The Web has had worldwide reach since its inception.
Users have different cultural expectations and speak different languages. In
this Quickstart you will learn how powerful new ASP.NET v2.0 features make it
easier to adapt your Web application to different countries, regions, and
markets.
In this article, we will discuss the
internationalization of web application using ASP.NET 2.0
Culture-sensitive Formatting
Setting a Preferred Language in Internet
Explorer
HTTP allows browsers to send a list of preferred
languages to the Web server using the Accept-Language HTTP request header field.
In Internet Explorer the list can be configured like this:
- Select the "Tools | Internet Options" command.
- Select the "Languages" button.
- In the dialog that is shown, click on the "Add"
button to add a new language and select a new culture. Click "OK".
- Ensure your preferred language is at the top of
the list. Select that language and click "Move Up". Click "OK" to exit the
dialog.
- Refresh the page using F5.
Initially the list is preconfigured to the language of
the Internet Explorer user interface, which makes sense as typically users want
to see Web content in the language of the computer they are working on. Other
browsers have similar features to configure this header field.
Auto-detecting the browser language for
culture-sensitive formatting:
The language list can be used to determine which
culture the user most likely prefers for formatting of numbers, dates and times.
ASP.NET v2.0 now provides functionality to easily detect the first language in
the list and use this for formatting:
<%@ Page Culture = "auto:en-US" %>
If the first language in the list matches the name of a
specific culture supported by the .NET Framework, ASP.NET will set the
CurrentCulture of the running thread to this culture. This happens early in the
page life cycle so that all subsequent culture-sensitive formatting will be done
with this culture.
If the first language in the list matches the name of a
neutral culture supported by the .NET Framework, ASP.NET will try to use the
function
CultureInfo.CreateSpecificCulture()
to create a specific culture for the purpose
of formatting. For example, this would map fr into the culture for French
(France). However, this determination could be inappropriate for somebody in the
French-speaking part of Canada, which is why an application should provide the
means to configure both culture and language
If the first language in the list isn't a culture
supported by the .NET Framework, ASP.NET will fall back to the culture specified
after the colon in the Culture declaration. This would be
en-US
- English (United States) in the example above.
This auto-detection functionality can be used in all
places where Culture can be specified declaratively, such as in the
globalization section of web.config. The auto-detection works the same for
UICulture, which is used for localization and is explained later.
The following sample demonstrates a Currency Exchange
Calculator that reacts to different language settings in the browser (see above
for information how to change this). It will display the date in the format
appropriate for the first language in the list and also uses the correct decimal
separator for the exchange values. Furthermore, this decimal separator can be
used for the entry of the value to be converted.
CODE:
XML:
<?xml
version="1.0" encoding="UTF-8"?>
<ExchangeRates>
<Currency
Region="US" Rate="1"/>
<Currency
Region="AU" Rate="1.32766861391397"/>
<Currency
Region="BR" Rate="2.78"/>
<Currency
Region="CA" Rate="1.2253"/>
<Currency
Region="CN" Rate="8.2765"/>
<Currency
Region="DK" Rate="5.5995"/>
<Currency
Region="DE" Rate="0.753352418261263"/>
<Currency
Region="HK" Rate="7.776"/>
<Currency
Region="IN" Rate="44.12"/>
<Currency
Region="JP" Rate="104.93"/>
<Currency
Region="MY" Rate="3.8"/>
<Currency
Region="MX" Rate="11.29"/>
<Currency
Region="NZ" Rate="1.41242937853107"/>
<Currency
Region="NO" Rate="6.2225"/>
<Currency
Region="SG" Rate="1.6495"/>
<Currency
Region="ZA" Rate="5.82"/>
<Currency
Region="KR" Rate="1055"/>
<Currency
Region="SE" Rate="6.7723"/>
<Currency
Region="CH" Rate="1.1545"/>
<Currency
Region="TW" Rate="32.16"/>
<Currency
Region="TH" Rate="39.67"/>
<Currency
Region="GB" Rate="0.521240552514986"/>
<Currency
Region="VE" Rate="1915.2"/>
</ExchangeRates>
Global_Vb.aspx:
<%@ Page
Language="VB" AutoEventWireup="true" Culture="auto:en-US" %>
<%@ Import
Namespace="System.Globalization" %>
<%@ Import
Namespace="System.Xml" %>
<%@ Import
