Placing a stacklayout in the center of the screen - xaml

I tried to insert the horizontaloptions="CenterAndExpand" code into all of the stacklayout path but didn't work.
It's still in the upper-left corner :(
Somebody any idea? I actually don't use the grid, I just left it there.
My Code:
<ContentPage.Content>
<AbsoluteLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand">
<Image AbsoluteLayout.LayoutFlags="All" AbsoluteLayout.LayoutBounds="0,0,1,1" Source="BackgroundPicture.jpg" Aspect="AspectFill"/>
<Grid >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<StackLayout>
<StackLayout Orientation="Horizontal">
<local:RoundedEntry x:Name="RegFirstNameEntry" Placeholder="Firstname" WidthRequest="177"></local:RoundedEntry>
<local:RoundedEntry x:Name="RegLastNameEntry" Placeholder="Lastname" WidthRequest="177"></local:RoundedEntry>
</StackLayout>
<StackLayout Orientation="Horizontal">
<local:RoundedEntry x:Name="RegPhoneNumberEntry" Placeholder="Phone" WidthRequest="177" Keyboard="Telephone"></local:RoundedEntry>
<local:RoundedEntry x:Name="RegEmailEntry" Placeholder="Email" WidthRequest="177"></local:RoundedEntry>
</StackLayout>
<StackLayout Orientation="Vertical">
<local:RoundedEntry x:Name="RegPasswordEntry" Placeholder="Password" IsPassword="True" ></local:RoundedEntry>
<local:RoundedEntry x:Name="RegPasswordAgainEntry" Placeholder="Password" IsPassword="True"></local:RoundedEntry>
</StackLayout>
</StackLayout>
</Grid>
</AbsoluteLayout>
</ContentPage.Content>
</ContentPage>

It's because your StackLayout defaults are FillAndExpand.
To center it inside Grid set StackLayout's HorizontalOptions="Center" VerticalOptions="Center".

Related

Xamarin Listview cannot scroll to bottm

I modify the sample https://learn.microsoft.com/zh-tw/samples/xamarin/xamarin-forms-samples/userinterface-xaminals/ ,
replace the collectionview with listview . after replacing I found the listview cannot scroll to bottom (there are total 17 items , but only show 6 items)
This error only happen on Android,but it works well on IOS.
How to solve this problem?
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:controls="clr-namespace:Xaminals.Controls"
xmlns:data="clr-namespace:Xaminals.Data"
x:Class="Xaminals.Views.MonkeysPage"
Title="Monkeys">
<RelativeLayout
VerticalOptions="FillAndExpand"
HorizontalOptions="FillAndExpand">
<StackLayout Orientation="Vertical"
VerticalOptions="FillAndExpand"
Padding="10">
<ListView ItemsSource="{x:Static data:MonkeyData.Monkeys}"
x:Name="CollectionView1"
RowHeight="100">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Grid VerticalOptions="CenterAndExpand" Padding = "20, 0" >
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Image
Grid.RowSpan="2"
Aspect="AspectFill"
HeightRequest="60"
Source="{Binding ImageUrl}"
WidthRequest="60" />
<Label
Grid.Row="0"
Grid.Column="1"
FontAttributes="Bold"
Text="{Binding Name}" />
<Label
Grid.Row="1"
Grid.Column="1"
FontAttributes="Italic"
Text="{Binding Price}"
VerticalOptions="End" />
<Image Grid.Row="2" Grid.Column="0" Source="bear.png" HeightRequest="25" WidthRequest="25">
<Image.GestureRecognizers>
<TapGestureRecognizer
NumberOfTapsRequired="1" />
</Image.GestureRecognizers>
</Image>
</Grid>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<ActivityIndicator x:Name="activityIndicator" Color="Red" VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand" RelativeLayout.XConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height, Factor=0.33}" RelativeLayout.YConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height,Factor=0.33}" />
</RelativeLayout>
</ContentPage>
The solution is change the RelativeLayout to Stacklayout:
<StackLayout
VerticalOptions="FillAndExpand"
HorizontalOptions="FillAndExpand">
<StackLayout Orientation="Vertical"
VerticalOptions="FillAndExpand"
Padding="10">
<ListView ItemsSource="{x:Static data:MonkeyData.Monkeys}"
x:Name="CollectionView1"
RowHeight="100">
.....
</ListView>
</StackLayout>
</StackLayout>
If you want to use RelativeLayout, you need to use XConstraint, YConstraint,WidthConstraint,HeightConstraint to layout the child view instead of VerticalOptions="FillAndExpand", HorizontalOptions="FillAndExpand".

