asp.net - 使用 SQL 数据库在 Gridview 编辑模式下级联下拉列表
问题描述
我尝试在 GridView 中以级联模式使用四个下拉列表进行数据编辑。我已经在三个列表中成功实现了级联功能，但第四个列表不起作用。我的 aspx 页面和 VB 代码是
<%@ Page Language="VB" MaintainScrollPositionOnPostback="true" Debug="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<style>
body
{ font-family:verdana;
font-size:10pt;
}
</style>
<script runat="server">
Protected Sub ddlclassification_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs)
Dim ddlclassification, ddlbase, ddlLocoType, ddlEquipment As DropDownList
Dim ShedBYClassification As SqlDataSource
Dim LocoTypeBYShed As SqlDataSource
Dim EquipBYLocoType As SqlDataSource
Dim currentRowInEdit As Integer = GridView1.EditIndex
ddlclassification = CType(sender, DropDownList)
ddlbase = CType(GridView1.Rows(currentRowInEdit).FindControl("ddlbase"), DropDownList)
ddlLocoType = CType(GridView1.Rows(currentRowInEdit).FindControl("ddlLocoType"), DropDownList)
ddlEquipment = CType(GridView1.Rows(currentRowInEdit).FindControl("ddlEquipment"), DropDownList)
ShedBYClassification = CType(GridView1.Rows(currentRowInEdit).FindControl("ShedBYClassification"), SqlDataSource)
ShedBYClassification.SelectParameters("ClassificationName").DefaultValue = ddlclassification.SelectedValue
LocoTypeBYShed = CType(GridView1.Rows(currentRowInEdit).FindControl("LocoTypeBYShed"), SqlDataSource)
LocoTypeBYShed.SelectParameters("ClassificationName").DefaultValue = ddlclassification.SelectedValue
EquipBYLocoType = CType(GridView1.Rows(currentRowInEdit).FindControl("EquipBYLocoType"), SqlDataSource)
EquipBYLocoType.SelectParameters("LocoTypeName").DefaultValue = ddlLocoType.SelectedValue
ddlbase.DataBind()
ddlLocoType.DataBind()
ddlEquipment.DataBind()
End Sub
Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs)
If (e.Row.RowState And DataControlRowState.Edit) = DataControlRowState.Edit Then
Dim dv As System.Data.DataRowView = e.Row.DataItem
Dim ddlclassification As DropDownList = e.Row.FindControl("ddlclassification")
ddlclassification.SelectedValue = dv("classificationName")
Dim ddlbase As DropDownList = e.Row.FindControl("ddlbase")
Dim ddlLocoType As DropDownList = e.Row.FindControl("ddlLocoType")
Dim ddlEquipment As DropDownList = e.Row.FindControl("ddlEquipment")
Dim dsc As SqlDataSource = e.Row.FindControl("ShedBYClassification")
Dim dsclocotype As SqlDataSource = e.Row.FindControl("LocoTypeBYShed")
Dim dscEquipment As SqlDataSource = e.Row.FindControl("EquipBYLocoType")
dsc.SelectParameters("ClassificationName").DefaultValue = dv("classificationName")
dsclocotype.SelectParameters("ClassificationName").DefaultValue = dv("ClassificationName")
dscEquipment.SelectParameters("LocoTypeName").DefaultValue = dv("LocoTypeName")
ddlbase.DataBind()
ddlLocoType.DataBind()
ddlEquipment.DataBind()
ddlbase.SelectedValue = dv("Shed")
ddlLocoType.SelectedValue = dv("LocoTypeName")
ddlEquipment.SelectedValue = dv("EquipName")
End If
End Sub
Protected Sub GridView1_RowUpdating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewUpdateEventArgs)
Dim ddlclassification As DropDownList = CType(GridView1.Rows(e.RowIndex).FindControl("ddlclassification"), DropDownList)
Dim ddlbase As DropDownList = CType(GridView1.Rows(e.RowIndex).FindControl("ddlbase"), DropDownList)
Dim ddlLocoType As DropDownList = CType(GridView1.Rows(e.RowIndex).FindControl("ddlLocoType"), DropDownList)
Dim ddlEquipment As DropDownList = CType(GridView1.Rows(e.RowIndex).FindControl("ddlEquipment"), DropDownList)
