分享一个网络图片控件(WebImage for wp8)

  闲话不多说，直接上代码！！！转载请附上原作者地址哦！！！thx！！！

  WebImage.xaml页面代码如下：

 

<UserControl x:Class="WpDemo.Controls.WebImage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
FontFamily="{StaticResource PhoneFontFamilyNormal}"
FontSize="{StaticResource PhoneFontSizeNormal}"
Foreground="{StaticResource PhoneForegroundBrush}"
d:DesignHeight="480" d:DesignWidth="480">

<Grid x:Name="LayoutRoot">
<Image x:Name="ImgShow" Stretch="UniformToFill" Visibility="Collapsed"/>
<Grid x:Name="gdWait">
<Rectangle x:Name="rectProgress" Fill="#FFFFB3E0" Stroke="Black" VerticalAlignment="Bottom"/>
<TextBlock x:Name="tbProgress" HorizontalAlignment="Center" TextWrapping="Wrap" VerticalAlignment="Center" Foreground="White" Text="0"/>
</Grid>
</Grid>
</UserControl>

WebImage.xaml.cs类如下:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Navigation;
using Microsoft.Phone.Controls;
using Microsoft.Phone.Shell;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.ComponentModel;
using System.IO;

namespace WpDemo.Controls
{
public partial class WebImage : UserControl
{
private static String CacheFolder = "cloud_cache_image";
private BitmapImage _imgSource = null;

public static readonly DependencyProperty SourceProperty = DependencyProperty.Register("Source", typeof(ImageSource), typeof(WebImage), null);
public static readonly DependencyProperty StretchProperty = DependencyProperty.Register("Stretch", typeof(Stretch), typeof(WebImage), new PropertyMetadata(Stretch.UniformToFill));
public static readonly DependencyProperty ImgUriProperty = DependencyProperty.Register("ImgUri", typeof(string), typeof(WebImage), new PropertyMetadata("", OnImgUriChanged));

private string _ImgUri;

public ImageSource Source
{
get { return ImgShow.Source; }
set { ImgShow.SetValue(Image.SourceProperty, value); }
}

public Stretch Stretch
{
get { return ImgShow.Stretch; }
set { ImgShow.SetValue(Image.StretchProperty, value); }
}

public string ImgUri
{
get
{
return _ImgUri;
}
set
{
_ImgUri = value;
SetImgSource(_ImgUri);
}
}

void SetImgSource(string uri)
{
string cacheName = Path.Combine(CacheFolder, ParseUri(uri));
_imgSource = new BitmapImage();
_imgSource.ImageOpened += imgSource_ImageOpened;
if (IsolatedStorageFileHelper.FileExists(cacheName))
{
using (Stream stream = IsolatedStorageFileHelper.OpenFile(cacheName))
{
_imgSource.SetSource(stream); ;
}
ImgShow.Visibility = System.Windows.Visibility.Visible;
gdWait.Visibility = System.Windows.Visibility.Collapsed;
}
else
{
_imgSource.DownloadProgress += imgSource_DownloadProgress;
_imgSource.ImageFailed += imgSource_ImageFailed;
_imgSource.UriSource = new Uri(uri, UriKind.Absolute);
}
ImgShow.Source = _imgSource;
}

void imgSource_ImageFailed(object sender, ExceptionRoutedEventArgs e)
{
_imgSource.ImageOpened -= imgSource_ImageOpened;
_imgSource.ImageFailed -= imgSource_ImageFailed;
_imgSource.DownloadProgress -= imgSource_DownloadProgress;
}

void imgSource_ImageOpened(object sender, RoutedEventArgs e)
{
ImgShow.Visibility = System.Windows.Visibility.Visible;
gdWait.Visibility = System.Windows.Visibility.Collapsed;
BitmapImage img = (BitmapImage)sender;
WriteableBitmap wb = new WriteableBitmap(img);
using (Stream stream = IsolatedStorageFileHelper.CreateFile(Path.Combine(CacheFolder, ParseUri(img.UriSource.AbsoluteUri))))
{
wb.SaveJpeg(stream, img.PixelWidth, img.PixelHeight, 0, 100);
}
_imgSource.ImageOpened -= imgSource_ImageOpened;
_imgSource.ImageFailed -= imgSource_ImageFailed;
_imgSource.DownloadProgress -= imgSource_DownloadProgress;
}

void imgSource_DownloadProgress(object sender, DownloadProgressEventArgs e)
{
rectProgress.Height = gdWait.ActualHeight * (e.Progress / 100.0);
tbProgress.Text = e.Progress.ToString();
_imgSource.DownloadProgress -= imgSource_DownloadProgress;
}

public WebImage()
{
InitializeComponent();
}

private static void OnImgUriChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
WebImage img = obj as WebImage;
img.ImgUri = e.NewValue as string;
}

private string ParseUri(string uri)
{
return uri.Replace("://", "").Replace("/", "_");
}
}
}

using System;
using System.Collections.Generic;
using System.IO.IsolatedStorage;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml.Serialization;

namespace WpDemo.Common
{
public class IsolatedStorageFileHelper
{
private static IsolatedStorageFile _Store = null;
private static IsolatedStorageFile Store
{
get
{
if (_Store == null)
{
_Store = IsolatedStorageFile.GetUserStoreForApplication();
}
return _Store;
}
}
public static void CreateFolder(string dir)
{
if (Store.DirectoryExists(dir))
return;
Store.CreateDirectory(dir);
}
public static void DeleteFolder(string dir)
{
if (Store.DirectoryExists(dir))
return;
Store.DeleteDirectory(dir);
}

public static void DeleteFile(string path)
{
if (!Store.FileExists(path))
return;
Store.DeleteFile(path);
}

public static IsolatedStorageFileStream CreateFile(string path)
{
string[] parts = path.Split('\\');
string dir = "";
for (int i = 0; i < parts.Length - 1; i++)
{
string part = parts[i];
dir = System.IO.Path.Combine(dir, part);
if (!Store.DirectoryExists(dir))
Store.CreateDirectory(dir);
}
return Store.CreateFile(path);
}

public static bool FileExists(string path)
{
return Store.FileExists(path);
}

public static IsolatedStorageFileStream OpenFile(string path)
{
return Store.OpenFile(path, System.IO.FileMode.Open);
}

public static void SerializeObject(object obj, string path)
{
if (Store.FileExists(path))
Store.DeleteFile(path);
XmlSerializer xml = new XmlSerializer(obj.GetType());
using (var stream = CreateFile(path))
{
xml.Serialize(stream, obj);
}
}

public static T DeSerializeObject<T>(string path)
{
if (!Store.FileExists(path))
return default(T);
XmlSerializer xml = new XmlSerializer(typeof(T));
object obj = null;
using (var stream = OpenFile(path))
{
obj = xml.Deserialize(stream);
}
return (T)obj;
}
}
}

用法如下:xmlns:MyControl="clr-namespace:CloudWpDemo.Controls"

<StackPanel Grid.Column="0" Width="200">
<MyControl:WebImage ImgUri="{Binding Img_url}" Margin="5,5,5,5"></MyControl:WebImage>
<!--<Image Source="{Binding Img_url}"></Image>
<TextBlock Text="{Binding Name}"></TextBlock>-->
</StackPanel>

 我测试过蛮多次。。。。此控件挺好用的！！！希望对你的开发有用！！！！