GridView实战一:自定义分页、排序、修改、插入、删除

前言:

  在某次公司面试时被问到对GridView操作的熟悉程度,在那之前一直用Repeater内嵌table标签对GridView操作确实很少,于是最近在项目的后台上对GridView进行了一番实操,本文和后面的另一篇GridView实战二:使用ObjectDataSource数据源控件均是这段时间的一些总结。

  GridView优点就是集数据绑定、分页、排序、删、改于一身,提高了开发效率;缺点嘛,就是运行效率低,并且它本身不带添加功能。于是GridView用于后台开发是一个不错的选择,而前台页面还是少用为妙咯。

实战一:

1.本次实战效果图如下:

图一.展示状态

图二.编辑状态

图三.添加记录状态

2.具体代码

.aspx页面

  1         <asp:GridView runat="server" ID="gv" AutoGenerateColumns="false"
  2              AllowPaging="true" PageSize="1" AllowSorting="true" DataKeyNames="ID"
  3              OnRowDataBound="gv_OnRowDataBound" OnRowDeleting="gv_OnRowDeleting"
  4              OnRowEditing="gv_OnRowEditing" OnRowCancelingEdit="gv_OnRowCancelingEdit"
  5              OnRowUpdating="gv_OnRowUpdating" OnSorting="gv_OnSorting">
  6              <HeaderStyle BackColor="graytext" />
  7             <Columns>
  8                 <asp:TemplateField>
  9                     <HeaderStyle Width="20%" />
 10                     <HeaderTemplate>
 11                         <asp:LinkButton runat="server" ID="lbtnSortName" Text="Name" CommandName="Sort" CommandArgument="Name">
 12                         </asp:LinkButton>
 13                     </HeaderTemplate>
 14                     <ItemTemplate><%#Eval("Name") %></ItemTemplate>
 15                     <EditItemTemplate>
 16                         <asp:TextBox runat="server" ID="tbxName" Text='<%#Eval("Name") %>'></asp:TextBox> 
 17                         <asp:RegularExpressionValidator runat="server" ID="revName" ControlToValidate="tbxName"
 18                              ValidationExpression="[a-zA-Z]+" ErrorMessage="Please input your English name!" Display="Dynamic">
 19                         </asp:RegularExpressionValidator>
 20                         <asp:RequiredFieldValidator runat="server" ID="rfvName" ControlToValidate="tbxName"
 21                             ErrorMessage="Please input your name" Display="Dynamic">
 22                         </asp:RequiredFieldValidator> 
 23                     </EditItemTemplate>
 24                 </asp:TemplateField> 
 25                 <asp:TemplateField>
 26                     <HeaderStyle Width="10%"/>
 27                     <HeaderTemplate>
 28                         <asp:LinkButton runat="server" ID="lbtnSortSex" Text="Sex" CommandName="Sort" CommandArgument="Sex">
 29                         </asp:LinkButton> 
 30                     </HeaderTemplate> 
 31                     <ItemTemplate>
 32                         <asp:RadioButtonList Enabled="false" runat="server" ID="rblSexShow" RepeatDirection="Horizontal" 
 33                             RepeatColumns="2">
 34                         </asp:RadioButtonList>
 35                     </ItemTemplate> 
 36                     <EditItemTemplate>
 37                          <asp:RadioButtonList runat="server" ID="rblSexEdit" RepeatDirection="Horizontal" RepeatColumns="2">
 38                          </asp:RadioButtonList>
 39                     </EditItemTemplate> 
 40                 </asp:TemplateField>
 41                 <asp:TemplateField>
 42                     <HeaderStyle Width="20%"/>
 43                     <HeaderTemplate>
 44                         <asp:LinkButton runat="server" ID="lbtnSortCountry" Text="Country" CommandName="Sort" CommandArgument="Country">
 45                         </asp:LinkButton>
 46                     </HeaderTemplate> 
 47                     <ItemTemplate><%#Eval("Country")%></ItemTemplate> 
 48                     <EditItemTemplate>
 49                         <asp:DropDownList runat="server" ID="ddlCountry"></asp:DropDownList>
 50                     </EditItemTemplate> 
 51                 </asp:TemplateField>
 52                 <asp:TemplateField>
 53                     <HeaderStyle Width="20%"/>
 54                     <HeaderTemplate>Hobby</HeaderTemplate>
 55                     <ItemTemplate><%#Eval("Hobby") %></ItemTemplate> 
 56                     <EditItemTemplate>
 57                         <asp:CheckBoxList runat="server" ID="cbxlHobby" RepeatDirection="Horizontal" RepeatColumns="5">
 58                         </asp:CheckBoxList>