e.NewValues("classification") = ddlclassification.SelectedValue
e.NewValues("Shed") = ddlbase.SelectedValue
e.NewValues("loco_type") = ddlLocoType.SelectedValue
e.NewValues("Equipt") = ddlEquipment.SelectedValue
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Cascading DropDownList Controls in a GridView Edit Mode</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<div>TEST</div>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
DataKeyNames="ID" DataSourceID="SqlDataSource1"
HorizontalAlign="Center" AllowSorting="True" OnRowDataBound="GridView1_RowDataBound" OnRowUpdating="GridView1_RowUpdating">
<Columns>
<asp:CommandField ShowDeleteButton="False" ShowEditButton="True" />
<asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False"
ReadOnly="True" SortExpression="ID" Visible="false" />
<asp:TemplateField HeaderText="Date" SortExpression="Date">
<ItemTemplate>
<asp:Label ID="Label3" runat="server"
Text='<%# Bind("Date", "{0:dd-MMM-yy}") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:Label ID="TextBox3" runat="server" Text='<%# Bind("Date", "{0:MM/dd/yyyy}") %>' ></asp:Label>
</EditItemTemplate>
<ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" Wrap="False" />
</asp:TemplateField>
<asp:TemplateField HeaderText="Classification of Case" SortExpression="classification">
<ItemTemplate>
<asp:Label ID="Label9" runat="server" Text='<%# Bind("classification") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="ddlclassification" runat="server" DataSourceID="ClassificationDDL" DataTextField="classificationName"
DataValueField="classificationName" AutoPostBack="true" OnSelectedIndexChanged="ddlclassification_SelectedIndexChanged">
</asp:DropDownList>
<asp:SqlDataSource ID="ClassificationDDL" runat="server"
ConnectionString="<%$ ConnectionStrings:EquipfailuresERConnectionString %>"
SelectCommand="SELECT [ClassificationName] FROM [ClassificationDDL] ORDER BY [ClassificationName]"
EnableCaching="True">
</asp:SqlDataSource>
</EditItemTemplate>
<ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" Wrap="True" />
</asp:TemplateField>
<asp:TemplateField HeaderText="Loco no." SortExpression="Loco">
<ItemTemplate>
<asp:Label ID="Label5" runat="server" Text='<%# Bind("Loco") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="TextBox5" runat="server" Text='<%# Bind("Loco") %>' ></asp:TextBox>
</EditItemTemplate>
<ItemStyle HorizontalAlign="Center" VerticalAlign="Middle"
Wrap="True" />
</asp:TemplateField>
<asp:TemplateField HeaderText="Home Rly" SortExpression="Homerly">
<ItemTemplate>
<asp:Label ID="Label7" runat="server" Text='<%# Bind("Homerly") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:Label ID="ddlRly" runat="server" Text='<%# Bind("Homerly") %>'></asp:Label>
</EditItemTemplate>
<ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" Wrap="True" />
</asp:TemplateField>
<asp:TemplateField HeaderText="Shed" SortExpression="Shed">
<ItemTemplate>
<asp:Label ID="Label6" runat="server" Text='<%# Bind("Shed") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="ddlbase" runat="server" DataSourceID="ShedBYClassification" DataTextField="ShedName" DataValueField="ShedName" AutoPostBack="true" />
<asp:SqlDataSource ID="ShedBYClassification" runat="server"
ConnectionString="<%$ ConnectionStrings:EquipfailuresERConnectionString %>"
SelectCommand="SELECT [ShedID], [ShedName] FROM [ShedDDL] WHERE ([ClassificationID] = @ClassificationName) ORDER BY ShedName" EnableCaching="True">
