I'm new to win8 app programming but has been assigned to write a windows store app to capture customers' signature and save it to SQL Server. After some research I found a great tutorial
http://www.codeproject.com/Articles/416878/Metro-Paint which shows how to draw and save the image locally. My question is how do I use the InkManager class in the tutorial to save the image to byte arrays so that I can save the image to SQLServer? Thanks!
private async void btnSaveWritingAsImage_Click(object sender, RoutedEventArgs e)
{
if (MyInkManager.GetStrokes().Count > 0)
{
try
{
Windows.Storage.Pickers.FileSavePicker SavePicker = new Windows.Storage.Pickers.FileSavePicker();
SavePicker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.Desktop;
SavePicker.DefaultFileExtension = ".png";
SavePicker.FileTypeChoices.Add("PNG", new string[] { ".png" });
SavePicker.FileTypeChoices.Add("JPG", new string[] { ".jpg" });
StorageFile filesave = await SavePicker.PickSaveFileAsync();
IOutputStream ab = await filesave.OpenAsync(FileAccessMode.ReadWrite);
if (ab != null)
await MyInkManager.SaveAsync(ab);
}
catch (Exception)
{
var MsgDlg = new MessageDialog("Only handwriting can be saved as image.", "Error while saving");
MsgDlg.ShowAsync();
}
}
else
{
var MsgDlg = new MessageDialog("Only handwriting can be saved as image.", "Error while saving");
await MsgDlg.ShowAsync();
}
}
add: (IBuffer.ToArray() is defined in WindowsRuntimeBufferExtensions)
using System.Runtime.InteropServices.WindowsRuntime;
then just do:
var buffer = await FileIO.ReadBufferAsync(image);//replace ab instead of image
var bytes = buffer.ToArray();
Related
i have problem with PushStreamContent in asp.net core.
It display video on the website but my problem is that it will buffer whole file and then play it when my goal is to buffer small part of it and play on the website. Code i have:
My endpoint for playing video in browser
public IActionResult Play(string file)
{
var fileName = "C:\\repo\\trailer1.mp4";
var video = new VideoStream(fileName);
var response = new PushStreamContent(video.WriteToStream, new MediaTypeHeaderValue("video/mp4"))
{
};
var objectResult = new ObjectResult(response);
objectResult.ContentTypes.Add(new Microsoft.Net.Http.Headers.MediaTypeHeaderValue("video/mp4"));
return objectResult;
}
Ive got VideoStreamClass to help with displaying video
public class VideoStream
{
private readonly string _filename;
public VideoStream(string filename)
{
_filename = #"C:\\repo\\trailer1.mp4";
}
public async Task WriteToStream(Stream outputStream, HttpContent content, TransportContext context)
{
try
{
var buffer = new byte[65536];
using (var video = File.Open(_filename, FileMode.Open, FileAccess.Read))
{
var length = (int)video.Length;
var bytesRead = 1;
while (length > 0 && bytesRead > 0)
{
bytesRead = video.Read(buffer, 0, Math.Min(length, buffer.Length));
await outputStream.WriteAsync(buffer, 0, bytesRead);
await outputStream.FlushAsync();
length -= bytesRead;
}
}
}
catch (Exception)
{ return; }
finally
{
outputStream.Dispose();
}
}
}
And here is my VideoOutputFormatter added to bootstraper
public class VideoOutputFormatter : IOutputFormatter
{
public bool CanWriteResult(OutputFormatterCanWriteContext context)
{
if (context == null)
throw new ArgumentNullException(nameof(context));
if (context.Object is PushStreamContent)
return true;
return false;
}
public async Task WriteAsync(OutputFormatterWriteContext context)
{
if (context == null)
throw new ArgumentNullException(nameof(context));
using (var stream = ((PushStreamContent)context.Object))
{
var response = context.HttpContext.Response;
if (context.ContentType != null)
{
response.ContentType = context.ContentType.ToString();
}
await stream.CopyToAsync(response.Body);
}
}
}
I've tried to add atributes to controller "UseBufferedOutputStream" and "UseBufferedInputStream" setted to false but this still dosent work for me
ObjectResult is intended for holding an in-memory object as a response. If you want to return an existing file, then PhysicalFileResult is probably your best bet.
