Web客戶端負載JPG和GIF到圖像

Question

在我的XAML，我有：

<Image Height="150" HorizontalAlignment="Left" Margin="0,4,0,0" Name="imgLogo" Stretch="Fill" VerticalAlignment="Top" Width="417" /> 
<Image Height="343" HorizontalAlignment="Left" Margin="0,155,0,0" Name="imgPhoto" Stretch="Fill" VerticalAlignment="Top" Width="417" /> 

在後面的C＃代碼，我有：

WebClient wcForLogo = new WebClient(); 
wcForLogo.DownloadStringCompleted += new DownloadStringCompletedEventHandler(wcForLogo_DownloadStringCompleted); 
wcForLogo.DownloadStringAsync(new Uri("http://mySite/logo.gif")); 

WebClient wcForPhoto = new WebClient(); 
wcForPhoto.DownloadStringCompleted += new DownloadStringCompletedEventHandler(wcForPhoto_DownloadStringCompleted); 
wcForPhoto.DownloadStringAsync(new Uri("http://mySite/photo.jpg")); 

但現在我不知道怎麼抓圖像並將其張貼在我創建的XAML控件中。

2個問題：

1. 有沒有辦法給e.Result直接複製到圖片控件，或者我應該緩存圖像，並使用緩存爲源，或者我應該保存圖像隔離存儲，然後將其用作源，然後在完成後刪除圖像？無論哪種情況，你能告訴我如何用代碼？
2. GIF和JPG的處理方式有何不同？如果是這樣，你能告訴我兩種不同的方式嗎？

Answer 1

如果您只想顯示圖片，則不必使用WebClient。您可以將圖像源中直接設置開放的，並且控制將下載的護理：

imgLogo.Source = new BitmapImage(new Uri("images/yourPicture.png", UriKind.Relative)); 

注意，GIF不受Image控件的支持。您仍然可以使用ImageTools庫中的轉換器顯示它們：Display GIF in a WP7 application with Silverlight

Answer 2

如果你想在獨立存儲中使用，以節省這樣

  WebClient m_webClient = new WebClient(); 

      Uri m_uri = new Uri("http://URL"); 

      m_webClient.OpenReadCompleted += new OpenReadCompletedEventHandler(webClient_OpenReadCompleted); 

      m_webClient.OpenReadAsync(m_uri); 




     } 



    void webClient_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e) 
    { 
     int count; 

     Stream stream = e.Result; 

     byte[] buffer = new byte[1024]; 


     using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication()) 
     { 




      using (System.IO.IsolatedStorage.IsolatedStorageFileStream isfs = new IsolatedStorageFileStream("IMAGES.jpg", FileMode.Create, isf)) 
      { 
       count = 0; 

       while (0 < (count = stream.Read(buffer, 0, buffer.Length))) 
       { 
        isfs.Write(buffer, 0, count); 
       } 

       stream.Close(); 
       isfs.Close(); 
      } 
     } 

要獲得的圖像格式isostore：

字節[]數據;

 using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication()) 
     { 

      using (IsolatedStorageFileStream isfs = isf.OpenFile(uri, FileMode.Open, FileAccess.Read)) 
      { 
       data = new byte[isfs.Length]; 
       isfs.Read(data, 0, data.Length); 
       isfs.Close(); 
      } 

     } 


     MemoryStream ms = new MemoryStream(data); 

     BitmapImage bi = new BitmapImage(); 

     bi.SetSource(ms); 

If you give the image name as image then set the source as bi: 

     image.source = bi; 

如果你想直接添加

WebClient client = new WebClient(); 
    Stream stream = client.OpenRead(imageUrl); 
    Bitmap bitmap = new Bitmap(stream); 
    image.source = bitmap; 

Answer 3

using System.Net; 
using System.IO; 
     private void Form1_Load(object sender, EventArgs e) 
     { 
      WebClient webclient = new WebClient(); 
      webclient.DownloadDataAsync(new Uri("http://mySite/logo.gif")); 
      webclient.DownloadDataCompleted += callback; 

     } 
     void callback(object sender,DownloadDataCompletedEventArgs e) 
     { 
      var ms = new MemoryStream(e.Result); 
      pictureBox1.Image = Image.FromStream(ms); 
     } 

Answer 4

比方說，你的圖像控制被稱爲MyImage，你可以做到這一點從一個URL加載圖像：

MyImage.Source = new System.Windows.Media.Imaging.BitmapImage(new Uri("http://mySite/photo.jpg")); 

沒有必要爲了下載圖像而做所有的管道工程，框架已經爲你做了！