 59                     </EditItemTemplate>
 60                 </asp:TemplateField>
 61                 <asp:TemplateField ItemStyle-HorizontalAlign="Center">
 62                     <HeaderStyle Width="10%"/>
 63                     <HeaderTemplate>
 64                         <asp:LinkButton runat="server" ID="lbtnShowAdd" Text="Add" OnClick="lbtnShowAdd_OnClick">
 65                         </asp:LinkButton>
 66                     </HeaderTemplate>
 67                     <ItemTemplate>
 68                         <asp:LinkButton runat="server" ID="lbtnEdit" Text="Edit" CommandName="Edit" />&emsp;
 69                         <asp:LinkButton runat="server" ID="lbtnDelete" Text="Delete" CommandName="Delete" />
 70                     </ItemTemplate>
 71                     <EditItemTemplate>
 72                         <asp:LinkButton runat="server" ID="lbtnSubmit" Text="Update" CommandName="Update" />&emsp;
 73                         <asp:LinkButton runat="server" ID="lbtnCancel" Text="Cancel" CommandName="Cancel" />
 74                     </EditItemTemplate> 
 75                 </asp:TemplateField>
 76             </Columns>
 77             <PagerSettings Visible="true" />
 78             <PagerStyle Font-Size="12px"/>
 79             <PagerTemplate>
 80                 <div style="float:left;margin-left:15px;color:#999;line-height:20px">
 81                     当前第<%#this.gv.PageIndex+1 %>/<%#this.gv.PageCount %>页
 82                 </div>
 83                 <div style="float:right;margin-right:15px;color:#999;line-height:20px">页</div>
 84                 <div style="float:right">
 85                     <asp:DropDownList runat="server" ID="ddlPaging" AutoPostBack="true"
 86                         OnSelectedIndexChanged="ddlPaging_OnSelectedIndexChanged">
 87                     </asp:DropDownList>
 88                 </div>
 89                 <div style="float:right;color:#999;line-height:20px">跳转到第</div>
 90             </PagerTemplate>
 91             <EmptyDataTemplate>
 92                 <div><b>Name:</b>
 93                     <asp:TextBox runat="server" ID="tbxName"></asp:TextBox>
 94                     <asp:RegularExpressionValidator runat="server" ID="revName" ControlToValidate="tbxName"
 95                          ValidationExpression="^[a-zA-Z]+$" Display="Dynamic" ErrorMessage="Please input your English name!">
 96                     </asp:RegularExpressionValidator>
 97                    <asp:RequiredFieldValidator runat="server" ID="rfvName" ControlToValidate="tbxName"
 98                         ErrorMessage="Please input your name" Display="Dynamic">
 99                     </asp:RequiredFieldValidator> 
100                 </div>
101                 <div><b>Sex:</b>
102                     <asp:RadioButtonList runat="server" id="rblSex" RepeatColumns="2" RepeatDirection="Horizontal">
103                         <asp:ListItem Value="M" Text="Male" Selected="True"></asp:ListItem>
104                         <asp:ListItem Value="F" Text="Female"></asp:ListItem>
105                     </asp:RadioButtonList>
106                 </div>
107                 <div><b>Country:</b>
108                     <asp:DropDownList runat="server" ID="ddlCountry">
109                     </asp:DropDownList>
110                     <asp:RequiredFieldValidator runat="server" ID="rfCountry" ControlToValidate="ddlCountry"
111                         ErrorMessage="Please Choose Country" Display="Dynamic">
112                     </asp:RequiredFieldValidator>
113                 </div>
114                 <div><b>Hobby:</b>
115                     <asp:CheckBoxList runat="server" ID="cbxlHobby" RepeatColumns="5" RepeatDirection="Horizontal">
116                     </asp:CheckBoxList>
117                 </div>
118                 <div>
119                     <asp:LinkButton runat="server" ID="lbtnSubmit" Text="Submit" OnClick="lbtnSubmit_OnClick" />
120                     <asp:LinkButton  runat="server" ID="lbtnCancel" Text="Cancel" OnClick="lbtnCancel_OnClick"
121                         CausesValidation="false"/>
122                 </div>
123             </EmptyDataTemplate> 
124         </asp:GridView>

