Develop Reference

How to load, edit and save xml in uwp app

Title says it all really. I've been stuck on this one for days and would appreciate some help. I've a main page and a settings page when the main page loads first time it tests for settings.xml in local folder and copies it if not found. Then when the user opens settings page it's supposed to load details from local folder allowing the user to edit before saving them back to the local folder from OnNavigatedFrom event.
Code to load from installation folder to local folder
// Has the file been copied already?
bool blFileExist = false;
try
{
await ApplicationData.Current.LocalFolder.GetFileAsync("settings.xml");
// No exception means it exists
blFileExist = true;
btnSettings.Foreground = new SolidColorBrush(Windows.UI.Colors.White);
}
catch (System.IO.FileNotFoundException)
{
// The file obviously doesn't exist
blFileExist = false;
btnSettings.Foreground = new SolidColorBrush(Windows.UI.Colors.Red);
}
catch (Exception)
{
}
if (!blFileExist)
{
try
{
// Cant await inside catch, but this works anyway
StorageFile stopfile = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync("settings.xml");
await stopfile.CopyAsync(ApplicationData.Current.LocalFolder);
}
catch (System.IO.FileNotFoundException)
{
}
catch (Exception)
{
}
}
Code to load and save settings page
private void loadSettings()
{
try
{
doc = XElement.Load("settings.xml");
nAIPlayers = int.Parse(doc.Element("ai_players").Value);
strCardBack = doc.Element("back").Value;
comboBoxAIPlayers.SelectedIndex = nAIPlayers - 1;
}
catch (System.IO.FileNotFoundException)
{
}
catch (Exception ex)
{
}
}
private async void saveSettings()
{
//try
//{
StorageFile file = await ApplicationData.Current.LocalFolder.GetFileAsync("settings.xml");
using (Stream fileStream = await file.OpenStreamForWriteAsync())
{
doc.SetElementValue("ai_players", nAIPlayers);
doc.SetElementValue("back", "Back_0");
doc.Save(fileStream);
}
/*}
catch (System.IO.FileNotFoundException)
{
}
catch (Exception ex)
{
}*/
}
I think the problem is I'm accessing the local file to save it and the installation file to load it. The result is no matter what I save it always reads the values in the original settings.xml
How do I load this from the local folder?
doc = XElement.Load("settings.xml");
Update
On the first iteration the code runs fine and the settings page code opens as it should. It's only after leaving the settings page and running saveSettings() method that it fails and throws an error when reloading the settings page and running loadSettings().
System.Xml.XmlException: Data at the root level is invalid. Line 5, position 12

You are doing it wrong because you are using XElement.Load(string) where string stands for URI, which in this case should be:
The Uri parameter must be a file system relative or absolute path.
and with that you will have a problem in UWP as normally you don't have the permission. It also won't work here with URIs like: "ms-appdata:///settings.xml".
Probably you can read a path to your LocalFolder and use it (may work, though haven't tested it), but much easier is to load the content from stream (or read string from file and then load XML from that string), for example like this:
var file = await ApplicationData.Current.LocalFolder.GetFileAsync("settings.xml");
using(var stream = await file.OpenStreamForReadAsync())
{
var doc = XElement.Load(stream);
// ...
}
Note also that there are other classes like XDocument or XmlDocument where you can load and manage you xml file. Everything depends on your needs.

C# Drag and Drop attached file from outlook email

I want to use/read attached files from an outlook email into a WinForm solution.
Ex: the email has a TXT file attached; I want to perform a Drag&Drog of the TXT file into the WinForm and read the TXT at the same time.

