(Cách tạo Columns động trong Gridview) – Việc tạo Columns động trong Gridview không những giúp người lập trình phát triển ứng dụng nhanh mà còn giúp việc chỉnh sửa khi có yêu cầu của khách hàng thuận lợi và dễ dàng. Chỉ cần thiết lập lại thông tin các cột cần hiển thị như: Tên, độ rộng, thứ tự, căn chỉnh, định dạng… là đã có thể hoàn thành yêu cầu mà hoàn toàn không phải chỉnh sửa lại mã nguồn. Có nhiều cách để lưu trữ thông tin cột sẽ hiển thị lên Gridview như: file XML, Table trong SQL… Bài viết dưới đây sẽ hướng dẫn các bạn cách tạo Columns động, lưu trữ thông tin cột hiển thị bằng file XML. Mỗi khi cần hiển thị thêm hoặc bỏ bớt cột trên Gridview thì chỉ cần chỉnh sửa lại file XML là xong.

Nghe những bài hát đỉnh nhất về Thấy cô giáo - Nghe trên Youtube



Code Example C#, Code Example VB.NET
Code Example C#, Code Example VB.NET




B1: Tạo CSDL Customers trong SQL Server

B2: Tạo Bảng Accounts có cấu trúc phía dưới

STTTên trườngKiểu trườngGhi chú
1AccountIDIntTrường tự tăng
2AccountCodenvarchar(25)
3AccNamenvarchar(250)
4AccAddressnvarchar(250)
5AccPhonenvarchar(50)
6AccFAXnvarchar(50)
7AccEmailnvarchar(50)
8AccWebsitenvarchar(150)
9AccDescnvarchar(1500)
10CreatedDatedatetime
11ModifiedDatedatetime


B3: Nhập dữ liệu cho bảng Accounts

B4: Tạo stored procedure trong SQL Server

USE[Customers]
GO

CREATE PROCEDURE [dbo].[Pro_Accounts_List]
      @Keyword nvarchar(250),
      @SortField nvarchar(50),
      @SortType nvarchar(10)
AS

declare@strSQL   nvarchar(1000)
declare @strWhere nvarchar(500)
declare @strOrder nvarchar (50)

set @strSQL= 'Select * from Accounts'
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

Go

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 DynamicallyColumnsGridView

    Public Class SqlDataProvider

#Region "Membres Prives"

        Shared _IsError As Boolean = False
        Private _connectionString AsString

#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() AsString
            Get
                Return _connectionString
            End Get
        End Property

#End Region

#Region "Functions"

        Public FunctionFillTable(ByVal ProcName As String, ByVal ParamArrayPara() As ObjectPara) As DataTable
            Try
                Dim tb AsNew DataTable
                Dim adap AsNew SqlDataAdapter(ProcName, _connectionString)
                adap.SelectCommand.CommandType = CommandType.StoredProcedure
                If NotPara Is NothingThen
                    For Eachp As ObjectParaIn Para
                        adap.SelectCommand.Parameters.Add(New SqlParameter(p.Name, p.Value))
                    Next
                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 PropertyName() As String
            Get
                Return _name
            End Get
            Set(ByVal value As String)
                _name = value
            End Set
        End Property

        Public PropertyValue() As Object
            Get
                Return _Value
            End Get
            Set(ByVal value As Object)
                _Value = value
            End Set
        End Property

    End Class

    Public Class GridViewColumnTemplate

        Public SubAddBoundColumn(ByVal grvObject As GridView, ByVal Title As String, ByValDataField As String, ByVal Align As String, ByVal Format As String)
            Dim objBoundColumn AsSystem.Web.UI.WebControls.BoundField
            objBoundColumn = NewSystem.Web.UI.WebControls.BoundField

            With objBoundColumn
                .DataField = DataField
                If Format <> "" Then
                    .DataFormatString = Format
                End If
                .HeaderText = Title
                Select CaseAlign.ToLower
                    Case "left"
                        .ItemStyle.HorizontalAlign = HorizontalAlign.Left
                    Case"right"
                        .ItemStyle.HorizontalAlign = HorizontalAlign.Right
                    Case "center"
                        .ItemStyle.HorizontalAlign = HorizontalAlign.Center
                End Select
            End With

            objBoundColumn.HeaderStyle.CssClass = Title.Replace("[L]", "") & "Header"
            objBoundColumn.ItemStyle.CssClass = Title.Replace("[L]", "") & "Cell"

            grvObject.Columns.Add(objBoundColumn)
        End Sub
    End Class

End Namespace

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

B6: Tạo File XML DynamicallyColumns.xml có cấu trúc phía dưới và đặt file trong thư mục App_Data


B7: Nhập dữ liệu cho File XML DynamicallyColumn
<?xml version="1.0" standalone="yes"?>
<root>
  <items>
      <ColumnName>AccountCode</ColumnName>
      <ColumnTitle>Account Code</ColumnTitle>
      <Alignment>left</Alignment>
      <Format></Format>
  </items>
  <items>
    <ColumnName>AccName</ColumnName>
    <ColumnTitle>Account Name</ColumnTitle>
    <Alignment>left</Alignment>
    <Format></Format>
  </items>
  <items>
    <ColumnName>AccAddress</ColumnName>
    <ColumnTitle>Address</ColumnTitle>
    <Alignment>left</Alignment>
    <Format></Format>
  </items>
  <items>
    <ColumnName>AccPhone</ColumnName>
    <ColumnTitle>Phone</ColumnTitle>
    <Alignment>left</Alignment>
    <Format></Format>
  </items>
  <items>
    <ColumnName>AccEmail</ColumnName>
    <ColumnTitle>Email</ColumnTitle>
    <Alignment>left</Alignment>
    <Format></Format>
  </items>
  <items>
    <ColumnName>CreatedDate</ColumnName>
    <ColumnTitle>CreatedDate</ColumnTitle>
    <Alignment>center</Alignment>
    <Format>{0:dd/dd/yyyy}</Format>
  </items>
</root>