说明:

1.显示状态时:对于只显示文字串的用<%#Eval("字段名")%>直接绑定,而对于单选组(性别)的内容就放在GridView的OnRowDataBound来绑定。

2.编辑状态时:复选组、单选组合下拉列表都在OnRowDataBound来绑定;这里没有用数据源控件,所以用<%#Bind("字段名")%>和<%#Eval("字段名")%>没区别,<%#Bind("字段名")%>的双向通讯不起作用。

3.新增状态:因为GridView自身附带新增记录的功能,所以选择在EmptyDataTemplate中实现新增的功能(借鉴其他同行的做法!);因为使用了验证控件,所以把取消按钮(操作不验证合法性)设为不触发验证。

4.分页功能:本例是将分页功能放置到gridview的PagerTemplate中实现。这里有两个注意点:

a.DropDownList设置AutoPostBack为true;

b.因为要触发DropDownList的OnSelectedIndexChanged事件,所以viewstate要启用。触发OnSelectedIndexChanged事件的条件是postback的selectedIndex和原始值不同,当viewstate启用时原始值就是viewstate中保存的值,当viewstate禁用时就是控件初始化时的selectedIndex或第一个选项。因此如果禁用了ViewState那么当选择回控件初始化时的选项时就不会触发OnSelectedIndexChanged事件了。

c.GridView的OnRowDataBound中每次postback都重新初始化DropDownList。因为DropDownList包含在GridView中是动态生成的,当PostBack时GridView并不会恢复其中的动态内容;如果把分页功能放在GridView以外实现,那么动态生成的时DropDownList的选项,就Postback时不用再初始化了。

d.因为DropDownList位于GridView里面,所以当把某个ListItem的enable设为false时,该选项就不生成(连Html代码都没了),如果放在GridView外只是显示为不可用而已,原因不明。为实现添加状态初始画面中存在默认不可选的listitem效果,用了html的disabled属性来设置。

