WP8.1 /silverlight 获取手机图片并且显示

参考：
http://www.cnblogs.com/tcjiaan/p/3930826.html 【WP 8.1开发】文件选取器的使用方法

---

MainPage.axml

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 TestPhoneAppOpenFile.Resources;
using Windows.Storage.Pickers;
using Windows.Storage;
using Windows.Storage.FileProperties;
using System.Windows.Media.Imaging;
using Windows.Storage.Streams;
using System.IO;

namespace TestPhoneAppOpenFile
{
public partial class MainPage : PhoneApplicationPage
{
// 构造函数
public MainPage()
{
InitializeComponent();

        // 用于本地化 ApplicationBar 的示例代码
        //BuildLocalizedApplicationBar();
    }
    protected override void OnNavigatedTo(NavigationEventArgs e)
    {
        if (e.NavigationMode == NavigationMode.Back && PickFiles.PickedFiles.Count > 0)
        {
            
            if (PickFiles.PickedFiles.Count > 0)
            {
                StorageFile file = PickFiles.PickedFiles[0];
                tb.Text = file.Path;
                getPic();
            }
          
        }
    }



    async void getPic() {
  
        try {
            StorageFile file = PickFiles.PickedFiles[0];
         
           var itemThumbnail = await file.GetThumbnailAsync(Windows.Storage.FileProperties.ThumbnailMode.PicturesView, 550);
            Stream stream = await file.OpenStreamForReadAsync();

            BitmapImage img = new BitmapImage();
          
          // img.SetSource(itemThumbnail.AsStream());
            img.SetSource(stream);

            PIC.Source = img;
            MessageBox.Show(""+img.PixelWidth+";"+ img.PixelHeight);
            // IBuffer buff = RandomAccessStreamToBuffer(samllThumb);//将IRandomAccessStream
        }
        catch (Exception ex){
            MessageBox.Show(ex.Message );
        }
    }
    private void Button_Click(object sender, RoutedEventArgs e)
    {

        openFile();

    }

    async void openFile() {

     
        FileOpenPicker openPicker = new FileOpenPicker();
        openPicker.ViewMode = PickerViewMode.Thumbnail;
        openPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;

        openPicker.FileTypeFilter.Add(".jpg");

        openPicker.FileTypeFilter.Add(".jpeg");

        openPicker.FileTypeFilter.Add(".png");

        openPicker.PickSingleFileAndContinue();　　　　//只能选择一个文件

        


    }

    // 用于生成本地化 ApplicationBar 的示例代码
    //private void BuildLocalizedApplicationBar()
    //{
    //    // 将页面的 ApplicationBar 设置为 ApplicationBar 的新实例。
    //    ApplicationBar = new ApplicationBar();

    //    // 创建新按钮并将文本值设置为 AppResources 中的本地化字符串。
    //    ApplicationBarIconButton appBarButton = new ApplicationBarIconButton(new Uri("/Assets/AppBar/appbar.add.rest.png", UriKind.Relative));
    //    appBarButton.Text = AppResources.AppBarButtonText;
    //    ApplicationBar.Buttons.Add(appBarButton);

    //    // 使用 AppResources 中的本地化字符串创建新菜单项。
    //    ApplicationBarMenuItem appBarMenuItem = new ApplicationBarMenuItem(AppResources.AppBarMenuItemText);
    //    ApplicationBar.MenuItems.Add(appBarMenuItem);
    //}
}

}

建个类来保存选择的图文件信息：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.Storage;

namespace TestPhoneAppOpenFile
{
public class PickFiles
{

        private static List<StorageFile> files = null;
        static PickFiles()
        {
            if (files == null)
            {
                files = new List<StorageFile>();
            }
        }
        public static List<StorageFile> PickedFiles
        {
            get { return files; }
        }
    

}

}

---

App.xaml.cs

private void Application_ContractActivated(object sender, Windows.ApplicationModel.Activation.IActivatedEventArgs e)
{
if (e.Kind == Windows.ApplicationModel.Activation.ActivationKind.PickFileContinuation)
{
Windows.ApplicationModel.Activation.FileOpenPickerContinuationEventArgs ca = e as Windows.ApplicationModel.Activation.FileOpenPickerContinuationEventArgs;
PickFiles.PickedFiles.Clear();
foreach (var f in ca.Files)
{
PickFiles.PickedFiles.Add(f);
}
}
}