Chú ý: Những cột hiển thị trên Gridivew chính là các giá trị được nhập trong file XML

B8: Mở file Default.aspxdưới dạng HTML và  nhập mã HTML

<%@ PageTitle="Dynamically add BoundField and TemplateField Columns to GridView in ASP.Net" Language="vb"MasterPageFile="~/Site.Master"AutoEventWireup="false"EnableEventValidation="false" CodeBehind="Default.aspx.vb" Inherits="DynamicallyColumnsGridView._Default" %>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
    <asp:ScriptManager ID="ScriptManager1"runat="server">
    </asp:ScriptManager>
    <h3>
       Dynamically add Columns to GridView in ASP.Net
    </h3>
    <asp:UpdatePanel ID="updatePanel"runat="server"UpdateMode="Conditional">
        <ContentTemplate>
            <table cellpadding="2"cellspacing="3"width="100%">
                <tr>
                    <td>
                       
                    </td>
                    <tdalign="right">
                        <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>
                <trid="trMessage"runat="server"visible="false">
                    <tdcolspan="2">
                        <asp:Label ID="lblMessage" runat="server" Text="No Data"></asp:Label>
                    </td>
                </tr>
                <tr>
                    <tdcolspan="2">
                        <asp:GridView ID="grvObject" runat="server"
                            CssClass="GridStyle"BorderColor="#cbcbcb"BorderStyle="solid"
                            BorderWidth="1"AutoGenerateColumns="false"width="100%">
                            <AlternatingRowStyleCssClass="GridStyle_AltRowStyle"/>
                            <HeaderStyle CssClass="GridStyle_HeaderStyle"/>
                            <RowStyle CssClass="GridStyle_RowStyle"/>
                            <pagerstyle cssclass="GridStyle_pagination"/>
                                                             
                        </asp:GridView>
                    </td>
                </tr>
            </table>
        </ContentTemplate>
    </asp:UpdatePanel>
</asp:Content>

B9: Viết Code cho file Default.aspx

'Visit http://thuthuatlaptrinh.blogspot.com for more ASP.NET Tutorials
Imports System.Data.SqlClient

Namespace DynamicallyColumnsGridView

    Public Class _Default
        Inherits System.Web.UI.Page

#Region "Private Members"

        Private oColumnTemplate AsNew GridViewColumnTemplate

#End Region

#Region "ColumnSettings"

        Private FunctionBindColumnSettings() As DataSet
            Dim objBind As DataSet = New DataSet()
            'Caching
            If Cache("Cache_DynamicColumns") Is Nothing Then
                objBind.ReadXml(Server.MapPath("App_Data\DynamicallyColumns.xml"))
                Cache("Cache_DynamicColumns") = objBind
            Else
                objBind = CType(Cache("Cache_DynamicColumns"), DataSet)
            End If
            Return objBind
        End Function

        Private SubLoadColumnSettings()
            Dim objSQL As New SqlDataProvider
            Dim objBind As New DataSet
            Dim iCount As Integer = 0
            Dim i As Integer = 0
            Dim sFieldTitle As String = ""
            Dim sFieldName As String = ""
            Dim sAlignment As String = ""
            Dim sFormat As String = ""

            grvObject.Columns.Clear()

            objBind = BindColumnSettings()

            If Not objBind Is Nothing Then
                If objBind.Tables(0).Rows.Count > 0 Then
                    iCount = objBind.Tables(0).Rows.Count
                    For i = 0 ToiCount - 1
                        Dim row As DataRow = objBind.Tables(0).Rows(i)
                        If Not IsDBNull(row("ColumnName")) Then
                            sFieldName = row("ColumnName").ToString()
                        End If
                        If Not IsDBNull(row("ColumnTitle")) Then
                            sFieldTitle = row("ColumnTitle").ToString()
                        End If
                        If Not IsDBNull(row("Alignment")) Then
                            sAlignment = row("Alignment").ToString()
                        End If
                        If Not IsDBNull(row("Format")) Then
                            sFormat = row("Format").ToString()
                        End If
                        oColumnTemplate.AddBoundColumn(grvObject, sFieldTitle, sFieldName, sAlignment, sFormat)
                    Next
                End If
            End If
        End Sub

#End Region

#Region "Bind Data"

        Private SubBindAccount()
            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 FunctionBindData() 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"), _
                                                                          NewObjectPara("@SortType", "DESC"))
            Return objBind
        End Function

#End Region

#Region "GridView Methods"

        Private SubgrvObject_PageIndexChanging(ByVal sender As Object, ByVal e AsSystem.Web.UI.WebControls.GridViewPageEventArgs) Handles grvObject.PageIndexChanging
            grvObject.PageIndex = e.NewPageIndex
            BindData()
        End Sub

#End Region

#Region "Event Handles"

        Protected SubPage_Load(ByVal sender AsObject, ByVal e As System.EventArgs) Handles Me.Load
            Try
                LoadColumnSettings()
                BindAccount()

                If Page.IsPostBack = False Then
                    Page.Form.DefaultButton = cmdQuickSearch.UniqueID
                End If
            Catch ex As Exception

            End Try
        End Sub

        Private SubcmdQuickSearch_Click(ByVal sender As Object, ByVal e As System.EventArgs) HandlescmdQuickSearch.Click
            BindAccount()
        End Sub

#End Region

    End Class

End Namespace

Code Example C#, Code Example VB.NET
Code Example C#, Code Example VB.NET




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