ListView HasUnevenRows does not work in xamarinforms

good afternoon, i have a listview with grid with two labels in the first column and an image in the second column, it happens that the image is disrespecting, without the image the label is in the correct size.
My problem is that the label doesn’t show all her content when it has the image
When you have the image the labels are wrong. image with resized error
Without the image, which would be expected but I don't know how to fix it for the cells to resize
error-free image
I've tried everything, if anyone can help me thank you
mycode
<ListView
x:Name="ListView_ListaRotas"
HasUnevenRows="True"
IsPullToRefreshEnabled="True"
ItemTapped="ListView_ListaRotas_ItemTapped"
Refreshing="ListView_ListaRotas_Refreshing"
SeparatorVisibility="None">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Frame
Margin="0,5"
Padding="5,0"
BorderColor="Gray"
Opacity="{Binding PermiteCheck, Converter={StaticResource Key=OpacityConverter}}">
<Grid
Margin="0"
Padding="1,0"
ColumnSpacing="0"
RowSpacing="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<StackLayout HorizontalOptions="StartAndExpand" VerticalOptions="CenterAndExpand">
<Label
FontAttributes="Bold"
FontSize="18"
HorizontalTextAlignment="Start"
Text="{Binding Ds_Observacao}"
VerticalTextAlignment="Start" />
<StackLayout Orientation="Horizontal">
<Label
FontSize="Medium"
Text="{Binding Nm_Posto}"
VerticalTextAlignment="Center" />
<Image
Aspect="AspectFit"
HeightRequest="20"
IsVisible="{Binding HasSketch}"
Source="rascunho.png"
WidthRequest="20" />
</StackLayout>
</StackLayout>
<Image
Grid.Column="1"
Aspect="AspectFit"
HorizontalOptions="EndAndExpand"
Source="{Binding TimeLine}"
VerticalOptions="Center" />
</Grid>
</Frame>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>

