学步园

public void GetImage(string imageName)
{
// Request the image file contents. 
_downloader.Open("GET", new Uri(imageName, UriKind.Relative), true);
_downloader.Send();
}
public void DownloaderCompleted(object o, EventArgs e)
{
// Populate the XAML Image object with the image file contents. 
ImageFrame.SetSource(_downloader, null);
} 
 

Public Sub GetImage(ByVal imageName As String)
' Request the image file contents. 
_downloader.Open("GET", New Uri(imageName, UriKind.Relative), True)
_downloader.Send()
End Sub
Public Sub DownloaderCompleted(ByVal o As Object, ByVal e As EventArgs)
' Populate the XAML Image object with the image file contents. 
ImageFrame.SetSource(_downloader, Nothing)
End Sub

public string[] GetImageList(string folderName)
{
List<string> results = new List<string>();
// Create an HTTP request with the path to the web service that
// returns a list of images from a specified folder. 
Uri listService = new Uri("Service.asmx/GetImageList", UriKind.Relative);
BrowserHttpWebRequest request = new BrowserHttpWebRequest(listService);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
// Set the folderName property for the body of the HTTP request. 
string formBody = "folderName=" + HttpUtility.UrlEncode(folderName);
UTF8Encoding encoding = new UTF8Encoding();
byte[] formBytes = encoding.GetBytes(formBody);
Stream body = request.GetRequestStream();
body.Write(formBytes, 0, formBytes.Length);
// Send the request and parse the returned XML for the list of
// file names (e.g. <string>image.jpg</string>) 
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream s = response.GetResponseStream();
XmlReader reader = XmlReader.Create(s);
reader.MoveToContent();
while (reader.Read())
{
if (reader.NodeType == XmlNodeType.Element)
if (reader.Name == "string")
results.Add(reader.ReadInnerXml());
}
reader.Close();
s.Close();
body.Close();
return results.ToArray();
}

Public Function GetImageList(ByVal folderName As String) As String()
Dim results As New List(Of String)
' Create an HTTP request with the path to the web service that 
' returns a list of images from a specified folder. 
Dim listService As Uri = New Uri("Service.asmx/GetImageList", UriKind.Relative)
Dim request As BrowserHttpWebRequest = New BrowserHttpWebRequest(listService)
request.Method = "POST"
request.ContentType = "application/x-www-form-urlencoded"
' Set the folderName property for the body of the HTTP request. 
Dim formBody As String = "folderName=" & HttpUtility.UrlEncode(folderName)
Dim encoding As UTF8Encoding = New UTF8Encoding()
Dim formBytes As Byte() = encoding.GetBytes(formBody)
Dim body As Stream = request.GetRequestStream()
body.Write(formBytes, 0, formBytes.Length)
' Send the request and parse the returned XML for the list of 
' file names (e.g. <string>image.jpg</string>) 
Dim response As HttpWebResponse = CType(request.GetResponse(), HttpWebResponse)
Dim s As Stream = response.GetResponseStream()
Dim reader As XmlReader = XmlReader.Create(s)
reader.MoveToContent()
Do While reader.Read()
If reader.NodeType = XmlNodeType.Element Then _
If reader.Name = "string" Then _
results.Add(reader.ReadInnerXml())
Loop
reader.Close()
s.Close()
body.Close()
Return results.ToArray()
End Function

<system.web>
<webServices>
<protocols>
<add name="HttpPost"/>
</protocols>
</webServices>
</system.web>

using System;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Web.Caching;
using System.IO;
using System.Collections.Generic;
[WebService(Namespace = "http://tempuri.org/")]
public class SampleDownloadServiceCS : System.Web.Services.WebService
{
public SampleDownloadServiceCS()
{
}
[WebMethod]
public string[] GetImageList(string folderName)
{
List<string> resultsList = new List<string>();
FileInfo[] fileList = new DirectoryInfo(Server.MapPath(folderName)).GetFiles();
foreach (FileInfo f in fileList)
{
switch (f.Extension)
{
case ".jpg":
resultsList.Add(f.Name);
break;
case ".png":
resultsList.Add(f.Name);
break;
case ".bmp":
resultsList.Add(f.Name);
break;
case ".gif":
resultsList.Add(f.Name);
break;
}
}
return resultsList.ToArray();
}
}

