My Xaml:
<StackLayout
Orientation="Vertical">
<StackLayout
Orientation="Horizontal">
//Group labels and back arrow
</StackLayout>
<ListView>
//Message list
</ListView>
<Grid>
//Plus symbol,Editor and send icon
</Grid>
</StackLayout>
Screenshot:
Issue:
In normal screen there is a bar on the top(red circled). When click the editor on the bottom top bar is hiding. I need the top bar always on top. This issue is only in IOS part, in android this feature is working fine. How can I fix this issue?
Its an iOS feature that the UI is adjusted upwards. You can shrink (or keep) the view via a custom renderer.
Check this great explanation.
And also this peace of code for a keyboard custom renderer on iOS.
Like the picture in the question my soft keyboard always touching the Editor. So I added a custom renderer for my Editor to solve that issue. After adding that custom renderer the top bar is always sticking on the top of the page.
I used the following custom renderer to solve the keyboard overlapping issue:
using System;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
using HBIClientFacingApp;
using HBIClientFacingApp.iOS;
[assembly:ExportRenderer( typeof(CustomEditor), typeof(CustomEditorRenderer))]
namespace YourNameSpace.iOS
{
public class CustomEditorRenderer: EditorRenderer
{
public ChatEntryRenderer()
{
UIKeyboard.Notifications.ObserveWillShow ((sender, args) => {
if (Element != null)
{
Element.Margin = new Thickness(0,0,0, args.FrameEnd.Height); //push the entry up to keyboard height when keyboard is activated
}
});
UIKeyboard.Notifications.ObserveWillHide ((sender, args) => {
if (Element != null)
{
Element.Margin = new Thickness(0); //set the margins to zero when keyboard is dismissed
}
});
}
}
}
I am using Swift 2.3 in Xcode 7.3. I have a UINavigationController with a UITableViewController. I am trying to set the titleView of the navigation item in the navigationBar to create a button centered in the navigation bar.
The indexTextBut is a UIButton hooked up from the story board. I have tried just creating a new button and it made no perceivable difference. The way I am currently doing it the button is there as it has the behavior it should but no image. I have tried just setting the title field as a string and even then I see nothing. I set the right and left barButtonItems using:
navItem.setRightBarButtonItems(barButtonItems, animated: false)
navItemArray.append(navItemCatDet)
self.navigationController?.navigationBar.setItems(navItemArray, animated: false)
Here is my relevant code. My big question is why can't I see the image of the button being set to the titleView. It has preset behavior and when I click where it should be I get that behavior. I've tried adjusting the frame of the UIButton and its UIImageView, and the size of the UIImageView's image but have had no luck. I included the line aobut tinting the background just incase it is related even though I have tried it with and without.
class MyTableViewController: UITableViewController, UITextFieldDelegate {
#IBOutlet weak var indexTextBut: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
var indexNavItemArray = [UINavigationItem]()
var indexNavItem = UINavigationItem()
indexNavItem.titleView = newButton
indexNavItemArray.append(indexNavItem)
self.navigationController?.navigationBar.barTintColor = UIColor(netHex:0xe63246)
self.navigationController?.navigationBar.setItems(indexNavItemArray, animated: false)
swift 3.0
var indexNavItemArray = [UINavigationItem]()
var indexNavItem = UINavigationItem()
indexNavItem.titleView = indexTextBut
indexTextBut.setTitle("button", for: .normal)
indexNavItemArray.append(indexNavItem)
self.navigationController?.navigationBar.barTintColor = UIColor.lightGray
self.navigationController?.navigationBar.setItems(indexNavItemArray, animated: false)
replace your code to above.
I'm designing a UI in Xamarin.Forms to collect feedback from users about our application. There is an Editor control at the bottom of this page. On an iPhone 4S, and in many landscape orientations, the keyboard completely obscures this editor control. On Android, this is not a big deal because the OS automatically scrolls (though the sizing behavior is a little weird.) On iOS, the only things resembling solutions are very wonky.
In native iOS, the solution is simple: wrap your views in a UIScrollView, then when the keyboard appears add that much space to the content size and scroll appropriately. Xamarin doesn't expose anything to control the scroll position in ScrollView, and ContentSize is private, so that's out. A few posts (here and here) seem to indicate ScrollView is at least part of the solution. It does appear Xamarin has some automatic scrolling behavior, but it's... curious.
My layout is fairly simple:
At the top, a fixed navigation bar that I do not want to scroll out of view.
Beneath that, a 180px tall image that represents a screenshot of the application.
Beneath that, a label with information such as the timestamp. (2-3 lines of text).
Beneath that, the editor, filling the remaining available space.
I've included code for a layout I've tried at the bottom of my post. I created a StackLayout that contains the image, the label, and the editor. I put that inside a ScrollView. Then, I create a RelativeLayout and place the navigation bar at the top-left with the ScrollView beneath it.
What I want to happen when the Editor is tapped is for the keyboard to be displayed and, if it obscures the Editor, for the layout to be nudged upwards to make the Editor visible. What happens instead is it seems like Xamarin scrolls the layout upwards by the keyboard height plus some margin that looks suspiciously like the keyboard utility bar height. This shoves the Editor upwards so high it's obscured by the navigation bar.
I've tried a lot of different tweaks and I'm at a loss. I can't control enough of the ScrollView to get the behavior I need. I've seen suggestions that use a BoxView resized when the Editor gains focus, but to make it work really well I'd still have to hook into the iOS notifications to get the appropriate size and have a fairly intimate knowledge of where my Editor's bounds are. It feels wrong.
Does anyone else have a solution to this on Xamarin.Forms? Even if I have to dip into native, I'd like an answer.
