When accessing to outlets from my CustomClass : UICollectionViewCell, they are appearing as not initialized and can not set a proper value.
Every example I've seen it uses a plain Class (no XIB) to set the UI.
[Register("CustomCommentCell")]
public partial class CustomCommentCell : UICollectionViewCell
{
public static readonly NSString Identifier = new NSString("CustomCommentCell");
public CustomCommentCell () : base()
{
}
public CustomCommentCell (IntPtr handle) : base (handle)
{
}
public void updateData()
{
this.lblComment.Text = "Test";
}
}
On the other hand, I have registered the Class:
this.tableComments.RegisterClassForCell (typeof(CustomCommentCell),commentCellId);
and have the GetCell properly set.
However, when trying to set the outlets to a specific value, it indicates it is null. (this.lblcomment = null) while it should have been a UILabel initialized.
Any clues?
to create the Custom CollectionViewCell using XIB. do the following
1) create C# class which inherits from UIcollectionViewCell
[Register("MyCustomCell")]
public class MyCustomCell : UICollectionViewCell
{
public static readonly NSString Key = new NSString ("MyCustomCell");
[Export ("initWithFrame:")]
public MyCustomCell(CoreGraphics.CGRect frame) : base (frame)
{
}
public override UIView ContentView {
get {
var arr= NSBundle.MainBundle.LoadNib ("MyCustomCell", this, null);
UIView view =arr.GetItem<UIView> (0);
view.Frame = base.ContentView.Frame;
base.ContentView.AddSubview (view);
return base.ContentView;
}
}
}
2) Add a IphoneView XIB file has the Same Name as that of Class created in step 1
3) Open XIB in XCODE and do the Following Changes
3.1)Select the FileOwner set the Class same name as Step 1
3.2)Select The View Set the Class name UIView
4) Design Your XIB Accordingly
I can't follow quite the problem you are seeing. What is a "Custom XIB outlet"? Why is this question tagged "custom-controls"? Is there some example code or pictures you can show to help explain the problem?
The approach I use for UICollectionViewCell's is the same as I use for UITableViewCell - see the tutorial - http://slodge.blogspot.co.uk/2013/01/uitableviewcell-using-xib-editor.html
Update: From the code you've posted as a comment (not sure if it's complete or not), I think it would be useful for you to follow through that tutorial. There are a few steps to complete including registering the custom class name and including using RegisterNibForCellReuse - one of those will probably fix this for you.
Related
On the start of my iOS application (that I am building with Xamarin and MvvmCross), I want to immediately change UIViewController to a UITabBarViewController. My code:
public class MainViewModel : BaseViewModel
{
public void Initialization()
{
ShowViewModel<TabLayoutViewModel>(); // Breaks here
}
}
public class MainViewController : BaseViewController<MainViewModel>
{
public override void ViewDidLoad()
{
base.ViewDidLoad();
this.ViewModel.Initialization();
}
}
public class TabLayoutViewController : MvxTabBarViewController<TabLayoutViewModel>
{
}
On the line ShowViewModel<TabLayoutViewModel>() it throws an exception:
A TabBarViewController cannot be presented as a child. Consider using
Root instead
I just want to push this controller on top of the stack. I know this is legal in plain iOS so there should be a way to do it with MvvmCross?
Update: Since MvvmCross 5.0.4 it is now possible to show a TabBarController as a child. Just mark your TabBarController with [MvxChildPresentation].
See this PR to the source code..
Original answer:
A TabBarController is not meant to be presented inside a UINavigationController. What you can do is to change the root ViewController of your Window. To do so, you can add the MvxRootPresentation attribute above the TabLayoutViewController class.
If you do need to show tabs inside a UINavigationController, you might find this question relevant.
I had to do just that last week.
What I do to quickly resolve this is simple:
1) Create a custom presenter that inherits from MvxIosViewPresenter (https://github.com/MvvmCross/MvvmCross/blob/develop/MvvmCross/iOS/iOS/Views/Presenters/MvxIosViewPresenter.cs).
2) Override the ShowChildViewController method, using the original as model and comment these two lines:
if (viewController is IMvxTabBarViewController)
throw new MvxException("A TabBarViewController cannot be presented as a child. Consider using Root instead");
3) Override the CreatePresenter method in Setup.cs:
protected override IMvxIosViewPresenter CreatePresenter()
{
return new CustomTabChildMvxIosViewPresenter(ApplicationDelegate, Window);
}
I am using Xamarin.iOS. I have created UIView with a few UITextFields. I am looking for best way to initialize text value in these textfields from code.
