I have a classic master-detail logic and trying to create instance of detail UIViewController with InstantiateViewController inside a click event.
Here is my code,
MasterViewController.cs
detailButton += delegate {
UIStoryboard Storyboard = UIStoryboard.FromName ("Main", null);
Console.WriteLine("InstantiateViewController() started");
var profileController = Storyboard.InstantiateViewController("ProfileController") as ProfileController;
Console.WriteLine("InstantiateViewController() ended");
profileController.Id = 5;
};
ProfileViewController.cs
public partial class ProfileController : UIViewController
{
public int Id { get; set; }
public override void ViewDidLoad()
{
Console.WriteLine("ViewDidLoad() called");
}
}
When I click the button output is,
InstantiateViewController() started
ViewDidLoad() called
InstantiateViewController() ended
This means profileController.Id is set after ViewDidLoad() which means I can't load data by Id in ViewDidload event beacuse Id is null.
So my question is why ViewDidLoad() called by InstantiateViewController(), in which method should I load data by Id?
Thanks.
VoewDidLoad is called when the ViewController is loaded into memory.
So, the correct place to get the data is on ViewDidAppear.
ViewDidAppear notifies the ViewController that its view was added to a view hierarchy.
UPDATE:
Based on the new information provided in comments you could do something like this:
public partial class ProfileController : UIViewController
{
private int _id;
public void SetupProfile (int id)
{
// Save the Id if necessary.
_id = id;
// Add event with this id related.
}
public override void ViewDidLoad()
{
Console.WriteLine("ViewDidLoad() called");
}
}
In alternative if you still want to do the event setup in ViewDidAppear you could use this approach with the events:
yourClass.Event -= MyHandler;
yourClass.Event += MyHandler;
I would do this via a custom segue.
1) Create a custom segue that can be re-used throughout your app:
public class CustomSeque : UIStoryboardSegue // or UIStoryboardPopoverSegue depending upon UI design so you can "POP" controller
{
public CustomSeque(String identifier, UIViewController source, UIViewController destination) : base (identifier, source, destination) { }
public override void Perform()
{
if (Identifier == "StackOverflow")
{
// Are you using a NavigationController?
if (SourceViewController.NavigationController != null)
SourceViewController.NavigationController?.PushViewController(DestinationViewController, animated: true);
else
SourceViewController.ShowViewController(DestinationViewController, this);
} else
base.Perform();
}
}
2) Then you can:
UIStoryboard Storyboard = UIStoryboard.FromName("Main", null);
Console.WriteLine("InstantiateViewController() started");
var profileController = Storyboard.InstantiateViewController("ProfileController") as ProfileController;
var seque = new CustomSeque($"StackOverflow", this, profileController);
profileController.Id = 5;
profileController.PrepareForSegue(seque, this); // instead of *this*, you can pass any NSObject that contains data for your controller
seque.Perform();
Console.WriteLine("InstantiateViewController() ended");
If your ProfileController looks like this:
public partial class ProfileController : UIViewController
{
public ProfileController (IntPtr handle) : base (handle)
{
Id = -99;
}
public int Id { get; set; }
public override bool ShouldPerformSegue(string segueIdentifier, NSObject sender)
{
if (segueIdentifier == "StackOverflow")
return true;
return base.ShouldPerformSegue(segueIdentifier, sender);
}
[Export("prepareForSegue:sender:")]
public override void PrepareForSegue(UIStoryboardSegue segue, NSObject sender)
{
base.PrepareForSegue(segue, sender);
Console.WriteLine("ProfileController.PrepareForSegue()");
Console.WriteLine($" - ID = {Id}");
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
Console.WriteLine("ProfileController.ViewDidLoad()");
Console.WriteLine($" - ID = {Id}");
}
public override void ViewWillAppear(bool animated)
{
base.ViewWillAppear(animated);
Console.WriteLine("ProfileController.ViewWillAppear()");
Console.WriteLine($" - ID = {Id}");
}
}
Your sequenced output would be:
InstantiateViewController() started
ProfileController.PrepareForSegue()
- ID = 5
ProfileController.ViewDidLoad()
- ID = 5
InstantiateViewController() ended
ProfileController.ViewWillAppear()
- ID = 5
Related
I have achieved desired result with MessagingCenter, but I have got an information from reading Xamarin articles that MessagingCenter is not the preferred way to trigger 30+ events. Additional to that I have to unsubscribe from MessagingCenter after action has been done. I want to have Settings page where I would have 30+ settings that have to be changed across whole application in different views. How I can inject SettingsViewModel into other ViewModels in Xamarin.Forms application?