This is an old question, but I'll provide another answer anyhow that doesn't involve using the Outlook objects.
This URL provides working code that is about 13 years old, but still seems to work, on how to handle the "FileGroupDescriptor" and "FileContents" data that Outlook passes to the DropDrop event. Just in case that link dies, here is the relevant code, copy/pasted directly:
DragEnter event:
private void Form1_DragEnter(object sender, System.Windows.Forms.DragEventArgs e)
{
// for this program, we allow a file to be dropped from Explorer
if (e.Data.GetDataPresent(DataFormats.FileDrop))
{ e.Effect = DragDropEffects.Copy;}
// or this tells us if it is an Outlook attachment drop
else if (e.Data.GetDataPresent("FileGroupDescriptor"))
{ e.Effect = DragDropEffects.Copy;}
// or none of the above
else
{ e.Effect = DragDropEffects.None;}
}
DragDrop event:
private void Form1_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
{
string [] fileNames = null;
try
{
if ( e.Data.GetDataPresent(DataFormats.FileDrop,false) == true)
{
fileNames = (string []) e.Data.GetData(DataFormats.FileDrop);
// handle each file passed as needed
foreach( string fileName in fileNames)
{
// do what you are going to do with each filename
}
}
else if (e.Data.GetDataPresent("FileGroupDescriptor"))
{
//
// the first step here is to get the filename
// of the attachment and
// build a full-path name so we can store it
// in the temporary folder
//
// set up to obtain the FileGroupDescriptor
// and extract the file name
Stream theStream = (Stream) e.Data.GetData("FileGroupDescriptor");
byte [] fileGroupDescriptor = new byte[512];
theStream.Read(fileGroupDescriptor,0,512);
// used to build the filename from the FileGroupDescriptor block
StringBuilder fileName = new StringBuilder("");
// this trick gets the filename of the passed attached file
for(int i=76; fileGroupDescriptor[i]!=0; i++)
{ fileName.Append(Convert.ToChar(fileGroupDescriptor[i]));}
theStream.Close();
string path = Path.GetTempPath();
// put the zip file into the temp directory
string theFile = path+fileName.ToString();
// create the full-path name
//
// Second step: we have the file name.
// Now we need to get the actual raw
// data for the attached file and copy it to disk so we work on it.
//
// get the actual raw file into memory
MemoryStream ms = (MemoryStream) e.Data.GetData(
"FileContents",true);
// allocate enough bytes to hold the raw data
byte [] fileBytes = new byte[ms.Length];
// set starting position at first byte and read in the raw data
ms.Position = 0;
ms.Read(fileBytes,0,(int)ms.Length);
// create a file and save the raw zip file to it
FileStream fs = new FileStream(theFile,FileMode.Create);
fs.Write(fileBytes,0,(int)fileBytes.Length);
fs.Close(); // close the file
FileInfo tempFile = new FileInfo(theFile);
// always good to make sure we actually created the file
if ( tempFile.Exists == true)
{
// for now, just delete what we created
tempFile.Delete();
}
else
{ Trace.WriteLine("File was not created!");}
}
}
catch (Exception ex)
{
Trace.WriteLine("Error in DragDrop function: " + ex.Message);
// don't use MessageBox here - Outlook or Explorer is waiting !
}
}
Note that this code doesn't Dispose of objects that it should, such as the MemoryStream and FileStream objects.

You can get the running Outlook instance by using the GetActiveObject method which allows to obtain a running instance of the specified object from the running object table (ROT). Then you can automate Outlook to get the currently selected or opened item from which an attachment might be dragged. See C# app automates Outlook (CSAutomateOutlook) for the sample code.

Windows phone c# File Save Picker Continuation

I am trying to learn to write a windows phone 8.1 app using c#.
I want the app to get location data, create a GPX file and write the data into a waypoint.
I can get the location, write the xml stuff I need and create a new file using the FileSavePicker.
The problem is the FileSavePicker will only create an empty file, but everything that is written into the ContinueFileSavePicker part will not work.
Does anyone know what I'm missing? Thanks
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
this.NavigationCacheMode = NavigationCacheMode.Required;
}
/// <summary>
/// Invoked when this page is about to be displayed in a Frame.
/// </summary>
/// <param name="e">Event data that describes how this page was reached.
/// This parameter is typically used to configure the page.</param>
protected async override void OnNavigatedTo(NavigationEventArgs e)
{
//await getLocation();
}
private async void Location_Click(object sender, RoutedEventArgs e)
{
await getLocation();
}
private void Save_Click(object sender, RoutedEventArgs e)
{
// Clear previous returned file name, if it exists, between iterations of this scenario
Status2.Text = "";
FileSavePicker savePicker = new FileSavePicker();
savePicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
// Dropdown of file types the user can save the file as
savePicker.FileTypeChoices.Add("Plain Text", new List<string>() { ".txt" });
// Default file name if the user does not type one in or select a file to replace
savePicker.SuggestedFileName = "New Document";
savePicker.PickSaveFileAndContinue();
}
//<summary>
//Handle the returned file from file picker
//This method is triggered by ContinuationManager based on ActivationKind
//</summary>
//<param name="args">File save picker continuation activation argment. It cantains the file user selected with file save picker </param>
public async void ContinueFileSavePicker(FileSavePickerContinuationEventArgs args)
{
StorageFile file = args.File;
if (file != null)
{
// Prevent updates to the remote version of the file until we finish making changes and call CompleteUpdatesAsync.
CachedFileManager.DeferUpdates(file);
// write to file
await FileIO.WriteTextAsync(file, file.Name);
// Let Windows know that we're finished changing the file so the other app can update the remote version of the file.
// Completing updates may require Windows to ask for user input.
FileUpdateStatus status = await CachedFileManager.CompleteUpdatesAsync(file);
if (status == FileUpdateStatus.Complete)
{
Status2.Text = "File " + file.Name + " was saved.";
}
else
{
Status2.Text = "File " + file.Name + " couldn't be saved.";
}
}
else
{
Status2.Text = "Operation cancelled.";
}
}