If you're interested in PushStreamContent, I believe the one you're using is for HttpClient, not ASP.NET. If you want a PushStreamContent equivalent, I have a FileCallbackResult that would work once it's updated for the latest .NET Core.
I am new in reactnative mobile application development. I need to download file from webservice url in windows UWP. I checked with react-natived-fs and rn-fetch-blob its working only in android and ios. In windows UWP how can i achieve this download files.. Any one please help me.
i just write a bridge for this. now its working fine. For download i did
[ReactMethod]
public async void download(string fileName, JObject _, IPromise promise)
{
try
{
StorageFolder localFolder = ApplicationData.Current.LocalFolder;
StorageFolder docFolder = KnownFolders.DocumentsLibrary;
string folderName = "DMSFolder";
StorageFile file = await localFolder.CreateFileAsync("sample1.pdf",CreationCollisionOption.ReplaceExisting);
StorageFile docfile = await docFolder.CreateFileAsync("sample1.zip",CreationCollisionOption.ReplaceExisting);
var cli = new HttpClient();
var uriBing = new Uri(#fileName);
Byte[] bytes = await cli.GetByteArrayAsync(uriBing);
IBuffer buffer = bytes.AsBuffer();
await Windows.Storage.FileIO.WriteBufferAsync(file, buffer);
await Windows.Storage.FileIO.WriteBufferAsync(docfile, buffer);
if (file != null)
{
promise.Resolve(null);
}
else
{
promise.Reject(null, "File Copied failed.");
}
}
catch (Exception e)//FieldAccessException
{
Console.WriteLine("Exception occured====>" + e);
promise.Reject(null, fileName, e);
}
}
I want to set image.Source via async stream in an UWP application. Otherwise the image will flicker when switch to other image source.
My code is as below. And the log shows it works. Certainly I put 2 image files in the corresponding path before I test the demo code.
But in fact I did not see any picture shown, why?
Log:
111111111111 image file path = C:\Users\tomxu\AppData\Local\Packages\a0ca0192-f41a-43ca-a3eb-f128a29b00c6_1qkk468v8nmy0\LocalState\2.jpg
22222222222
33333333333333
4444444444444
The thread 0x6d38 has exited with code 0 (0x0).
The thread 0x6a34 has exited with code 0 (0x0).
111111111111 image file path = C:\Users\tomxu\AppData\Local\Packages\a0ca0192-f41a-43ca-a3eb-f128a29b00c6_1qkk468v8nmy0\LocalState\1.jpg
22222222222
33333333333333
4444444444444
Code:
private async void setImageSource(string imageFilePath)
{
StorageFile sFile = await StorageFile.GetFileFromPathAsync(imageFilePath);
Debug.WriteLine("111111111111 image file path = " + imageFilePath);
Stream fileStream = await sFile.OpenStreamForReadAsync();
Debug.WriteLine("22222222222");
InMemoryRandomAccessStream ras = new InMemoryRandomAccessStream();
Debug.WriteLine("33333333333333");
await fileStream.CopyToAsync(ras.AsStreamForRead());
Debug.WriteLine("4444444444444");
BitmapImage bi = new BitmapImage();
bi.SetSource(ras);
image1.Source = bi;
}
private async void Button_Click(object sender, RoutedEventArgs e)
{
string fullFolder = ApplicationData.Current.LocalFolder.Path;
if (count % 2 == 1)
{
setImageSource(fullFolder + #"\1.jpg");
//image1.Source = new BitmapImage(new Uri(#"ms-appx:///Assets/1.jpg"));
}
else
{
setImageSource(fullFolder + #"\2.jpg");
//image1.Source = new BitmapImage(new Uri(#"ms-appx:///Assets/2.jpg"));
}
count++;
}
Here is an example of how I convert a base64 image string to a BitmapImage..
var ims = new InMemoryRandomAccessStream();
var bytes = Convert.FromBase64String(base64String);
var dataWriter = new DataWriter(ims);
dataWriter.WriteBytes(bytes);
await dataWriter.StoreAsync();
ims.Seek(0);
var img = new BitmapImage();
img.SetSource(ims);
ims.Dispose();
return img;
Try some of the things I'm doing there. Like I notice your code is not setting the seek of the InMemoryReadAccessStream
For your question, I have something to clarify with you.