Imports System
Imports System.Web
Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports System.Web.Caching
Imports System.IO
Imports System.Collections.Generic
<WebService(Namespace:="http://tempuri.org/")> _
Public Class SampleDownloadServiceVB
Inherits System.Web.Services.WebService
Public Sub New()
End Sub
<WebMethod()> _
Public Function GetImageList(ByVal folderName As String) As String()
Dim resultsList As New List(Of String)
Dim fileList As FileInfo() = New DirectoryInfo(Server.MapPath(folderName)).GetFiles()
For Each f As FileInfo In fileList
Select Case f.Extension
Case ".jpg"
resultsList.Add(f.Name)
Case ".png"
resultsList.Add(f.Name)
Case ".bmp"
resultsList.Add(f.Name)
Case ".gif"
resultsList.Add(f.Name)
End Select
Next
Return resultsList.ToArray()
End Function
End Class

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Net;
using System.Text;
using System.IO;
using System.Xml;
using System.Windows.Browser;
using System.Windows.Browser.Net;
using System.Collections.Generic;
namespace ImageViewerCS
{
public partial class Page : Canvas
{
// Variables to manage the list of images. 
private int _imageIndex;
private string _imageFolderName = "images";
private string[] _imageList;
// Downloader object to retrieve the image file contents. 
private Downloader _downloader = new Downloader();
public void Page_Loaded(object o, EventArgs e)
{
InitializeComponent();
// Add event handlers for Downloader and XAML elements. 
_downloader.Completed += DownloaderCompleted;
LeftArrow.MouseLeftButtonDown += OnPrevButtonClick;
RightArrow.MouseLeftButtonDown += OnNextButtonClick;
// Initialize list of image file names. 
_imageIndex = 0;
_imageList = GetImageList("images");
// Populate the XAML Image object with a default image. 
string defaultImageName = GetImageName(_imageIndex);
GetImage(defaultImageName);
ImageFileName.Text = defaultImageName;
}
public string[] GetImageList(string folderName)
{
List<string> results = new List<string>();
// Create an HTTP request with the path to the web service that
// returns a list of images from a specified folder. 
Uri listService = new Uri("Service.asmx/GetImageList", UriKind.Relative);
BrowserHttpWebRequest request = new BrowserHttpWebRequest(listService);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
// Set the folderName property for the body of the HTTP request. 
string formBody = "folderName=" + HttpUtility.UrlEncode(folderName);
UTF8Encoding encoding = new UTF8Encoding();
byte[] formBytes = encoding.GetBytes(formBody);
Stream body = request.GetRequestStream();
body.Write(formBytes, 0, formBytes.Length);
// Send the request and parse the returned XML for the list of
// file names (e.g. <string>image.jpg</string>) 
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream s = response.GetResponseStream();
XmlReader reader = XmlReader.Create(s);
reader.MoveToContent();
while (reader.Read())
{
if (reader.NodeType == XmlNodeType.Element)
if (reader.Name == "string")
results.Add(reader.ReadInnerXml());
}
reader.Close();
s.Close();
body.Close();
return results.ToArray();
}
public void GetImage(string imageName)
{
// Request the image file contents. 
_downloader.Open("GET", new Uri(imageName, UriKind.Relative), true);
_downloader.Send();
}
public void DownloaderCompleted(object o, EventArgs e)
{
// Populate the XAML Image object with the image file contents. 
ImageFrame.SetSource(_downloader, null);
}
public void OnPrevButtonClick(object o, EventArgs e)
{
// Request the previous image from the list. 
string imageName = GetImageName(_imageIndex - 1);
GetImage(imageName);
ImageFileName.Text = imageName;
}
public void OnNextButtonClick(object o, EventArgs e)
{
// Request the next image from the list. 
string imageName = GetImageName(_imageIndex + 1);
GetImage(imageName);
ImageFileName.Text = imageName;
}
private string GetImageName(int index)
{
// Retrieve the requested image file name from the list and
// update the index value. if (the requested index exceeds the
// length of the list, set the index to the beginning of the
// list (0). if (the requested index is less than 0, set the index
// to the last element in the list. 

