Xamarin Froms custom template in ListView - xaml

I'm working with the ListView in Xamarin Forms. So far, I've displayed some data using a custom DataTemplate. Now, I would like to extend this to display the text inside/ over an image. Something like this:
This is the code, I'm using so far. However, in this case the text is over the image:
<ListView x:Name="MyListView"
ItemsSource="{Binding myData}"
RowHeight="190"
HasUnevenRows="True">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<ViewCell.View>
<StackLayout Padding="10" Orientation="Vertical">
<Label Text="{Binding Title}"
FontSize="Large"
VerticalOptions="Center"
TextColor="#31659e">
</Label>
<Image Source="http://www.someurl.com/images/image1.jpg" Aspect="AspectFill"></Image>
</StackLayout>
</ViewCell.View>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
How could I achieve the result of the first image?
If anyone has some example/ links/ tips how to do that, that would be very helpful.
Thanks

You can use a RelativeLayout. It would look like this in your data templates ViewCell.View
<RelativeLayout>
<!-- Background -->
<Image Source="http://www.someurl.com/images/image1.jpg" Aspect="AspectFill"
RelativeLayout.XConstraint="{ConstraintExpression Type=RelativeToParent, Property=Width}"
RelativeLayout.YConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height}" />
<!-- Text -->
<StackLayout Padding="10" Orientation="Vertical" VerticalOptions="EndAndExpand"
RelativeLayout.XConstraint="{ConstraintExpression Type=RelativeToParent, Property=Width}"
RelativeLayout.YConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height}" >
<Label Text="{Binding Title}"
FontSize="Large"
TextColor="#31659e">
</Label>
<Label Text="{Binding SubTitle}"
TextColor="#31659e">
</Label>
</StackLayout>
</RelativeLayout>
This stretches the image and the stacklayout to the same height and aligns the content of the StackLayout at the botttom.

Related

Keep ListView.Header anchored/sticky/frozen to top when scrolling

How to keep the built-in Header of a ListView frozen to the top when scrolling vertically down through the ListView items?
Before flagging as duplicate: I tried to apply answers in Keep ListView.HeaderTemplate visible/static/sticky in UWP for Xamarin.Forms targeting Android without success.
Short code sample:
<ListView ItemsSource="{Binding MyList}"
HasUnevenRows="True"
SeparatorVisibility="Default"
CachingStrategy="RecycleElement">
<ListView.Header>
<Label HorizontalTextAlignment="Center"
FontAttributes="Bold"
Text="Header Title"/>
</ListView.Header>
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Label Text="{Binding Name}"/>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Here is an alternative approach to this if the list isn't long
<StackLayout>
<Label HorizontalTextAlignment="Center"
FontAttributes="Bold"
Text="Header Title"/>
<StackLayout BindableLayout.ItemsSource="{Binding MyList}">
<BindableLayout.ItemTemplate>
<DataTemplate>
<StackLayout>
<Label Text="{Binding Name}"/>
<!-- boxview as separator -->
<BoxView HeightRequest="1" Color="Aqua" HorizontalOptions="FillAndExpand"/>
</StackLayout>
</DataTemplate>
</BindableLayout.ItemTemplate>
</StackLayout>
</StackLayout>

Xamarin Forms Right center checkbox

Im making an Android application and Im trying to center right checkbox on all rows in the listview, but I cant do it.
I want do something like this. Thanks
https://imgur.com/FhecIT3
<StackLayout Orientation="Vertical">
<RelativeLayout>
<ListView ItemsSource="{Binding Funcionarios}"
HasUnevenRows="True"
Margin="20"
ItemTapped="ListView_ItemTapped">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal">
<image:CircleImage Source="{Binding Imagem}" Aspect="AspectFill" WidthRequest="60"
HeightRequest="60" BorderColor="Black" BorderThickness="2">
</image:CircleImage>
<StackLayout Orientation="Vertical">
<Label Text="{Binding Nome}" FontSize="Large"/>
<Label Text="{Binding Zona}"/>
<CheckBox IsChecked="False" />
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</RelativeLayout>
</StackLayout>
Try
<ViewCell>
<StackLayout Orientation="Horizontal">
<image:CircleImage Source="{Binding Imagem}" Aspect="AspectFill" WidthRequest="60" HeightRequest="60" BorderColor="Black" BorderThickness="2"> </image:CircleImage>
<StackLayout Orientation="Vertical">
<Label Text="{Binding Nome}" FontSize="Large"/>
<Label Text="{Binding Zona}"/>
</StackLayout>
<StackLayout Orientation="Vertical" HorizontalOptions="End">
<CheckBox IsChecked="False" VerticalOptions="Center"/>
</StackLayout>
</StackLayout>
</ViewCell>

