Windows Phone 图片扩展类
using System.IO; using System.Text; using System.Net; using System.Threading.Tasks; using System.Windows.Controls; using Windows.Storage; namespace System.Windows.Media.Imaging { /// <summary> /// ImageExtension图片附加属性 /// </summary> public class ImageExtension : DependencyObject { private const string WebImageCacheDirectoryName = "WebImageCache\\"; private static String LocalFolderPath { get { return ApplicationData.Current.LocalFolder.Path + "\\"; } } /// <summary> /// Source附加属性 /// </summary> public static readonly DependencyProperty SourceProperty = DependencyProperty.RegisterAttached( "Source", typeof(String), typeof(ImageExtension), new PropertyMetadata(String.Empty, OnSourceChanged) ); /// <summary> /// 设置图片源地址 /// </summary> /// <param name="image">Image控件</param> /// <param name="value">图片地址</param> public static void SetSource(Image image, String value) { image.SetValue(SourceProperty, value); } /// <summary> /// 获取图片地址 /// </summary> /// <param name="image">Image控件</param> /// <returns></returns> public static String GetSource(Image image) { return (String)image.GetValue(SourceProperty); } private static void OnSourceChanged(DependencyObject target, DependencyPropertyChangedEventArgs args) { String value = args.NewValue as String; Image image = target as Image; if (String.IsNullOrEmpty(value) == true || image == null) { return; } if (value.StartsWith("http")) { image.Source = GetBitmapImageFromWeb(value); } else { image.Source = GetBitmapImageFromLocalFolder(value); } } /// <summary> /// 获取独立存储图片 /// </summary> /// <param name="imageRelativePath"></param> /// <returns></returns> public static BitmapImage GetBitmapImageFromLocalFolder(String imageRelativePath) { String imageAbsolutePath = LocalFolderPath + imageRelativePath; return new BitmapImage(new Uri(imageAbsolutePath, UriKind.Absolute)); } /// <summary> /// 获取网络图片 /// </summary> /// <param name="imageUrl"></param> /// <returns></returns> public static BitmapImage GetBitmapImageFromWeb(String imageUrl) { String imageLoaclPath = MapLocalFilePath(imageUrl); if (File.Exists(imageLoaclPath)) { return new BitmapImage(new Uri(imageLoaclPath, UriKind.Absolute)); } BitmapImage bitmapImage = new BitmapImage(new Uri(imageUrl, UriKind.Absolute)); bitmapImage.ImageFailed += bitmapImage_ImageFailed; bitmapImage.ImageOpened += bitmapImage_ImageOpened; return bitmapImage; } private static void bitmapImage_ImageOpened(object sender, RoutedEventArgs e) { BitmapImage bitmapImage = (BitmapImage)sender; bitmapImage.ImageOpened -= bitmapImage_ImageOpened; String imageName = MapImageUrlToImageName(bitmapImage.UriSource.ToString()); SaveImageToLocalFolder(bitmapImage, WebImageCacheDirectoryName, imageName); } private static void bitmapImage_ImageFailed(object sender, ExceptionRoutedEventArgs e) { BitmapImage bitmapImage = (BitmapImage)sender; bitmapImage.ImageFailed -= bitmapImage_ImageFailed; } /// <summary> /// 获得图片数据流 /// </summary> /// <param name="image"></param> /// <returns></returns> public static byte[] ReadImageBytes(Image image) { if (image == null) { return new byte[0]; } return ReadImageBytes(image.Source as BitmapSource); } /// <summary> /// 获得图片数据流 /// </summary> /// <param name="bitmapSource"></param> /// <returns></returns> public static byte[] ReadImageBytes(BitmapSource bitmapSource) { byte[] imageBytes = new byte[0]; MemoryStream imageStream = ReadImageStream(bitmapSource); if (imageStream == null) { return imageBytes; } imageBytes = new byte[imageStream.Length]; imageStream.Read(imageBytes, 0, imageBytes.Length); imageStream.Dispose(); imageStream.Close(); return imageBytes; } /// <summary> /// 获得图片数据流 /// </summary> /// <param name="bitmapSource">位图数据源</param> /// <returns></returns> public static MemoryStream ReadImageStream(BitmapSource bitmapSource) { if (bitmapSource == null) { return null; } MemoryStream imageStream = new MemoryStream(); WriteableBitmap writeableBitmap = new WriteableBitmap(bitmapSource); writeableBitmap.SaveJpeg(imageStream, bitmapSource.PixelWidth, bitmapSource.PixelHeight, 0, 100); imageStream.Seek(0, SeekOrigin.Begin); return imageStream; } /// <summary> /// 获得图片数据流 /// </summary> /// <param name="image">图片控件</param> /// <returns></returns> public static MemoryStream ReadImageStream(Image image) { if (image == null) { return null; } return ReadImageStream(image.Source as BitmapSource); } /// <summary> /// 保存图片 /// </summary> /// <param name="image">图片控件</param> /// <param name="relativePath">独立存储的相对路径</param> /// <param name="imageName">文件名</param> /// <returns></returns> public static Boolean SaveImageToLocalFolder(Image image, String relativePath, String imageName) { if (image == null) { return false; } return SaveImageToLocalFolder(image.Source as BitmapSource, relativePath, imageName); } /// <summary> /// 保存图片 /// </summary> /// <param name="bitmapSource">位图数据源</param> /// <param name="relativePath">独立存储的相对路径</param> /// <param name="imageName">文件名</param> /// <returns></returns> public static Boolean SaveImageToLocalFolder(BitmapSource bitmapSource, String relativePath, String imageName) { return SaveImageToLocalFolder(ReadImageStream(bitmapSource), relativePath, imageName); } /// <summary> /// 保存图片 /// </summary> /// <param name="imageStream">图片数据流</param> /// <param name="relativePath">独立存储的相对路径</param> /// <param name="imageName">文件名</param> /// <returns></returns> public static Boolean SaveImageToLocalFolder(Stream imageStream, String relativePath, String imageName) { if (String.IsNullOrEmpty(imageName)) { return false; } if (imageStream == null) { return false; } if (String.IsNullOrEmpty(relativePath) == false) { Directory.SetCurrentDirectory(LocalFolderPath); if (Directory.Exists(relativePath) == false) { Directory.CreateDirectory(relativePath); } } String imageLoaclPath = LocalFolderPath + relativePath + imageName; FileStream fileStream = File.Create(imageLoaclPath); imageStream.CopyTo(fileStream, (Int32)imageStream.Length); fileStream.Flush(); imageStream.Dispose(); imageStream.Close(); fileStream.Dispose(); fileStream.Close(); return true; } private static String MapLocalFilePath(String fileName) { if (String.IsNullOrEmpty(fileName)) { return String.Empty; } if (fileName.StartsWith("http")) { return LocalFolderPath + WebImageCacheDirectoryName + MapImageUrlToImageName(fileName); } if (fileName.StartsWith("file")) { return fileName.Substring(8); } return LocalFolderPath + fileName; } private static String MapImageUrlToImageName(String imageUrl) { return MD5.GetMd5String(imageUrl) + ".img"; } } }
可 自动缓存图片 自动读取缓存图片
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