在界面上加载Windows Phone 8.1图像

Question

We are developing an app which have to attach an image at the runtime and display the same to the UI. We are using following set of code file for it:

private void Btn_Attach_File_Click(object sender, RoutedEventArgs e)
{
            FileOpenPicker fileOpenPicker = new FileOpenPicker();
            fileOpenPicker.FileTypeFilter.Add(".jpg");
            fileOpenPicker.FileTypeFilter.Add(".jpeg");
            fileOpenPicker.FileTypeFilter.Add(".png");
            fileOpenPicker.ContinuationData["Operate"] = "OpenImage";
            fileOpenPicker.PickSingleFileAndContinue();
          }  

Also, to continue the app after picking file from storage, here is the code :

public async void ContinueFileOpenPicker(FileOpenPickerContinuationEventArgs args)
        {
            if ((args.Files != null && args.Files.Count > 0))
            {
                IReadOnlyList<StorageFile> files = args.Files;

                Image myImage = new Image();
                foreach (StorageFile file in files)
                {
                    if (args.ContinuationData["Operate"] as string == "OpenImage" && args.Files !=          null && args.Files.Count > 0)
                    {
                        IRandomAccessStream fileStream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
                        System.Diagnostics.Debug.WriteLine(file.Name);
                        System.Diagnostics.Debug.WriteLine(file.Path);

                        using (StorageItemThumbnail thumbnail = await file.GetThumbnailAsync(ThumbnailMode.SingleItem, 190)) //, ThumbnailOptions.UseCurrentScale);
                        {
                            if (thumbnail != null && thumbnail.Type == ThumbnailType.Image)
                            {
                                BitmapImage bitmapImage = new BitmapImage();
                                bitmapImage.SetSource(thumbnail);

                                myImage.Source = bitmapImage;

                            }
                        }
                    }
                }
            }
        }

Above code is in xaml.cs file. But the problem is, even though I'm loading the file, there is no attachment on UI. Do we need to make any changes to the corresponding xaml file? we've searched a lot on it but couldn't find any solution.

Thanks in advance,

Answer 1

First, make an image control in xaml:

<Image Name="img"/>

In codebehind after the loop:

this.img.Source = myImage.Source;
//For better perf according to the docs, specify this
//this.img.Source.DecodePixelWidth = 200

Certainly it's possible to make a binding instead of using the Name property, but this is the easiest way.

Read the docs: MSDN

One other thing, the loop foreach (StorageFile file in files) isn't that useful if you have one file, and if you have more than one file it will take the last file.

Feel free to ask for more info!

Happy coding :)!