Xamarin two labels in each end in one line

I have implemented a listview and in each item I want to have two labels, in each end horizontally. But in reality it just put the two labels next to eachother left aligned.
I read that maybe this is not possible with a stacklayout, as it doesn't take up more space than needed. (Even tried fill and fillandExpand which didn't help.)
Instead I should use a grid. But I have options on my listview, as grouping, refresh, caching, tapped, which I guess I don't have on a grid?
I would like to succeed with a listview if that is possible. Anyone have some insights to this layout issue?
Here is my xaml code:
<?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="MyApp.Page.ItemsTest">
<ListView x:Name="ItemView"
ItemsSource="{Binding ItemGroup}"
CachingStrategy="RecycleElement"
IsGroupingEnabled="true"
HasUnevenRows="True"
ItemTapped="Handle_ItemTapped">
<ListView.GroupHeaderTemplate>
<DataTemplate>
<ViewCell>
<StackLayout BackgroundColor="#FFA500" Orientation="Vertical" Padding="10">
<StackLayout Orientation="Horizontal">
<Label Text="{Binding Heading}" TextColor="White" FontAttributes="Bold" />
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.GroupHeaderTemplate>
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Padding="10" HorizontalOptions="FillAndExpand">
<Label Text="{Binding Name}" FontAttributes="Bold" HorizontalTextAlignment="Start"/>
<Label Text="{Binding Start, StringFormat='{0:HH:mm}'}" FontAttributes="Bold" HorizontalTextAlignment="End"/>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</ContentPage>
Central part is this:
<StackLayout Orientation="Horizontal" Padding="10" HorizontalOptions="FillAndExpand">
<Label Text="{Binding Name}" FontAttributes="Bold" HorizontalTextAlignment="Start"/>
<Label Text="{Binding Start, StringFormat='{0:HH:mm}'}" FontAttributes="Bold" HorizontalTextAlignment="End"/>
</StackLayout>
Update:
As requested I have a colored the background of the two labels and the stacklayout. It's the same output if I use HorizontalOptions="End" and HorizontalTextAlignment="End" at the same time or each one alone. Also if I remove the HorizontalOptions="FillAndExpand" on the stacklayout, it's still the exact same graphical output. (The orange color was already present)
Maybe you could use a Grid instead of the StackLayout and place each Label in a different Column:
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"></ColumnDefinition>
<ColumnDefinition Width="*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<Label Grid.Column="0" Text="{Binding Name}" FontAttributes="Bold" HorizontalTextAlignment="Start"/>
<Label Grid.Column="1" Text="{Binding Start, StringFormat='{0:HH:mm}'}" FontAttributes="Bold" HorizontalTextAlignment="End"/>
</Grid>
You could also use nested StackLayout
<StackLayout>
<Label />
<Label Text="Gender:" FontAttributes="Bold"/>
<StackLayout Orientation="Horizontal">
<Label HorizontalOptions="Start" Text="First Name: " FontAttributes="Bold"/>
<Entry HorizontalOptions="EndAndExpand" Placeholder="First Name" MaxLength="256" Text="{Binding FirstName}"></Entry>
</StackLayout>
</StackLayout>

StackLayout is not viewable inside RelativeLayout

I'm trying to add a floating action button to my page, to do so I wrapped my stack layout with a relative layout and add the FAB in the relative layout.
<ContentPage.Content>
<RelativeLayout BackgroundColor="Transparent">
<fab:FloatingActionButton
x:Name="fabBtn"
Source="plus.png"
Size="Normal"
Clicked="Handle_FabClicked"
NormalColor="Green"
RippleColor="Blue"
RelativeLayout.XConstraint="{ConstraintExpression Type=RelativeToParent, Property=Width, Factor=1, Constant=-75}"
RelativeLayout.YConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height, Factor=1, Constant=-75}" />
<StackLayout
Spacing="10"
Padding="5"
VerticalOptions="FillAndExpand"
HorizontalOptions="FillAndExpand"
RelativeLayout.XConstraint="{ConstraintExpression Type=RelativeToParent, Property=Width, Factor=1}"
RelativeLayout.YConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height, Factor=1}">
<Label Text="Latest news/activities" FontSize="Medium" VerticalOptions="Start"/>
<ScrollView VerticalOptions="CenterAndExpand">
<ListView
x:Name="lsvActivities"
HasUnevenRows="True">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Padding="3">
<StackLayout Orientation="Vertical" HorizontalOptions="StartAndExpand">
<Label Text="{Binding title}" VerticalOptions="StartAndExpand"/>
<Label Text="{Binding date}" VerticalOptions="End"/>
</StackLayout>
<StackLayout HorizontalOptions="End" WidthRequest="100" HeightRequest="100" BackgroundColor="Blue">
<Label Text="image here"/>
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</ScrollView>
<Label Text="Good Mording" FontSize="Large" VerticalOptions="End" HorizontalOptions="Center"/>
</StackLayout>
</RelativeLayout>
</ContentPage.Content>
But it locks like the StackLayout is out of the boundary of the layout or something.
What is problem? and how I can display both the FAB and the StackLayout, where the floating action button should always be on top of the StackLayout elements
Are you trying to have the StackLayout occupy the entire screen (with the button on top)? If so, this part isn't going to do that:
RelativeLayout.XConstraint="{ConstraintExpression Type=RelativeToParent, Property=Width, Factor=1}"
RelativeLayout.YConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height, Factor=1}">
That is placing the top left corner of the StackLayout at the bottom right of the screen.
Per the Xamarin docs:
Unlike AbsoluteLayout, RelativeLayout does not have the concept of the
moving anchor and does not have facilities for positioning elements
relative to the bottom or right edges of the layout.
In other words, AbsoluteLayout will try to adjust for you if you place something at the bottom right corner. RelativeLayout won't.
You probably want the constraints noted above on the StackLayout to be WidthConstraint and HeightConstraint, and set the XConstraint and YConstraint to 0.
And as Sven-Michael says, drop the ScrollView.
EDIT
The XAML should look like:
RelativeLayout.WidthConstraint="{ConstraintExpression Type=RelativeToParent, Property=Width, Factor=1}"
RelativeLayout.HeightConstraint="{ConstraintExpression Type=RelativeToParent, Property=Height, Factor=1}"
RelativeLayout.XConstraint="{ConstraintExpression Type=Constant,Constant=0}"
RelativeLayout.YConstraint="{ConstraintExpression Type=Constant,Constant=0}"

