Xamarin Form - ScrollView and its Content - xamarin.forms

I have created one sample application and in that I have taken one ContentPage and did its design as below
<ContentPage>
<ScrollView Orientation="Horizontal" x:Name="scroll">
<StackLayout HeightRequest="50" Orientation="Horizontal">
<Label x:Name="lbl1" Text="label1!" VerticalOptions="Center" HorizontalOptions="Center" />
<Label x:Name="lbl2" Text="label2" VerticalOptions="Center" HorizontalOptions="Center" />
<Label x:Name="lbl3" Text="label3" VerticalOptions="Center" HorizontalOptions="Center" />
<Label x:Name="lbl4" Text="label4" VerticalOptions="Center" HorizontalOptions="Center" />
</StackLayout>
</ScrollView>
</ContentPage>
It works absolute fine , but when I take ContentView instead of ContentPage , I got blank page on emulator.
Is it bug ? or I did something wrong in this.

Xamarin.Forms works by bringing Pages in and out of the view. A ContentPage is a Page, but a ContentView is NOT a Page.
If it helps, a ContentView is analagous to a UserControl in WPF.
See this forum for some other explanations on the subject.

Related

Xamarin Forms CarouselView and ScrollView already scrolled without visited

I have a CarouselView with inside a ScrollView .
I've seen it plastered across documentation that it's not advisable to nest a scrollview inside any other scrollable layout, but what else can I do when I need to be able to scroll between items and each item must have scrollable content also.
Now my problem is with iOS (with all version after 10+) and Android (will all version after 6+). Let's assume we have 10 items and during the first display I make a vertical scroll in the middle of the content. When I get to the fifth view it is not displayed as a new element and therefore from the top but in the middle. If I do it to the second, the sixth mirrors the second and so on. In practice it seems that the views are linked by 5 in 5.
Here is my simple code:
<CarouselView ItemsSource="{Binding Monkeys}"
HorizontalScrollBarVisibility="Never" >
<CarouselView.ItemTemplate>
<DataTemplate>
<StackLayout Orientation="Vertical" Spacing="0">
<ScrollView VerticalScrollBarVisibility="Never" HorizontalScrollBarVisibility="Never" >
<StackLayout>
<Image
Source="{Binding ImageUrl}" HeightRequest="350"
Aspect="AspectFill" />
<Label Text="{Binding Name}"
LineBreakMode="TailTruncation"/>
<Label Text="{Binding Details}" FontSize="35" />
<Label Text="{Binding Details}" FontSize="35" TextColor="Aqua"/>
<Label Text="{Binding Details}" FontSize="35" TextColor="Fuchsia"/>
<Label Text="{Binding Details}" FontSize="35" TextColor="OliveDrab"/>
</StackLayout>
</ScrollView>
<Label Text="Fixed Button" BackgroundColor="Red" TextColor="White" HeightRequest="50" HorizontalTextAlignment="Center" VerticalTextAlignment="Center" />
</StackLayout>
</DataTemplate>
</CarouselView.ItemTemplate>
</CarouselView>
GIF dimostration

Xamarin Forms 4.1: ScrollView scroll is covering header view in android device 9.0

In Xamarin Forms 4.1, When scroll, scrollview content is covering/overflow the headerview and scrollview content is not shown completely.
Tried with IsClippedToBounds to true.
Created scrollviewrenderer, OnDraw() -> set clip to bound property. But didn't worked.
Example: Here is the XAML design
<Stacklayout>
<HeaderView/>
<ScrollView IsClippedToBounds="true">
<Stacklayout>
<label text="1"/>
........
........
<label text="100"/>
</Stacklayout>
</ScrollView>
</Stacklayout>
I make a custom control as the headerview in your description. And test on Xamarin.forms 4.1, works well.
MyCustomConrol:
<StackLayout Orientation="Horizontal" BackgroundColor="Aqua">
<Label x:Name="Title_label" Text="Title" TextColor="Black" FontSize="25" HorizontalOptions="StartAndExpand" Margin="8,0,4,0"/>
<Button x:Name="btnHello" Text="Hello" HorizontalOptions="EndAndExpand" Margin="4,0,8,0"/>
</StackLayout>
MainPage.xaml
<StackLayout>
<local:MyCustomControl></local:MyCustomControl>
<!--<HeaderView/>-->
<ScrollView IsClippedToBounds="true">
<StackLayout>
<Label Text="1"/>
<Label Text="2"/>
<Label Text="3"/>
……………
…………………
</StackLayout>
</ScrollView>
Result:
You could download from ScrollView/XamarinDemo folder of GitHub for reference.
https://github.com/WendyZang/Test.git
If you want your header to be always visible then rather than placinf your content in Header, it will be better to place your header content first then below that place your listview. Thus, your header remains intact and listview scrolls.

