I was using this Microsoft sample http://code.msdn.microsoft.com/wpapps/Basic-Camera-Sample-52dae359#content because I needed to implement camera functionality in my application. Ans this is working fine until I try to switch to front camera then the app just closes and I get this
The program '[3032] TaskHost.exe' has exited with code -532265403 (0xe0464645)
I was going through the code and I found out that this part of code causes the problem
public FlashState FlashState
{
get { return (FlashState) (uint) PhotoCaptureDevice.GetProperty(KnownCameraPhotoProperties.FlashMode); }
set
{
try
{
PhotoCaptureDevice.SetProperty(KnownCameraPhotoProperties.FlashMode, value);
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex.Message);
}
}
}
It doesn't hit catch, just closes the app. The same thing is happening if I set Front Camera as a default one. Did anyone had this problem?
[SOLUTION]
Ok, after trying everything - event posting here, now I have a solution. In the try block above I added this line
if (CameraSensorLocation == CameraSensorLocation.Front)
return;
so now it doesn't crush, and the front camera is working fine. They should change this in official sample.
Ok, after trying everything - even posting here, now I have a solution. In the try block above I added this line
if (CameraSensorLocation == CameraSensorLocation.Front) return;
so now it doesn't crush, and the front camera is working fine.
Related
I have been trying to get the back button to work for windows phone using vb, however I cant find anything on the internet, anything I do find is for c#
Can someone please tell me how I can make the back button go to the previous page as every time the back button is pressed it quits out of the app.
thanks
I'm not good at VB so, I'll make it in C# and consider to do it in your way in VB
In the Constructor of a page, write this code :
Windows.Phone.UI.Input.HardwareButtons.BackPressed += HardwareButtons_BackPressed;
In the Page's class, write this :
void HardwareButtons_BackPressed(object sender, Windows.Phone.UI.Input.BackPressedEventArgs e)
{
if (this.Frame.CanGoBack)
{
this.Frame.GoBack();
}
else
{
Application.Current.Exit();
}
}
Consider to write it in all pages.
In a Hub view App with subItems Pages, my question is when I navigate to a sub item detail Page and then use command navigate goback, the view always returns to pageroot hub section01.
How can I return the MainHub Page to the original calling section that went to the sub page in the first place?
My research has been fruitless. I don't think snaps are my answer but hey any advice is appreciated.
I apologize if this is a very simple question but...
Thx.
Ok. Thanks for the answers. After looking at this problem for three days I have found a solution but not quite an answer.
this.NavigationCacheMode = Windows.UI.Xaml.Navigation.NavigationCacheMode.Enabled;
By enabling Navigation Caching the page will return to it's sender position. However I still desire to return to the Hub root page to a specific section. If anyone still has info on how to achieve this I would be grateful.
Seasons Greetings.
Well the newbie here has also discovered the MyHub.ScrollToSection(MyHub.Sections[0]);
This allows you to navigate directly to a section thereby bringing it into the current view.
I'm trying to find an answer to the same question. This is what I've found so far. I welcome any better solutions.
Option 1
Enable caching for the page. Note that this must be set in the page constructor or XAML. This will increase memory usage but will improve performance of your app when you navigate back to a cached page.
this.NavigationCacheMode = Windows.UI.Xaml.Navigation.NavigationCacheMode.Enabled;
More information here: http://msdn.microsoft.com/en-us/library/windows/apps/xaml/windows.ui.xaml.controls.page.navigationcachemode.aspx
Option 2
Manually save a controls state between page navigations. The example below is using the NavigationHelper class which is added to a new Windows Store project by default.
private void OnNavigationHelperSaveState(obj sender, SaveStateEventArgs e)
{
e.PageState["SelectedSection"] = this.MainHub.SectionsInView;
}
private void OnNavigationHelperLoadState(obj sender, LoadStateEventArgs e)
{
if (e.PageState != null)
{
var sections = e.PageState["SelectedSection"] as IList<HubSection>;
if (sections != null && sections.Any())
{
this.MainHub.ScrollToSection(sections[0]);
}
}
}
More information here: http://msdn.microsoft.com/en-gb/library/windows/apps/hh986968.aspx
you could get the Hub's descendant scrollviewer and register to scrollchanged events, store the scrollOffsets and restore them as soon as the user navigates back to the page by applying the values to the hub's scrollviewer.
I guess you would have to register to the hub's loaded event to get the descending scrollviewer (you can use an Extension method from WinRt XAML Toolkit that allows you to get the descendants by Type (e.g. Scrollviewer)
greetings!
you can delete un back stack with this :
if(this.Frame.CanGoBack)
{
this.Frame.BackStack.RemoveAt(0);
}
Have you tried what i suggested?
Unforunately Hub can't be extended to do this and access it's Scrollviewer so you have to do this with an attached Property or plainly in your page.cs .