.aspx.cs代码

  1 public partial class _Default : System.Web.UI.Page 
  2 {
  3     private DataManager dm = new DataManager();
  4 
  5     protected void Page_Load(object sender, EventArgs e)
  6     {
  7         if (!IsPostBack)
  8         {
  9             this.gv.DataSource = dm.GetDt();
 10             this.gv.DataBind();
 11 
 12             //记录最近一次排序方向
 13             ViewState["Direction"] = SortDirection.Descending;
 14         }
 15     }
 16 
 17     protected void gv_OnRowDataBound(object sender, GridViewRowEventArgs e)
 18     {
 19         DataRowView drv = e.Row.DataItem as DataRowView;
 20 
 21         if (e.Row.RowType == DataControlRowType.DataRow)
 22         {
 23             //显示时
 24             if (this.gv.EditIndex == -1)
 25             {
 26                 //设置性别
 27                 RadioButtonList rbl = e.Row.FindControl("rblSexShow") as RadioButtonList;
 28                 rbl.Items.Add(new ListItem("Male", "M"));
 29                 rbl.Items.Add(new ListItem("Female", "F"));
 30                 if ((drv["Sex"] as string).ToLower().Equals("m"))
 31                     rbl.Items[0].Selected = true;
 32                 else
 33                     rbl.Items[1].Selected = true;
 34             } 
 35             //修改时:
 36             else if(e.Row.RowIndex == this.gv.EditIndex)
 37             {
 38                 //性别
 39                 RadioButtonList rbl = e.Row.FindControl("rblSexEdit") as RadioButtonList;
 40                 rbl.Items.Add(new ListItem("Male", "M"));
 41                 rbl.Items.Add(new ListItem("Female", "F"));
 42                 if ((drv["Sex"] as string).ToLower().Equals("m"))
 43                     rbl.Items[0].Selected = true;
 44                 else
 45                     rbl.Items[1].Selected = true;
 46                 //国籍
 47                 DropDownList ddlCountry = e.Row.FindControl("ddlCountry") as DropDownList;
 48                 DataTable countryDt = dm.GetCountry();
 49                 ListItem li = null;
 50                 for(int i=0;i<countryDt.Rows.Count;++i)
 51                 {
 52                     string cn = countryDt.Rows[i]["cn"] as string;
 53                     li = new ListItem(cn, cn);
 54                     if (cn.Equals(drv["Country"] as string))
 55                         li.Selected = true;
 56                     ddlCountry.Items.Add(li);
 57                 }
 58                 //兴趣
 59                 CheckBoxList cbl = e.Row.FindControl("cbxlHobby") as CheckBoxList;
 60                 DataTable hobbyDt = dm.GetHobby();
 61                 string hobbys = drv["Hobby"] as string;
 62                 ListItem hobbyLi = null;
 63                 string hstr = string.Empty;
 64                 for (int i = 0; i < hobbyDt.Rows.Count; i++)
 65                 {
 66                     hstr = hobbyDt.Rows[i]["hobby"] as string;
 67                     hobbyLi = new ListItem(hstr, hstr);
 68                     if (hobbys.IndexOf(hstr)>=0)
 69                         hobbyLi.Selected = true;
 70                     cbl.Items.Add(hobbyLi);
 71                 }
 72             }
 73         }
 74         else if (e.Row.RowType == DataControlRowType.Pager)
 75         {
 76             //绑定分页控件
 77             DropDownList ddlPaging = e.Row.FindControl("ddlPaging") as DropDownList;
 78             for (int i = 0; i < this.gv.PageCount; i++)
 79             {
 80                 ddlPaging.Items.Add(new ListItem(Convert.ToString(i + 1), Convert.ToString(i)));
 81             }
 82             ddlPaging.SelectedIndex = this.gv.PageIndex;
 83         }
 84         else if (e.Row.RowType == DataControlRowType.EmptyDataRow)
 85         {
 86             //添加记录画面
 87 //国籍
 88             DropDownList ddlCountry = e.Row.FindControl("ddlCountry") as DropDownList;
 89             DataTable countryDt = dm.GetCountry();
 90             ListItem li =  new ListItem("Please Select","");
 91             li.Attributes["disabled"] = "disabled";
 92             li.Selected = true;
 93             ddlCountry.Items.Add(li);
 94             for (int i = 0; i < countryDt.Rows.Count; ++i)
 95             {
 96                 string cn = countryDt.Rows[i]["cn"] as string;
 97                 li = new ListItem(cn, cn);
 98                 ddlCountry.Items.Add(li);
 99             }
100             //兴趣
101             CheckBoxList cbl = e.Row.FindControl("cbxlHobby") as CheckBoxList;
102             DataTable hobbyDt = dm.GetHobby();
103             ListItem hobbyLi = null;
104             string hstr = string.Empty;
105             for (int i = 0; i < hobbyDt.Rows.Count; i++)
106             {
107                 hstr = hobbyDt.Rows[i]["hobby"] as string;
108                 hobbyLi = new ListItem(hstr, hstr);
109                 cbl.Items.Add(hobbyLi);
110             }
111         }
112     }
113 
114     /// <summary>
115 /// 分页控件的OnSelectedIndexChanged
116 /// </summary>
117 /// <param name="sender"></param>
118 /// <param name="e"></param>
119     protected void ddlPaging_OnSelectedIndexChanged(object sender, EventArgs e)
