Assume we have a CustomView with Entry (or any other view) inside of it:
public class CustomView : ContentView
{
public CustomView()
{
var entry = new Entry();
Content = entry;
}
}
How to expose entry's Text property to make view's Text property that is bindable? So view's Text property should be two-way bindable and it should be synchronised with entry's Text property.
You can create your own BindableProperties. In this case, as it's an entry, make sure the default binding mode is 2-way. Then you can just set the BindingContext of the Entry to the current object, and bind the ContentView.Text to the the Entry.TextProperty.
public class CustomView : ContentView
{
public CustomView ()
{
var entry = new Entry ();
entry.SetBinding (Entry.TextProperty, "Text");
entry.BindingContext = this;
}
public static readonly BindableProperty TextProperty =
BindableProperty.Create ("Text", typeof(string), typeof(CustomView), default(string), BindingMode.TwoWay);
public string Text {
get { return (string)GetValue (TextProperty); }
set { SetValue (TextProperty, value); }
}
}
Related
I created a usercontrol with 2 properties :
Url : image url (string)
Color : color to tint the image (System.Windows.Media.Color)
There is my XAML to call the usercontrol :
<myUserControl:MyImageTint Url="Assets/Images/decoration.png" Color="{Binding ImageColor}"/>
There is my code behind in the usercontrol
public static readonly DependencyProperty UrlProperty = DependencyProperty.Register("Url", typeof(string), typeof(MyImageTint), new PropertyMetadata(string.Empty));
public static readonly DependencyProperty ColorProperty = DependencyProperty.Register("Color", typeof(Color), typeof(MyImageTint), new PropertyMetadata(null));
public string Url
{
get
{
return (string)GetValue(UrlProperty);
}
set
{
SetValue(UrlProperty, value);
}
}
public string Color
{
get
{
return (string)GetValue(ColorProperty);
}
set
{
SetValue(ColorProperty, value);
}
}
Now I would like to use this properties to tinted my image.
In the Url setter I can set my image url and display it. But I can't use the color to tint the image. The property is null.
How can I use this property in the same function ?
I tinted my image in the usercontrol Loaded event, like this and I can use my properties
private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
TintMyImage(Url, Color);
}
Is it the best way ?
I have a ViewModel called LocationsViewModel, in which I have a ObservableCollection<LocationViewModel>. Additionally I have a LocationsView, which is an MvxCollectionViewController, in which I create a binding set and bind a MvxCollectionViewSource to the ObservableCollection.
In the LocationCell, which is a MvxCollectionViewCell, I want to display a MonoTouch.Dialog which is bound to various properties in the currently
selected LocationViewModel. The easiest way seems to be to create a nested MvxDialogViewController in the MvxCollectionViewCell, however to bind the
Elements in the MvxDialogViewController, I obviously need to create a Binding Target. My question is really can I pass a binding target from the MvxCollectionViewCell to the MvxDialogViewController?
Let me also try to explain it briefly with some code to improve the understanding.
LocationsViewModel.cs
public class LocationsViewModel : MvxViewModel
{
...
public ObservableCollection<LocationViewModel> Locations
{
get { return _locationDataService.Locations.Locations; }
}
...
}
LocationViewModel.cs
public class LocationViewModel : MvxNotifyPropertyChanged
{
...
//Tons of public properties like:
public string Name
{
get { return LinkedDataModel.Name; }
set
{
LinkedDataModel.Name = value;
RaisePropertyChanged(() => Name);
}
}
public double CurrentNoiseLevel
{
get { return LinkedDataModel.CurrentNoiseLevel; }
set
{
LinkedDataModel.CurrentNoiseLevel = value;
RaisePropertyChanged(() => CurrentNoiseLevel);
}
}
...
