I'm creating an IPad application using C#, Mono develop and Monotouch.
I've been using Monotouch.Dialog to create functionality similar to the wifi-settings on an iPhone. I'm using StyledStringElement with an accessory and am now trying to differentiate between tapping the row and tapping the DetailDisclosureButton.
I've been found out that I should override the UITableViewDelegate.AccessoryButtonTapped on the UITableView. I've tried to created a derived class from UITableViewDelegate and hook this into the Monotouch.Dialog. But this is where I got stuck. I didn't manage to replace the existing UITableViewDelegate with my extended version.
So my questions are:
Is this the preferred way of handling this event (to be able to differentiate between a tap on the element and a tap on the DetailDisclosureButton) ?
If not, any pointer on how to accomplish this ?
I have been searching the web for a (similar) example but have not found any yet. Any examples that you know of that could get me started ?
Thanks,
boris
event EventHandler accessoryPushed;
public override void AccessoryButtonTapped (UITableView tableView, NSIndexPath indexPath)
{
if(!accessoryPushed)
{
accessoryPushed(this,EventArgs.Empty);
}
}
You will need to add this to the DailogViewController code that you are using (this will override the tapping action). Instead of a simple function, you may want an event to be triggered, so just handle the event in your main code. That is probably your best bet.
Once you change this line, you will have to implement new functions like AccessorySelected (just mimic the path the code follows when a row is selected except with accessory).
On the other hand, you could try a different navigation method, often disclosure buttons are annoying and you don't want to click on them except to get simple information about the button (like a help feature).
I haven't found any other examples, sorry!
Related
I want to detect the scroll of tableview in my class. I used decelerationEnded method of UITableViewDelegate but it got crashed.
Ideally you should be using a UITableViewSource assigned to your UITableView.Source property. You no longer require a delegate class, you can override all of the necessary methods within the source, which is the currently preferred method of achieving the result your after. You are most likely looking to override the method called 'Scrolled' within the UITableViewSource. However I would suggest making use of 'DecelerationEnded' as well if you're trying to do something depending on if your scroll view is at the 'bottom' or 'top' of the UITableViews content (That's just a little tip based off of some experience with this in a recent project.)
For Xamarin.Forms.DatePicker It is not obvious that the date field is "tapable" I want to change the text color of it to blue so the user will think it is clickable?
I see a background color property but not forecolor/text color?
Let me know how I can do that.
I did it just creating a class like that on my Android Project and making no changes on my Forms Pages:
using Xamarin.Forms;
using xxxx.Droid;
[assembly: ExportRenderer(typeof(Xamarin.Forms.DatePicker), typeof(MyDatePickerRederer))]
namespace xxxx.Droid
{
public class MyDatePickerRederer : Xamarin.Forms.Platform.Android.DatePickerRenderer
{
protected override void OnElementChanged(Xamarin.Forms.Platform.Android.ElementChangedEventArgs<Xamarin.Forms.DatePicker> e)
{
base.OnElementChanged(e);
this.Control.SetTextColor(Android.Graphics.Color.Black);
}
}
}
I don't think that the forecolor/text color is accessible at this time and I'm not sure if it will be in the future or not. Typically what you would do in this scenario is create a Custom Renderer to get down into the native implementation of the UIDatePicker control for iOS and change it's properties there. The problem with that in this case is that if you look through the iOS SDK documentation as well, I don't believe there is a way to customize the text on the UIDatePicker picker control. This is why you can't do it in Xamarin.Forms either.
At this point you will probably have to create your own custom control/renderer to make such a small change. Frustrating, I know, but unfortunately that this point I don't think you can actually accomplish the simple thing you are looking to do. :-(
I need to implement a login/logout using MVVMCross, iOS only to start. After the user logs in, I want to close the view and make the "real" first view the root controller. For logout, I want to do the same in reverse. Whenever the LoginViewModel is requested, clear the root and replace it.
This Remove ViewController from stack indicates there is a ClearTop parameter, but it looks like it is gone in v3?
I then found this What is the best way to handle GoBack for the different MvvmCross (v3) platforms and I implemented this Presenter:
public override void Close(IMvxViewModel toClose)
{
if (toClose is LoginViewModel)
{
ClearBackStack();
Show(new MvxViewModelRequest() { ViewModelType = typeof(FirstViewModel)});
return;
}
base.Close(toClose);
}
public override void Show(MvxViewModelRequest request)
{
if (request.ViewModelType == typeof (LoginViewModel))
{
ClearBackStack();
}
base.Show(request);
}
Is this the correct way to handle this? Is there an easier mechanism (pre-v3 like)? Should I be overriding ChangePresentation instead?
Also, is there a mechanism to call ShowViewModel from a View? Do I need to resolve the IMvxViewDispatcher or is there a more straight forward method?
Yes, if you want to do custom presentation techniques then the easiest way is to implement your own view presenter.
For an introduction and some links on this, see How can I implement SplitView in another view in MvvmCross?
You are free to write code directly in your views, including navigation logic using resolved IoC objects. However, mvvmCross tries to encourage you to put this logic in the viewmodels - especially so that the 'logic' is more easily shared between platforms.
NOTE: There are two similar SO questions (1) (2), but neither of them provides an answer.
TL;DR: How can one dismiss the keyboard in a MonoTouch.Dialog by letting the user touch any empty space in the view?