120     {
121         this.gv.PageIndex = (sender as DropDownList).SelectedIndex;
122         this.gv.DataSource = dm.GetDt();
123         this.gv.DataBind();
124     }
125 
126     /// <summary>
127 /// 删除记录
128 /// </summary>
129 /// <param name="sender"></param>
130 /// <param name="e"></param>
131     protected void gv_OnRowDeleting(object sender, GridViewDeleteEventArgs e)
132     {
133         dm.DelRecord(Convert.ToInt32(this.gv.DataKeys[e.RowIndex].Value));
134         this.gv.PageIndex = 0;
135         this.gv.DataSource = dm.GetDt();
136         this.gv.DataBind();
137     }
138 
139     /// <summary>
140 /// 修改记录
141 /// </summary>
142 /// <param name="sender"></param>
143 /// <param name="e"></param>
144     protected void gv_OnRowEditing(object sender, GridViewEditEventArgs e)
145     {
146         this.gv.EditIndex = e.NewEditIndex;
147         this.gv.DataSource = dm.GetDt();
148         this.gv.DataBind();
149     }
150 
151     /// <summary>
152 /// 取消修改
153 /// </summary>
154 /// <param name="sender"></param>
155 /// <param name="e"></param>
156     protected void gv_OnRowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
157     {
158         this.gv.EditIndex = -1;
159         this.gv.DataSource = dm.GetDt();
160         this.gv.DataBind();
161     }
162 
163     /// <summary>
164 /// 更新记录
165 /// </summary>
166 /// <param name="sender"></param>
167 /// <param name="e"></param>
168     protected void gv_OnRowUpdating(object sender, GridViewUpdateEventArgs e)
169     {
170         GridViewRow gvr = this.gv.Rows[e.RowIndex];
171         int id = Convert.ToInt32(this.gv.DataKeys[e.RowIndex].Value);
172         string name = (gvr.Cells[0].FindControl("tbxName") as TextBox).Text;
173         string sex = (gvr.Cells[1].FindControl("rblSexEdit") as RadioButtonList).SelectedValue;
174         string country = (gvr.Cells[2].FindControl("ddlCountry") as DropDownList).SelectedValue;
175         System.Text.StringBuilder hobbys = new System.Text.StringBuilder();
176         foreach (ListItem li in (gvr.Cells[3].FindControl("cbxlHobby") as CheckBoxList).Items)
177         {
178             if (li.Selected)
179                 hobbys.Append(li.Value+",");
180         }
181         if (hobbys.Length >= 2)
182             hobbys.Remove(hobbys.Length - 1, 1);
183         dm.UpdateRecord(id, name, country, sex, hobbys.ToString());
184 
185         this.gv.EditIndex = -1;
186         this.gv.DataSource = dm.GetDt();
187         this.gv.DataBind();
188     }
189 
190     /// <summary>
191 /// 提交新记录
192 /// </summary>
193 /// <param name="sender"></param>
194 /// <param name="e"></param>
195     protected void lbtnSubmit_OnClick(object sender, EventArgs e)
196     {
197         LinkButton lbtnSubmit = sender as LinkButton;
198         GridViewRow tr = lbtnSubmit.NamingContainer as GridViewRow;
199         string name = (tr.Cells[0].FindControl("tbxName") as TextBox).Text;
200         string sex = (tr.Cells[0].FindControl("rblSex") as RadioButtonList).SelectedValue;
201         string country = (tr.Cells[0].FindControl("ddlCountry") as DropDownList).SelectedValue;
202         System.Text.StringBuilder hobbys = new System.Text.StringBuilder();
203         foreach (ListItem li in (tr.Cells[0].FindControl("cbxlHobby") as CheckBoxList).Items)
204         {
205             if (li.Selected)
206                 hobbys.Append(li.Value + ",");
207         }
208         if (hobbys.Length >= 2)
209             hobbys.Remove(hobbys.Length - 1, 1);
210         dm.AddRecord(name,country,sex,hobbys.ToString());
211 
212         this.gv.PageIndex = 0;
213         this.gv.DataSource = dm.GetDt();
214         this.gv.DataBind();
215     }
216 
217     /// <summary>
218 /// 退出添加新记录
219 /// </summary>
220 /// <param name="sender"></param>
221 /// <param name="e"></param>
222     protected void lbtnCancel_OnClick(object sender, EventArgs e)
223     {
224         this.gv.DataSource = dm.GetDt();
225         this.gv.DataBind();
226     }
227 
228     /// <summary>
229 /// 显示添加画面
230 /// </summary>
231 /// <param name="sender"></param>
232 /// <param name="e"></param>
233     protected void lbtnShowAdd_OnClick(object sender, EventArgs e)
234     {
235         this.gv.DataSource = null;
236         this.gv.DataBind();
237     }
238 
239     /// <summary>
240 /// 排序
241 /// </summary>
242 /// <param name="sender"></param>
243 /// <param name="e"></param>
244     protected void gv_OnSorting(object sender, GridViewSortEventArgs e)
245     {
246         DataTable dt = dm.GetDt();
247         string direction = string.Empty;
248         if (e.SortDirection == (SortDirection)Enum.Parse(typeof(SortDirection),Convert.ToString(ViewState["Direction"])))
249             direction = "asc";
250         else
251             direction = "desc";
252         dt.DefaultView.Sort = string.Format("{0} {1}", e.SortExpression, direction);
253         ViewState["Direction"] = (direction.Equals("asc") ? SortDirection.Descending : SortDirection.Ascending);
254         this.gv.DataSource = dt;
255         this.gv.DataBind();
256     }
257 }

