DPC：Creating a DataBound List of Radio Buttons--預(yù)覽

2024-07-21 02:16:50

字體：大中小

供稿：網(wǎng)友

<% @import namespace="system.data" %> 
<% @import namespace="system.data.sqlclient" %> 
<script language="vb" runat="server"> 
  sub page_load(sender as object, e as eventargs) 
    if not page.ispostback then 
      binddata() 
    end if   
  end sub 
 
   
  sub binddata() 
    '1. create a connection 
    dim myconnection as new sqlconnection(configurationsettings.appsettings("connectionstring")) 
 
    '2. create the command object, passing in the sql string 
        const strsql as string = "select publisherid, name from tblpublishers order by name" 
        dim mycommand as new sqlcommand(strsql, myconnection) 
 
    myconnection.open() 
 
    radlstpubs.datasource = mycommand.executereader(commandbehavior.closeconnection) 
    radlstpubs.databind()   
 
  end sub 
 
 
 
  sub btnviewbooks_click(sender as object, e as eventargs) 
    'if the user has not selected an item from the radiobuttonlist, 
    'do nothing 
    if radlstpubs.selecteditem is nothing then exit sub 
     
    '1. create a connection 
    dim myconnection as new sqlconnection(configurationsettings.appsettings("connectionstring")) 
 
    '2. create the command object, passing in the sql string 
        dim strsql as string = "select title, description from tblbooks " & _ 
                " where publisherid = " & radlstpubs.selecteditem.value & _ 
                " order by title" 
        dim mycommand as new sqlcommand(strsql, myconnection) 
 
    myconnection.open() 
 
    dgbooks.datasource = mycommand.executereader(commandbehavior.closeconnection) 
    dgbooks.databind()   
     
    lbltitle.text = "books published by " & radlstpubs.selecteditem.text 
  end sub 
</script> 
 
<html> 
<body> 
 
  <h1>radio button list demo</h1> 
  this demo illustrates how to use data-binding to dynamically 
  create a radio button list based on database information. 
  the data below is from the 
  <a href="http://www.4guysfromrolla.com/webtech/chapters/">sample chapters database</a>. 
  first, the radio button list is bound to the <code>tblpublishers</code> table.  then, 
  when you select a publisher, a datagrid web control is populated with 
  the books provided by the selected publisher.  (adding paging to the datagrid would be 
  a snap.  just read: <a href="http://www.4guysfromrolla.com/webtech/072101-1.shtml">paing 
  database results in asp.net</a>!) 
  <hr> 
 
  <form runat="server"> 
     
    choose a publisher's books to view 
    <asp:radiobuttonlist id="radlstpubs" runat="server" font-name="verdana" 
            datavaluefield="publisherid" datatextfield="name" /> 
     
    <asp:button id="btnviewbooks" runat="server" font-name="verdana" 
          text="view published books" onclick="btnviewbooks_click" /> 
     
     
    <asp:label id="lbltitle" runat="server" font-name="verdana" 
          font-size="large" font-bold="true" /> 
    <asp:datagrid id="dgbooks" runat="server" 
      font-name="verdana" font-size="smaller" 
      headerstyle-backcolor="purple" headerstyle-forecolor="white" 
      headerstyle-font-size="small" headerstyle-font-bold="true" 
      autogeneratecolumns="false"> 
     
      <columns> 
       
        <asp:boundcolumn headertext="book title" headerstyle-horizontalalign="center" 
                datafield="title" /> 
        <asp:boundcolumn headertext="synopsis" headerstyle-horizontalalign="center" 
                datafield="description" /> 
      </columns> 
    </asp:datagrid> 
     
  </form>

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