In my project, i have more view elements in container and I need to use LayoutTo method to move the item with animation effect. but there is no changes in UI.
protected virtual Task<bool> OnLayoutItem(View element, Rect rect)
{
return element.LayoutTo(rect, 200, Easing.CubicIn);
}
Please share your ideas to make it work.
Related
I have a 'main' map page from which the user can either add data to the map or click on existing data to see the details. This is done with PushModalAsync() where I navigate to a new page. My problem is in both of those new pages I have a new map with a new MapView that is 'underneath' the MapView from the 'main' page. Both the MapView and Map itself are new objects on the secondary pages.
After navigating to my new pages, the previous MapView shows in the area of the screen where it existed (on 'main' page) where my new MapView also exists. In other words, on my new map pages my map is laid out differently and partially sits higher in the layout than the 'main' map does. The part that sits higher is the only part of the new map that is visible and I can interact with. The part that sits on the same area is the 'main' map view and I cannot interact with it and it blocks my new map.
I tried this with PushAsync as well (not modal) and nothing changed. How is one supposed to have multiple maps in an app across multiple pages? Is this even possible with ArcGIS? This app used to be with Google Maps/Apple and the exact same layout worked just fine.
Edit: Code here (with irrelevant parts removed) This page is navigated to from another page with a map on it wherein this map is covered if it is laid out in the same area of the first map. From this page I navigate to a 3rd page where both maps show up. Removal works successfully, however when I try to add I get an error saying I cannot add a null child to a view group:
public partial class EventDetails : ContentPage
{
public Xamarin.Forms.Grid MapGrid = new Xamarin.Forms.Grid()
{
RowDefinitions =
{
new RowDefinition { Height = 220 },
new RowDefinition { Height = GridLength.Auto }
},
ColumnDefinitions =
{
new ColumnDefinition { Width = 500 }
},
HorizontalOptions = LayoutOptions.Center
};
public Map DetailMap;
public MapView MyDetailMapView = new MapView();
public EventDetails(MapLog eventDetails, string strMapType)
{
DetailMap = new Map(BasemapType.ImageryWithLabels, eventDetails.Latitude, eventDetails.Longitude, iMapDetail);
MyDetailMapView.Map = DetailMap;
MyDetailMapView.ViewpointChanged += MyMapView_ViewpointChanged;
var scrollView = new ScrollView
{
Content = mainStack
};
MapGrid.Children.Add(MyDetailMapView, 0, 0);
MapGrid.Children.Add(scrollView, 0, 1);
Content = MapGrid;
}
#if __ANDROID__
protected override void OnAppearing()
{
if (!MapGrid.Children.Contains(MyDetailMapView))
{
try
{
MapGrid.Children.Add(MyDetailMapView);
}
catch (Exception ex)
{
DisplayAlert("Err", ex.Message, "Ok");
}
}
base.OnAppearing();
}
protected override void OnDisappearing()
{
if (MapGrid.Children.Contains(MyDetailMapView))
MapGrid.Children.Remove(MyDetailMapView);
base.OnDisappearing();
}
#endif
}
EDIT*: I updated my Xamarin Forms version and ARCGIS Runtime and now the solution to remove/add the map does work without issue.
I had other similar problems with having two maps for android in Xamarin Forms ArcGIS and the solution was removing the MapView from the visual tree when you navigate to the new page.
You need to remove the MapView before you Navigate to the second page by:
[your parent layout].Children.Remove(MyMapView);
await Navigation.PushAsync(new SecondPage());
And in your first page you need to make sure to add the MapView back to the Visual Tree when you come back to the page:
protected override void OnAppearing()
{
if (!GridMap.Children.Contains(MyMapView))
GridMap.Children.Add(MyMapView);
base.OnAppearing();
}
That solved all my problems with two maps. Thanks to this post in ESRI forum
Navigation between 2 MapViews in Xamarin Android
I'm using iOS/Xamarin
When the user clicks a button, I'd like to change the background color of my view controller's main view (View).
In the button click event, I tried this:
partial void MyButton_TouchUpInside(UIButton sender)
{
InvokeOnMainThread(() =>
{
SetBackgroundColor(View);
});
}
but it doesn't work. I tried a few other main thread/uithread things but no luck.
If I call SetBackgroundColor(View) from the ViewDidLoad of course it works. I suspect this is a UI thread issue.
Any advice?
Thanks!
You can use the BackgroundColor property on the UIViewController's View property.
partial void MyButton_TouchUpInside(UIButton sender)
{
View.BackgroundColor = UIColor.Red;
}
Turns out the above code is good - somewhere else in the code someone was setting another layer on top of the background so I never saw it =/
Is there a (half) generic way to handle rotation/orientation in Xamarin Forms for different views and platforms (Android, iOS, WinPhone)?
The UI does rotate, and that is nice enough, though it wreaks havoc to my layout (absolute layout right now). I suppose with a Stacklayout I could make it a litte more flexible, but would then hit a road block somewhere else when the layout is more intricate.
Can I somehow display different views for portrait and landscape, with the same ViewModel? (I am using XLABs based MVVM.)
Possible solutions I have found:
http://blog.rthand.com/post/2014/07/24/Different-XAML-layouts-for-different-device-orienations-in-XamarinForms.aspx is lacking iOS and I wonder if it will handle MVVM too well, seems good though and I am investigating it right now
http://www.jimbobbennett.io/orientation-with-xamarin-forms/ sounds promising but the sample is iOS only, the linked GIT repository has no documentation at all, it just says "Xamarin Helpers"
http://www.sellsbrothers.com/posts/Details/13740 might also be a possibility for programmatically created views. Though in my tests I did not get a size changed event (though I listened at a different code place) for ios simulator when rotating. (The solution is based on size changed to detect rotation.)
