或者用javascript也可以做到： 下边是一个改变背景的例子，举一反三啦 <!-- Program 4-2 --> <html> <script language="JavaScript"> <!-- theTime = new Date(); theHour = theTime.getHours(); if (theHour < 18) // < 6pm local time document.writeln("<body background='night.gif' text='White'>"); else document.writeln("<body background='night.gif' text='White'>"); //--> </script> This is the text of the body... </body> </html>
下边是一个改变背景的例子，举一反三啦
<!--
Program 4-2
-->
<html>
<script language="JavaScript">
<!--
theTime = new Date();
theHour = theTime.getHours();
if (theHour < 18) // < 6pm local time
document.writeln("<body background='night.gif' text='White'>");
else
document.writeln("<body background='night.gif' text='White'>");
//-->
</script>
This is the text of the body...
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head><script language="JScript">
<!--
function ShowHTMLContent() {
var strURL = 'http://<% = Request.ServerVariables["SERVER_NAME"] %><% = Request.Path %>?<% = Request.QueryString %>';
var strDisplay = new String;
var objHTTP = new ActiveXObject("microsoft.XMLHTTP")
objHTTP.open('GET', strURL, false);
objHTTP.send();
var strReply = objHTTP.responseText;
var intStart = strReply.indexOf('<!' + '--start-->') + 12;
var intEnd = strReply.indexOf('<!' + '--end-->');
if ((intStart > 0) && (intEnd > intStart))
var strDisplay = strReply.substring(intStart, intEnd);
document.all['outHTML'].innerText = strDisplay + ' ';
}
function SetCheck(strCheckboxName) {
document.all[strCheckboxName].checked = true;
}
//-->
</script><!-- #include file="style.inc" -->
</head>
<body bgcolor="#ffffff" onload="ShowHTMLContent()">
<!--------------------------------------------------------------------------->
<span class="heading">HtmlTable Control</span><p /><!--start-->
<table id="MyControl" runat="server" />
<!--end--><p /><div id="outError" runat="server" /><p />
<font face="Courier New" size="2"><div style="background-color:gainsboro; padding-left:10px" id="outHTML">Fetching HTML content...</div></font><form runat="server" method="get">
<table border="0">
<tr>
<td align="right" nowrap="nowrap" colspan="2">Number of Rows =</td>
<td nowrap="nowrap"><select id="selRows" size="1" runat="server">
<option>1</option><option>2</option><option>3</option><option>4</option></select></td>
<td nowrap="nowrap"> </td>
<td align="right" nowrap="nowrap" colspan="2">Number of Columns =</td>
<td nowrap="nowrap"><select id="selCols" size="1" runat="server">
<option>1</option><option>2</option><option>3</option><option>4</option><option>5</option><option>6</option></select></td>
</tr><tr>
<td nowrap="nowrap"><input type="checkbox" id="chkAlign" runat="server" /> Set: </td><td align="right" nowrap="nowrap">Align =</td><td nowrap="nowrap"><select id="selAlign" size="1" runat="server" onchange="SetCheck('chkAlign')">
<option></option><option>AbsBottom</option><option>AbsMiddle</option><option>Baseline</option><option>Bottom</option><option>Left</option>
<option>Middle</option><option>Right</option><option>TextTop</option><option>Top</option></select></td><td nowrap="nowrap"></td>
<td nowrap="nowrap"><input type="checkbox" id="chkBgColor" runat="server" /> Set: </td><td align="right" nowrap="nowrap">BgColor =</td><td nowrap="nowrap"><input type="text" size="15" id="txtBgColor" runat="server" onkeypress="SetCheck('chkBgColor')" /></td>
</tr><tr>
<td nowrap="nowrap"><input type="checkbox" id="chkBorder" runat="server" /> Set: </td><td align="right" nowrap="nowrap">Border =</td><td nowrap="nowrap"><input type="text" size="3" id="txtBorder" runat="server" onkeypress="SetCheck('chkBorder')" />px</td><td></td>
<td nowrap="nowrap"><input type="checkbox" id="chkBorderColor" runat="server" /> Set: </td><td align="right" nowrap="nowrap">BorderColor =</td><td nowrap="nowrap"><input type="text" size="15" id="txtBorderColor" runat="server" onkeypress="SetCheck('chkBorderColor')" /></td>
