Question

在我的XAML中，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" />

在后面的C＃代码中，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"));

但是现在我不知道如何捕获图像并将其发布到我构建的XAML控件中。

2个问题：

有没有办法将e.Result直接复制到Image控件，或者我应该缓存图像并使用缓存作为源，还是应该将图像保存到隔离存储中，然后将其用作源，当我完成它后删除图像？无论哪种情况，你能告诉我如何使用代码吗？
GIF和JPG的处理方式有何不同？如果是这样，你能告诉我两种不同的方式吗？

Answer 1

如果您只想显示图片，则无需使用WebClient。您可以直接在图像源中设置Uri，控件将负责下载：

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

请注意，Image控件不支持GIF。您仍然可以使用ImageTools库中的转换器显示它们：Display GIF in a WP7 application with Silverlight

Answer 2

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 3

如果你想保存在这样的隔离存储中

            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();
            }
        }

获取isosore的图像形式：

byte [] data;

        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;

如果您想直接添加

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

Answer 4

假设您的图片控件名为MyImage，您可以这样做以从网址加载图片：

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

无需为了下载图像而完成所有管道工作，框架已经为您完成了这项工作！

WebClient加载JPG＆amp; GIF到图像

4 个答案: