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" /> 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" /> 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.Page2 {3 private DataManager dm = new DataManager();45 protected void Page_Load(object sender, EventArgs e)6 {7 if (!IsPostBack)8 {9 this.gv.DataSource = dm.GetDt();10 this.gv.DataBind();1112 //记录最近一次排序方向13 ViewState["Direction"] = SortDirection.Descending;14 }15 }1617 protected void gv_OnRowDataBound(object sender, GridViewRowEventArgs e)18 {19 DataRowView drv = e.Row.DataItem as DataRowView;2021 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 else33 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 else45 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 }113114 /// <summary>115 /// 分页控件的OnSelectedIndexChanged116 /// </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 }125126 /// <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 }138139 /// <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 }150151 /// <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 }162163 /// <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());184185 this.gv.EditIndex = -1;186 this.gv.DataSource = dm.GetDt();187 this.gv.DataBind();188 }189190 /// <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());211212 this.gv.PageIndex = 0;213 this.gv.DataSource = dm.GetDt();214 this.gv.DataBind();215 }216217 /// <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 }227228 /// <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 }238239 /// <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 else251 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 DataManager2 {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67 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");1718 //Default Data19 dt.Rows.Add(new object[] { 1,"Mary","F","China","Cooking,Music"});20 dt.Rows.Add(new object[] { 2, "John", "M", "China", "Tennis" });21 }2223 if (countryDt == null)24 {25 countryDt=new DataTable();26 countryDt.Columns.Add("cn");2728 //Default Data29 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 }3536 if (hobbyDt == null)37 {38 hobbyDt = new DataTable();39 hobbyDt.Columns.Add("hobby");4041 //Default Data42 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 }4950 public DataTable GetDt()51 {52 return dt;53 }5455 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 }6465 return result;66 }6768 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 }8081 return result;82 }8384 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 });9091 return true;92 }9394 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 else101 return -1;102 }103104 public DataTable GetCountry()105 {106 return countryDt;107 }108109 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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