SettingsViewModel.cs:
namespace MessagingCenterApp.ViewModels
{
public class SettingsViewModel : BaseViewModel, ISettingsViewModel
{
public ICommand ChangeCommand { get; set; }
public SettingsViewModel()
{
Title = "Settings";
this.BoxColor = Color.Red;
this.ChangeCommand = new Command(this.ChangeColor);
}
private void ChangeColor()
{
this.BoxColor = Color.FromHex(this.BoxColorS);
MessagingCenter.Send<Object, Color>(this, "boxColor", this.BoxColor);
}
private Color _boxColor;
public Color BoxColor
{
get => _boxColor;
set
{
_boxColor = value;
this.OnPropertyChanged();
}
}
private string _boxColorS;
public string BoxColorS
{
get => Preferences.Get("BoxColor", "#17805d");
set
{
Preferences.Set("BoxColor", value);
this.ChangeColor();
this.OnSettingsChanged();
this.OnPropertyChanged();
}
}
public event EventHandler<SettingsChangedEventArgs> SettingsChanged;
private void OnSettingsChanged() => this.SettingsChanged?.Invoke(this, new SettingsChangedEventArgs(this.Settings));
public Settings Settings { get; private set; }
}
}
HomeViewModel.cs:
namespace MessagingCenterApp.ViewModels
{
public class HomeViewModel : BaseViewModel
{
public HomeViewModel()
{
this.Title = "Home";
MessagingCenter.Subscribe<Object, Color>(this, "boxColor", (sender, arg) =>
{
System.Diagnostics.Debug.WriteLine("received color = " + arg);
this.BoxColor = arg;
});
this.BoxColor = Color.Red;
this.SettingsViewModel = new SettingsViewModel();
this.SettingsViewModel.SettingsChanged += OnSettingsChanged;
}
private void OnSettingsChanged(object sender, SettingsChangedEventArgs e)
{
throw new NotImplementedException();
}
private Color _boxColor;
public Color BoxColor
{
get => _boxColor;
set
{
_boxColor = value;
OnPropertyChanged();
}
}
private ISettingsViewModel SettingsViewModel { get; }
}
}
Should I somehow do all in MainViewModel? I mean:
namespace MessagingCenterApp.ViewModels
{
public class MainViewModel : BaseViewModel
{
public MainViewModel()
{
this.SettingsViewModel = new SettingsViewModel();
this.HomeViewModel = new HomeViewModel(this.SettingsViewModel);
}
public SettingsViewModel SettingsViewModel { get; set; }
public HomeViewModel HomeViewModel { get; }
}
}
Then initialized it in AppShell? I could not get this approach working.
Important! I don't want to use any MVVM framework! Only native behaviour.
mvvmcross' Messenger is alleged to be "lighter weight" than X-Form's built-in Messaging Center.
I use mvvmcross Messenger by defining some helper methods in a "BasePage". Then each page inherits from "BasePage" rather than "ContentPage".
This automatically handles "unsubscribe" of each method. And makes it easier to manage mvvmcross' "subscription tokens".
