Convert a xamarin.forms.view to an uiview ...? - view

I work on a xamarin.iOS project and I need to convert a Xamarin.Forms.View to an UIView. I managed to do what I want on Android, but not on iOS.
I have tried to use this method found here:
public static UIView ConvertFormsToNative(Xamarin.Forms.View view, CGRect size)
{
var renderer = RendererFactory.GetRenderer (view);
renderer.NativeView.Frame = size;
renderer.NativeView.AutoresizingMask = UIViewAutoresizing.All;
renderer.NativeView.ContentMode = UIViewContentMode.ScaleToFill;
renderer.Element.Layout (size.ToRectangle());
var nativeView = renderer.NativeView;
nativeView.SetNeedsLayout ();
return nativeView;
}
But it's not work in my project ...
Thank you in advance for your help !

Don't forget using Xamarin.Forms.Forms.Init(); in the appdelegate.
I tried with a Xamarin map control but it does not work. I use this and voila!
public partial class ViewControllerCliente : UIViewController........
var map = new Map(
MapSpan.FromCenterAndRadius(
new Position(37, -122), Distance.FromMiles(0.3)))
{
IsShowingUser = true,
HeightRequest = 200,
WidthRequest = 200,
VerticalOptions = LayoutOptions.FillAndExpand
};
var stack = new StackLayout { Spacing = 0 };
stack.Children.Add(map);
this.Add(ConvertFormsToNative(stack,new CGRect(0, 180,
UIScreen.MainScreen.Bounds.Width,360)));

Related

Is there an property like android:actionBarSize in iOS?

I'm developing in Xamarin and I don't know how change the height of navigation bar.
For android is easier because you've got a clear property "ActionBarSize"
I've tried a lot of things. Create a comun NavigationPage with HeightRequest property does not work
Thanks a lot
In iOS we could set a custom TitlView by using custom renderer .
using Foundation;
using UIKit;
using Xamarin.Forms.Platform.iOS;
using Xamarin.Forms;
using xxx.iOS;
using CoreGraphics;
using xxx;
using ObjCRuntime;
[assembly: ExportRenderer(typeof(ContentPage), typeof(MyPageRenderer))]
namespace xxx.iOS
{
public class MyPageRenderer: PageRenderer
{
public override void ViewWillAppear(bool animated)
{
base.ViewWillAppear(animated);
var page = Element as ContentPage;
NavigationController.NavigationBar.Hidden = true;
double height = IsiphoneX();
UIView backView = new UIView()
{
BackgroundColor = UIColor.White,
Frame = new CGRect(0,20,UIScreen.MainScreen.Bounds.Width, height),
};
UIButton backBtn = new UIButton() {
Frame = new CGRect(20, height-44, 40, 44),
Font = UIFont.SystemFontOfSize(18),
} ;
backBtn.SetTitle("Back", UIControlState.Normal);
backBtn.SetTitleColor(UIColor.Blue, UIControlState.Normal);
backBtn.AddTarget(this,new Selector("GoBack"),UIControlEvent.TouchUpInside);
UILabel titleLabel = new UILabel() {
Frame=new CGRect(UIScreen.MainScreen.Bounds.Width/2-75, 0,150, height),
Font = UIFont.SystemFontOfSize(20),
Text = page.Title,
TextColor = UIColor.Black,
Lines = 0,
};
UILabel line = new UILabel() {
Frame = new CGRect(0, height, UIScreen.MainScreen.Bounds.Width, 0.5),
BackgroundColor = UIColor.Black,
};
backView.AddSubview(backBtn);
backView.AddSubview(titleLabel);
backView.AddSubview(line);
View.AddSubview(backView);
}
double IsiphoneX()
{
double height = 44; //set height as you want here !!!
if (UIDevice.CurrentDevice.CheckSystemVersion(11, 0))
{
if (UIApplication.SharedApplication.Delegate.GetWindow().SafeAreaInsets.Bottom > 0.0)
{
height = 64; //set height as you want here !!!
}
}
return height;
}
[Export("GoBack")]
void GoBack()
{
NavigationController.PopViewController(true);
}
public override void ViewWillDisappear(bool animated)
{
base.ViewWillDisappear(animated);
NavigationController.NavigationBar.Hidden = false;
}
}
}

How to convert Xamarin Forms view to a Native view iOS/Android with the same size?

I am using the example here, but I am struggeling to fill in the right size parameter here so that it represents the same size as the forms view.
https://michaelridland.com/xamarin/creating-native-view-xamarin-forms-viewpage/
public static UIView ConvertFormsToNative(Xamarin.Forms.View view, CGRect size)
{
var renderer = RendererFactory.GetRenderer(view);
renderer.NativeView.Frame = size;
renderer.NativeView.AutoresizingMask = UIViewAutoresizing.All;
renderer.NativeView.ContentMode = UIViewContentMode.ScaleToFill;
renderer.Element.Layout(size.ToRectangle());
var nativeView = renderer.NativeView;
nativeView.SetNeedsLayout();
return nativeView;
}
And for Android:
public static ViewGroup ConvertFormsToNative(Xamarin.Forms.View view, Rectangle size)
{
var vRenderer = RendererFactory.GetRenderer (view);
var viewGroup = vRenderer.ViewGroup;
vRenderer.Tracker.UpdateLayout ();
var layoutParams = new ViewGroup.LayoutParams ((int)size.Width, (int)size.Height);
viewGroup.LayoutParameters = layoutParams;
view.Layout (size);
viewGroup.Layout (0, 0, (int)view.WidthRequest, (int)view.HeightRequest);
return viewGroup;
}
}
What values from my Xamarin Forms should be put in, so that it will represent the CGRect required to have the same on the Native View.
var rect = new CGRect();
rect.X = (nfloat)view.X;
rect.Y = (nfloat)view.Y;
rect.Width = (nfloat)view.Width;
rect.Height = (nfloat)view.Height;
Solved it, where "view" is the Xamarin Forms view.