First you register an handler for the Loaded event of your hub. In the handler you get the descending scrollviewer (with the help of WINRT XAML Toolkit maybe) and register for it's ViewChanged Event.
You store the paremeters you like somewhere they don't get deleted on page navigation and restore and attach them to the scrollviewer on backwards-navigation.
I can give you example code in the afternoon.
Greetings
It's not a ridiculous request. Try this:
public static class Concurrency
{
public static HubSection GotoSection { get; set; }
}
public class MainPage : Page
{
protected override void OnNavigatedTo(NavigationEventArgs e)
{
if (Concurrency.GotoSection != null)
MainHub.ScrollToSection(Concurrency.GotoSection);
Concurrency.GotoSection = null;
base.OnNavigatedTo(e);
}
protected override void OnNavigatedFrom(NavigationEventArgs e)
{
Concurrency.GotoSection = MainHub.SectionsInView.First();
base.OnNavigatedFrom(e);
}
}
The reason this.NavigationCacheMode = Windows.UI.Xaml.Navigation.NavigationCacheMode.Enabled; may not be the correct solution is because you might want your hub to be refreshed. If the detail page resulted in an edit (or especially a delete) a back navigation would show stale data, and subject your app to un unexpected state if the user interacts with dead data.
Best of luck!
Enable cache mode on your page at initialization
public MainHubPage()
{
. .......
this.NavigationCacheMode = NavigationCacheMode.Enabled;
.......
}
You need to add Loaded method to Page constructor.
MainHub.Loaded += async (s, e) => await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
//here you can scroll
MainHub.ScrollToSection(Loyaltysection);
});
I did extensive documentation study on ViewPagers and on Camera apps, infact everything works quite fine, except for a major issue on GingerBread, which I haven't found any question about on S.O. so I'll try asking this one...
In my application there is a ViewPager (support library v4) which shows two fragments:
One, will call it the main fragment, the one showing when the activity starts, certain information are shown to the user, including an imageview, which is initially empty and hidden.
By swyping to the next fragment, the user sees the camera preview, which gets created when the activity is created (even if it not showing until the swype) and the button to take a picture.
When the picture is taken, the view is programmatically taken back to the main fragment, the
imageview is loaded with the new photo and unhidden so the user can see the image mixed with the other preexisting information.
If the user does not like picture, he can swype back again to the camera fragment and take another one, and so all over until he is satisfied with the result.
For this reason, before flipping back to the main fragment, I call mCamera.restartPreview() and ensure the camera is ready should the user swype back.
Everything works smoothly and fine on Android 4.x, but when I test this on a 2.3.3 (API Level 10) the camera preview remains in foreground when the main fragment is called back, and hides the view. You can see, and even scroll, the remainder of the view, in the portion of teh screen where the camerafragment shows the buttons, but the rest is overlapped by the camera preview.
Here is the code of the relevant functions:
CameraFragment onPictureTaken()
private PictureCallback mPicture = new PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (pictureFile == null){
Log.d(TAG, "Error creating media file, check storage permissions: ");
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
Log.e(TAG, "FILE " +pictureFile.getAbsoluteFile().toString());
Bitmap bitmap = rotated(data);
bitmap.compress(CompressFormat.JPEG, PICTURE_QUALITY, fos);
bitmap.recycle(); //devo davvero chiamarla esplicitamente ??
mediaFile = pictureFile;
mPreview.restartPreview();
// go back to newpin activity to show it
((NewPinActivity) myActivity).newPin.setMedia(mediaFile.getAbsoluteFile().toString());
((NewPinActivity) myActivity).takeBack();
} catch (FileNotFoundException e) {
Log.d(TAG, "File not found: " + e.getMessage());
}
}
};
and the mainfragment takeBack() method
public void takeBack(){
mViewPager.setCurrentItem(0, true);
String mainFragTag = "android:switcher:"+R.id.newpinpager+":0";
Fragment fragMain = this.getSupportFragmentManager().findFragmentByTag(mainFragTag);
try {
((NewPinMainFragment)fragMain).showPhoto(newPin.getMedia());
} catch (NullPointerException e){
}
}
Does anybody have a clue if this is an issue with the ViewPager and GingerBread or with the CameraPreview and Gingerbread or what ?
I found the answer by myself, I'll post it here in case it's going to be useful to others.
Apparently the problem was cause by the smoothscroll option of setCurrentItem method.
The issue was fixed by changing
mViewPager.setCurrentItem(0, true);
to
mViewPager.setCurrentItem(0, false);
I have got a MVC4 application where I used 51Degrees (Lite) to detect device and accordingly select the mobile (.mobile.cshtml) or desktop (.cshtml) view. 51Degrees can properly do that job. However if I want to switch from Mobile to Desktop view (on a mobile device) using HttpContext.SetOverriddenBrowser(BrowserOverride.Desktop) it doesn't work. FYI, it works without 51Degrees.
