Sử dụng Control Dropdownlist trong ASP.Net GridView

By Unknown - Friday, July 3, 2015 - No Comments

(Using Dropdownlist in a Gridview) – Control Dropdowlist thường xuyên được sử dụng trên các Form nhập dữ liệu, và nó giúp người sử dụng dễ dàng lựa chọn giá trị từ các danh sách có sẵn. Bài viết dưới đây sẽ hướng dẫn các bạn cách sử dụng Control Dropdownlist trong Gridview. Trong Gridview sẽ gồm có 2 Dropdownlist và mỗi khi lựa chọn Dropdownlist châu lục nó sẽ lọc danh sách các quốc gia trong châu lục được chọn rồi điền vào Dropdownlist quốc gia.

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- B1: Tạo CSDL Customers trong SQL Server

- B2: Tạo Bảng Accounts có cấu trúc phía dưới

STT	Tên trường	Kiểu trường	Ghi chú
1	AccountID	Int	Trường tự tăng
2	AccountCode	nvarchar(25)
3	AccName	nvarchar(250)
4	AccAddress	nvarchar(250)
5	AccPhone	nvarchar(50)
6	AccFAX	nvarchar(50)
7	AccEmail	nvarchar(50)
8	AccWebsite	nvarchar(150)
9	AccDesc	nvarchar(1500)
10	CountryID	Int
11	CreatedDate	datetime
12	ModifiedDate	datetime

- B3: Nhập dữ liệu cho bảng Accounts

Chú ý: Trong Script chúng tôi cung cấp đã có chức năng Create và Insert dữ liệu cho 2 bảng Continents và Countries.

- B4: Tạo stored procedure trong SQL Server

USE [Customers]

Cteate PROCEDURE [dbo].[Pro_Accounts_List]

@Keyword nvarchar(250),

@SortField nvarchar(50),

@SortType nvarchar(10)

declare @strSQL nvarchar(1000)

declare @strWhere nvarchar(500)

declare @strOrder nvarchar (50)

set @strSQL= 'Select *, Countries.ContinentID

FROM Accounts INNER JOIN

Countries ON Accounts.CountryID = Countries.CountryID'

set @strWhere =' Where 1=1 '

if @Keyword<>''

set @strWhere= @strWhere +' And (AccountCode like N''%' +@Keyword+'%''

Or AccName like N''%' +@Keyword+'%'' Or AccAddress like N''%' +@Keyword+'%''

Or AccPhone like N''%' +@Keyword+'%'' Or AccFAX like N''%' +@Keyword+'%''

Or AccEmail like N''%' +@Keyword+'%'' Or AccWebsite like N''%' +@Keyword+'%'')'

if @SortField='CreatedDate'

Begin

set @strOrder =' Order by CreatedDate'

End

Else

Begin

set @strOrder =' Order by AccName'

End

set @strSQL=@strSQL+@strWhere+@strOrder

print @strSQL

exec sp_executesql @strSQL

Bạn có thể tải về bảng cơ sở dữ liệu SQL bằng cách nhấn vào liên kết tải về dưới đây

- B5: Tạo Project trong Microsoft Visual Studio 2010

Trong Visual Studio tạo 1 Class có tên: Utility và nhập đoạn Code phía dưới cho Class này.

Imports System.Data.SqlClient

Imports System.Data

Namespace AccessingDropDownListInsideGridView

Public Class SqlDataProvider

#Region "Membres Prives"

Shared _IsError As Boolean = False

Private _connectionString As String

#End Region

#Region "Constructeurs"

Public Sub New()

Try

_connectionString = ConfigurationManager.ConnectionStrings("SiteSqlServer").ConnectionString

_IsError = False

Catch ex As Exception

_IsError = True

End Try

End Sub

#End Region

#Region "Proprietes"

Public ReadOnly Property ConnectionString() As String

Get

Return _connectionString

End Get

End Property

#End Region

#Region "Functions"

Public Function FillTable(ByVal sql As String) As DataTable

Try

Dim tb As New DataTable

Dim adap As New SqlDataAdapter(sql, _connectionString)

adap.Fill(tb)

Return tb

Catch ex As Exception

Return Nothing

End Try

End Function

Public Function FillTable(ByVal ProcName As String, ByVal ParamArray Para() As ObjectPara) As DataTable