}
LocationsView.cs
[Register("LocationView")]
public class LocationsView
: MvxCollectionViewController
{
static readonly NSString LocationCellId = new NSString("LocationCell");
private readonly bool _isInitialized;
public LocationsView()
: base(new UICollectionViewFlowLayout()
{
MinimumInteritemSpacing = 0f,
ScrollDirection = UICollectionViewScrollDirection.Horizontal,
MinimumLineSpacing = 0f
})
{
_isInitialized = true;
ViewDidLoad();
}
public new LocationsViewModel ViewModel
{
get { return (LocationsViewModel)base.ViewModel; }
set { base.ViewModel = value; }
}
public sealed override void ViewDidLoad()
{
if (!_isInitialized)
return;
base.ViewDidLoad();
CollectionView.RegisterClassForCell(typeof(LocationCell), LocationCellId);
var source = new MvxCollectionViewSource(CollectionView, LocationCellId);
CollectionView.Source = source;
CollectionView.PagingEnabled = true;
var set = this.CreateBindingSet<LocationsView, LocationsViewModel>();
set.Bind(source).To(vm => vm.Locations);
set.Apply();
CollectionView.ReloadData();
}
}
LocationCell.cs
public class LocationCell : MvxCollectionViewCell
{
[Export("initWithFrame:")]
public LocationCell(RectangleF frame)
: base(string.Empty, frame)
{
InitView();
}
public LocationCell(IntPtr handle)
: base(string.Empty, handle)
{
InitView();
}
private void InitView()
{
var cell = new LocationCellDialog();
ContentView.Add(cell.View);
}
public class LocationCellDialog
: MvxDialogViewController
{
public LocationCellDialog()
: base(UITableViewStyle.Grouped, null, true)
{ }
public override void ViewDidLoad()
{
base.ViewDidLoad();
//How do I get the target here?
var target = ??;
Root = new RootElement
{
new Section
{
new StringElement().Bind(target, t => t.Name),
new StringElement().Bind(target, t => t.CurrentNoiseLevel)
}.Bind(target, t => t.Name),
};
}
}
}
So the question is can I simply pass along a binding target from the parent LocationCell to nested LocationCellDialog or is that a no go?
Each bindable view in MvvmCross has its own DataContext
For a top level View this DataContext is the ViewModel
For a Cell within a List, Table or Collection then the DataContext is set to the object in the list which the Cell is currently showing.
If you want to data-bind any property within a Cell to a property path on the DataContext then you can do so using the Fluent binding syntax.
For example, to bind the Text value of a child UILabel called myLabel to a child property Name on a Person in the list you could use:
this.CreateBinding(myLabel).For(label => label.Text).To<Person>(p => p.Name).Apply();
Or if you wanted to bind the Text to the Person itself you could use:
this.CreateBinding(myLabel).For(label => label.Text).Apply();
In your LocationCell I think you are saying you want to bind the DataContext of the nested LocationCellDialog to the DataContext of the containing cell.
To do this you should be able to use:
private void InitView()
{
var cell = new LocationCellDialog();
ContentView.Add(cell.View);
this.CreateBinding(cell).For(cell => cell.DataContext).Apply();
}
i use Monotouch.Dialog (Xamarin.iOS Version: 6.2.0.65) to create a RadioGroup with RadioElements. I only want the 'search' functionality in the second screen (where the user selects from the long list), so i created a separate DialogViewController where i enabled the search filter (enableSearch = true).
When typing in the search box, the app crashes in the GetCell method of the RadioElement.
"Object reference not set to an instance of an object" on line 1064 of Element.cs. Do i have GC problems? I managed to simulate it in a small app... Don't pay attention some weird field members, thats me testing if i'm begin GC...
using MonoTouch.Dialog;
using MonoTouch.Foundation;
using MonoTouch.UIKit;
namespace SearchCrash
{
// The UIApplicationDelegate for the application. This class is responsible for launching the
// User Interface of the application, as well as listening (and optionally responding) to
// application events from iOS.
