The DataGrid is an important control in asp.net, and often we make the DataGrid paginated and sortable, sometimes with the option to be added. These are the methods that are often needed, but they are relatively simple.
Design ideas:
For convenience, we connect the Orders table of the Northwind database for SQL Server 2000 and get a data view of the table from the database. Use the SortCommand event in the DataGrid to implement sorting. Implement the selection with a template column plus a CheckBox control. You can use the paging option in the DataGrid's Property builder or modify the HTML implementation pagination yourself.
Html:
Add a DataGrid, named Dgorder.
A template column is added, and a CheckBox control named CB is placed in the template column. This column is used to implement the selection
Adds a sort expression sortexpression to each column that you want to sort.
Use the dataformatstring of the column to format the column, like dataformatstring= "{0:d}" to display the date format.
Set pagesize= "15" to display 15 rows of data per page, allowpaging= "True" to allow paging.
Entire HTML page code:
<form id= "Form1" method= "POST" runat= "Server" >
<asp:datagrid id= "Dgorder" runat= "Server" height= "515px" width= "718px" autogeneratecolumns= "False" allowsorting= " True "cellpadding=" 4 "borderwidth=" 1px "bordercolor=" #A0ABEB "pagesize=" borderstyle= "Solid" backcolor= "white" Gridlines= "Vertical" forecolor= "Black" allowpaging= "true" showfooter= "true" >
<selecteditemstyle forecolor= "white" backcolor= "Black" ></SelectedItemStyle>
<alternatingitemstyle backcolor= "#EEEEEE" ></AlternatingItemStyle>
<footerstyle forecolor= "White" backcolor= "#6876C5" ></FooterStyle>
<Columns>
<asp:TemplateColumn>
<ItemTemplate>
<font face= "Song Body" >
<asp:checkbox id= "Cb" runat= "Server" ></asp:CheckBox></FONT>
</ItemTemplate>
</asp:TemplateColumn>
<asp:boundcolumn datafield= "OrderID" sortexpression= "OrderID" headertext= "ID" >
</asp:BoundColumn>
<asp:boundcolumn datafield= "ShipCountry" sortexpression= "ShipCountry" headertext= "ShipCountry" >
</asp:BoundColumn>
<asp:boundcolumn datafield= "ShippedDate" sortexpression= "ShippedDate" headertext= "ShippedDate" DataFormatString = ' {0:d} ' >
</asp:BoundColumn>
<asp:boundcolumn datafield= "Freight" sortexpression= "Freight" headertext= "Freight" >
</asp:BoundColumn>
<asp:boundcolumn datafield= "shipaddress" sortexpression= "shipaddress" headertext= "ShipAddress" >
</asp:BoundColumn>
</Columns>
<pagerstyle horizontalalign= "Center" forecolor= "Black" position= "Topandbottom" backcolor= "White" mode= " NumericPages "></PagerStyle>
</asp:datagrid>
</form>
The background class adds the following code:
Imports System.Data.SqlClient
' Get the Data View, the parameter is the column to sort
Private Function GETDV (ByVal strsort as String) as DataView
' Define a database connection
Dim DV as DataView
Dim CN as New SqlConnection ()
Try
' Initialize connection string
CN. ConnectionString = "Data source=pmserver;initial catalog=northwind;persist security Info=false;user Id=sa; Password=sa; "
CN. Open ()
' Get data from the Orders table from Northwind
Dim ADP as SqlDataAdapter = New SqlDataAdapter ("select * from Orders", CN)
Dim DS as New DataSet ()
Adp. Fill (DS)
' Get the Data View
DV = ds. Tables (0). DefaultView
Catch ex as Exception
#If DEBUG Then
Session ("Error") = ex. ToString ()
Response.Redirect (".. /error.aspx ") ' The Public error handling page of the Jump program
#End If
Finally
' Close the connection
CN. Close ()
End Try
' Sort
Dv. Sort = StrSort
Return DV
End Function
Private Sub Page_Load (ByVal sender as System.Object, ByVal e as System.EventArgs) Handles MyBase.Load
If not IsPostBack Then
ViewState ("strsort") = "OrderID"
Dgorder.datasource = GETDV (ViewState ("StrSort"). ToString ())
Dgorder.databind ()
End If
End Sub
' Sort
Private Sub Dgorder_sortcommand (ByVal source as Object, ByVal e As System.Web.UI.WebControls.DataGridSortCommandEventArgs) Handles Dgorder.sortcommand
Dgorder.currentpageindex = 0
' Get sorted columns
ViewState ("strsort") = E.sortexpression.tostring ()
Dgorder.datasource = GETDV (ViewState ("StrSort"). ToString ())
Dgorder.databind ()
End Sub
' Paging
Private Sub dgorder_pageindexchanged (ByVal source as Object, ByVal e As System.Web.UI.WebControls.DataGridPageChangedEventArgs) Handles dgorder.pageindexchanged
' Get page number of pagination
Dgorder.currentpageindex = E.newpageindex
Dgorder.datasource = GETDV (ViewState ("StrSort"). ToString ())
Dgorder.databind ()
End Sub
The results of the operation are as follows: (Click on the column headers to sort)
In order to know which records the user chooses, we can use DataGridItem's FindControl to get the checkbox value, we add a button, and then write the following code:
Private Sub button1_click (ByVal sender as System.Object, ByVal e as System.EventArgs) Handles Button1.Click
Dim Item as DataGridItem
Dim Strscript as String
Strscript = "<script Language=javascript>alert" (""
' Loop the entry of the table, FindControl
For each item in Me.dgOrder.Items
If CType (item. FindControl ("CB"), System.Web.UI.WebControls.CheckBox). Checked Then
Try
Strscript + = Item. Cells (1). Text & Space (2)
Catch ex as Exception
End Try
End If
Next
Strscript + = "was selected!" ') </script> "
RegisterClientScriptBlock ("System Messages", Strscript)
End Sub
The code above RegisterClientScriptBlock adds a Java Script Popup dialog box. (In fact, VB Script dialog box than Java Script dialog more display and control mode, but Netscape browser does not support, you can according to the corresponding project in the program to choose what kind of script).
Summarize:
DataGrid is our common Web control, sometimes we can mix with DataList, by modifying the HTML page, can achieve good page effect. It's just an example of how I wrote the Data Access section (SQL) to the page to make it easier to understand the whole process. In software development, we generally have access to the data part of the data layer, page call data layer to get the data, so logic clear, modify and maintenance are very convenient.