<SelectParameters>
<asp:Parameter Name="ClassificationName" />
</SelectParameters>
</asp:SqlDataSource>
</EditItemTemplate>
<ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" Wrap="True" />
</asp:TemplateField>
<asp:TemplateField HeaderText="Loco Type" SortExpression="loco_type">
<ItemTemplate>
<asp:Label ID="Label11" runat="server" Text='<%# Bind("loco_type") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="ddlLocoType" runat="server" DataSourceID="LocoTypeBYShed" DataTextField="LocoTypeName" DataValueField="LocoTypeName"
AutoPostBack="true" />
<asp:SqlDataSource ID="LocoTypeBYShed" runat="server"
ConnectionString="<%$ ConnectionStrings:EquipfailuresERConnectionString %>"
SelectCommand="SELECT [LocoTypeID], [LocoTypeName] FROM [LocoTypeDDL] WHERE ([ClassificationID] = @ClassificationName) ORDER BY LocoTypeName" EnableCaching="True">
<SelectParameters>
<asp:Parameter Name="ClassificationName" />
</SelectParameters>
</asp:SqlDataSource>
</EditItemTemplate>
<ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" Wrap="True" />
</asp:TemplateField>
<asp:TemplateField HeaderText="Equipment" SortExpression="Equipt">
<ItemTemplate>
<asp:Label ID="Label8" runat="server" Text='<%# Bind("Equipt") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="ddlEquipment" runat="server" DataSourceID="EquipBYLocoType" DataTextField="EquipName" DataValueField="EquipName"
AutoPostBack="true" />
<asp:SqlDataSource ID="EquipBYLocoType" runat="server"
ConnectionString="<%$ ConnectionStrings:EquipfailuresERConnectionString %>"
SelectCommand="SELECT [EquipID], [EquipName] FROM [EquipmentDDL] WHERE ([LocoTypeID] = @LocoTypeName) ORDER BY EquipName" EnableCaching="True">
<SelectParameters>
<asp:Parameter Name="LocoTypeName" />
</SelectParameters>
</asp:SqlDataSource>
</EditItemTemplate>
<ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" Wrap="True" />
</asp:TemplateField>
</Columns>
<FooterStyle Font-Bold="True" Font-Names="Tahoma"
Font-Size="Medium" HorizontalAlign="Center" VerticalAlign="Middle" />
<HeaderStyle Font-Names="Tahoma"
Font-Size="Small" />
<RowStyle Font-Names="Tahoma" Font-Size="Small" />
</asp:GridView>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:EquipfailuresERConnectionString %>"
SelectCommand="TESTINNER" SelectCommandType="StoredProcedure" UpdateCommand="EnRRlyupdate" UpdateCommandType="StoredProcedure">
</asp:SqlDataSource>
<br />
</div>
</form>
</body>
</html>
下拉列表的 SQL 数据如下：
第一个下拉列表 - 'ClassificationDDL' SQL 表
+------------------------+------------------------+
| ClassificationID | ClassificationName |
+:----------------------:+:----------------------:+
| Loco | Loco |
| Crew/Loco Operation | Crew/Loco Operation |
| Traffic/wrongly logged | Traffic/wrongly logged |
| Stalling | Stalling |
+------------------------+------------------------+
第二个下拉列表 - 'ShedDDL' SQL 表
+------------------------+----------+--------+
| ClassificationID | ShedName | ShedID |
+:----------------------:+:--------:+:------:+
| Loco | BSL | BSL |
| Loco | AQ | AQ |
| Loco | KYN | KYN |
| Stalling | Other | Other |
| Stalling | BSL | BSL |
| Stalling | AQ | AQ |
| Stalling | KYN | KYN |
| Crew/Loco Operation | Other | Other |
| Crew/Loco Operation | BSL | BSL |
| Crew/Loco Operation | AQ | AQ |
| Crew/Loco Operation | KYN | KYN |
| Traffic/wrongly logged | BSL | BSL |
| Traffic/wrongly logged | AQ | AQ |
| Traffic/wrongly logged | KYN | KYN |
| Traffic/wrongly logged | Other | Other |