Namespace="System.Data" %>
<!DOCTYPE
html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html
xmlns="http://www.w3.org/1999/xhtml"
>
<head
runat="server">
<title>Currency
Exchange Calculator</title>
</head>
<script
runat="server">
Private
Sub
Page_Load(ByVal
sender
As
Object,
ByVal
e As
EventArgs)
If
(Not
IsPostBack
Or
CStr(Session("CultureName"))
<> CultureInfo.CurrentCulture.Name)
Then
DateTimePlaceholder.Text = DateTime.Now.ToLongDateString()
' Populate
the drop-down with currency names
' If possible
set the default selected currency to the currency of the CurrentCulture
Dim
UserRegion
As
New
RegionInfo(CultureInfo.CurrentCulture.Name)
Dim
TargetRegion
As
RegionInfo
Dim
dir As
String
= Server.MapPath("")
Dim
ExchangeRateTextReader
As
New
XmlTextReader(Server.MapPath("~/ExchangeRates.xml"))
Dim
ExchangeRateDataSet
As
New
DataSet("ds")
ExchangeRateDataSet.ReadXml(ExchangeRateTextReader)
Dim
CurrencyTable
As
DataTable = ExchangeRateDataSet.Tables("Currency")
Dim
CurrencyTableReader
As
DataTableReader = CurrencyTable.CreateDataReader()
CurrencyDropDown.Items.Clear()
' Make sure
list is empty on culture change in current session
While
CurrencyTableReader.Read()
TargetRegion
= New
RegionInfo(CurrencyTableReader.GetString(0))
Dim
Currency
As
New
ListItem(TargetRegion.CurrencyEnglishName, CurrencyTableReader.GetString(1))
If
TargetRegion.ISOCurrencySymbol = UserRegion.ISOCurrencySymbol
Then
Currency.Selected =
True
End
If
CurrencyDropDown.Items.Add(Currency)
End
While
Session("CultureName") = CultureInfo.CurrentCulture.Name
End
If
End
Sub
'Page_Load
Private
Function
CalculateExchangeValue(ByVal
Rate As
String)
As
String
Dim
Value
As
Double
Try
Value =
Double.Parse(ConvertValue.Text)
Catch
Value = 0
End
Try
Dim
ExchangeValue
As
Double
=
Double.Parse(Rate,
CultureInfo.InvariantCulture) /
Double.Parse(CurrencyDropDown.SelectedItem.Value,
CultureInfo.InvariantCulture) * Value
Return
ExchangeValue.ToString("F")
End
Function
'CalculateExchangeValue
Private
Function
CurrencyName(ByVal
RegionName
As
String)
As
String
Dim
result
As
String
Try
Dim
ri As
New
RegionInfo(RegionName)
result =
ri.CurrencyEnglishName
Catch
result =
"Unknown"
End
Try
Return
result
End
Function
'CurrencyName
Private
Sub
ConvertButton_Click(ByVal
sender
As
Object,
ByVal
e As
EventArgs)
ExchangeGrid.DataBind()
End
Sub
'ConvertButton_Click
</script>
<body
bgcolor="moccasin">
<form
id="form1" runat="server">
<div>
<h2>
Currency
Exchange Calculator</h2>
<asp:Label
ID="DateTimePlaceholder" runat="server" Text="DateTimePlaceholder"></asp:Label><br
/><br
/>
Enter an
amount, choose a currency and click the Convert button to calculate the
exchange
values.<br
/>
<br
/>
<asp:TextBox
ID="ConvertValue" runat="server">100</asp:TextBox>
<asp:DropDownList
ID="CurrencyDropDown" runat="server">
</asp:DropDownList>
<asp:Button
ID="ConvertButton" runat="server" Text="Convert" OnClick="ConvertButton_Click"
/>
<asp:XmlDataSource
DataFile="ExchangeRates.xml" ID="XmlExchangeRates"
runat="server"></asp:XmlDataSource>
<br
/>
<asp:GridView
AutoGenerateColumns="False" DataSourceID="XmlExchangeRates" ID="ExchangeGrid"
runat="server"
>
<Columns>
<asp:TemplateField
HeaderText="Name">
<ItemTemplate>
<asp:Label
ID="ColumnCurrency" runat="server" Text='<%#
CurrencyName(CStr(Eval("Region")))
%>'></asp:Label>
</ItemTemplate>
<ItemStyle
HorizontalAlign="Left"
/>
<HeaderStyle
HorizontalAlign="Left"
/>
</asp:TemplateField>
<asp:TemplateField
HeaderText="Exchange Value">
<ItemTemplate>
<asp:Label
ID="ColumnExchangeValue" runat="server" Text='<%#
CalculateExchangeValue(CStr(Eval("Rate")))
%>'></asp:Label>
</ItemTemplate>
<ItemStyle
HorizontalAlign="Right"
/>
<HeaderStyle
HorizontalAlign="Right"
/>
</asp:TemplateField>
</Columns>
</asp:GridView>
<br
/>
Disclaimer:
The rate calculation above is based on exchange rates published on Dec 9th, 2004
by the United States Federal Reserve Bank of New York. For up-to-date exchange
rates please go to the website of this
organization. This sample application
is not intended to provide accurate or up-to-date currency conversions.</div>
</form>
</body>
</html>
![Internationaliziing1-in-vb.net.gif]()
In order to view text in some East Asian languages and
some languages with complex scripts, you might need to install the appropriate
font for Internet Explorer. Refer to Internet Explorer Help Topics for more
information (see in the index under "foreign languages used in Web pages").
Alternatively you can install additional fonts from the Regional and Language
Options of the Control Panel.
v