Develop Reference

Controlling all presented modals iOS

I have a Xamarin iOS app where I am presenting several modals one after the other.
Modal1 -> Modal2 -> Modal3 -> etc.
I would like to control and move all of their Frames. Is there any way that I can access all the modals that I have presented?
I tried something like:
var rootView = UIApplication.SharedApplication.KeyWindow.RootViewController.PresentedViewController;
foreach (UIView v in rootView)
{
//some code
}
Any tips would be very much appreciated. Thanks!

Try to use the following code :
public void GetAllMoadlViewController ()
{
UIViewController presentViewController = this.PresentingViewController;
UIViewController lastVC = this;
while(presentViewController!=null)
{
// One by one to get all ModalViewController that you present
var temp = presentViewController;
presentViewController = presentViewController.PresentingViewController;
lastVC = temp;
//do some thing you want
}
}

How to remove volume HUD on Xamarin Forms?

I have made a customrenderer to render a MPVolumeView inside of a xamarin.forms app. Whenever I adjust the volume, I get this big system HUD on screen that is blocking the content on screen. Looks something like this:
How do I remove this? This is my custom renderer:
public class AudioOutputViewRenderer : ViewRenderer<AudioOutputView, UIView>
{
MPVolumeView view;
protected override void OnElementChanged(ElementChangedEventArgs<AudioOutputView> e)
{
base.OnElementChanged(e);
TintColor = UIColor.FromRGB(54, 66, 94);
if (Control == null)
{
view = new MPVolumeView()
{
ShowsRouteButton = false,
ShowsVolumeSlider = true
};
SetNativeControl(view);
}
}
}

I didnt understand perpose of the AudioOutputViewRenderer
But to hide the MPVolumeView you need next:
in your IosProject -> AppDelegate -> method FinishedLaunching add next code
var volumeView = new MPVolumeView(new CGRect(-1000,0,0,0));// -1000 will hide your view from user
volumeView.ClipsToBounds = true;
var slider = volumeView.Subviews.First(x => x is UISlider) as UISlider;
UIApplication.SharedApplication.KeyWindow.RootViewController.View.AddSubview(volumeView);
After you can use var slider to change volume like this
slider.Value = [your vlm];

How to change the title of Timepicker and localization in custom renderer

I have Xamarin forms time picker following custom renderer for IOS
[assembly: ExportRenderer(typeof(TimePicker), typeof(Time24PickerRenderer))]
namespace LabOraTimeStamp.iOS.Renderers
{
public class Time24PickerRenderer:TimePickerRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<TimePicker> e)
{
base.OnElementChanged(e);
var timePicker = (UIDatePicker)Control.InputView;
timePicker.Locale = new NSLocale("no_nb");
//Get the Done button
var toolbar = (UIToolbar)Control.InputAccessoryView;
var doneBtn = toolbar.Items[1];
//Set the Done to OK
doneBtn.Title = "OK";
}
}
}
I wanted to change the default "done" to "Ok".
1) How can I do that? the line mentioned above for setting the title does not affect anything.
2) I already implemented localization for xamarin forms.I just wanted to use existing Resx values from custom renderer to show the string for appropriate culture.How can I achieve that?

So the reason why your code isn't working is because the done button is created with the UIBarButtonSystemItem.Done style. It doesn't care about the Title property. Renderer code here.
To work around that issue you could try replacing the Xamarin created done button with your own custom Ok button.
//Get the Done button
var toolbar = (UIToolbar)Control.InputAccessoryView;
// Replace Xamarin's buttons with custom ones.
var spacer = new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace);
var doneButton = new UIBarButtonItem();
doneButton.Title = "OK";
doneButton.Clicked += (o, a) => Control.ResignFirstResponder();
toolbar.SetItems(new [] { spacer, doneButton}, false);