Horizontal ScrollView - xamarin.forms

I know there are many about this topic (Scroll horizontally in Xamarin.Forms ScrollView), but I could not implement the horizontal scrollview which scrolls horizontally.
public class DetailView : ContentPage
{
public DetailView ()
{
StackLayout stack = new StackLayout {
Orientation = StackOrientation.Horizontal,
};
for (int i = 0; i < 40; i++)
stack.Children.Add (new Button { Text = "Button" });
var scrollView = new ScrollView
{
Orientation = ScrollOrientation.Horizontal,
Content = stack
};
Content = scrollView;
}
}
Any ideas?
try this:
public DetailView()
{
var scrollableContent = new StackLayout()
{
Orientation = StackOrientation.Horizontal,
HorizontalOptions = LayoutOptions.Fill,
Children =
{
new BoxView(){HeightRequest=40, WidthRequest=40, BackgroundColor = Color.Red},
new BoxView(){HeightRequest=40, WidthRequest=40, BackgroundColor = Color.Green},
new BoxView(){HeightRequest=40, WidthRequest=40, BackgroundColor = Color.Blue},
new BoxView(){HeightRequest=40, WidthRequest=40, BackgroundColor = Color.Maroon},
}
};
Content = new ScrollView()
{
HorizontalOptions = LayoutOptions.FillAndExpand,
Orientation = ScrollOrientation.Horizontal,
Content = scrollableContent,
};
}

How to fade in and out images in Xamarin iOS

I've created a launch animation in Xamarin for an iOS app but I can't seem to get the images to fade in and out gracefully. I think I need to use the .FadeTo() method but I'm unable to apply it to my code properly. I'm trying to get the first image to fade in then fade out while the second image fades in and so on. Any help is appreciated - I'm a newb!
Here's my code:
using System.Drawing;
using MonoTouch.UIKit;
namespace MapView {
public class ImageViewController : UIViewController {
UIImageView animatedlaunchImage;
public override void ViewDidLoad ()
{
base.ViewDidLoad ();
Title = "Animated ImageView";
View.BackgroundColor = UIColor.White;
// an animating image
animatedlaunchImage = new UIImageView();
animatedlaunchImage.AnimationImages = new UIImage[] {
UIImage.FromBundle ("Splash01.png")
, UIImage.FromBundle ("Splash02.png")
, UIImage.FromBundle ("Splash03.png")
, UIImage.FromBundle ("Splash04.png")
, UIImage.FromBundle ("Splash05.png")
} ;
animatedlaunchImage.AnimationRepeatCount = 1;
animatedlaunchImage.AnimationDuration = 3;
animatedlaunchImage.Frame = new RectangleF(0, 0, 320, 568);
View.AddSubview(animatedlaunchImage);
animatedlaunchImage.StartAnimating ();
}
}
}
Include CoreAnimation and add these lines of code after you create the UIImageView,
CATransition customTransition = new CATransition();
customTransition.FadeInDuration = 1.0f;
customTransition.FadeOutDuration = 1.0f;
customTransition.TimingFunction = CAMediaTimingFunction.FromName(
CAMediaTimingFunction.EaseInEaseOut);
customTransition.Type = CATransition.TransitionFade;
animatedlaunchImage.Layer.AddAnimation(customTransition, null);
Translated from this objective-c question.

GetSizeForItem not triggering

I want to have different height for each cell in my UICollectionView. Therefore I am overriding the GetSizeForItem method in the UICollectionViewDelegateFlowLayout like this:
public class MyCollectionViewDelegateFlowLayout : UICollectionViewDelegateFlowLayout
{
public override CGSize GetSizeForItem(UICollectionView collectionView, UICollectionViewLayout layout, NSIndexPath indexPath)
{
// TODO custom height logic
return new SizeF(100, 100);
}
}
This is how I create the UICollectionView and use the custom delegate class:
var flowLayout = new UICollectionViewFlowLayout()
{
ItemSize = new SizeF(320, 80),
ScrollDirection = UICollectionViewScrollDirection.Vertical,
MinimumLineSpacing = 0,
MinimumInteritemSpacing = 0,
SectionInset = new UIEdgeInsets(UIScreen.MainScreen.ApplicationFrame.Height - 100, 0, 0, 0)
};
var collectionView = new UICollectionView(UIScreen.MainScreen.ApplicationFrame, flowLayout);
collectionView.Delegate = new MyCollectionViewDelegateFlowLayout();
collectionView.RegisterNibForCell(MyCollectionCell.Nib, MyCollectionCell.Key);
var source = new MvxCollectionViewSource(collectionView, MyCollectionCell.Key);
collectionView.Source = source;
The problem is that the GetSizeForItem method never gets triggered. Any idea how to solve this?
From Xamarin's forums here, it looks like you can't use Delegate and Source at the same time.

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