Your pictures are always in the application data folder. If you want to show it at runtime by programming, the easy way is using the ms-appdata URI scheme to refer to files that come from the app's local, roaming, and temporary data folders. Then, you could use this URL to initialize the BitmapImage object. With this way, you don't need to manually manipulate the file stream.
private void setImageSource(int i)
{
BitmapImage bi = new BitmapImage(new Uri("ms-appdata:///local/"+i+".png"));
image1.Source = bi;
}
private int count = 0;
private void Button_Click(object sender, RoutedEventArgs e)
{
if (count % 2 == 1)
{
setImageSource(1);
}
else
{
setImageSource(2);
}
count++;
}
If you say you have to manipulate the file stream to initialize the BitmaImage, then please add some break points to debug your code. If you add break points to check the InMemoryRandomAccessStream after call CopyToAsync method, you will see that its size is 0. It meant that the file stream has not been wrote to it. To solve this issue, you need to set a buffer size for it. Note: you used ras.AsStreamForRead() method, it's incorrect. You're writing stream to it, so you need to call ras.AsStreamForWrite().
The code looks like the following:
private async void setImageSource(string imageFilePath)
{
StorageFile sFile = await StorageFile.GetFileFromPathAsync(imageFilePath);
using (Stream fileStream = await sFile.OpenStreamForReadAsync())
{
using (InMemoryRandomAccessStream ras = new InMemoryRandomAccessStream())
{
await fileStream.CopyToAsync(ras.AsStreamForWrite((int)fileStream.Length));
ras.Seek(0);
BitmapImage bi = new BitmapImage();
bi.SetSource(ras);
img.Source = bi;
}
}
}
private int count = 0;
private void Button_Click(object sender, RoutedEventArgs e)
{
string fullFolder = ApplicationData.Current.LocalFolder.Path;
if (count % 2 == 1)
{
setImageSource(fullFolder + #"\1.jpg");
}
else
{
setImageSource(fullFolder + #"\2.jpg");
}
count++;
}
In addition, like #visc said, you need to call ras.Seek(0) method to reset the stream to beginning, else the image will not show there.
I am creating Thumbnail and showing in frame by using this code
Platform -> windows 8 metro apps using c#
http://code.msdn.microsoft.com/windowsapps/File-and-folder-thumbnail-1d530e5d
in windows 8 metro apps using c#. i need to save or Store ( in device )the thumbnail image which i am creating at run time. in DisplayResult() of constants.cs class file i need to save that image in device how to achieve this . please give me some idea or example i am very new in mobile and never worked on Image and thumbnails Part . Thanks in advance .