Monotouch - NavigationBar with extra padding ios 7

I'm trying to adapt my app for iOS 7. It's written with Xamarin and C#.
I'm having trouble with extra padding for the left button in the navigationbar.
I have a helper method for rendering my back-button which looks like this:
public static UIBarButtonItem GetBackButton (this UIViewController controller)
{
var backImage = new UIImage ("Images/back.png");
var backButton = new UIButton (UIButtonType.Custom);
backButton.Frame = new RectangleF (0, 0, 44, 44);
backButton.SetImage (backImage, UIControlState.Normal);
backButton.TouchUpInside += (object sender, EventArgs e) => {
var cancelBackNavigation = false;
if (controller is UIViewControllerBase) {
if (((UIViewControllerBase)controller).PrepareNavigateBack () != true) {
cancelBackNavigation = true;
}
}
if (cancelBackNavigation == false) {
controller.NavigationController.PopViewControllerAnimated (true);
}
};
return new UIBarButtonItem (backButton);
}
The navigationbar adds lots of padding before the back-button and making the image inside the back-button look very far away from its real position. The code above works fine in iOS 6.
I don't wanna use ContentEdgeInsets cause it will stretch the image and making it ugly.
Anyone with an idea of what to do?

I tried looking up your issue and found out that first, you need to hide the back button as follows:
NavigationItem.HidesBackButton = true;
Then for setting the button, you need to set it this way:
NavigationItem.BackBarButtonItem = yourButton;
That way, you won`t have the extra indentation.
Also you might find the following question useful:
Make a custom back button for UINavigationController

This is how I setup my NavigationBar
controller.View.BackgroundColor = Theme.BackgroundColor;
controller.NavigationItem.SetHidesBackButton (true, false);
controller.NavigationController.Toolbar.TintColor = Theme.BackgroundColor;
controller.NavigationController.NavigationBar.TintColor = Theme.BackgroundColor;
controller.NavigationController.SetNavigationBarHidden (show == false, false);
controller.NavigationController.NavigationBar.BackgroundColor = Theme.BackgroundColor;
controller.NavigationController.NavigationBar.SetTitleTextAttributes (Theme.NavigationBarTextAttributes);
controller.NavigationController.NavigationBar.Subviews [0].Alpha = 0.01f;

Programatically create a Popup with a Child element initialised by Caliburn Micro

Windows.Media.Captures has a handy CameraCaptureUI class that can be instantiated as follows to show a dialog to the user to capture photos or videos:
// Create dialog to Capture Video
CameraCaptureUI dialog = new CameraCaptureUI();
dialog.VideoSettings.Format = CameraCaptureUIVideoFormat.Mp4;
StorageFile file = await dialog.CaptureFileAsync(CameraCaptureUIMode.Video);
if (file != null)
{
// Do something with file...
}
I would like to create my own custom audio capture class that works in a very similar way:
// Create dialog to Capture Audio
AudioCaptureUI dialog = new AudioCaptureUI();
StorageFile file = await dialog.CaptureFileAsync();
if (file != null)
{
// Do something with file...
}
To do the above, I created the following three files:
AudioCaptureUI - The class that a user instantiates to show the audio capture dialog
AudioCaptureView - UI View for the audio capture experience
AudioCaptureViewModel - ViewModel that contains all the audio capture logic
To create a full screen audio capture dialog, I have figured out that the best way is to use a Popup and set its child to the AudioCaptureView. The problem I have with this approach is that it is pushing me use a View-First pattern. Since I am using Caliburn Micro, I wanted to be able to use CM to instantiate a View by creating the ViewModel first.
What I currently have is something on the following lines:
public class AudioCaptureUI
{
private Popup _popup;
private TaskCompletionSource<StorageFile> _taskCompletionSource;
public IAsyncOperation<StorageFile> CaptureFileAsync()
{
// Force my View to be full screen
AudioCaptureView audioCaptureView = new AudioCaptureView
{
Width = Window.Current.Bounds.Width,
Height = Window.Current.Bounds.Height
};
// Creating View, instead of a ViewModel. Renders Caliburn Micro useless!
_popup = new Popup { Child = audioCaptureView };
if (_popup.Child != null)
{
SubscribeEvents();
_popup.IsOpen = true;
}
return AsyncInfo.Run(WaitForInput);
}
...
}
The above pattern works. However, I am forced to wire all my actions manually and cannot leverage Caliburn Micro's MVVM goodness.
How else should I instantiate a ViewModel programatically from my AudioCaptureUI class?
It is also important to highlight that I am working on a Windows Store app and using the WinRT CM port.