说明:

1.显示、编辑、新增时数据绑定都集中在gv_OnRowDataBound方法中,通过e.Row.RowType来分别处理。

2.排序:通过DataTable.DefaultView来实现,用一个ViewState变量存放最近一次的排序方向的反方向,来使每次排序的方向都不同。GridView的SortDirection为只读属性,所以别指望设定它来实现排序哦!

3.modify、update、delete和cancel按钮的实现利用GridView预设的CommandName来处理

CommandName 值

说明

“Cancel”

取消编辑操作并将 GridView 控件返回为只读模式。引发 RowCancelingEdit 事件。

“Delete”

删除当前记录。引发 RowDeleting 和 RowDeleted 事件。

“Edit”

将当前记录置于编辑模式。引发 RowEditing 事件。

“Page”

执行分页操作。将按钮的 CommandArgument 属性设置为“First”、“Last”、“Next”、“Prev”或页码,以指定要执行的分页操作类型。引发 PageIndexChanging 和 PageIndexChanged 事件。

“Select”

选择当前记录。引发 SelectedIndexChanging 和 SelectedIndexChanged 事件。

“Sort”

对 GridView 控件进行排序。引发 Sorting 和 Sorted 事件。

“Update”

更新数据源中的当前记录。引发 RowUpdating 和 RowUpdated 事件。

当然也可以自己写OnCommand的处理代码来处理,就是烦一点。

数据操作类:

  1 public class DataManager
  2 {
  3     private static DataTable dt = null;//用户记录
  4     private static DataTable countryDt = null;//国籍
  5     private static DataTable hobbyDt = null;//兴趣
  6 
  7     public DataManager()
  8     {
  9         if (dt == null)
 10         {
 11             dt = new DataTable();
 12             dt.Columns.Add("ID");
 13             dt.Columns.Add("Name");
 14             dt.Columns.Add("Sex");
 15             dt.Columns.Add("Country");
 16             dt.Columns.Add("Hobby");
 17 
 18             //Default Data
 19             dt.Rows.Add(new object[] { 1,"Mary","F","China","Cooking,Music"});
 20             dt.Rows.Add(new object[] { 2, "John", "M", "China", "Tennis" });
 21         }
 22 
 23         if (countryDt == null)
 24         {
 25             countryDt=new DataTable();
 26             countryDt.Columns.Add("cn");
 27             
 28             //Default Data
 29             countryDt.Rows.Add(new object[] { "China" });
 30             countryDt.Rows.Add(new object[] { "French" });
 31             countryDt.Rows.Add(new object[] { "America" });
 32             countryDt.Rows.Add(new object[] { "Afria" });
 33             countryDt.Rows.Add(new object[] { "Japan" });
 34         }
 35 
 36         if (hobbyDt == null)
 37         {
 38             hobbyDt = new DataTable();
 39             hobbyDt.Columns.Add("hobby");
 40 
 41             //Default Data
 42             hobbyDt.Rows.Add(new object[] { "Cooking" });
 43             hobbyDt.Rows.Add(new object[] { "Music" });
 44             hobbyDt.Rows.Add(new object[] { "Reading" });
 45             hobbyDt.Rows.Add(new object[] { "Movies" });
 46             hobbyDt.Rows.Add(new object[] { "Tennis" });
 47         }
 48     }
 49 
 50     public DataTable GetDt()
 51     {
 52         return dt;
 53     }
 54 
 55     public bool DelRecord(int id)
 56     {
 57         DataRow[] drs = dt.Select("ID=" + id);
 58         bool result = false;
 59         if (drs.Length == 1)
 60         {
 61             dt.Rows.Remove(drs[0]);
 62             result = true;
 63         }
 64 
 65         return result;
 66     }
 67 
 68     public bool UpdateRecord(int id, string name, string country, string sex, string hobby)
 69     {
 70         DataRow[] drs = dt.Select("ID=" + id);
 71         bool result = false;
 72         if (drs.Length == 1)
 73         {
 74             drs[0]["Name"] = name;
 75             drs[0]["Country"] = country;
 76             drs[0]["Hobby"] = hobby;
 77             drs[0]["Sex"] = sex;
 78             result = true;
 79         }
 80 
 81         return result;
 82     }
 83 
 84     public bool AddRecord(string name, string country, string sex, string hobby)
 85     {
 86         DataRow[] drs = dt.Select();
 87         Array.Sort<DataRow>(drs, new Comparison<DataRow>(SortHandler));
 88         int newId = 1+Convert.ToInt32(drs[0]["ID"]);
 89         dt.Rows.Add(new object[] {newId,name,sex,country,hobby });
 90 
 91         return true;
 92     }
 93 
 94     private int SortHandler(DataRow arg1, DataRow arg2)
 95     {
 96         if (Convert.ToInt32(arg1["ID"]) == Convert.ToInt32(arg2["ID"]))
 97             return 0;
 98         else if (Convert.ToInt32(arg1["ID"]) < Convert.ToInt32(arg2["ID"]))
 99             return 1;
100         else
101             return -1;
102     }
103 
104     public DataTable GetCountry()
105     {
106         return countryDt;
107     }
108 
109     public DataTable GetHobby()
110     {
111         return hobbyDt;
112     }
113 }

这里没什么好说的,就是AddRecord方法中用到了Array.Sort方法,这个方法我用得很少,不过觉得挺好用的,定义一个方法作为第二个参数传入就可以了。

总结:

  不适用数据源控件的优点是,新增记录时可以马上看到新增的记录;缺点是即使实现了分页功能,但每次还是从数据库中读取全部数据,效率低。而使用ObejctDataSource来绑定就可以解决从数据库读取全部数据的问题,并且附带数据缓存(应用程序级缓存)的功能,省心多了。但却又因ObjectDataSource不支持重新绑定,而使新增记录时不能马上看到新增的记录的缺点。

  关于ObjectDataSource配合GridView的使用将在《GridView实战二:使用ObjectDataSource数据源控件》讲述。

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