Set platform specific control to only one platform in xamarin forms

I have a page that contains a listview and Search bar control. There is a custom listview for android. My code as following:
<ContentPage.Content>
<ContentView>
<OnPlatform x:TypeArguments="View">
<OnPlatform.iOS>
<StackLayout Spacing="0">
<SearchBar x:Name="IosSearch"
Placeholder="Search"
TextChanged="IosSearchBar_OnTextChanged"
SearchButtonPressed="OnSearch" BackgroundColor="#19588F">
</SearchBar>
<ListView x:Name="EmpListViewIos"
ItemsSource="{Binding EmpModel.GroupedItems}"
ItemSelected="OnItemSelected"
SeparatorVisibility="Default">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Padding="8">
<StackLayout Spacing="4" Orientation="Horizontal">
<Label Text="{Binding FullName}" FontSize="15" TextColor="Gray" LineBreakMode="NoWrap"/>
</StackLayout>
<StackLayout Spacing="4" Orientation="Horizontal">
<Label Text="{Binding Department}" FontSize="Small" TextColor="#F68933" LineBreakMode="WordWrap"/>
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
</OnPlatform.iOS>
<OnPlatform.Android>
<StackLayout x:Name="androidListView">
<SearchBar x:Name="DroidSearch"
Placeholder="Search"
TextChanged="DroidSearchBar_OnTextChanged"
SearchButtonPressed="OnSearch" BackgroundColor="#19588F">
</SearchBar>
<local:CustomListView x:Name="customListView"
Items="{Binding EmpModel.Items}"
VerticalOptions="FillAndExpand" MyListItemSelected="nativeListView_ItemSelected"
SeparatorColor="Black">
</local:MyListView>
</StackLayout>
</OnPlatform.Android>
<OnPlatform.WinPhone>
<StackLayout Spacing="0">
<SearchBar x:Name="WinSearch"
Placeholder="Search"
TextChanged="WinSearchBar_OnTextChanged"
SearchButtonPressed="OnSearch" BackgroundColor="#19588F">
</SearchBar>
<ListView x:Name="EmpListViewWin"
ItemsSource="{Binding EmpModel.GroupedItems}"
ItemSelected="OnItemSelected"
SeparatorVisibility="Default">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Padding="8">
<StackLayout Spacing="4" Orientation="Horizontal">
<Label Text="{Binding FullName}" FontSize="15" TextColor="Gray" LineBreakMode="NoWrap"/>
</StackLayout>
<StackLayout Spacing="4" Orientation="Horizontal">
<Label Text="{Binding Department}" FontSize="Small" TextColor="#F68933" LineBreakMode="WordWrap"/>
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
</OnPlatform.WinPhone>
</OnPlatform>
</ContentView>
</ContentPage.Content>
</ContentPage>
As the representation of data is different due to that I am required custom listview for android according to it's layout defined. The above code works fine. The only problem is the redundancy, the search bar control is common for all platform but when I put the search bar control above the <ContentView> it doesn't work throws exception. Similarly the ListView is common for ios and windows only there is custom listview for android but I am forced to repeat the code for windows also same as android.
Can anyone suggest a more efficient way to achieve this. How can I apply platform specific condition only for android and common for windows and ios.
You could share the iOS and WinPhone views using a static resource:
<ContentPage>
<ContentPage.ResourceDictionary>
<StackLayout x:Key="iosOrWpView">
...
</StackLayout>
</ContentPage.ResourceDictionary>
<ContentView>
<OnPlatform x:TypeArguments="View" iOS="{StaticResource iosOrWpView}"
WinPhone="{StaticResource iosOrWpView}">
<OnPlatform.Android>
<StackLayout x:Name="androidListView">
...
</StackLayout>
</OnPlatform.Android>
</OnPlatform>
</ContentView>
<ContentPage>