You could always port the WindowManager to WinRT in your own project. Looking at the source I don't think too much will need to change. https://caliburnmicro.codeplex.com/SourceControl/latest#src/Caliburn.Micro.Platform/net40/WindowManager.cs
You could bring over the Interface as well and use DI but for the sake of time here is the stand alone class. The main part for Model first binding is the ViewLocator.LocateForModel which returns the View from the ViewModel (aka the magic)
using System;
using System.Collections.Generic;
using Windows.UI.Xaml.Controls.Primitives;
namespace Caliburn.Micro
{
public class WindowManager
{
public virtual void ShowPopup(object rootModel, object context = null, IDictionary<string, object> settings = null)
{
var popup = CreatePopup(rootModel, settings);
var view = ViewLocator.LocateForModel(rootModel, popup, context);
popup.Child = view;
//popup.SetValue(View.IsGeneratedProperty, true);
ViewModelBinder.Bind(rootModel, popup, null);
Caliburn.Micro.Action.SetTargetWithoutContext(view, rootModel);
var activatable = rootModel as IActivate;
if (activatable != null)
{
activatable.Activate();
}
var deactivator = rootModel as IDeactivate;
if (deactivator != null)
{
popup.Closed += delegate { deactivator.Deactivate(true); };
}
popup.IsOpen = true;
//popup.CaptureMouse();
}
protected virtual Popup CreatePopup(object rootModel, IDictionary<string, object> settings)
{
var popup = new Popup();
ApplySettings(popup, settings);
return popup;
}
bool ApplySettings(object target, IEnumerable<KeyValuePair<string, object>> settings)
{
if (settings != null)
{
var type = target.GetType();
foreach (var pair in settings)
{
var propertyInfo = type.GetPropertyCaseInsensitive(pair.Key);
if (propertyInfo != null)
{
propertyInfo.SetValue(target, pair.Value, null);
}
}
return true;
}
return false;
}
}
}
Then all you need to do is create an instance and give it a ViewModel:
var windowManager = new WindowManager();
windowManager.ShowPopup(new MyPopupThingViewModel());
Note: I've only used this in an 8.1 app so not 100% sure if it will completely work with 8.0

You might have some success with the Caliburn.Micro WindowManager. There isn't a great deal about it in the official documentation (you're best off searching Google and the CM discussions). I've used it in one of my applications where I needed to host a particular ViewModel in a new window, and wanted to utilise all of the Caliburn.Micro goodness (and my existing Views).
Have a look at the Caliburn.Micro.IWindowManager interface, you'll see some handy methods that you can call from a WindowManager instance (depending on the popup type you're after).
public interface IWindowManager
{
bool? ShowDialog(object rootModel, object context = null, IDictionary<string, object> settings = null);
void ShowPopup(object rootModel, object context = null, IDictionary<string, object> settings = null);
void ShowWindow(object rootModel, object context = null, IDictionary<string, object> settings = null);
}
In my application, to pop up my a Window with my ViewModel of choice, I did something along these lines (your names inserted):
// Some basic Window settings.
dynamic settings = new ExpandoObject();
settings.Title = "Test Window";
settings.WindowStartupLocation = WindowStartupLocation.Manual;
settings.SizeToContent = SizeToContent.Manual;
settings.Width = 450;
settings.Height = 300;
var localAudioCaptureViewModel new AudioCaptureViewModel ();
WindowManagerFactory.WindowManager.ShowWindow(localAudioCaptureViewModel, null, settings); // I didn't require context (null)
Caliburn.Micro should resolve your Views to the correct ViewModels, and you're good to go.