I have a Xamarin.Forms app and want to set the NavigationBar to be translucent. But when I do, I get a strange behavior with the Xamarin views:
ListViews or TableViews behave correctly. But when I wrap them in a RefreshView, they are overlapped by the UINavigationBar.
-- TRANSLUCENCY WITHOUT REFRESHVIEW: OKAY
<ContentPage>
<ListView>
...
</ListView>
</ContentPage>
-- TRANSLUCENCY WITHOUT REFRESHVIEW: BUGGY
<ContentPage>
<RefreshView> <----
<ListView>
...
</ListView>
</RefreshView>
</ContentPage>
Am I missing something?
Repro on GitHub: https://github.com/awaescher/xamarin-repro
How to make a translucent NavigationBar: https://xamgirl.com/transparent-navigation-bar-in-xamarin-forms/
We can use navigationPage.BarBackgroundColor = Color.Transparent to achieve that .
NavigateFromMenu method modified as follow :
case (int)MenuItemType.TranslucentWithoutRefreshView:
MenuPages.Add(id, CreateTranslucentNavigationPage(new TranslucentWithRefreshPage(),false));
break;
case (int)MenuItemType.TranslucentWithRefreshView:
MenuPages.Add(id, CreateTranslucentNavigationPage(new TranslucentWithRefreshPage(),true));
break;
Then in CreateTranslucentNavigationPage method :
private Xamarin.Forms.NavigationPage CreateTranslucentNavigationPage(Xamarin.Forms.Page page, bool value)
{
var navigationPage = new Xamarin.Forms.NavigationPage(page);
if (value)
{
navigationPage.BarBackgroundColor = Color.Transparent;
navigationPage.BarTextColor = Color.Black;
}
//Xamarin.Forms.PlatformConfiguration.iOSSpecific.NavigationPage.SetIsNavigationBarTranslucent(navigationPage, true);
return navigationPage;
}
The effect :
Related
I'm trying to mount a view using VerticalStackLayout, but the second (Border) disappears when I add another CollectionView sample element, how can I resolve this, if I comment out the first element(CollectionView) the second appears pasted at the top.
Yes, that is because the CollectionView automatically full fill the page. So you couldn't see the Border.
Some workaround here:
1.You could set the HeightRequest for the CollectionView:
<CollectionView x:Name="CollectionViewTransactions" ... HeightRequest="300">
2.if there is more item in CollectionView, you could put it in a ScrollView:
<ScrollView Orientation="Vertical">
<CollectionView x:Name="CollectionViewTransactions" ... HeightRequest="300">
</ScrollView>
3.You may also customize the HeightRequest for CollectionView depending on the count of item. The following code is just for example.
In xaml file，set binding for HeightRequest
<CollectionView x:Name="CollectionViewTransactions" HeightRequest="{Binding Height}" ...>
In ViewModel, define a property for height and update it when adding a new item:
public int Height
{
get
{
return height;
}
set
{
height = value;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Height)));
}
}
public void SetNewHeight()
{
Height = 70 * ItemCollection.Count; //
}
All of the above three ways can show border below the CollectionView. You could have a try based on your design
For more info, you could refer to CollectionView.
Hope it works for you.
I have a implement syncfusion Carousel and binding items using ItemTemplate.When i load the items to Carousel all item appears in Carousel view.But i need to add a doted indicator for it.
When user swipe though the Carousel by the dots should indicate current position.
When reading from documentation of syncfusion rotator have this functionality.
I need to add this to carousel view.
Here you can find all the SfCarousel Class Members.
And there's no property for the dots you refered in the SfCarousel print.
In fact, I think you are confusing it with another component called SfRotator. (that has an identical example like your print). and the property you are looking for is called: DotPlacement.
And can have the following states:
None //No Dots
Default //Dots Inside the Rotator View
OutSide //Dots Outside the Rotator View
We have analyzed your query and currently we don’t have dots view support in CarouselView. However, we can fulfill this requirement by using Border or Button control as like below code snippet.
Custom DotsView:
XAML:
<border:SfBorder BorderColor="{Binding ThumbBorder}" HorizontalOptions="Center" VerticalOptions="Center" BorderWidth="5" CornerRadius="50" />
Carousel View:
XAML:
<carousel:SfCarousel x:Name="carousel" Grid.Row="0" Offset="0" ItemsSource="{Binding ImageCollection}" ItemTemplate="{StaticResource itemTemplate}"
ItemHeight="200" SelectionChanged="Carousel_SelectionChanged"
ItemWidth="200" />
<StackLayout Grid.Row="1" HorizontalOptions="Center" x:Name="rotatorThumb" BackgroundColor="Transparent" Orientation="Horizontal"/>
C#:
public MainPage()
{
InitializeComponent();
Command command = new Command((object thumb) =>
{
var thumbView = thumb as DotsView;
if (thumbView != null)
{
((rotatorThumb.Children[carousel.SelectedIndex] as DotsView).BindingContext as CarouselModel).
ThumbBorder = Color.LightGray;
carousel.SelectedIndex = thumbView.Index;
(thumbView.BindingContext as CarouselModel).ThumbBorder = Color.Red;
}
});
for (var i = 0; i < ImageCollection.Count; i++)
{
var itemView = new DotsView() { BindingContext = ImageCollection[i], Index = i };
if (carousel.SelectedIndex == i)
(itemView.BindingContext as CarouselModel).ThumbBorder = Color.Red;
TapGestureRecognizer thumbTap = new TapGestureRecognizer();
thumbTap.Command = command;
itemView.GestureRecognizers.Add(thumbTap);
thumbTap.CommandParameter = itemView;
rotatorThumb.Children.Add(itemView);
}
}
Output:
Sample
I used to use the Frame control of Xamarin.Forms as a CardView for Android, but I updated the Xamarin.Forms package to version 3.1.0 and the frame appearence has changed. It doesn't have elevation and shadows. I tried to create a custom renderer, but doesn't work.