Try

Dim tb As New DataTable

Dim adap As New SqlDataAdapter(ProcName, _connectionString)

adap.SelectCommand.CommandType = CommandType.StoredProcedure

If Not Para Is Nothing Then

For Each p As ObjectPara In Para

adap.SelectCommand.Parameters.Add(New SqlParameter(p.Name, p.Value))

End If

adap.Fill(tb)

Return tb

Catch ex As Exception

Return Nothing

End Try

End Function

#End Region

End Class

Public Class ObjectPara

Dim _name As String

Dim _Value As Object

Sub New(ByVal Pname As String, ByVal PValue As Object)

_name = Pname

_Value = PValue

End Sub

Public Property Name() As String

Get

Return _name

End Get

Set(ByVal value As String)

_name = value

End Set

End Property

Public Property Value() As Object

Get

Return _Value

End Get

Set(ByVal value As Object)

_Value = value

End Set

End Property

End Class

End Namespace

Chú ý: Thuộc tính SiteSqlServer chính là chuỗi Connect với SQL Server trong file Web.Config

- B6: Mở file Default.aspx dưới dạng HTML và nhập mã HTML

<%@ Page Title="Accessing a DropDownList inside a GridView in Asp.net" Language="vb" MasterPageFile="~/Site.Master" AutoEventWireup="false" EnableEventValidation= "false" CodeBehind="Default.aspx.vb" Inherits="AccessingDropDownListInsideGridView._Default" %>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">

<asp:ScriptManager ID="ScriptManager1" runat="server">

</asp:ScriptManager>

<h3>

Accessing a DropDownList inside a GridView in Asp.net

</h3>

<asp:UpdatePanel ID="updatePanel" runat="server" UpdateMode="Conditional">

<tr>

<td>

</td>

<asp:Label ID="plKeyword" runat="server" Text="Keyword"></asp:Label>

<asp:TextBox ID="txtSearch" CssClass="form-control" ToolTip="Enter Keyword" runat="server" width="200px"></asp:TextBox>

<asp:ImageButton ID="cmdQuickSearch" runat="server" causesvalidation="false" imageurl="~/images/icon_search.gif"></asp:ImageButton>

</td>

</tr>

<asp:Label ID="lblMessage" runat="server" Text="No Data"></asp:Label>

</td>

</tr>

<tr>

<asp:GridView ID="grvObject" runat="server" AllowPaging="true" PageSize="12"

CssClass="GridStyle" BorderColor="#cbcbcb" BorderStyle="solid"

BorderWidth="1" AutoGenerateColumns="false" DataKeyNames="AccountID" width="100%">

<asp:TemplateField HeaderText="Number">

<asp:Label ID="lblRowNumber" Text='<%# Container.DataItemIndex + 1 %>' runat="server" />

</ItemTemplate>

</asp:TemplateField>

<asp:BoundField ItemStyle-Width="10%" DataField="AccountCode" HeaderText="AccountCode" />

<asp:BoundField ItemStyle-Width="15%" DataField="AccName" HeaderText="AccountName" />

<asp:BoundField ItemStyle-Width="10%" DataField="AccPhone" HeaderText="Phone" />

<asp:TemplateField HeaderText="Continents">

<asp:DropDownList Width="120" runat="server" id="ddlContinents" CssClass="form-control" AutoPostBack="true" OnSelectedIndexChanged="ddlContinents_SelectedIndexChanged">

</asp:DropDownList>

</ItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="Countries">

<asp:DropDownList Width="200" runat="server" CssClass="form-control" id="ddlCountries">

</asp:DropDownList>

</ItemTemplate>

</asp:TemplateField>

</Columns>

</asp:GridView>

</td>

</tr>

</table>

</ContentTemplate>

</asp:UpdatePanel>

</asp:Content>

- B7: Viết Code cho file Default.aspx

C# Code

//Visit http://www.laptrinhdotnet.com for more ASP.NET Tutorials

using Microsoft.VisualBasic;

using System;

using System.Collections;

using System.Collections.Generic;

using System.Data;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.HtmlControls;

using System.Diagnostics;

namespace AccessingDropDownListInsideGridView

{

public partial class _Default : System.Web.UI.Page

{

#region "ComboData"

private void LoadDropDownList(DropDownList ucControl, string DataValueField, string DataTextField, string sql)