If you are already using XLabs then you could use IXFormsApp and property 'Orientation' and event handler 'Rotation'. You would have to add the native observers per platform and set IXFormsApp's 'Orientation' there which would cause the event handler to invoke.
For example on iOS:
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
var xapp = new XFormsAppiOS();
xapp.Init(this);
var resolverContainer = new SimpleContainer();
resolverContainer.Register<IXFormsApp>(xapp);
Resolver.SetResolver(resolverContainer.GetResolver());
var a = new App();
LoadApplication(a);
UIDevice.Notifications.ObserveOrientationDidChange((s, e) =>
{
xapp.Orientation = ... // set orientation here
});
Now you can monitor orientation changes by resolving IXFormsApp:
xapp = Resolver.Resolve<IXFormsApp>();
if (xapp.Orientation == Orientation.Landscape) { ... } else { ... }
xapp.Rotation += (sender, args) =>
{
switch (args.Value)
{
case Orientation.LandscapeLeft:
break;
default:
// etc.
break;
}
};
As for layouts I would imagine RelativeLayout would be the most convenient choice as you could put the orientation inside the Constraint's. On rotation make the layout refresh itself.
In my project we need to retrieve/show the aspx page in flash builder 4.6 and we are trying the code like in mxml application(main page)...
protected function imgtesting_clickHandler(event:MouseEvent):void
{
// TODO Auto-generated method stub
var win:Imageview=PopUpManager.createPopUp(this ,Imageview,true) as Imageview;
win.testobjpckt=this;
PopUpManager.centerPopUp(win);
}
and in title window(popup) the code is like....
<dgFooter:IFrame id="iframe" width="984"
height="352" autoResize="true"
horizontalScrollPolicy="off"
overlayDetection="true"
url="http://localhost/......../Default.aspx"
verticalScrollPolicy="off"/>
Here we are able to get the aspx page in to flashbuilder 4.6 and we are able to show the controls of aspx page and those controls are also working and the ISSUE is:
"DESIGN:THE DESIGN OF THE ASPX PAGE IS OVERLAPPING ON THE POPUP(TITLE WINDOW) AND POSITION OF THE CONTROLS ARE ALSO CHANGING IN FLASH BUILDER AND THE ASPX WHOLE PAGE DESIGN IS CHANGING(IN THE SENSE POSITIONS OF CONTROLS ARE CHANGING) SO WE ARE REALLY STRUGGLING A LOT TO GET THE DESIGN IN TO FLASH BUILDER PROPERLY FROM VISUAL STUDIO TO FLASH BUILDER".
SO WE REALLY NEED A SOLUTION TO SOLVE THIS ISSUE.IF ANY HELP I WILL THANKFUL TO THEM A LOT...
Finally i got the solution for the designing,what i did is...
I just changed the Action-script file for IFRAME by adjusting the x,y coordinates like..
override protected function commitProperties():void
{
super.commitProperties();
if(positionChanged)
{
var point:Point = localToGlobal(new Point(154,24));
callJS(methodMove, point.x, point.y);
positionChanged = false;
}
if(sizeChanged)
{
callJS(methodResize, width, height);
sizeChanged = true;
}
}
so,this makes my issue solved......
I have an app in which I have a lot of references and the load time was not acceptable to me. I have removed the splash screen image and created an animated loading screen by having a separate project with no reference to the main application which then navigates to the first page of the rest of the app. It does start up fast now but it's a little lacking still.
I would like to do another animation right before the load screen goes away. The only way I can think of to do this is to actually preload the assemblies needed for the navigation to the next page, do an animation, and then navigate.
I have tried
OnNavigatedFrom but the animation doesn't have time to run since the page will be replaced by the new page very quickly from that point.
OnNavigatingFrom is no help either as it is called as soon as I call NavigationService.Navigate();
Searching the web and Stack Overflow :)
I also considered faking it a bit by having the next page show a duplicate of the load screen and do the last animation there, but it can't match the current state of the load screen animation and is harder to maintain
Thanks for any ideas!
If you want to force the loading of an assembly, just reference a type from this assembly.
For instance, something like Console.WriteLine(typeof(YourAssembly.SomeType)); will force the loading of YourAssembly.
Now for your problem, maybe you can use usercontrols? Put the content of your main page in a user control. Display the loading page, create the usercontrol in the background, let the animation play, then when the animation is done playing replace the page's content with the usercontrol.
It turns out that you can preload by just creating a new instance of the page you are going to navigate to. Unfortunately that has to be done on the UI thread which can cause animation slowdown, at least in my experience.
Here is a sample of how to do an animation, then preload, then do another animation before navigating. :
public partial class LoadScreen : PhoneApplicationPage
{
public LoadScreen()
{
InitializeComponent();
this.Loaded += OnLoaded;
}
private void OnLoaded(object sender, RoutedEventArgs routedEventArgs)
{
var sb = new Storyboard();
// create your animation here
sb.Completed += (sender, args) => PreLoad();
sb.Begin();
}
private void PreLoad()
{
// this is the part that actually takes time and causes things to get loaded
// you may need it in a try/catch block depending on what is in your constructor
var page = new PageToNavigateTo();
// now create an animation at the end of which we navigate away
var sbOut = new Storyboard();
// create your animation here
sbOut.Completed += (sender, args) => NavigateToNextScreen();
sbOut.Begin();
}
private void NavigateToNextScreen()
{
// navigate here
}
protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
{
base.OnNavigatedFrom(e);
// remove the loading screen from the backstack so the user doesn't see it again when hitting the back button
NavigationService.RemoveBackEntry();
}
}