BasePage.xaml.cs:
// If not using mvvmcross, this could inherit from ContentPage instead.
public class BasePage : MvxContentPage
{
protected readonly IMvxMessenger Messenger;
public BasePage()
{
this.Messenger = Mvx.IoCProvider.Resolve<IMvxMessenger>();
}
protected override void OnAppearing()
{
base.OnAppearing();
// Examples of subscribing to messages. Your subclasses of BasePage can also do this.
this.Subscribe<MyMessage1>(OnMyMessage1);
this.SubscribeOnMainThread<MyMessage2>(OnMyMessage2);
}
protected override void OnDisappearing()
{
UnsubscribeAll();
base.OnDisappearing();
}
#region Messenger Subscriptions
protected List<MvxSubscriptionToken> _subscriptions = new List<MvxSubscriptionToken>();
/// <summary>
/// Create subscription and add to "_subscriptions".
/// Call this from subclass' OnAppearing, once per subscription.
/// Automatically unsubscribed in OnDisappearing.
/// </summary>
/// <param name="token"></param>
/// <param name="msgType"></param>
protected void Subscribe<T>(Action<T> onMessage) where T : MvxMessage
{
var token = this.Messenger.Subscribe<T>(onMessage);
// Hold token to avoid GC of the subscription.
_subscriptions.Add(token);
}
protected void SubscribeOnMainThread<T>(Action<T> onMessage) where T : MvxMessage
{
var token = this.Messenger.SubscribeOnMainThread<T>(onMessage);
// Hold token to avoid GC of the subscription.
_subscriptions.Add(token);
}
/// <summary>
/// OnDisappearing calls this.
/// </summary>
private void UnsubscribeAll()
{
if (_subscriptions.Count > 0)
{
foreach (MvxSubscriptionToken token in _subscriptions)
{
// Per "https://www.mvvmcross.com/documentation/plugins/messenger", this is sufficient to Unsubscribe:
// "Subscriptions can be cancelled at any time using the Unsubscribe method on the IMvxMessenger or by calling Dispose() on the subscription token."
token.Dispose();
}
_subscriptions.Clear();
}
}
#endregion
}
For view models, class would be "BaseViewModel", that your view models inherit from. Contents similar to above, but different method names for Appearing/Disappearing.
BaseViewModel.cs:
public class BaseViewModel : MvxViewModel
{
...
// mvvmcross' MvxViewModel provides these.
protected override void ViewAppearing()
{
...
}
protected override void ViewDisappearing()
{
...
}
... Messenger Subscriptions methods ...
}
I'm trying to implement this code here in my project:
The differences are that instead of a ScrollView I'm using a RecyclerView and that instead of having my RecyclerView directly in the Activity I have inside a fragment that sets the listener I need.
The problem is that while the OnScrollChanged(int l, int t, int oldl, int oldt) gets actually called everytime I scroll, the parameters it obtains are always 0 and I don't understand why, so ScrollChangedTarget doesn't work as intended.
This is the custom RecyclerView:
public class NotifyingScrollRecyclerView : RecyclerView
{
private Activity activity;
private View headerView;
private View footerView;
public delegate void ScrollChangedHandler(int l, int t, int oldl, int oldt, EventArgs e);
public event ScrollChangedHandler scrollChanged;
public EventArgs e = null;
//Enabling all required constructors
public NotifyingScrollRecyclerView(Context context) : base(context)
{
}
public NotifyingScrollRecyclerView(Context context, IAttributeSet attrs) : base(context, attrs)
{
}
public NotifyingScrollRecyclerView(IntPtr ptr, JniHandleOwnership ownership) : base(ptr, ownership)
{
}
public NotifyingScrollRecyclerView(Context context, IAttributeSet attrs, int defStyle) : base(context, attrs, defStyle)
{
}
//This method attribute allows us to register the inbuilt OnScrollChanged event that fires when scrolling a ScrollView
[Android.Runtime.Register("onScrollChanged", "(IIII)V", "GetOnScrollChanged_IIIIHandler")]
protected override void OnScrollChanged(int l, int t, int oldl, int oldt)