I'm writing an app using MonoTouch.Dialog and a UITabBarController. One of my tabs is "Settings"...
When the user starts typing, the keyboard obstructs the tabbar...
Using MonoTouch.Dialog, the only way to dismiss the keyboard is to go to the last field and press the "return" key. Considering the fact that the user cannot press any tab until the keyboard is gone, I would like a better way to do it. Namely, to dismiss if the user taps anywhere else on the screen.
Without MonoTouch.Dialog, it's a snap: simply override TouchesBegan and call EndEditing. But this doesn't work with MT.D. I've tried subclassing DialogViewController and overriding TouchesBegan there, but it doesn't work. I'm currently at a loss.
Or, I wonder, would I be better off ditching the tabbar so I can use a UINavigationController with a "Back" button on top, which won't be hidden by the keyboard?
I suggest you use a tap gesture recognizer that will not cause interference with the TableView event handlers:
var tap = new UITapGestureRecognizer ();
tap.AddTarget (() => dvc.View.EndEditing (true));
dvc.View.AddGestureRecognizer (tap);
tap.CancelsTouchesInView = false;
You missed my question about it also: Can the keyboard be dismissed by touching outside of the cell in MonoTouch.Dialog?
:-)
This is my #1 feature request for MonoTouch.Dialog.
To answer your question: No. It is not possible. I have searched and asked around and have not found any answers.
I assume because it is just a sectioned (grouped) table and if it wasn't sectioned, there wouldn't be any spot to click. However, that is just my speculation.
I wish that miguel or someone that works on monotouch would answer this and say if it is even possible. Possibly a future enhancement?
I figured out a workaround that satisfies me well enough, so I'm answering my own question.
// I already had this code to set up the dialog view controller.
var bc = new BindingContext (this, settings, "Settings");
var dvc = new DialogViewController (bc.Root, false);
// **** ADD THIS ****
dvc.TableView.DraggingStarted += (sender, e) => {
dvc.View.EndEditing (true);
};
This will dismiss the keyboard whenever the user drags the view a little bit. There's no touch event I could find associated with the tableview, so this is the next best thing. I'd welcome any other ideas. Cheers!
One workaround to use the dragging gesture instead of the tap as proposed (that do not interfere with the table view gestures) is to override MonoTouch.Dialog.DialogViewController.SizingSource (or MonoTouch.Dialog.DialogViewController.Source if you don't want uneven rows) and give it to the DialogViewController. I don't know if it is very clean or safe.
public class CustomTableViewSource : MonoTouch.Dialog.DialogViewController.SizingSource
{
public CustomTableViewSource(MonoTouch.Dialog.DialogViewController dvc) : base(dvc)
{
}
public override void DraggingStarted(UIScrollView scrollView)
{
base.DraggingStarted(scrollView);
if (scrollView != null)
{
scrollView.EndEditing(true);
}
}
}
I am developing a control for an IPAD application (My first time doing Apple development). Its a simple control that mimics a grid - consists of a collection of UIViews (each of which represents a cell) all added to a parent UIView (in a grid like fashion).
One of the requirements is to implement a swipe gesture - the users swipe across the grid to activate/inactivate the cell - this corresponds to a 1/0 in the database.
I create a UISwipeGesture and added it to each of my UIView which represents a cell. That appears to be an incorrect approach as it fires the event for the UIView in which the swipe originated but not across all the UIViews.
My understanding would be that i need to implement the SwipeGesture across the parent UIView which contains all these children UIView. However if i do that how will i know which child UIView has been swiped over? Or any other approach which would make sense?
I know this thread is fairly old, but I created a Swipe extension method that might have helped.
View.Swipe(UISwipeGestureRecognizerDirection.Right).Event += Swipe_Event;
void Swipe_Event(ViewExtensions.SwipeClass sender, UISwipeGestureRecognizer recognizer)
{
View view = sender.View; // do something with view that was swiped.
}
This may not answer your question, but I can speak to the approach I've taken here with a similar use case:
1) I would abandon UIScrollView and use UITableView. You'll notice that UITableView inherits from UIScrollView and has all the performance benefits of virtualization and cell / view re-use. Which you'll find terribly useful as you work towards optimizing your app for performance on device.
2) Utilize the UITableViewCell's ContentView to create custom "Grid" cells. Or better yet, utilize MonoTouch.Dialog if you're not required to create Grid rows ad-hoc.
3) Use this awesome class (props to #praeclarum) to setup gestures in MonoTouch. You essentially provide a UIGestureRecognizer as a generic argument. You can then utilize the LocationInView method to grab the point in the UITableView where the gesture occurred
public void HandleSwipe(UISwipeGestureRecognizer recognizer)
{
if(recognizer.State == UIGestureRecognizerState.Ended) {
var point = recognizer.LocationInView(myTableView);
var indexPath = myTableView.IndexPathForRowAtPoint(point);
// do associated calculations here
}
}
I think you're correct that the gesture recognizer has to be attached to the parent view. In the action method associated with the gesture recognizer I think you can use the Monotouch equivalent of CGRectContainsPoint() to determine whether the swipe occurred in a particular subview. I imagine you would have to iterate through the subviews until you found the one in which the swipe occurred. I'm not aware of a method that would immediately identify the swiped subview.