I can pass text data in the constructor of UIViewContoller, but I don't have access to textFields inside it (they are null). I can change text value of textFields in viewDidLoad method.
I don't want to create additional fields in controller class to store data passed by constructor and use them in viewDidLoad. Do you know better solution ?
I don't want to create additional fields in controller class to store
data passed by constructor and use them in viewDidLoad.
But that's how it's meant to be done.
Alternatively, you can create less fields/properties in your viewcontroller if you use a MVVM pattern:
public class UserViewModel {
public string Name { get; set;}
public string Title { get; set;}
}
public class UserViewController : UIViewController
{
UserViewModel viewModel;
public UserViewController (UserViewModel viewModel) : base (...)
{
this.viewModel = viewModel;
}
public override void ViewDidLoad ()
{
userName.Text = viewModel.Name;
userTitle.Text = viewModel.Title;
}
}
That's the kind of pattern which gives you a lot of code reuse accross platforms (android, WP, ...) and clearly separate concerns. It's a (very) little bit of extra code, but it's worth every byte.
Stackoverflow question https://stackoverflow.com/a/13555814/1678391 was answered about setting variable sized cells in a UICollectionViewController. I'm trying to figure out how to do this with a UICollectionView object contained in a UIViewController. GetSizeForItem is what I need but don't see where to get it.
My implementation adds a UICollectionView to my UIViewController via Xcode. In my code I'm doing the following;
public partial class CustomViewController : UIViewController
{
public override void ViewDidLoad()
{
collectionView.RegisterClassForCell(typeof(MyCell), cellId);
}
public override void ViewWillAppear(bool animated)
{
collectionView.Source = new CollectionViewSource(items, cellId);
}
class CollectionViewSource : UICollectionViewSource
{
}
class MyCell : UICollectionViewCell
{
}
}
According to http://docs.go-mono.com GetSizeForItem is available only for UICollectionViewDelegateFlowLayout class.
To use that method you should implement UICollectionViewDelegateFlowLayout subclass and assing it to Delegate property of UICollectionViewController. Example.
I have an app (written using MonoTouch and currently working) that I want to add landscape orientation to. I am using a UITabBarController.
I don't see how to create a controller that will allow me to override the "ShouldAutorotate..." method. Can anybody point me to an example using a UITabBarController in MonoTouch?
TweetStation contains a sample precisely for this setup, and propagates the rotation down all of the nested view controllers.
Are you subclassing UITabBarController?
You are probably non subclassing and just adding a vanilla controller in Interface Builder. You have to subclass to override that property.
First make a new class like this:
//Test this, it's off the top of my head
[Register("YourTabController")]
public class YourTabController : UITabBarController
{
public YourTabController (IntPtr handle) : base (handle) { }
[Export("initWithCoder:")]
public YourTabController (NSCoder coder) : base (coder) { }
//Override should rotate
public bool ShouldAutoRotateToInterfaceOrientation(UIInterfaceOrientation o)
{ return true; }
}
Then, if you already have a UITabBarController in IB, there is a 'Class' property that you set to the name of your new class.
I am using a custom UITableViewDelegate and in my controller I want to run some code when the tableview has a rowselected. I noticed the UITableViewDelegate already has an event called RowSelected but you cannot use it I'm guessing because there is a method in UITableViewDelegate with the exact same name.
If I write:
mytableviewdelegate.RowSelected += myeventhandler;
This will not compile and gives the error:
"Cannot assign to 'RowSelected' because it is a 'method group'"
Any ideas, I have a work around which is fine so Im really looking at working out if this is a bug in MonoTouch?
How are you implementing the custom UITableViewDelegate? I would suggest using Monotouch's UITableViewSource as it combines both the UITableViewDataSource and the UITableViewDelegate into one file which makes things so much easier.
Some example code:
(in your UIViewController that contains the UITableView)
tableView.Source = new CustomTableSource();
Then you'll want to create a new class for this:
public class CustomTableSource : UITableViewSource
{
public CustomTableSource()
{
// constructor
}
// Before you were assigning methods to the delegate/datasource using += but
// in here you'll want to do the following:
public override int RowsInSection (UITableView tableView, int section)
{
// you'll want to return the amount of rows you're expecting
return rowsInt;
}
// you will also need to override the GetCells method as a minimum.
// override any other methods you've used in the Delegate/Datasource
// the one you're looking for in particular is as follows:
public override void RowSelected (UITableView tableView, NSIndexPath indexPath)
{
// do what you need to here when a row is selected!
}
}
That should help you get started. In the UITableViewSource class you can always type public override and MonoDevelop will show you what methods are available to be overriden.