{
base.OnScrollChanged(l, t, oldl, oldt);
scrollChanged(l, t, oldl, oldt, e);
}
}
//Set an event listener
public class ScrollViewChangedListener
{
private Activity activity;
private NotifyingScrollRecyclerView scrollView;
private Android.Support.V7.App.ActionBar actionBar;
private Drawable actionBarDrawable;
be changed
public ScrollViewChangedListener(Activity a, NotifyingScrollRecyclerView n)
{
n.scrollChanged += ScrollChangedTarget;
this.activity = a;
this.scrollView = n;
this.actionBar = ((UserPageActivity)a).SupportActionBar;
this.actionBarDrawable = a.GetDrawable(Resource.Drawable.actionbar_background);
this.actionBarDrawable.SetAlpha(0);
}
//Handle the changing of the scroll
public void ScrollChangedTarget(int l, int t, int oldl, int oldt, EventArgs e)
{
//You set the View you want to be your header as a header height, and then get it's height
int headerHeight = activity.FindViewById<ImageView>(Resource.Id.profilebanner).Height -
this.actionBar.Height;
float ratio = (float)Math.Min(Math.Max(t, 0), headerHeight) / headerHeight;
int newAlpha = (int)(ratio * 255);
this.actionBarDrawable.SetAlpha(newAlpha);
this.actionBar.SetBackgroundDrawable(this.actionBarDrawable);
}
}
This is the Activity which calls the fragment (it doesn't do anything in particular aside calling the fragment in this case):
[Activity(Label = "UserPageActivity")]
public class UserPageActivity : BaseActivity
{
protected override int LayoutResource => Resource.Layout.activity_user_page;
UserViewModel viewModel;
TextView username;
TextView usernameToolbar;
Button followButton;
ViewPager pager;
UserTabsAdapter adapter;
bool IsLoggedUser;
protected override void OnCreate(Bundle savedInstanceState)
{
IsLoggedUser = Intent.GetStringExtra("userId").Equals(LoginController.GetInstance().CurrentUser.Email);
base.OnCreate(savedInstanceState);
viewModel = new UserViewModel();
viewModel.UserLoaded += new UserViewModel.UserLoadedHandler(OnUserLoaded);
viewModel.LoadUserCommand.Execute(Intent.GetStringExtra("userId"));
username = FindViewById<TextView>(Resource.Id.profilename);
usernameToolbar = FindViewById<TextView>(Resource.Id.usernamePage);
followButton = FindViewById<Button>(Resource.Id.followButton);
username.Text = Intent.GetStringExtra("username");
usernameToolbar.Text = Intent.GetStringExtra("username");
adapter = new UserTabsAdapter(this, SupportFragmentManager);
pager = FindViewById<ViewPager>(Resource.Id.user_viewpager);
var tabs = FindViewById<TabLayout>(Resource.Id.tabs);
pager.Adapter = adapter;
tabs.SetupWithViewPager(pager);
pager.OffscreenPageLimit = 5;
pager.PageSelected += (sender, args) =>
{
var fragment = adapter.InstantiateItem(pager, args.Position) as IFragmentVisible;
fragment?.BecameVisible();
};
}
private void OnUserLoaded(bool loaded)
{
}
protected override void OnStart()
{
base.OnStart();
if (IsLoggedUser)
{
followButton.Visibility = ViewStates.Gone;
}
else
{
bool following;
if (LoginController.GetInstance().CurrentUser.FollowsUsers.ContainsKey(Intent.GetStringExtra("userId")))
{
followButton.Text = "Unfollow";
following = true;
}
else
{
followButton.Text = "Follow";
following = false;
}
followButton.Click += (object sender, EventArgs e) =>
{
followButton.Enabled = false;
if (following)
{
UserService service = ServiceLocator.Instance.Get<UserService>();
service.SetUser(LoginController.GetInstance().CurrentUser);
service.RemoveFollowsUserCommand.Execute(viewModel.LoadedUser.Email);
service.SetUser(viewModel.LoadedUser);
service.RemoveFollowedByUserCommand.Execute(LoginController.GetInstance().CurrentUser.Email);
followButton.Text = "Follow";
following = false;
}
else
{
UserService service = ServiceLocator.Instance.Get<UserService>();
service.SetUser(LoginController.GetInstance().CurrentUser);
service.AddFollowsUserCommand.Execute(viewModel.LoadedUser);