[Register ("AppDelegate")]
public partial class AppDelegate : UIApplicationDelegate
{
// class-level declarations
UIWindow window;
public UINavigationController NavigationController { get; set; }
//
// This method is invoked when the application has loaded and is ready to run. In this
// method you should instantiate the window, load the UI into it and then make the window
// visible.
//
// You have 17 seconds to return from this method, or iOS will terminate your application.
//
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
window = new UIWindow(UIScreen.MainScreen.Bounds);
this.NavigationController = new UINavigationController();
this.NavigationController.PushViewController(new FirstViewController(this.NavigationController), true);
window.RootViewController = this.NavigationController;
window.MakeKeyAndVisible();
return true;
}
}
public class FirstViewController : DialogViewController
{
private UINavigationController controller;
private LocatiesRootElement locRootElement;
private RadioGroup radioGroup;
public FirstViewController(UINavigationController c) : base(new RootElement("Test"), true)
{
this.controller = c;
}
public override void ViewDidLoad()
{
Section section = new Section();
radioGroup = new RadioGroup(0);
locRootElement = new LocatiesRootElement("test", radioGroup, this.controller);
section.Add(locRootElement);
Root.Add(section);
}
}
public class LocatiesRootElement : RootElement
{
private UINavigationController navigationController;
private LocatiesViewController locatiesViewController;
public LocatiesRootElement(string selectedLocatie, RadioGroup group, UINavigationController controller) : base("Locatie", group)
{
this.navigationController = controller;
this.locatiesViewController = new LocatiesViewController(this);
}
public override void Selected(DialogViewController dvc, UITableView tableView, NSIndexPath path)
{
this.navigationController.PushViewController(this.locatiesViewController, true);
}
}
public class LocatiesViewController : DialogViewController
{
public LocatiesViewController(LocatiesRootElement root) : base(root, true)
{
this.EnableSearch = true;
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
Section sectionList = new Section();
RadioElement radioElement1 = new RadioElement("item 1");
RadioElement radioElement2 = new RadioElement("item 2");
sectionList.Add(radioElement1);
sectionList.Add(radioElement2);
Root.Add(sectionList);
}
}
}
Try enabling the search after you instantiate the DialogViewController.
Like this :
public LocatiesRootElement(string selectedLocatie, RadioGroup group, UINavigationController controller) : base("Locatie", group)
{
this.navigationController = controller;
this.locatiesViewController = new LocatiesViewController(this);
this.locatiesViewController.EnableSearch = true;
}
Hopefully that will work for you.
The bug report here includes a workaround for the root cause of the issue you're experiencing, but also talks about how filtering will then cause a usability issue of marking the nth element as selected even after a filter has been applied.
https://github.com/migueldeicaza/MonoTouch.Dialog/issues/203
If you don't want to update the core MTD code, you could use that same technique by putting it in your own UIBarSearchDelegate. Unfortunately, the default SearchDelegate class is internal, so you'll need to add all of the code in your delegate. I was able to do this and get it working without changing the MTD source:
public override void LoadView()
{
base.LoadView();
((UISearchBar)TableView.TableHeaderView).Delegate = new MySearchBarDelegate(this);
}
And then you use this instead of the base method:
public override void TextChanged (UISearchBar searchBar, string searchText)
{
container.PerformFilter (searchText ?? "");
foreach (var s in container.Root)
s.Parent = container.Root;
}
I have a MvxBaseBindableCollectionViewCell which loads a xib that contains a custom button. I would like to be able to pass this custom button a ViewModel to bind to. Is this possible?
I'm trying to acheive something like MyButton.ViewModel = ViewModel.ChildViewModel and have ViewModel.ChildViewModel.Name show as the button title.