_imageIndex = index;
if (index >= _imageList.Length)
_imageIndex = 0;
if (index < 0)
_imageIndex = _imageList.Length - 1;
return _imageFolderName + "/" + _imageList[_imageIndex];
}
}
}

Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Documents
Imports System.Windows.Ink
Imports System.Windows.Input
Imports System.Windows.Media
Imports System.Windows.Media.Animation
Imports System.Windows.Shapes
Imports System.Net
Imports System.Text
Imports System.IO
Imports System.Xml
Imports System.Windows.Browser
Imports System.Windows.Browser.Net
Imports System.Collections.Generic
Partial Public Class Page
Inherits Canvas
' Variables to manage the list of images. 
Private _imageIndex As Integer
Private _imageFolderName As String = "images"
Private _imageList As String()
' Downloader object to retrieve the image file contents. 
Private _downloader As New Downloader()
Public Sub Page_Loaded(ByVal o As Object, ByVal e As EventArgs)
InitializeComponent()
'' Add event handlers for Downloader and XAML elements.
AddHandler _downloader.Completed, AddressOf DownloaderCompleted
AddHandler LeftArrow.MouseLeftButtonDown, AddressOf OnPrevButtonClick
AddHandler RightArrow.MouseLeftButtonDown, AddressOf OnNextButtonClick
'' Initialize list of image file names.
_imageIndex = 0
_imageList = GetImageList("images")
' Populate the XAML Image object with a default image. 
Dim defaultImageName As String = GetImageName(_imageIndex)
GetImage(defaultImageName)
ImageFileName.Text = defaultImageName
End Sub
Public Function GetImageList(ByVal folderName As String) As String()
Dim results As New List(Of String)
' Create an HTTP request with the path to the web service that 
' returns a list of images from a specified folder. 
Dim listService As Uri = New Uri("Service.asmx/GetImageList", UriKind.Relative)
Dim request As BrowserHttpWebRequest = New BrowserHttpWebRequest(listService)
request.Method = "POST"
request.ContentType = "application/x-www-form-urlencoded"
' Set the folderName property for the body of the HTTP request. 
Dim formBody As String = "folderName=" & HttpUtility.UrlEncode(folderName)
Dim encoding As UTF8Encoding = New UTF8Encoding()
Dim formBytes As Byte() = encoding.GetBytes(formBody)
Dim body As Stream = request.GetRequestStream()
body.Write(formBytes, 0, formBytes.Length)
' Send the request and parse the returned XML for the list of 
' file names (e.g. <string>image.jpg</string>) 
Dim response As HttpWebResponse = CType(request.GetResponse(), HttpWebResponse)
Dim s As Stream = response.GetResponseStream()
Dim reader As XmlReader = XmlReader.Create(s)
reader.MoveToContent()
Do While reader.Read()
If reader.NodeType = XmlNodeType.Element Then _
If reader.Name = "string" Then _
results.Add(reader.ReadInnerXml())
Loop
reader.Close()
s.Close()
body.Close()
Return results.ToArray()
End Function
Public Sub GetImage(ByVal imageName As String)
' Request the image file contents. 
_downloader.Open("GET", New Uri(imageName, UriKind.Relative), True)
_downloader.Send()
End Sub
Public Sub DownloaderCompleted(ByVal o As Object, ByVal e As EventArgs)
' Populate the XAML Image object with the image file contents. 
ImageFrame.SetSource(_downloader, Nothing)
End Sub
Public Sub OnPrevButtonClick(ByVal o As Object, ByVal e As EventArgs)
' Request the previous image from the list. 
Dim imageName As String = GetImageName(_imageIndex - 1)
GetImage(imageName)
ImageFileName.Text = imageName
End Sub
Public Sub OnNextButtonClick(ByVal o As Object, ByVal e As EventArgs)
' Request the next image from the list. 
Dim imageName As String = GetImageName(_imageIndex + 1)
GetImage(imageName)
ImageFileName.Text = imageName
End Sub
Private Function GetImageName(ByVal index As Integer) As String
' Retrieve the requested image file name from the list and 
' update the index value. If the requested index exceeds the 
' length of the list, set the index to the beginning of the 
' list (0). If the requested index is less than 0, set the index 
' to the last element in the list. 

_imageIndex = index
If index >= _imageList.Length Then _imageIndex = 0
If index < 0 Then _imageIndex = _imageList.Length - 1
Return _imageFolderName & "/" & _imageList(_imageIndex)
End Function
End Class