service.SetUser(viewModel.LoadedUser);
service.AddFollowedByUserCommand.Execute(LoginController.GetInstance().CurrentUser);
followButton.Text = "Unfollow";
following = true;
}
followButton.Enabled = true;
};
}
}
}
class UserTabsAdapter : FragmentStatePagerAdapter
{
string[] titles;
public override int Count => titles.Length;
public UserTabsAdapter(Context context, Android.Support.V4.App.FragmentManager fm) : base(fm)
{
titles = context.Resources.GetTextArray(Resource.Array.user_sections);
}
public override Java.Lang.ICharSequence GetPageTitleFormatted(int position) =>
new Java.Lang.String(titles[position]);
public override Android.Support.V4.App.Fragment GetItem(int position)
{
switch (position)
{
case 0: return UserContestsFragment.NewInstance();
case 1: return UserPartecipationsFragment.NewInstance();
case 2: return GlobalContestFragment.NewInstance();
case 3: return MessagesFragment.NewInstance();
}
return null;
}
public override int GetItemPosition(Java.Lang.Object frag) => PositionNone;
}
This is the fragment which setups the listener for the recyclerview:
public class UserContestsFragment : AbstractRefresherFadingToolbarFragment<Contest>
{
public static UserContestsFragment NewInstance() =>
new UserContestsFragment { Arguments = new Bundle() };
public override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
}
public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
ContestViewModel viewModel = new ContestViewModel();
base.ViewModel = viewModel;
base.LoadItemsCommand = viewModel.LoadAllByCreatorUserCommand;
base.param = Activity.Intent.GetStringExtra("userId");
base.adapter = new ContestsAdapter(Activity, viewModel);
var view = base.OnCreateView(inflater, container, savedInstanceState);
ScrollViewChangedListener listener = new ScrollViewChangedListener(Activity, recyclerView);
return view;
}
And this is the abstract fragment needed by that fragment which is in charge of setting up the layout:
public abstract class AbstractRefresherFadingToolbarFragment<T> : Android.Support.V4.App.Fragment, IFragmentVisible
{
public ICollectionViewModel<T> ViewModel;
public ICommand LoadItemsCommand;
public object param; //parametro per il LoadItemsCommand
public ItemsAdapter<T> adapter;
public SwipeRefreshLayout refresher;
public ProgressBar progress;
public NotifyingScrollRecyclerView recyclerView;
//LruCache cache = new LruCache((int)(Runtime.GetRuntime().MaxMemory() / 4));
public override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
}
public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.Inflate(Resource.Layout.fragment_fading_toolbar, container, false);
recyclerView = view.FindViewById<NotifyingScrollRecyclerView>(Resource.Id.recyclerView);
//ScrollViewChangedListener listener = new ScrollViewChangedListener((UserPageActivity)Activity, recyclerView);
//adapter.cache = cache;
recyclerView.HasFixedSize = true;
recyclerView.SetAdapter(adapter);
recyclerView.SetItemViewCacheSize(4);
//recyclerView.ChildViewAttachedToWindow += new EventHandler<RecyclerView.ChildViewAttachedToWindowEventArgs>(OnChildViewAttached);
//recyclerView.ChildViewDetachedFromWindow += new EventHandler<RecyclerView.ChildViewDetachedFromWindowEventArgs>(OnChildViewDetached);
refresher = view.FindViewById<SwipeRefreshLayout>(Resource.Id.refresher);
refresher.SetColorSchemeColors(Resource.Color.accent);
progress = view.FindViewById<ProgressBar>(Resource.Id.progressbar_loading);
progress.Visibility = ViewStates.Gone;
return view;
}
}
I didn't read your entire code but I looked at the site you linked in your question. The functionality of the hidden action bar you want to use is handled by CollapsingToolbarLayout in the support library. To know how to use it, go to Cheesesquare. It is a complete example of the support library widgets and can be built and run without any changes.