Xamarin - lower half of view cut off

Some times when loading a View, it does not fully load on Iphone.. see the screenshot.. (Images are blurred on purpose..) At least, it does not load with proper dimensions. it is usually fixed by rotating the phone to landscape and back.. is there a way to avoid this?
here is my view:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:vm="clr-namespace:GalShare.ViewModel"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:ffimageloading="clr-namespace:FFImageLoading.Forms;assembly=FFImageLoading.Forms"
xmlns:forms="clr-namespace:RedCorners.Forms;assembly=RedCorners.Forms"
mc:Ignorable="d"
x:Class="GalShare.Views.Gallery">
<NavigationPage.TitleView>
<Grid Padding="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="180"/>
<ColumnDefinition Width="10"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="45"/>
</Grid.RowDefinitions>
<Button Grid.Row="0" Grid.Column="0" Text="Back" x:Name="Backbutton" Clicked="Backbutton_Clicked"></Button>
<Button Grid.Row="0" Grid.Column="2" Text="Ph. contact info" x:Name="PhInfo" Clicked="PhInfo_Clicked"></Button>
</Grid>
</NavigationPage.TitleView>
<ContentPage.Content>
<AbsoluteLayout HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
<StackLayout
AbsoluteLayout.LayoutFlags="All"
AbsoluteLayout.LayoutBounds="0,0,1,1">
<ContentView x:Name="Messagecontainer" Padding="5">
<forms:Frame2 CornerRadius="8"
HasShadow="True"
ShadowRadius="8"
ShadowColor="Black"
Padding="5"
BackgroundColor="LightGray">
<Label x:Name="Messagefield"></Label>
</forms:Frame2>
</ContentView>
<CollectionView ItemsSource="{Binding Galleries}" Margin="0" x:Name="MyCollection" SelectionMode="Single" SelectionChanged="CollectionView_SelectionChanged">
<CollectionView.ItemsLayout>
<GridItemsLayout Orientation="Vertical"
Span="2" />
</CollectionView.ItemsLayout>
<CollectionView.ItemTemplate>
<DataTemplate>
<ContentView Padding="8">
<forms:Frame2 CornerRadius="15"
HasShadow="True"
ShadowRadius="5"
HeightRequest="190"
BackgroundColor="LightGray"
Padding="1">
<StackLayout HorizontalOptions="Start" VerticalOptions="Start" Padding="2">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="140"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<ffimageloading:CachedImage Grid.Row="0" Grid.Column="0" x:Name="myImage" Source="{Binding ThumbUrl}" Aspect="AspectFit" CacheDuration="1" HorizontalOptions="CenterAndExpand" VerticalOptions="CenterAndExpand" DownsampleToViewSize="False"></ffimageloading:CachedImage>
<StackLayout Padding="0" Margin="0" Spacing="0" Grid.Column="0" Grid.Row="1">
<StackLayout Spacing="0" Margin="0" Padding="5,0,5,0">
<ImageButton HorizontalOptions="Center" Padding="0" WidthRequest="28" Aspect="AspectFit" HeightRequest="28" Margin="0" Source="{Binding likeImg}" x:Name="Favoriteimage" Clicked="LikeButton_Clicked" ></ImageButton>
<!-- <Button CharacterSpacing="0" HorizontalOptions="Center" Padding="0" WidthRequest="50" HeightRequest="28" Margin="0" Text="Like" x:Name="Favoriteimage" Clicked="Button_Clicked" ></Button>-->
</StackLayout>
<Label x:Name="Picname" Text="{Binding ImageName}" IsVisible="{Binding showname}" FontSize="Micro" VerticalOptions="End" VerticalTextAlignment="Center" HorizontalTextAlignment="Center" ></Label>
</StackLayout>
</Grid>
</StackLayout>
</forms:Frame2>
</ContentView>
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
</StackLayout>
<StackLayout IsVisible="{Binding isBusy}" x:Name="LoadingLayout" Padding="12"
AbsoluteLayout.LayoutFlags="PositionProportional"
AbsoluteLayout.LayoutBounds="0.5,0.5,-1,-1">
<ActivityIndicator IsVisible="{Binding IsBusy}"
IsRunning="{Binding IsBusy}" />
<Label Text="Loading gallery..." IsVisible="{Binding IsBusy}" HorizontalOptions="Center" TextColor="Black"/>
</StackLayout>
</AbsoluteLayout>
</ContentPage.Content>
</ContentPage>
Because you used AbsoluteLayout as root layout of the ContentPage . If you want to put the ActivityIndicator on the CollectionView , you could use Grid and put them in the same cell .
<Grid VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<StackLayout Grid.Row="0" Grid.Column="0" BackgroundColor="Red" x:Name="LoadingLayout" Padding="12">
//...
</StackLayout>
<StackLayout Grid.Row="0" Grid.Column="0" IsVisible="{Binding isBusy}" x:Name="LoadingLayout" Padding="12" VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand">
<ActivityIndicator IsVisible="{Binding IsBusy}"
IsRunning="{Binding IsBusy}" />
<Label Text="Loading gallery..." IsVisible="{Binding IsBusy}" HorizontalOptions="Center" TextColor="Black"/>
</StackLayout>
</Grid>
If the problem still exists, you could share your sample so that I can test it on my side .