+------------------------+----------+--------+
第三个下拉列表 - 'LocoTypeDDL' SQL 表
+------------------------+--------------+--------------+
| ClassificationID | LocoTypeID | LocoTypeName |
+:----------------------:+:------------:+:------------:+
| Loco | Conventional | Conventional |
| Loco | 3-Phase | 3-Phase |
| Crew/Loco Operation | Conventional | Conventional |
| Crew/Loco Operation | 3-Phase | 3-Phase |
| Crew/Loco Operation | Other | Other |
| Traffic/wrongly logged | Conventional | Conventional |
| Traffic/wrongly logged | 3-Phase | 3-Phase |
| Traffic/wrongly logged | Other | Other |
| Stalling | Conventional | Conventional |
| Stalling | 3-Phase | 3-Phase |
| Stalling | Other | Other |
+------------------------+--------------+--------------+
第 4 个下拉列表 - 'EquipmentDDL' SQL 表
+--------------+---------------------------+---------------------------+
| LocoTypeID | EquipName | EquipID |
+:------------:+:-------------------------:+:-------------------------:+
| Other | Other | Other |
| Conventional | Air Blast Circuit Breaker | Air Blast Circuit Breaker |
| Conventional | Air Dryer | Air Dryer |
| Conventional | Arno | Arno |
| Conventional | Aux. compressor | Aux. compressor |
| Conventional | Auxiliary Motor | Auxiliary Motor |
| Conventional | Axle Box | Axle Box |
| Conventional | Battery | Battery |
| 3-Phase | 110V MCB | 110V MCB |
| 3-Phase | 415V MCB | 415V MCB |
| 3-Phase | Air Dryer | Air Dryer |
| 3-Phase | Angle transmitter | Angle transmitter |
| 3-Phase | Aux. compressor | Aux. compressor |
| 3-Phase | Aux. converter GTO (BUR) | Aux. converter GTO (BUR) |
+--------------+---------------------------+---------------------------+
选择命令（存储过程“TESTINNER”）是
Select ERfailures.ID, ERfailures.Date, ERfailures.Loco, ERfailures.Shed, ERfailures.Homerly, ERfailures.Equipt, ERfailures.classification, ERfailures.Sub_head, ERfailures.loco_type, ClassificationDDL.ClassificationName, ShedDDL.ShedName, LocoTypeDDL.LocoTypeName, EquipmentDDL.EquipName from ERfailures
INNER JOIN ClassificationDDL ON ERfailures.classification = ClassificationDDL.ClassificationName
INNER JOIN ShedDDL ON ERfailures.Shed = ShedDDL.ShedName AND ERfailures.classification = ShedDDL.ClassificationID
INNER JOIN LocoTypeDDL ON ERfailures.loco_type = LocoTypeDDL.LocoTypeName AND ERfailures.classification = LocoTypeDDL.ClassificationID
INNER JOIN EquipmentDDL ON ERfailures.Equipt = EquipmentDDL.EquipName AND ERfailures.loco_type = EquipmentDDL.LocoTypeID
更新命令（存储过程）“EnRRlyupdate”是
UPDATE ERfailures SET Date = @Date, Loco = @Loco, Shed = @Shed, Homerly = (CASE WHEN @Shed ='BSL' THEN 'CR' WHEN @Shed ='AQ' THEN 'ER' WHEN @Shed ='KYN' THEN 'ECR' ELSE 'xyz' END), Equipt = @Equipt, classification = @classification, loco_type = @loco_type WHERE ID = @ID
第二个下拉列表（ddlbase）和第三个下拉列表（ddlLocoType）基于第一个下拉列表（ddlclassification）中的选定值。第 4 个下拉列表 (ddlEquipment) 基于第 3 个下拉列表中的选定值。第 1、第 2 和第 3 下拉菜单工作正常，但第 4 下拉菜单不起作用（表示值未根据第 3 下拉列表中选择的值显示。请帮助使该项目可行。
解决方案
推荐阅读
- python - 如果包含输入类型文件，Django 表单返回 404 Page not found
- arrays - 如何根据单元格值将地址传递给 Vlookup（Google 表格）
- excel - 数据透视缓存“类型不匹配”中的数据透视表错误
- reactjs - 样式化组件：溢出在 Safari 中不起作用
- go - 一个按钮内具有不同对齐方式的文本字段
- flutter - Parse Server SDK - Include Object 方法不适用于在颤动中获取整个对象
- c# - C#正则表达式十进制数从复杂字符串中拆分出来
- assembly - x86-64 ASM。选择寄存器使用的最佳方式
- eclipse-hono - 无法通过 Helm 安装 Eclipse Hono - 错误 - 无法下载“eclipse-iot/hono”（提示：运行 `helm repo update 可能会有所帮助）
- javascript - 如何在 JS 中嵌套 Promise 并在不同时间解决它们？