Xamarin Forms group controls without modifying layout

I've got following view:
<ContentPage.Content>
<AbsoluteLayout HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
<StackLayout AbsoluteLayout.LayoutFlags="All" AbsoluteLayout.LayoutBounds="0,0,1,1">
<StackLayout VerticalOptions="CenterAndExpand" Margin="20, 0, 20, 0">
<StackLayout>
<Label Text="Login" HorizontalOptions="CenterAndExpand" />
<Entry Text="{Binding Login, Mode=OneWayToSource}"></Entry>
</StackLayout>
<StackLayout>
<Label Text="Hasło" HorizontalOptions="CenterAndExpand" />
<Entry IsPassword="True" Text="{Binding Password, Mode=TwoWay}"></Entry>
</StackLayout>
<Button Text="Zaloguj się" Command="{Binding SignInCommand}"></Button>
</StackLayout>
</StackLayout>
<BoxView AbsoluteLayout.LayoutFlags="All" AbsoluteLayout.LayoutBounds="0,0,1,1" BackgroundColor="Gray" Opacity="0.5" InputTransparent="false" IsVisible="{Binding IsBusy}" />
<ActivityIndicator IsRunning="{Binding IsBusy}" AbsoluteLayout.LayoutFlags="All" AbsoluteLayout.LayoutBounds="0,0,1,1" VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" />
</AbsoluteLayout>
</ContentPage.Content>
I want to move BoxView and ActivityIndicator to external control to make reusable component. The problem is that to achieve this I need to "group" these controls to obtain one child element.
The question is if is there any element I can use to group my controls, but which will not affect the way how controls are displayed? Alternatevlly which element I can use and how to still have effect of overlay over whole page and loading indicator?
I was trying to use AbsoluteLayout, StackLayout etc. but I couldn't position it to persist initial effect (overlay on whole page and loading indicator in the center with opacity = 1).
You can use DependencyService and reuse it in any page.
Check this tutorial.
There is also a working sample.

Xamarin Forms Present a Page from Right to Left

Actually I am trying to show a Master Detail Page with Menu button on right side. I am not getting any option to present a Page modally from right to left and same dismiss also left to right. Can anyone help me on this.
You can use FlowDirection
<MasterDetailPage
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="RTL.MasterDetailPage"
Padding="25"
FlowDirection="RightToLeft">
<MasterDetailPage.Master>
<ContentPage Title=" ">
<StackLayout>
<Button Text="Menu item" />
</StackLayout>
</ContentPage>
</MasterDetailPage.Master>
<MasterDetailPage.Detail>
<ContentPage>
<Label Text="My page"/>
</ContentPage>
</MasterDetailPage.Detail>
</MasterDetailPage>
https://blog.xamarin.com/right-to-left-localization-xamarin-forms/
Better work around is,
Disable Navigation tool bar,
NavigationPage.SetHasNavigationBar(this, false);
Create custom tool bar with Hamburger image,
<StackLayout Orientation="Horizontal" VerticalOptions="Start" HorizontalOptions="FillAndExpand">
<Image Source="hamburger" Margin="2,0,0,0" HeightRequest="35" WidthRequest="25">
<Image.GestureRecognizers>
<TapGestureRecognizer Command="{Binding ToggleMasterCommand}" CommandParameter="1"></TapGestureRecognizer>
</Image.GestureRecognizers>
</Image>
<Label Text="Header text" HorizontalOptions="CenterAndExpand" HorizontalTextAlignment="Center" VerticalOptions="CenterAndExpand" VerticalTextAlignment="Center"/>
<Image Source="notification" HeightRequest="30" WidthRequest="30">
<Image.GestureRecognizers>
<TapGestureRecognizer Command="{Binding NotificationCommand}"></TapGestureRecognizer>
</Image.GestureRecognizers>
</Image>
</StackLayout>
Apply FlowDirection for each page. either Xaml or code behind through Visual Element
You can see a demo for setting Visual Element through code behind here

Xamarin forms card layout using xaml

I am trying to build Xaml for Xamarin , I am able to get the UI But the label is not getting binded. (Android Platform)
Also tried Text="{Binding Name}" for label. But not getting any labels rendered. Do i need to write up any additional code ?
<ContentPage.Content>
<ListView SelectedItem="{Binding SelectedResult}" x:Name="listview1" ItemsSource="{Binding QueryResults}">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Frame Padding="0,0,0,10">
<Frame.Content>
<Frame Padding="15,15,15,15" HeightRequest="36" OutlineColor="Aqua" BackgroundColor="Blue">
<Frame.Content>
<StackLayout Padding="20,0,0,0" Orientation="Horizontal" HorizontalOptions="StartAndExpand">
<Label Text="label text for test" TextColor="Yellow">
</Label>
</StackLayout>
</Frame.Content>
</Frame>
</Frame.Content>
</Frame>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
It worked for me.
Here is the code:
`
<Frame Padding="15,15,15,15" HeightRequest="36" OutlineColor="Aqua" BackgroundColor="Blue">
<Frame.Content>
<StackLayout Padding="20,0,0,0" Orientation="Horizontal" HorizontalOptions="StartAndExpand">
<Label Text="{Binding Name}" TextColor="Yellow">
</Label>
</StackLayout>
</Frame.Content>
</Frame>
`
There was frame inside frame so it was overlapping.
Hope this helps!
Even though very late reply after 3 months :p

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