(Here's an example layout that demonstrates the problem, there's a little bit of weird structure because I was debugging. The funky colors are also a relic of layout debugging.)
using System;
using Xamarin.Forms;
namespace TestScroll
{
public class MainPage : ContentPage {
public MainPage() {
InitializeComponent();
}
private ScrollView _scroller;
protected void InitializeComponent() {
var mainLayout = new RelativeLayout();
var navbar = new Label() {
BackgroundColor = Color.Blue,
TextColor = Color.White,
Text = "I am the Nav Bar",
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.StartAndExpand
};
var subLayout = new ScrollView() {
VerticalOptions = LayoutOptions.FillAndExpand,
HorizontalOptions = LayoutOptions.FillAndExpand
};
_scroller = subLayout;
var subStack = new StackLayout();
subStack.Spacing = 0;
subLayout.Content = subStack;
var image = new BoxView() {
Color = Color.Green,
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.Fill,
HeightRequest = 300
};
subStack.Children.Add(image);
var infoLabel = new Label() {
BackgroundColor = Color.Blue,
TextColor = Color.Black,
Text = "Timestamp!\r\nOther stuff!",
VerticalOptions = LayoutOptions.Start
};
subStack.Children.Add(infoLabel);
var editor = new Editor() {
VerticalOptions = LayoutOptions.FillAndExpand
};
subStack.Children.Add(editor);
mainLayout.Children.Add(navbar,
Constraint.Constant(0),
Constraint.Constant(20),
Constraint.RelativeToParent((parent) => parent.Width),
Constraint.Constant(70));
mainLayout.Children.Add(subLayout,
Constraint.Constant(0),
Constraint.RelativeToView(navbar, (parent, view) => navbar.Bounds.Bottom),
Constraint.RelativeToParent((parent) => parent.Width),
Constraint.RelativeToView(navbar, TestConstraint));
Content = mainLayout;
}
private double TestConstraint(RelativeLayout parent, View view) {
double result = parent.Height - view.Bounds.Height;
Console.WriteLine ("Lower stack height : {0}", result);
Console.WriteLine ("Scroll content size: {0}", _scroller.ContentSize);
return result;
}
}
}
One thing I notice is that you are adding a ScrollView (subLayout) to another ScrollView (_scroller).
Also, I ran into this same problem on iOS except all of my controls were within a Grid. Simply putting the Grid into a single ScrollView fixed the problem, without having to change content sizes or anything like that.
This question sat for a long time unanswered, here's what I did. I don't know that it's the 'answer', and I do appreciate hvaughan3's answer that's currently here and I will try it if I ever get the time.
My page behaved like I wanted on Android, so I didn't do anything specific for that.
So I wrote specific code for iOS that used the notifications UIKeyboardWillShow and UIKeyboardWillHide. These notifications provide information about the bounds the keyboard will take up. So when I get a 'show' notification, I manipulate my layout to allow room for an element of that size I place underneath the keyboard. When I get a 'hide' notification, I reset the layout.
It's janky and a little embarrassing, I hope to come back with news I tried another solution like hvaughan3's and it worked.
I've got a spark List with an item renderer. When I click on an element, the renderer becomes larger and when I click again, it becomes small again.
The problem is that list doesn't resize with the content. I've tried to dispatch an event from the renderer passing its content size and resize list in this way:
private function refreshList(event:ResultEvent):void
{
var size:Number = (event.result as Number) + 6;
if (size >= mylist.width)
{
consultingNumber++;
mylist.width = size;
}
else
{
consultingNumber--;
if (consultingNumber == 0)
mylist.width = size;
}
mylist.invalidateDisplayList();
}
consultingNumber is the number of 'opened' renderer.
It works quite well, but when all renderer is 'closed' an horizontal scrollbar appear.
Tracing list's width it result correct but the scrollbar is there even if I set horizontalScrollPolicy to off.
Try calling myList.invalidateSize() instead of myList.invalidateDisplayList();
Here is some more information about the flex component lifecycle which should get you on the right track:
http://weblog.mrinalwadhwa.com/2009/06/21/flex-4-component-lifecycle/
http://www.slideshare.net/rjowen/adobe-flex-component-lifecycle-presentation
Cheers
I have a weird problem with verticalScrollPosition in Flex.
I have a content Canvas and a wrapper Canvas. The content is large (5000px X 5000px), the wrapper is 800px X 800px.
public var wrapper:Canvas = new Canvas();
public var content:Canvas = new Canvas();
wrapper.addChild(content);
application.addChild(wrapper);
I would like to set the wrapper's scrollbar position dynamically anytime. I can do it by calling its properties:
wrapper.verticalScrollPosition = A;
wrapper.horizontalScrollPosition = B;
This is working fine. But! If I set a default scrollbar position when the Canvas is complete:
wrapper.addEventListener(FlexEvent.CREATION_COMPLETE, function(e:FlexEvent):void{
wrapper.verticalScrollPosition = DEFAULT_A;
wrapper.horizontalScrollPosition = DEFAULT_B;
});
I can't set the verticalScrollPosition anymore:
wrapper.verticalScrollPosition = C;
trace(wrapper.verticalScrollPosition); // Outputs: DEFAULT_A
So the problem only exist if I set a default position using 'FlexEvent.CREATION_COMPLETE'.
What am I doing wrong here?
Thanks in advance.
I've found a horrible workaround - I wait 1 microsecond to set the default state:
wrapper.addEventListener(FlexEvent.CREATION_COMPLETE, function(e:FlexEvent):void{
setTimeout(
function():void{wrapper.verticalScrollPosition = DEFAULT_A;},
1
);
});
I think we can agree it's really ugly. How can I make it better?
I've found the problem. I attached the event listener to the child of the wrapper. When I added the listener to the wrapper itself it works.
So lesson I've learnt: always track the topmost ui element's events you have to work with.