</tr><tr>
<td nowrap="nowrap"><input type="checkbox" id="chkCellPadding" runat="server" /> Set: </td><td align="right" nowrap="nowrap">CellPadding =</td><td nowrap="nowrap"><input type="text" size="3" id="txtCellPadding" runat="server" onkeypress="SetCheck('chkCellPadding')" />px</td><td></td>
<td nowrap="nowrap"><input type="checkbox" id="chkCellSpacing" runat="server" /> Set: </td><td align="right" nowrap="nowrap">CellSpacing =</td><td nowrap="nowrap"><input type="text" size="3" id="txtCellSpacing" runat="server" onkeypress="SetCheck('chkCellSpacing')" />px</td>
</tr><tr>
<td nowrap="nowrap"><input type="checkbox" id="chkHeight" runat="server" /> Set: </td><td align="right" nowrap="nowrap">Height =</td><td nowrap="nowrap"><input type="text" size="3" id="txtHeight" runat="server" onkeypress="SetCheck('chkHeight')" />px</td><td></td>
<td nowrap="nowrap"></td><td align="right" nowrap="nowrap">ID =</td><td nowrap="nowrap"><% = MyControl.ID %></td>
</tr><tr>
<td nowrap="nowrap"><input type="checkbox" id="chkVisible" runat="server" /> Set: </td><td align="right" nowrap="nowrap">Visible =</td><td nowrap="nowrap"><select id="selVisible" size="1" runat="server" onchange="SetCheck('chkVisible')"><option>True</option><option>False</option></select></td><td></td>
<td nowrap="nowrap"><input type="checkbox" id="chkWidth" runat="server" /> Set: </td><td align="right" nowrap="nowrap">Width =</td><td nowrap="nowrap"><input type="text" size="3" id="txtWidth" runat="server" onkeypress="SetCheck('chkWidth')" />px</td>
</tr><tr>
<td></td><td></td><td></td><td></td>
<td nowrap="nowrap"><input type="button" Value="Reset" onclick="javascript:location.href='http://<% = Request.ServerVariables["SERVER_NAME"] %><% = Request.Path %>'"></td><td nowrap="nowrap"></td><td nowrap="nowrap"><input type="submit" Value="Update" runat="server" /></td>
</tr>
</table>
</form><script language="C#" runat="server">void Page_Load(Object sender, EventArgs e)
{
outError.InnerHtml = "";try
{
// create the table
int intRows = Convert.ToInt32(selRows.Value);
int intCols = Convert.ToInt32(selCols.Value);
int intRowCount;
int intColCount;
HtmlTableRow objRow;
HtmlTableCell objCell;for (intRowCount = 0; intRowCount <= intRows - 1; intRowCount++)
{
objRow = new HtmlTableRow();for (intColCount = 0; intColCount <= intCols - 1; intColCount++)
{
objCell = new HtmlTableCell();
objCell.InnerHtml = "R" + intRowCount + "C" + intColCount;
objRow.Cells.Add(objCell);
}
MyControl.Rows.Add(objRow);
}if (IsPostBack)
{
if (chkAlign.Checked) MyControl.Align = selAlign.Value;
if (chkBgColor.Checked) MyControl.BgColor = txtBgColor.Value;
if (chkBorder.Checked) MyControl.Border = Convert.ToInt32(txtBorder.Value);
if (chkBorderColor.Checked) MyControl.BorderColor = txtBorderColor.Value;
if (chkCellPadding.Checked) MyControl.CellPadding = Convert.ToInt32(txtCellPadding.Value);
if (chkCellSpacing.Checked) MyControl.CellSpacing = Convert.ToInt32(txtCellSpacing.Value);
if (chkHeight.Checked) MyControl.Height = txtHeight.Value;
if (chkVisible.Checked) MyControl.Visible = Convert.ToBoolean(selVisible.Value);
if (chkWidth.Checked) MyControl.Width = txtWidth.Value;
}selAlign.Value = MyControl.Align.ToString();
txtBgColor.Value = MyControl.BgColor;
txtBorder.Value = MyControl.Border.ToString();
txtBorderColor.Value = MyControl.BorderColor;
txtCellPadding.Value = MyControl.CellPadding.ToString();
txtCellSpacing.Value = MyControl.CellSpacing.ToString();
txtHeight.Value = MyControl.Height;
selVisible.Value = MyControl.Visible.ToString();
txtWidth.Value = MyControl.Width;
}
catch (Exception objError)
{
outError.InnerHtml = "<b>* Error</b>: " + objError.Message + "<p />";
}
}</script><!--------------------------------------------------------------------------->
<!-- #include file="foot.inc" -->
</body>
</html>
这是Wrox的原代码，看看