Here is the code to select display mode (Application_Start() in Global.asax.cs):
DisplayModeProvider.Instance.Modes.Insert(0, new DefaultDisplayMode("mobile")
{ContextCondition = Context =>Context.Request.Browser["IsMobile"] == "True"
});
Here is the view switcher controller action code:
public class ViewSwitcherController : Controller
{
public RedirectResult SwitchView(bool mobile, string ReturnUrl="/Login/Login")
{
// If the mobile user has requested to view the mobile view
// remove any overridden user agent for the current request
if (Request.Browser.IsMobileDevice == mobile)
HttpContext.ClearOverriddenBrowser();
else
// Otherwise override the browser setting to desktop mode
HttpContext.SetOverriddenBrowser(mobile ? BrowserOverride.Mobile : BrowserOverride.Desktop);
return Redirect(ReturnUrl);
}
}
Here is the code in the view to switch to Desktop view:
#Html.ActionLink("Desktop view", "SwitchView", "ViewSwitcher", new { mobile = false, ReturnUrl = Request.Url.PathAndQuery }, new { rel = "external" })
Please let me know if I'm missing something.
Thanks in advance.
Sorry for my long delayed answer.
The following solution was provided by one of the developers at 51Degrees:
DisplayModeProvider.Instance.Modes.Insert(0, new DefaultDisplayMode("mobile")
{
ContextCondition = Context => Context.GetOverriddenBrowser()["IsMobile"] == "true"
});
So replacing Context.Request.Browser["IsMobile"] with Context.GetOverriddenBrowser()["IsMobile"] fixes my problem.
Hope that helps.
I know this is a bit dated, but I ran into this tonight. Same symptoms. Works without Mobi51, does not with. My working theory is that Request.Browser.IsMobileDevice is touched by Mobi51 and it takes control of that property and sets its value regardless of what you would expect .NET to do with it.
My current solution is this. When I check in my viewstart file to switch layouts I check that both Request.Browser.IsMobileDevice and Context.GetOverridenBrowser().IsMobileDevice are true.
When it's truly Mobile, both will be true. When it's truly desktop, both are false. When it's a mobile view requesting desktop, Request.Browser.IsMobileDevice will be true (because Mobi51 says so) and Context.GetOverridenBrowser().IsMobileDevice will be false. Here's my viewstart
#{
Layout = Request.Browser.IsMobileDevice && Context.GetOverriddenBrowser().IsMobileDevice
? "~/Views/Shared/_LayoutMobile.cshtml"
: "~/Views/Shared/_Layout.cshtml";
}
I'm still vetting this and have to add desktop to mobile switching still (which I can already see a problem, but the change to make that direction work as well is easy enough , but in my five minutes of testing so far tonight this has worked. I'm curious if you found another reason/way to work with this, or if this solution is satisfactory for you.
I am creating a silver light application using Navigation app template. It is for internal use and hence uses windows authenticatoin. There is a dashboard page which shows couple of records filtered by logged in users id. To get the user id (which is an int) I call a web service by overriding the GetAuthenticatedUser and pass the username (from IPrincipal). This service takes some time to return the details.
When I navigate to dashboard app, it renders completely with no data because the user service is a async operation and I am not able to make the rendering wait till my GetAuthenticatedUser finishes completely. So I created a Login page which just shows a progress bar till I get the user object and then navigate to dashboard. If someone tries to access the dashboard directly by using the URL, i want them to navigate back to Login page.
So in the dashboard constructor I added the following code
if (!UserService.Current.User.IsAuthenticated)
{
MessageBox.Show("Navigating away");
Frame objContainer = this.Parent as Frame;
objContainer.Navigate(new Uri("/Views/Login.xaml", UriKind.Relative));
}
Thogh I get the message box prompt, it does not actually take me to Login page but stays in dashboard page. I also tried putting this code in OnNavigatedTo override with no luck.
I also tried using NavigationService instead of Frame as below, with no luck
if (!UserService.Current.User.IsAuthenticated)
{
MessageBox.Show("Navigating away");
this.NavigationService.Navigate(new Uri("/Views/Login.xaml", UriKind.Relative));
}
it still does not work. Does anyone know how to make some page accessible only if I have fully valid user object? if they try to access the restricted page without this, I want them to be able to redirected to Login page, how can this be achieved?
I am using Silverlight 3 Beta
Shreedhar
I finally found a way around this. In the Constructo i Hooked up the Loaded event handler and in the event handler I am navigating to a different page and it works fine now.
public Dashboard()
{
InitializeComponent();
this.Loaded += new RoutedEventHandler(Dashboard_Loaded);
}
void Dashboard_Loaded(object sender, RoutedEventArgs e)
{
if (!UserService.Current.User.IsAuthenticated)
{
Frame objContainer = this.Parent as Frame;
if (objContainer != null)
{
objContainer.Navigate(new Uri("/Views/Login.xaml", UriKind.Relative));
}
}
}
This piece of code works just fine!
Shreedhar