Try this. The below code will save picked audio file's album art in TempFolder
private async void btnPickFile_Click(object sender, RoutedEventArgs e)
{
string[] Music = new string[] { ".mp3", ".wma", ".m4a", ".aac" };
FileOpenPicker openPicker = new FileOpenPicker();
foreach (string extension in Music)
{
openPicker.FileTypeFilter.Add(extension);
}
StorageFile file = await openPicker.PickSingleFileAsync();
if (file != null)
{
await SaveThumbnail("MySongThumb.png", file);
}
}
private async Task SaveThumbnail(string ThumbnailName, StorageFile file)
{
if (file != null)
{
using (StorageItemThumbnail thumbnail = await file.GetThumbnailAsync(ThumbnailMode.MusicView, 100))
{
if (thumbnail != null && thumbnail.Type == ThumbnailType.Image)
{
var destinationFile = await ApplicationData.Current.TemporaryFolder.CreateFileAsync(ThumbnailName, CreationCollisionOption.GenerateUniqueName);
Windows.Storage.Streams.Buffer MyBuffer = new Windows.Storage.Streams.Buffer(Convert.ToUInt32(thumbnail.Size));
IBuffer iBuf = await thumbnail.ReadAsync(MyBuffer, MyBuffer.Capacity, InputStreamOptions.None);
using (var strm = await destinationFile.OpenAsync(FileAccessMode.ReadWrite))
{
await strm.WriteAsync(iBuf);
}
}
}
}
}
UPDATE 1
private async Task<StorageFile> SaveThumbnail(StorageItemThumbnail objThumbnail)
{
if (objThumbnail != null && objThumbnail.Type == ThumbnailType.Image)
{
var picker = new FileSavePicker();
picker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
picker.FileTypeChoices.Add("JPEG Image", new string[] { ".jpg" });
picker.FileTypeChoices.Add("PNG Image", new string[] { ".png" });
StorageFile destinationFile = await picker.PickSaveFileAsync();
if (destinationFile != null)
{
Windows.Storage.Streams.Buffer MyBuffer = new Windows.Storage.Streams.Buffer(Convert.ToUInt32(objThumbnail.Size));
IBuffer iBuf = await objThumbnail.ReadAsync(MyBuffer, MyBuffer.Capacity, InputStreamOptions.None);
using (var strm = await destinationFile.OpenAsync(FileAccessMode.ReadWrite))
{
await strm.WriteAsync(iBuf);
}
}
return destinationFile;
}
else
{
return null;
}
}
I am writing a unit test to validate the serialization of objects and I am able to successfully save the file without any issue. I can even browse the file and validate the contents are correct. However, when I attempt to open the file for reading I always receive an UnauthorizedAccess exception.
Here is the code used to save the item:
public static async Task SaveItem<T>(string folderName, T item)
where T : BaseBusinessItem
{
if (string.IsNullOrEmpty(folderName))
{
throw new ArgumentNullException("folderName");
}
if (item == null)
{
throw new ArgumentNullException("item");
}
try
{
var folder = await ApplicationData.Current.LocalFolder
.CreateFolderAsync(folderName, CreationCollisionOption.OpenIfExists);
var file =
await
folder.CreateFileAsync(item.UniqueID.GetHashCode().ToString(), CreationCollisionOption.ReplaceExisting);
var stream = await file.OpenAsync(FileAccessMode.ReadWrite);
using (var outStream = stream.GetOutputStreamAt(0))
{
var serializer = new DataContractJsonSerializer(typeof(T));
serializer.WriteObject(outStream.AsStreamForWrite(), item);
await outStream.FlushAsync();
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.ToString());
}
}
Here is the code used to restore the item:
public static async Task<T> RestoreItem<T>(string folderName, string hashCode)
where T : BaseBusinessItem, new()
{
if (string.IsNullOrEmpty(folderName))
{
throw new ArgumentNullException("folderName");
}
if (string.IsNullOrEmpty(hashCode))
{
throw new ArgumentNullException("hashCode");
}
var folder = await ApplicationData.Current.LocalFolder.GetFolderAsync(folderName);
var file = await folder.GetFileAsync(hashCode);
var inStream = await file.OpenSequentialReadAsync();
var serializer = new DataContractJsonSerializer(typeof(T));
var retVal = (T)serializer.ReadObject(inStream.AsStreamForRead());
return retVal;
}
And the unit test:
[TestMethod]
public async Task TestFileSaveLoad()
{
await _ds.SaveItem("TestFolder");
Guid ID = _item.UniqueID;
_ds = await ItemDataSource.LoadItem("TestFolder", ID.GetHashCode().ToString());
}
Any ideas or troubleshooting steps I might be missing. The unit test app manifest includes the following capabilities: Document Library, Internet (Client). The following declarations are in place: File Open Picker, File Save Picker and File Type Associations.
Thanks!
This code snippet helped me accomplish my goal. Hope this is helpful for someone else:
http://codepaste.net/gtu5mq