BackgroundColor in control blocked click - xamarin

I have Frame with Grid in content. When i added contentWiew (with content) to Grid there are two options:
1. If contentWiew have BackgroundColor = "Transparent" then when i click to the contentWiew pressing happen in Frame (contentWiew skiped through it).
2. If contentWiew have BackgroundColor = NotTransparent (Red,Yellow) then when i click to the contentWiew pressing happen in contentWiew ().
Part of the code:
Label mainText = new Label { Text = "TestText", FontSize = 14 };
var contntView = new ContentView () { BackgroundColor = Color.Transparent , HorizontalOptions = LayoutOptions.End, VerticalOptions = LayoutOptions.Start };
contntView.Content = mainText;
mainGrid.Children.Add (contntView,0,1);
I need to do exactly the turnover =) When ContentView is Transparent - catch click. When ContentView is not Transparent - skip click to Frame.
How can I control this process, regardless of BackgroundColor?

You can partially control this process using any View's InputTransparent property. If it's set to true, the view will be transparent to touch events.

Related

Xamarin Forms ScrollView scrolls automatically to the beginning when any child element is clicked

I created a Horizontal / Vertical Scrollview in Xamarin Forms that contains several types of childs like:
Labels
CustomCheckboxes
ImageViews
Pickers
Sliders
Here is my code:
ScrollView scrollTracks = new ScrollView
{
BackgroundColor = Color.Black,
VerticalOptions = LayoutOptions.StartAndExpand,
HorizontalOptions = LayoutOptions.FillAndExpand,
Content = layoutTracks,
Orientation = ScrollOrientation.Both
};
When I click some child elements like the CustomCheckboxes, or the Labels, or the ImageViews, the program scroll automatically the view to the beginning.
I tested this on the UWP platform.
How can I make the program to stop doing this?
Add this tag to the ScrollView solved my issue:
IsTabStop = false
Here the code:
ScrollView scrollTracks = new ScrollView
{
BackgroundColor = Color.Black,
VerticalOptions = LayoutOptions.StartAndExpand,
HorizontalOptions = LayoutOptions.FillAndExpand,
Content = layoutTracks,
Orientation = ScrollOrientation.Both,
IsTabStop = false
};

How to Hide Navigation bar back button title globally in xamarin.ios

I used this code in AppDelegate,
UIBarButtonItem.Appearance.SetBackButtonTitlePositionAdjustment (new UIOffset (-100, -60), UIBarMetrics.Default);
But it position is changed to bottom. I have attached the result screenshot.
Solution1 : set Title Color instead of Title Position
UITextAttributes attribute = new UITextAttributes {TextColor = UIColor.Clear };
UIBarButtonItem.Appearance.SetTitleTextAttributes(attribute, UIControlState.Normal);
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UIBarButtonItem.Appearance.SetBackButtonTitlePositionAdjustment (new UIOffset (-100, 0), UIBarMetrics.Default);

Xamarin horizontal view with buttons

any ideas how to prepare such an element as at the picture ?
I need 5 buttons to be there so i could swipe through them but only 3 one them are visible all the time. I need this to work on android and ios in xamarin forms.
Try this Add ScrollView and set it's orientation to horizontal
ScrollView = new ScrollView
{
Orientation = ScrollOrientation.Horizontal
};
//ScrollView.Scrolled += ScrollView_Scrolled;
ItemsStackLayout = new StackLayout
{
Orientation = StackOrientation.Horizontal,
Padding = new Thickness(0),
Spacing = 0,
HorizontalOptions = LayoutOptions.FillAndExpand
};
ScrollView.Content = ItemsStackLayout;
you can set the width of the elements inside 1/3 of the view width
FYI I use the same in my app