Edit:
RecyclerView has a method named AddOnScrollListener. Use it instead of the OnScrollChanged. If you use an inherited class from RecyclerView, you can call it in all of the constructors of that class.
I have tried to look out for an answer to the behavior of my views but I seem not find any question or solution related to it. My recycler views seemed to be set up well. I just realized that my app is not responding in the right way to the OnClickListeners.
I have set up toasts in my adapter for the recycler view click events. When i have 10 views. When i click on a view, it gives a text of another view. It seems it randomly gives me the text of another view amongst the 9 remaining views. What could be the cause of this?
Activity
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
FrameLayout content = (FrameLayout)FindViewById(Resource.Id.content_frame);
LayoutInflater.Inflate(Resource.Layout.Main, content);
setUpRecyclerView();
}
public void setUpRecyclerView(){
rv = FindViewById<RecyclerView>(Resource.Id.recyclerView);
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
layoutManager.Orientation = LinearLayoutManager.Vertical;
layoutManager.ReverseLayout = true;
layoutManager.StackFromEnd = true;
rv.HasFixedSize = true;
rv.SetLayoutManager(layoutManager);
}
Adapter
public class FeedViewHolder : RecyclerView.ViewHolder, View.IOnClickListener, View.IOnLongClickListener
{
public FeedViewHolder(View itemView):base(itemView)
{
//binding of variables here
itemView.SetOnClickListener(this);
itemView.SetOnLongClickListener(this);
}
public void OnClick(View v)
{
itemClickListener.OnClick(v, AdapterPosition, false);
}
public bool OnLongClick(View v)
{
itemClickListener.OnClick(v, AdapterPosition, true);
return true;
}
public class FeedAdapter : RecyclerView.Adapter, ItemClickListener
{
public FeedAdapter(RssObject rssObject, Context mContext)
{
this.mContext = mContext;
this.inflater = LayoutInflater.From(mContext);
activity = (MainActivity)mContext;
}
public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
hold = holder as FeedViewHolder;
//binding
hold.itemClickListener = this;
}
public void OnClick(View view, int position, bool isLongClick)
{
Toast.MakeText(activity, "Main text : " + hold.txtContent.Text, ToastLength.Long).Show();
}
public override int ItemCount
{
get { return rssObject.items.Count; }
}
}
}
}
I seem to be hitting a brick wall when trying to use a component called SideBarNavigation.
I have created a new ViewController in designer and given it a button called NewButton, when I go to load the app it crashes on this line :-
SidebarController = new SidebarNavigation.SidebarController(this, NavController, menuController);
RootViewController.cs
using UIKit;
using SidebarNavigation;
using Inchcape.iOS;
namespace Inchcape.IOS
{
public partial class RootViewController : UIViewController
{
private UIStoryboard _storyboard;
// the sidebar controller for the app
public SidebarNavigation.SidebarController SidebarController { get; private set; }
// the navigation controller
public NavController NavController { get; private set; }
// the storyboard
public override UIStoryboard Storyboard
{
get
{
if (_storyboard == null)
_storyboard = UIStoryboard.FromName("Main", null);
return _storyboard;
}
}
public RootViewController() : base(null, null)
{
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
var introController = (IntroController)Storyboard.InstantiateViewController("IntroController");
var menuController = (MenuViewController)Storyboard.InstantiateViewController("MenuViewController");
// create a slideout navigation controller with the top navigation controller and the menu view controller
NavController = new NavController();
NavController.PushViewController(introController, false);
SidebarController = new SidebarNavigation.SidebarController(this, NavController, menuController);
SidebarController.MenuWidth = 220;
SidebarController.ReopenOnRotate = false;
}
}
}
MenuViewController.cs
using Foundation;
using Inchcape.iOS;
using System;
using UIKit;
namespace Inchcape.iOS
{
[Register("MenuViewController")]
public partial class MenuViewController : BaseController
{
public MenuViewController (IntPtr handle) : base (handle)
{
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
var contentController = (ContentController_)Storyboard.InstantiateViewController("ContentController_");
//ContentButton.TouchUpInside += (o, e) => {
// if (NavController.TopViewController as ContentController == null)
// NavController.PushViewController(contentController, false);
// SidebarController.CloseMenu();
//};
}
}
}
Has anyone experienced this at all???