The answer is found here
Reads:
Writing a text file These methods use to write a new text file in the
Local folder:
Create the new file using the method StorageFolder.CreateFileAsync.
Open the file using the method StorageFile.OpenAsync, Which returns a stream.
Open to DataWriter over the stream returned by openAsync.
Write the text to the stream With the DataWriter.WriteString method.
Flush and close the DataWriter StoreAsync using the method.
In my case the information I have in an array of bytes called "B". Then:
Await FileIO.WriteBytesAsync (File, B)

How to access isolated storage file from HTML or Javascript for Windows Phone and PhoneGap Application

I am using PhoneGap to develop application for Windows, Android and iOS platform.
I have one problem and need expert assistance from you guys.
I have created one plugin for Windows Phone. Plugin is basically download images from URL and stored in isolated storage folder inside Downloads folder this is working successfully.
Now my problem is does there any way to access isolated storage files from javascript. for example i have downloaded one image and stored in isolated storage ("Download/logo.png) now i have to set this image to my html image source. e.g. <img src="ms-appdata:///local/Downloads/logo.png"/>
But couldn't get success. i have tried several way without luck.
I have using following code to save files in isolated storage.
//This code is working fine for saving image from url to isolated storage
IsolatedStorageFile ISF = IsolatedStorageFile.GetUserStoreForApplication();
//Create directory if does not exists
if (ISF.DirectoryExists(IMAGE_FOLDER_PATH) == false)
{
Debug.WriteLine("Directory created");
ISF.CreateDirectory(IMAGE_FOLDER_PATH);
}
WebClient client = new WebClient();
string modeuleName = hamBurgerMenu[MODULENAME_COLUMN_INDEX];
client.OpenReadCompleted += (s, e) =>
{
if (e.Error == null)
{
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
using (var isoStore = IsolatedStorageFile.GetUserStoreForApplication())
{
string fullPath = Path.Combine(IMAGE_FOLDER_PATH, modeuleName + ".png");
var bi = new BitmapImage();
bi.SetSource(e.Result);
var wb = new WriteableBitmap(bi);
using (var isoFileStream = isoStore.CreateFile(fullPath))
{
var width = wb.PixelWidth;
var height = wb.PixelHeight;
Extensions.SaveJpeg(wb, isoFileStream, width, height, 0, 100);
}
}
});
}
};
client.OpenReadAsync(new Uri(imageURL, UriKind.Absolute));
I have tried following solutions but couldn't get success at all.
<img src="file:///C:|/Data/Users/DefApps/AppData/{9DB..............0CC}/local/Downloads/logo.png"/>
<img src="ms-appdata:///local/Downloads/logo.png"/>
<img src="ms-appx:///Downloads/logo.png"/>
Your comments or suggestion would be highly appreciated!
Thanks & Regards,
Imdadhusen

I have resolved the issue using below code. The purpose of posting answer is it might help other people who are searching for the same.
Now i am saving downloaded images at app's Local Folder.
Following function will download image from live URL.
private void downloadImage(string imageURL, string[] hamBurgerMenu)
{
string ext = Path.GetExtension(imageURL.Trim());
try
{
WebClient client = new WebClient();
client.OpenReadCompleted += (s, e) =>
{
if (e.Error == null)
{
Deployment.Current.Dispatcher.BeginInvoke(async () =>
{
await saveImage(e.Result, imageURL);
});
}
else
{
//Download Image Not Found
}
};
client.OpenReadAsync(new Uri(imageURL, UriKind.Absolute));
}
catch (Exception e)
{
//Download Error
}
}
Now i am saving the downloaded image using below function
// Save a downloaded images to the app’s local folder.
public async Task saveImage(Stream photoToSave, string imageURL)
{
StorageFile photoFile = null;
try
{
string ext = Path.GetExtension(imageURL.Trim());
photoFile = await localFolder.CreateFileAsync(ext, CreationCollisionOption.ReplaceExisting);
using (var photoOutputStream = await photoFile.OpenStreamForWriteAsync())
{
await photoToSave.CopyToAsync(photoOutputStream);
}
}
catch (Exception e)
{
//Error while saving file
}
}
Now we can access the file using following path at HTML page or Client side script
Important:- <APP_ID> e.g. {8A027331-C7348-182D188-8A02473-1247801} should be replace with your Application ID. It will be 32 digit key.
<img src="C:\\Data\\Users\\DefApps\\AppData\\<APP_ID>\\local\\ Mobile.jpg" alt="Mobile.jpg" />