To explain what I'm trying to say, see the pictures below. First picture is the old behaviour of frame. The appearence is exactly like CardView in Android and the second picture is the new behaviour, for the version 3.1.0 of Xamarin.Forms. The frame doesn't have elevation and shadows.
Old behaviour:
New behaviour
Here is my code that I use the Frame (for Android Platform, CardView is a simple frame)
<customViews:CardView>
<StackLayout Spacing="0">
<StackLayout.Margin>
<OnPlatform x:TypeArguments="Thickness" Android="16"/>
</StackLayout.Margin>
<ContentView>
<OnPlatform x:TypeArguments="View">
<OnPlatform.iOS>
<customViews:HeaderDivider/>
</OnPlatform.iOS>
</OnPlatform>
</ContentView>
public class CardView : Frame
{
public CardView()
{
Padding = 0;
if (Device.RuntimePlatform == Device.iOS)
{
HasShadow = false;
OutlineColor = Color.Transparent;
BackgroundColor = Color.Transparent;
}
}
}
<Frame HasShadow="true">
<Label Text="Test"/
</Frame>
I guess after Update default value for HasShadow in Frame is set to false;
How can I hide contentview using binding.How to use binding in On platform argument? please check following screen shot for issue.
In screeen shot example like showjoin isvisible true. then it's fine. but showjoin is false then by default contentview is displayed because of in onflatform is true.
please help me too sort-out this issue
If all you are wanting to do is hide the ContentView when your platform is Android, I would suggest using the OnPlatform in your xaml. Also, setting the IsVisible property of a ContentView twice won't work well usually.
Using your xaml from above:
<OnPlatform x:TypeArguments="View">
<On Platform="iOS">
<ContentView Margin="20,10,20,20" HeightRequest="40">
<!-- Rest of ContentView code -->
</ContentView>
</On>
<!-- You must specify an Android view -->
<On Platform="Android">
<!-- Use a simple boxview with height and width 0 to create an empty view -->
<BoxView HeightRequest="0" WidthRequest="0" IsVisible="False"/>
</On>
</OnPlatform>
This will only show the ContentView on your page when using iOS and nothing on Android.
a) Create one Boolean property in Viewmodel e.g. IsContentViewVisible
b) Bind this property to contentview IsVisible property e.g. IsVisible = "{Binding IsContentViewVisible}", also make sure Raisepropertychanged event should be in place.
c) As per your need you set the IsContentViewVisible property to False/true in your ViewModel
The question is not all to clear... but if you want to avoid the XAML OnPlatform override ( because it is not using Binding ), you can delete it in XAML and just add the correct logic in your ShowJoinButton bool property.
You can check platform in code ( even in your ViewModel ) like so:
if(Device.RuntimePlatform == Device.iOS) ...
If you still want to have everything in XAML, that is also possible of course.
You can use Binding inside OnPlatform, thing to take note is the type argument has to be BindingBase!
<OnPlatform x:TypeArguments="BindingBase" iOS="{Binding MyBool}" Android="{Binding MyBool}"/>
Below is the code to write binding in ViewModel class
private const string ShowJoinButtonPropertyName = "ShowJoinButton";
private bool showJoinButton = false;
public bool ShowJoinButton
{
get { return showJoinButton; }
set { SetProperty(ref showJoinButton, value, ShowJoinButtonPropertyName); }
}
Wherever you want to hide/show you need to use the below code
if (Device.RuntimePlatform == Device.Android)
{
ShowJoinButton = false;
}
else
{
ShowJoinButton = true;
}
Hope it helps!
I originally implemented this feature but simply adding an image to a button. Then I realized I could simply add a tap gesture to an image (w/o using a button). Any recommendations which is the best way to go and why? Thanks.
I use my own "OnClick" event for Image :) with a custom control:
public class MyImage : Xamarin.Forms.Image
{
public static BindableProperty OnClickProperty =
BindableProperty.Create("OnClick", typeof(Command), typeof(MyImage));
public Command OnClick
{
get { return (Command)GetValue(OnClickProperty); }
set { SetValue(OnClickProperty, value); }
}
public MyImage()
{
GestureRecognizers.Add(new TapGestureRecognizer() {Command = new Command(DisTap)});
}
private void DisTap(object sender)
{
if (OnClick != null)
{
OnClick.Execute(sender);
}
}
}
Then use it with MVVM like:
<local:MyImage Source="{Binding Img}" OnClick="{Binding ImgTapCommand}" />
It depends of visual effect you want to achieve.
If you use Button you'll have tapped animation (depens of platform) and specific buttton border. You have much less control how the image will look like (it's on the left side of button text).
If you use a plain TapGestureRecognizer you'll have a normal image with full control of aspect ratio/size etc.
You could use absolute layout, which can be used to place two elements above each other, make sure to make the button is the second element.
<AbsoluteLayout>
<Image Source="clock.png" AbsoluteLayout.LayoutBounds="0.2,0.2,35,35" AbsoluteLayout.LayoutFlags="PositionProportional"/>
<Button AbsoluteLayout.LayoutBounds="0.2,0.2,35,35" AbsoluteLayout.LayoutFlags="PositionProportional" BorderColor="Transparent" BackgroundColor="Transparent" Command="{Binding AlertMeCommand}"/>
</AbsoluteLayout>