{

SqlDataProvider objSQL = new SqlDataProvider();

DataTable objBind = objSQL.FillTable(sql);

ucControl.Items.Clear();

if (objBind != null)

{

ucControl.DataTextField = DataTextField;

ucControl.DataValueField = DataValueField;

ucControl.DataSource = objBind;

ucControl.DataBind();

ucControl.Items.Insert(0, (new ListItem("---Select---", "-1")));

}

#endregion

#region "Bind Data"

private void BindAccount()

{

DataTable objBind = new DataTable();

objBind = BindData();

if (objBind != null)

{

if (objBind.Rows.Count > 0)

{

grvObject.DataSource = objBind;

grvObject.DataBind();

trMessage.Visible = false;

grvObject.Visible = true;

}

else

{

trMessage.Visible = true;

grvObject.Visible = false;

}

updatePanel.Update();

}

private DataTable BindData()

{

SqlDataProvider objSQL = new SqlDataProvider();

DataTable objBind = objSQL.FillTable("Pro_Accounts_List", new ObjectPara("@Keyword", txtSearch.Text), new ObjectPara("@SortField", "CreatedDate"), new ObjectPara("@SortType", "DESC"));

return objBind;

}

#endregion

#region "GridView Methods"

protected void grvObject_RowDataBound(object sender, GridViewRowEventArgs e)

{

if (e.Row.RowType == DataControlRowType.DataRow)

{

int ContinentID =Convert.ToInt32(DataBinder.Eval(e.Row.DataItem, "ContinentID"));

int CountryID = Convert.ToInt32(DataBinder.Eval(e.Row.DataItem, "CountryID"));

DropDownList ddlContinents = (DropDownList)e.Row.FindControl("ddlContinents");

if (ddlContinents != null)

{

string sSQL = "Select ContinentID, ContinentName from Continents";

LoadDropDownList(ddlContinents, "ContinentID", "ContinentName", sSQL);

if (ContinentID != -1)

{

ddlContinents.SelectedValue = ContinentID.ToString();

ddlContinents_SelectedIndexChanged(ddlContinents, System.EventArgs.Empty);

}

DropDownList ddlCountries = (DropDownList)e.Row.FindControl("ddlCountries");

if ((ddlCountries != null))

{

ddlCountries.Items.Insert(0, (new ListItem("---Select---", "-1")));

ddlCountries.SelectedValue = CountryID.ToString();

}

protected void grvObject_PageIndexChanging(object sender, System.Web.UI.WebControls.GridViewPageEventArgs e)

{

grvObject.PageIndex = e.NewPageIndex;

BindAccount();

}

#endregion

#region "Event Handles"

protected void Page_Load(object sender, System.EventArgs e)

{

try

{

if (!IsPostBack)

{

Page.Form.DefaultButton = cmdQuickSearch.UniqueID;

BindAccount();

}

catch

{

}

protected void cmdQuickSearch_Click(object sender, System.EventArgs e)

{

BindAccount();

}

protected void ddlContinents_SelectedIndexChanged(object sender, EventArgs e)

{

DropDownList ddlObject = (DropDownList)sender;

DropDownList ddlContinents = new DropDownList();

DropDownList ddlCountries = new DropDownList();

GridViewRow row = (GridViewRow)ddlObject.NamingContainer;

int ItemID = -1;

ddlContinents = (DropDownList)row.FindControl("ddlContinents");

ddlCountries = (DropDownList)row.FindControl("ddlCountries");

if (ddlContinents != null)

{

ItemID =Convert.ToInt32(ddlContinents.SelectedValue);

}

if (ItemID != -1)

{

string sSQL = "Select CountryID, CountryName from Countries where ContinentID=" + ItemID;

LoadDropDownList(ddlCountries, "CountryID", "CountryName", sSQL);

}

updatePanel.Update();

}

#endregion

}

VB.NET Code

'Visit http://www.laptrinhdotnet.com for more ASP.NET Tutorials

Imports System.Data.SqlClient

Namespace AccessingDropDownListInsideGridView

Public Class _Default

Inherits System.Web.UI.Page

#Region "Private Members"