how to apply max height and enable scroll to Xamarin.Forms.Editor

I wanted chat application type user interface in my app & i am targeting android and iOS.
I am using Xamarin.Forms.Editor for reply
Editor _replyEntry = new Editor
{
HorizontalOptions = LayoutOptions.FillAndExpand,
TextColor = Color.Black
}
in this case the editor height remains constant and allows scrolling and editor does not expands
Then i used InvalidateMeasure()
_replyEntry .TextChanged += (sender, e) => { this.InvalidateMeasure(); };
in this case editor expands as when the text requires more space but does not allow scroll inside editor and if user types long message then editor does not allows scroll and text goes behind the keyboard and not visible to user
Is there any way to enable scroll and give max height to edit either in xamarin.forms of by writing custom renderer
Thanks
Here is my code
public class abc : ContentPage
{
public abc()
{
Image attchment = new Image
{
Source = "attachment.png",
HorizontalOptions = LayoutOptions.Start
};
Editor _replyEntry = new Editor
{
HorizontalOptions = LayoutOptions.FillAndExpand,
TextColor = Color.Black,
};
Button _sendButton = new Button
{
Text = "Send",
TextColor = Color.Black,
BackgroundColor = Color.Transparent,
HorizontalOptions = LayoutOptions.End
};
StackLayout replyStack = new StackLayout
{
Orientation = StackOrientation.Horizontal,
Padding = new Thickness(10),
Spacing = 10,
VerticalOptions = LayoutOptions.End,
Children = { attchment, _replyEntry, _sendButton }
};
Content = replyStack;
}
}
It looks like you will have to use a custom renderer to achieve what you are wanting.
There is a post here that has pretty much the same thing with what you are trying to achieve for Android.
In that demo it has an expanding multi-line EditText control (android:singleLine="false"), with only vertical scrollbars (android:scrollbars="vertical"), whilst disabling the horizontal scrollbars (android:scrollHorizontally="false").
You need to ensure the Editor' parent is expanding, then the editor will automatically expand too. If you make an empty contentpage and add an Editor, the is will just expand. If you place it inside a stacklayout, the you need to ensure that the stacklayout is expanding.

How to add a click handler to content page in xamarin forms

I am new at Xamarin.Forms and are trying to add a click event to my content page. I want an event to start when the user clicks on the page, no matter where.
I've created similar functionality in a WinPhone app, where I could solve my problem with OnLeftMouseButtonDown which was available on PhoneApplicationPage, but I could not find a suitable counterpart in the ContentPage. Any suggestions?
In order to get this working you have to add a Layout to the ContentPage, as you will want to specify some content, and set the HorizontalOptions and VerticalOptions to LayoutOptions.FillAndExpand.
This is not enough though to handle the taps correctly though.
You also need to specify a BackgroundColor for the Layout. I set mine to Color.Transparent. If you try without specifying a Color it does not work.
You then have to attach a TapGestureRecognizer to the ContentPage in order to catch the clicks that are made.
Although this works well with Labels and Buttons in my test below, still receiving the TapGestures for WindowsPhone on both types, along with the Button click event firing - this does not fully work with Android - as the Button click will prevent the TapGesture event from firing.
The other alternative is to try putting an 'invisible' Grid over the top of everything. However the issue with this approach is that you will loose the Click event handler from firing with WindowsPhone and also loose the Click event handler from firing with Android. The good part though - is that you can detect a click anywhere, although not pass this on. It just depends what your trying to achieve at the end of the day.
StackLayout objStackLayout = new StackLayout()
{
Orientation = StackOrientation.Horizontal,
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.FillAndExpand,
BackgroundColor = Color.Transparent
};
//
Label objLabel1 = new Label();
objLabel1.BackgroundColor = Color.Red;
objLabel1.Text = "label1";
objLabel1.HorizontalOptions = LayoutOptions.Start;
objLabel1.VerticalOptions = LayoutOptions.Start;
objLabel1.WidthRequest = 100;
objLabel1.HeightRequest = 300;
objStackLayout.Children.Add(objLabel1);
//
Label objLabel2 = new Label();
objLabel2.BackgroundColor = Color.Green;
objLabel2.Text = "label2";
objLabel2.Font = Font.OfSize("Arial", 48);
objLabel2.WidthRequest = 100;
objLabel2.HeightRequest = 300;
objStackLayout.Children.Add(objLabel2);
//
Button objButton1 = new Button();
objButton1.Text = "Click Me";
objButton1.WidthRequest = 300;
objButton1.HeightRequest = 300;
objStackLayout.Children.Add(objButton1);
//
this.Content = objStackLayout;
TapGestureRecognizer objTapGestureRecognizer1 = new TapGestureRecognizer();
objTapGestureRecognizer1.Tapped += ((o2, e2) =>
{
System.Diagnostics.Debug.WriteLine("Clicked!");
});
this.Content.GestureRecognizers.Add(objTapGestureRecognizer1);

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