I have a requirement where I initially have a list of messages only ordered by date/time. The requirement if for the user to be able to click on a UISegmentedControl (list of 4 buttons) and be able to change the UITableView from a straight list to a grouped list (ie. grouped by category of message).
From what I've read, once the style is set on a UITableView you can not change it. So what is the best approach to satisfy this requirement? Kill the view and re-create with the appropriate style?
Not that it makes a huge difference, I am using Xamarin Studio and C#, targeting Mono 3.2.1 and iOS 6+
Rather than killing the view and re-instantiating, just maintain references to two UITableViews, one of each of the appropriate types. Toggle between them using your Controller class. The following simple example puts the toggling button in the same UIView as the table, which is probably not appropriate, but otherwise shows the technique:
public class ChangeableSource : UITableViewSource
{
public bool Grouped { get; set; }
public override int NumberOfSections(UITableView tableView)
{
if(Grouped)
{
return 4;
}
else
{
return 1;
}
}
public override int RowsInSection(UITableView tableview, int section)
{
return 3;
}
public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath)
{
var cell = tableView.DequeueReusableCell("Default");
if(cell == null)
{
cell = new UITableViewCell(UITableViewCellStyle.Default, "Default");
}
cell.TextLabel.Text = String.Format("IndexPath {0} {1}", indexPath.Section, indexPath.Row);
return cell;
}
}
public class ToggleTableView : UIView
{
UITableView ungroupedView;
UITableView groupedView;
ChangeableSource changeableSource;
public void SetStyle(bool grouped)
{
changeableSource.Grouped = grouped;
if(changeableSource.Grouped)
{
ungroupedView.RemoveFromSuperview();
AddSubview(groupedView);
}
else
{
groupedView.RemoveFromSuperview();
AddSubview(ungroupedView);
}
}
public bool GetStyle()
{
return changeableSource.Grouped;
}
public ToggleTableView()
{
var btn = new UIButton(new RectangleF(10, 10, 150, 40));
btn.SetTitle("Change", UIControlState.Normal);
btn.TouchUpInside += (s,e) => ToggleStyle(this, new EventArgs());
var tvFrame = new RectangleF(0, 60, UIScreen.MainScreen.Bounds.Width, UIScreen.MainScreen.Bounds.Height - 60);
ungroupedView = new UITableView(tvFrame, UITableViewStyle.Plain);
groupedView = new UITableView(tvFrame, UITableViewStyle.Grouped);
AddSubview(btn);
AddSubview(ungroupedView);
changeableSource = new ChangeableSource();
changeableSource.Grouped = false;
ungroupedView.Source = changeableSource;
groupedView.Source = changeableSource;
}
public event EventHandler<EventArgs> ToggleStyle = delegate {};
}
public class TogglingTableController : UIViewController
{
public TogglingTableController() : base ()
{
}
public override void DidReceiveMemoryWarning()
{
// Releases the view if it doesn't have a superview.
base.DidReceiveMemoryWarning();
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
var view = new ToggleTableView();
view.ToggleStyle += (s,e) =>
{
view.SetStyle(! view.GetStyle());
};
this.View = view;
}
}
[Register ("AppDelegate")]
public class AppDelegate : UIApplicationDelegate
{
UIWindow window;
TogglingTableController viewController;
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
window = new UIWindow(UIScreen.MainScreen.Bounds);
viewController = new TogglingTableController();
window.RootViewController = viewController;
window.MakeKeyAndVisible();
return true;
}
}
public class Application
{
static void Main(string[] args)
{
UIApplication.Main(args, null, "AppDelegate");
}
}