ASP.NET Tutorial/Data Binding/Expressions
Содержание
Binding Expression
<source lang="csharp">
<%@Page debug="true"%> <script language="C#" runat="server" > DateTime theTime; protected void Page_Load(object o, EventArgs e) {
theTime = DateTime.Now; Page.DataBind();
}
</script>
The time is: <%# theTime %>
</source>
Databind the result of a method call
<source lang="csharp">
<script runat="server" language="C#"> protected void Page_Load(object o, EventArgs e) {
if(IsPostBack) {
Page.DataBind();
}
} protected double CalculateFactorial(int input) {
double result = 1;
for(;input > 0; input--) {
result *= input;
}
return result;
}
</script>
<form runat="server">
Databind the result of a method call.
<asp:Textbox runat="server" id="theInput" />
<asp:RequiredFieldValidator
runat="server" ControlToValidate="theInput" ErrorMessage="input is required" />
<asp:RangeValidator
runat="server" ControlToValidate="theInput" ErrorMessage="input must be >= 0 and < 20" Type="integer" MinimumValue="0" MaximumValue="20" />
<asp:Button
runat="server" type="submit" Text="Calculate Factorial" />
The result is: <%# CalculateFactorial(Int32.Parse(theInput.Text)).ToString() %> </form></source>
DataList with data binding expression
<source lang="csharp">
<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server">
<title>Extracting Rows From Templates</title>
</head> <body>
<form id="form1" runat="server">
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:NorthWind %>"
SelectCommand="SELECT TOP 10 * FROM customers">
</asp:SqlDataSource>
<asp:DataList ID="list" runat="server" DataSourceID="SqlDataSource1"
ExtractTemplateRows="true" RepeatColumns="3" BorderStyle="Solid" BorderWidth="1px">
<alternatingitemstyle backcolor="PaleGoldenrod" />
<headerstyle backcolor="Brown" forecolor="White" font-size="Larger"
font-bold="True" horizontalalign="Center" />
<HeaderTemplate>
<asp:table ID="Table1" runat="server">
<asp:tablerow ID="Tablerow1" runat="server">
<asp:tablecell ID="Tablecell1" runat="server">Customer</asp:TableCell>
<asp:tablecell ID="Tablecell2" runat="server">Contact</asp:TableCell>
</asp:tablerow>
</asp:table>
</HeaderTemplate>
<ItemTemplate>
<asp:table ID="Table2" runat="server">
<asp:tablerow ID="Tablerow2" runat="server" font-bold="true">
<asp:tablecell ID="Tablecell3" runat="server">
<%# Eval("CustomerID") %>
</asp:tablecell>
<asp:tablecell ID="Tablecell4" runat="server">
<%# Eval("ContactName") %>
</asp:tablecell>
</asp:tablerow>
<asp:tablerow ID="Tablerow3" runat="server">
<asp:tablecell ID="Tablecell5" runat="server" columnspan="2">
<%# Eval("Address") + " - " +
Eval("City") %>
</asp:tablecell>
</asp:tablerow>
</asp:table>
</ItemTemplate>
</asp:datalist>
</form>
</body> </html></source>
Put simple data binding expressions
<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs"
Inherits="Default"%>
<%@ Import Namespace="System.Drawing" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server">
<title>Simple Data Binding</title>
</head> <body>
<form id="form1" runat="server">
<asp:DropDownList ID="SelColors" runat="server" AutoPostBack="True">
<asp:ListItem>Orange</asp:ListItem>
<asp:ListItem>Green</asp:ListItem>
<asp:ListItem>Cyan</asp:ListItem>
<asp:ListItem>Red</asp:ListItem>
<asp:ListItem>Blue</asp:ListItem>
</asp:DropDownList>
<asp:Label runat="server" ID="lblColor" EnableTheming="false"
ForeColor="<%# Color.FromName(SelColors.SelectedValue) %>"
Text="<%# "You selected: " + SelColors.SelectedValue %>" />
<asp:Label runat="server" ID="Label4" Text="<%# "on " + DateTime.Now %>" />
</form>
</body> </html> File: Default.aspx.cs using System; using System.Data; using System.Configuration; using System.Data.SqlClient; using System.Collections; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Drawing;
public partial class Default : System.Web.UI.Page {
void Page_Load(object sender, EventArgs e)
{
DataBind();
}
}</source>