If you want to custom bind a cell, then there's a tutorial on this in http://slodge.blogspot.co.uk/2013/01/uitableviewcell-using-xib-editor.html
If you want to create a fully bindable UIButton within that View then you can do this using some inheritance like:
[Register("MyButton")]
public class MyButton
: UIButton
, IMvxServiceConsumer
{
private IList<IMvxUpdateableBinding> _bindings;
private const string BindingText = "SpecialTitle Customer.Name";
public MyButton()
{
}
public MyButton(IntPtr handle)
: base(handle)
{
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
foreach (var binding in _bindings)
{
binding.Dispose();
}
_bindings.Clear();
}
base.Dispose(disposing);
}
private object _dc;
public object DataContext
{
get { return _dc; }
set
{
_dc = value;
if (_bindings == null)
{
var binder = this.GetService<IMvxBinder>();
_bindings = binder.Bind(_dc, this, BindingText).ToList();
}
else
{
foreach (var binding in _bindings)
{
binding.DataContext = _dc;
}
}
}
}
public string SpecialTitle
{
get { return this.GetTitle(UIControlState.Normal); }
set { this.SetTitle(value, UIControlState.Normal); }
}
}
Aside> MvvmCross v3 "Hot Tuna" will contain some helper classes to make this a bit simpler to do.
Situation:-
In my code I have to use the LWUIT Component object for the listview controls. The controls are dynamic and hence can be in any number.
Right now I am creating Component objects according to the controls(in numbers) i.e.- for every control to be created first the Component object is creating.
This process slows down the rendering of the listview when the controls are increasing.
Solution:-
If I create the Component object and use it in a loop for all the controls it is taking the reference of the object and hence displays all the listview items(controls) with the same data.
Now I am able to think of one last option of Cloning my object and using it to create the controls.
Problem:-
But I can't find any way in LWUIT by which I can achieve the copying of object.
What can be the alternatives in LWUIT to solve this problem?
P.S.-The listview items are of same type, but with different data.
Use a List component and the Renderer design pattern to create a "rubber stamp" component where you can display a large number of elements easily. See an explanation of this in the Codename One blog.
Create these classes first :
public class ListUtil {
private Vector data = new Vector();
private Content[] contents;
public ListUtil(Vector vData)
{
data = vData;
contents = new Content[vData.size()];
}
public List createList(Display display, CListCell renderer, ActionListener listener)
{
CList theList;
for(int i = 0; i < data.size(); i++)
{
contents[i] = new Content(String.valueOf(data.elementAt(i)));
}
theList = new CList(display, contents, renderer, listener);
return theList;
}
}
public class Content
{
private String row;
public Content(String row)
{
this.row = row;
}
public String getRow()
{
return (row);
}
}
public class CListCell extends Container implements ListCellRenderer {
private Label focus = new Label("");
public CListCell()
{
super();
// create and add the components here among the components which will display data
}
public Component getListCellRendererComponent(List list, Object value, int index, boolean isSelected)
{
Content entry = null;
if (value instanceof Content)
entry = (Content)value;
componentDisplayingDataAddedIntoThisListCellRenderer.setText(entry.getRow());
return this;
}
public Component getListFocusComponent(List arg0)
{
return focus;
}
}
public class CList extends List {
private Display disp;
public CList(Display display, Object[] data, CListCell renderer, ActionListener actionListener)
{
super(data);
setListCellRenderer(renderer);
setIgnoreFocusComponentWhenUnfocused(true);
addActionListener(actionListener);
setScrollAnimationSpeed(getScrollAnimationSpeed()/4);
disp = display;
}
public void pointerReleased(int x,int y)
{
if (isEnabled() && hasFocus())
super.pointerReleased(x, y);
}
public void keyReleased(int keyCode)
{
if (isEnabled() && hasFocus())
{
if (disp.getGameAction(keyCode) == Display.GAME_FIRE)
pointerReleased(getX(),getY());
else
super.keyReleased(keyCode);
}
}
}
To create your List and add it to a Form :
public class myForm extends Form implements ActionListener
{
private Vector listSource = // your vector of data
private CListCell renderer = new CListCell();
private List theList = (new ListUtil(listSource)).createList(Display.getInstance(),renderer, this);
...
public void actionPerformed(ActionEvent evt)
{
if (evt.getSource() == theList)
doSomething();
}
}