phone:webbrowser does not open PDF files (Windows Phone 8)

I have build an app with a webbrowser in it. It's working fine but when I try to navigate to an adress like bla.pdf the webbrowser shows nothing.
I solved this problem with automatically open the Internet Explorer if the adress is linking to a pdf file.
Is there a better solution? I want to open that PDF file in my own app and I dont want to open the Internet Explorer everytime. Any suggestions?

If you've got a locally downloaded PDF that is in Isolated Storage you can launch the PDF Reader application (or any other applications registered to open PDF files) using LaunchFileAsync.
private async void LaunchFileButton_Click(object sender, RoutedEventArgs rea)
{
// Access isolated storage.
StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;
// Access the PDF.
StorageFile pdfFile = await local.GetFileAsync("file1.pdf");
// Launch the bug query file.
Windows.System.Launcher.LaunchFileAsync(pdfFile);
}
(adapted from MSDN, see section on "launching a file").
If it's a remote URL then you can use LaunchUriAsync (which will use IE to download the file first).
You will need to try this on a device with the PDF Reader application installed - it won't work on the Emulator.

You should read following article if you are not familiar with Async: MSDN Asynchronous Programming with Async and Await
I couldn't test my app because my WP8 Phone is currently not available and I can't install an PDF reader on the emulator.
Call following method to start the download
WebClient pdfDownloader = null;
string LastFileName = ""; //To save the filename of the last created pdf
private void StartPDFDownload(string URL)
{
pdfDownloader = new WebClient(); //prevents that the OpenReadCompleted-Event is called multiple times
pdfDownloader.OpenReadCompleted += DownloadPDF; //Create an event handler
pdfDownloader.OpenReadAsync(new Uri(URL)); //Start to read the website
}
async void DownloadPDF(object sender, OpenReadCompletedEventArgs e)
{
byte[] buffer = new byte[e.Result.Length]; //Gets the byte length of the pdf file
await e.Result.ReadAsync(buffer, 0, buffer.Length); //Waits until the rad is completed (Async doesn't block the GUI Thread)
using (IsolatedStorageFile ISFile = IsolatedStorageFile.GetUserStoreForApplication())
{
try
{
LastFileName = "tempPDF" + DateTime.Now.Ticks + ".pdf";
using (IsolatedStorageFileStream ISFileStream = ISFile.CreateFile(LastFileName))
{
await ISFileStream.WriteAsync(buffer, 0, buffer.Length);
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message + Environment.NewLine + ex.HResult,
ex.Source, MessageBoxButton.OK);
//Catch errors regarding the creation of file
}
}
OpenPDFFile();
}
private async void OpenPDFFile()
{
StorageFolder ISFolder = Windows.Storage.ApplicationData.Current.LocalFolder;
try
{
IStorageFile ISFile = await ISFolder.GetFileAsync(LastFileName);
await Windows.System.Launcher.LaunchFileAsync(ISFile);
//http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj206987%28v=vs.105%29.aspx
}
catch (Exception ex)
{
//Catch unknown errors while getting the file
//or opening the app to display it
}
}
To call these methods from your WebBrowser-Control you need to catch the navigating event.
YourWebBrowserControl.Navigating += YourWebBrowserControl_Navigating;
void YourWebBrowserControl_Navigating(object sender, NavigatingEventArgs e)
{
if(e.Uri.AbsolutPath.EndsWith("pdf"))
{
StartPDFDownload(e.Uri.ToString());
}
}
Don't forget that you'll have to delete the files created someday.

Try this to open a PDF from a WebControl:
void MyWebBrowserControl_Navigating(object sender, NavigatingEventArgs e)
{
if (e.Uri.AbsolutPath.ToLower().EndsWith(".pdf"))
{
var success = Windows.System.Launcher.LaunchUriAsync(e.Uri);
}
}