#End Region

#Region "ComboData"

Private Sub LoadDropDownList(ByVal ucControl As DropDownList, ByVal DataValueField As String, ByVal DataTextField As String, ByVal sql As String)

Dim objSQL As New SqlDataProvider

Dim objBind As DataTable = objSQL.FillTable(sql)

ucControl.Items.Clear()

If Not objBind Is Nothing Then

With ucControl

.DataTextField = DataTextField

.DataValueField = DataValueField

.DataSource = objBind

.DataBind()

End With

ucControl.Items.Insert(0, (New ListItem("---Select---", "-1")))

End If

End Sub

#End Region

#Region "Bind Data"

Private Sub BindAccount()

Dim objBind As New DataTable

objBind = BindData()

If Not objBind Is Nothing Then

If objBind.Rows.Count > 0 Then

grvObject.DataSource = objBind

grvObject.DataBind()

trMessage.Visible = False

grvObject.Visible = True

Else

trMessage.Visible = True

grvObject.Visible = False

End If

updatePanel.Update()

End If

End Sub

Private Function BindData() As DataTable

Dim objSQL As New SqlDataProvider

Dim objBind As DataTable = objSQL.FillTable("Pro_Accounts_List", New ObjectPara("@Keyword", txtSearch.Text.Trim), _

New ObjectPara("@SortField", "CreatedDate"), _

New ObjectPara("@SortType", "DESC"))

Return objBind

End Function

#End Region

#Region "GridView Methods"

Private Sub grvObject_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs) Handles grvObject.RowDataBound

If e.Row.RowType = DataControlRowType.DataRow Then

Dim ContinentID As Integer = DataBinder.Eval(e.Row.DataItem, "ContinentID")

Dim CountryID As Integer = DataBinder.Eval(e.Row.DataItem, "CountryID")

Dim ddlContinents As DropDownList = DirectCast(e.Row.FindControl("ddlContinents"), DropDownList)

If Not ddlContinents Is Nothing Then

Dim sSQL As String = "Select ContinentID, ContinentName from Continents"

LoadDropDownList(ddlContinents, "ContinentID", "ContinentName", sSQL)

If ContinentID <> -1 Then

ddlContinents.SelectedValue = ContinentID

ddlContinents_SelectedIndexChanged(ddlContinents, System.EventArgs.Empty)

End If

Dim ddlCountries As DropDownList = DirectCast(e.Row.FindControl("ddlCountries"), DropDownList)

If Not ddlCountries Is Nothing Then

ddlCountries.Items.Insert(0, (New ListItem("---Select---", "-1")))

ddlCountries.SelectedValue = CountryID

End If

End Sub

Private Sub grvObject_PageIndexChanging(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewPageEventArgs) Handles grvObject.PageIndexChanging

grvObject.PageIndex = e.NewPageIndex

BindAccount()

End Sub

#End Region

#Region "Event Handles"

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

Try

If Page.IsPostBack = False Then

'Default Submit Button

Page.Form.DefaultButton = cmdQuickSearch.UniqueID

BindAccount()

End If

Catch ex As Exception

End Try

End Sub

Private Sub cmdQuickSearch_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdQuickSearch.Click

BindAccount()

End Sub

Protected Sub ddlContinents_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)

Dim ddlObject As DropDownList = DirectCast(sender, DropDownList)

Dim ddlContinents As DropDownList = New DropDownList

Dim ddlCountries As DropDownList = New DropDownList

Dim row As GridViewRow = DirectCast(ddlObject.NamingContainer, GridViewRow)

Dim ItemID As Integer = -1

ddlContinents = DirectCast(row.FindControl("ddlContinents"), DropDownList)

ddlCountries = DirectCast(row.FindControl("ddlCountries"), DropDownList)

If Not ddlContinents Is Nothing Then

ItemID = ddlContinents.SelectedValue

End If

If ItemID <> -1 Then

Dim sSQL As String = "Select CountryID, CountryName from Countries where ContinentID=" & ItemID

LoadDropDownList(ddlCountries, "CountryID", "CountryName", sSQL)

End If

updatePanel.Update()

End Sub

#End Region

End Class

End Namespace

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