Overlay label, list and a button on top of an image on Xamarin.Forms

I want to make a page where there is a picture and basically the everything else on the page on top of the image.
Something similar to this
XAML Code like :
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="Project.Page">
<ScrollView>
<AbsoluteLayout>
<Image Source="{Binding ContentImage}}" Aspect="AspectFill" AbsoluteLayout.LayoutFlags="All" AbsoluteLayout.LayoutBounds="0,0,1,1"/>
<Label Text="{Binding label}" FontSize="15" AbsoluteLayout.LayoutFlags="PositionProportional" AbsoluteLayout.LayoutBounds="0,1,-1,-1" />
</AbsoluteLayout>
</ScrollView>
I have this so far. But this only has the label way at the bottom right, and I can't seem to get the list or buttons to work properly. I was thinking maybe just have the image be the background, but the image is supposed to change by the push of a button or something and I am not entirely sure if you can do that with a background image.
Is something like this possible with Xamarin.Forms?
Sorry if my English is poor! It's my second language!
Thanks in advance!
EDIT: I was able to use the image as background and change by a button click. Now I just need to find out how to actually position a ListView.
I moved some items around from a demo, this is just one way to handle it using an AbsoluteLayout and Grid
<AbsoluteLayout x:Name="ViewLayout">
<Image Source="coffee.png" Aspect="AspectFill" AbsoluteLayout.LayoutBounds="1,1,1,1" AbsoluteLayout.LayoutFlags="All" />
<AbsoluteLayout x:Name="ViewControls" AbsoluteLayout.LayoutBounds="1,1,1,.50" AbsoluteLayout.LayoutFlags="All" BackgroundColor="#66000000" Margin="10,10,10,10">
<StackLayout Orientation="Vertical" Margin="20,20,20,20" BackgroundColor="Transparent" AbsoluteLayout.LayoutFlags="All" AbsoluteLayout.LayoutBounds="1,1,1,1">
<Grid Margin="1">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Label Text="Salted Caramel Mocha Frappuccino" TextColor="White" HorizontalOptions="CenterAndExpand" VerticalTextAlignment="Center" Grid.Column="0" Grid.ColumnSpan="3" Grid.RowSpan="2" />
<Button Text="Extra Shot" BackgroundColor="#77000000" BorderRadius="4" BorderColor="White" BorderWidth="2" TextColor="White" Grid.Row="0" Grid.Column="3" />
<Button Text="Whipped Cream" BackgroundColor="#77000000" BorderRadius="4" BorderColor="White" BorderWidth="2" TextColor="White" Grid.Row="1" Grid.Column="3" />
</Grid>
<Grid Margin="1">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Button Text="Tall (12oz)" BackgroundColor="#77000000" BorderRadius="4" BorderColor="White" BorderWidth="2" TextColor="White" HorizontalOptions="FillAndExpand" Grid.Column="0" />
<Button Text="Grande (16oz)" BackgroundColor="#77000000" BorderRadius="4" BorderColor="White" BorderWidth="2" TextColor="White" HorizontalOptions="FillAndExpand" Grid.Column="1" />
<Button Text="Venti (20oz)" BackgroundColor="#77000000" BorderRadius="4" BorderColor="White" BorderWidth="2" TextColor="White" HorizontalOptions="FillAndExpand" Grid.Column="2" />
</Grid>
</StackLayout>
</AbsoluteLayout>
</AbsoluteLayout>

Using a scroll in a xamarin.forms listview

I am returning about 20 rows of data in my listview and it is just showing 12.
How can I introduce a scroll in my listview below. I tried putting a scrollview around it but no luck.
<StackLayout Grid.Column="1" Orientation="Vertical" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand" Padding="0" Spacing="0">
<SearchBar x:Name="searchBar" Placeholder="Search" SearchCommandParameter="{Binding Source={x:Reference searchBar}, Path=Text}"/>
<StackLayout VerticalOptions="FillAndExpand">
<StackLayout VerticalOptions="FillAndExpand" Padding="1" BackgroundColor="Black">
<ListView x:Name="dataList" BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Label FontSize="20" VerticalOptions="CenterAndExpand" TextColor="Black" Text="{Binding HeadLines}"></Label>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
</StackLayout>
</StackLayout>
Answer
Your XAML structure is wrong. Please have a look my code, and try it. Hope, It will help you.
Code
<Grid VerticalOptions="FillAndExpand">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<SearchBar Grid.Column="0" x:Name="searchBar" Placeholder="Search" SearchCommandParameter="{Binding Source={x:Reference searchBar}, Path=Text}" />
<ListView Grid.Column="2" x:Name="dataList" BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Label FontSize="20" VerticalOptions="CenterAndExpand" TextColor="Black" Text="{Binding HeadLines}">
</Label>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</Grid>