESC ");
123
124 for (int i = 0; i < sortColumns.Length; i++)
125 {
126
127 if (ascSortExpression.Equals(sortColumns[i]))
128 {
129 sortColumns[i] = descSortExpression;
130 }
131
132 else if (descSortExpression.Equals(sortColumns[i]))
133 {
134 Array.Clear(sortColumns, i, 1);
135 }
136 }
137
138 return String.Join(",", sortColumns).Replace(",,", ",").TrimStart(",".ToCharArray());
139
140 }
141 /**//// <summary>
142 /// 取得目前的表達式對所選列進行排序
143 /// </summary>
144 protected void SearchSortExpression(string[] sortColumns, string sortColumn, out string sortOrder, out int sortOrderNo)
145 {
146 sortOrder = "";
147 sortOrderNo = -1;
148 for (int i = 0; i < sortColumns.Length; i++)
149 {
150 if (sortColumns[i].StartsWith(sortColumn))
151 {
152 sortOrderNo = i + 1;
153 if (AllowMultiColumnSorting)
154 {
155 sortOrder = sortColumns[i].Substring(sortColumn.Length).Trim();
156 }
157 else
158 {
159 sortOrder = ((SortDirection == SortDirection.Ascending) ? "ASC" : "DESC");
160 }
161 }
162 }
163 }
164 /**//// <summary>
165 /// 繪製升序降序的圖片
166 /// </summary>
167 protected void DisplaySortOrderImages(string sortExpression, GridViewRow dgItem)
168 {
169 string[] sortColumns = sortExpression.Split(",".ToCharArray());
170
171 for (int i = 0; i < dgItem.Cells.Count; i++)
172 {
173 if (dgItem.Cells[i].Controls.Count > 0 && dgItem.Cells[i].Controls[0] is LinkBut​​ton)
174 {
175 string sortOrder;
176 int sortOrderNo;
177 string column = ((LinkBut​​ton)dgItem.Cells[i].Controls[0]).CommandArgument;
178 SearchSortExpression(sortColumns, column, out sortOrder, out sortOrderNo);
179 if (sortOrderNo > 0)
180 {
181 string sortImgLoc = (sortOrder.Equals("ASC") ? SortAscImageUrl : SortDescImageUrl);
182
183 if (sortImgLoc != String.Empty)
184 {
185 Image imgSortDirection = new Image();
186 imgSortDirection.ImageUrl = sortImgLoc;
187 dgItem.Cells[i].Controls.Add(imgSortDirection);
188
189 }
190 else
191 {
192
193 if (AllowMultiColumnSorting)
194 {
195 Literal litSortSeq = new Literal();
196 litSortSeq.Text = sortOrderNo.ToString();
197 dgItem.Cells[i].Controls.Add(litSortSeq);
198
199 }
200 }
201 }
202 }
203 }
204
205 }
206 #endregion
207 }
第二：詳盡的分頁資訊顯示，此功能沒有封裝成控制項形式，直接在GridView_DataBound事件中對尾頁操作即可。
以下是多列排序與分頁顯示程式碼的示範


<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;

LinkBut​​ton linkBtnFirst = (LinkBut​​ton)pagerRow.Cells[0].FindControl("linkBtnFirst");
LinkBut​​ton linkBtnPrev = (LinkBut​​ton)pagerRow.Cells[0].FindControl("linkBtnPrev");
LinkBut​​ton linkBtnNext = (LinkBut​​ton)pagerRow.Cells[0].FindControl("linkBtnNext");
LinkBut​​ton linkBtnLast = (LinkBut​​ton)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 = "目前頁： " + currentPage.ToString() +
" / " + CustomersGridView.PageCount.ToString();
}
}

</script>

<html>
<body>
<form id="Form1" runat="server">
<h3>
GridView PagerTemplate 範例</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="頁碼:" runat="server" />
<asp:DropDownList ID="PageDropDownList" AutoPostBack="true" OnSelectedIndexChanged="PageDropDownList_SelectedIndexChanged"
runat="server" />
<asp:LinkBut​​ton CommandName="Page" CommandArgument="First" ID="linkBtnFirst" runat="server">首頁</asp:LinkBut​​ton>
<asp:LinkBut​​ton CommandName="Page" CommandArgument="Prev" ID="linkBtnPrev" runat="server">上一頁</asp:LinkBut​​ton>
<asp:LinkBut​​ton CommandName="Page" CommandArgument="Next" ID="linkBtnNext" runat="server">下一頁</asp:LinkBut​​ton>
<asp:LinkBut​​ton CommandName="Page" CommandArgument="Last" ID="linkBtnLast" runat="server">末頁</asp:LinkBut​​ton>
</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>
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