Listview does not contain a definition for selecteditems

Listview does not contain a definition for selecteditems - c#

I am using Xamarin.Forms.I want to remove the selected item in listview after clicking Remove button.
My xaml
<ListView x:Name="ProductsListView"
HasUnevenRows="True"
BackgroundColor="#ecf0f1"
SeparatorVisibility="None"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Margin="6,4,6,4"
BackgroundColor="White">
<StackLayout Orientation="Horizontal">
<Label Text="Item ID" Margin="25,10,4,4" FontSize="Small" TextColor="Black" />
<Label Text="{Binding retail_modified_item_id}" Margin="25,10,4,4" TextColor="Black" FontSize="12" />
</StackLayout>
<StackLayout Orientation="Horizontal">
<Label Text="Name" Margin="25,2,8,4" TextColor="Black" FontSize="Small" />
<Label Text="{Binding name}" Margin="32,1,8,4" TextColor="Black" FontSize="Small" />
<Switch IsToggled="false" Margin="210,2,2,2" Toggled="Switch_Toggled" />
</StackLayout>
<StackLayout Orientation="Horizontal">
<Label Text="OldPrice" Margin="25,2,8,4" TextColor="Black" FontSize="Small"/>
<Label Text="{Binding old_price}" Margin="32,1,8,4" TextColor="Black" FontSize="Small" />
</StackLayout>
<StackLayout Orientation="Horizontal">
<Label Text="NewPrice" Margin="25,2,8,4" TextColor="Black" FontSize="Small" />
<Label Text="{Binding new_price}" Margin="32,1,8,4" TextColor="Black" FontSize="Small" />
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
My cs code
private void reject(object sender, EventArgs args)
{
foreach (var v in ProductsListView.SelectedItems)
{
ProductsListView.ItemSelected.Remove(v);
}
DisplayAlert("Rejected","Request Rejected!!", "OK");
}
I am getting this error:
listview does not contain a definition for selecteditem, ItemSelected

You can try cast it to ProductListView,
var selectedItems = (ListView/* or ProductListView*/)sender; //-> you need casting to access it.
And you can change list view item source
public void reject(your_list_of_model_type your_list_of_model)
{
your_list_of_model.RemoveRange(selectedItems);
ProductListView.ItemSource = your_list_of_model;
}
Solution 2 :
Here is what you could do :
This be my model class :
public class Item
{
public string ItemName { get; set; }
public string ItemDetails { get; set; }
}
And in my XAML or you can write this in code as well, bind to the Command Parameter of your Item template :
<Button Text="Delete" CommandParameter="{Binding ItemName}" Clicked="DeleteClicked"></Button>
Full Item Template will be like below :
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<ViewCell.View>
<StackLayout Orientation="Horizontal">
<Label Text="{Binding ItemName}" HorizontalOptions="StartAndExpand" FontSize="30"></Label>
<Button Text="Delete" CommandParameter="{Binding ItemName}" Clicked="DeleteClicked">
</Button>
</StackLayout>
</ViewCell.View>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
And in you code file you can do this :
public void DeleteClicked(object sender, EventArgs e)
{
var item = (Xamarin.Forms.Button)sender;
Item listitem = (from itm in allItems
where itm.ItemName == item.CommandParameter.ToString()
select itm)
.FirstOrDefault<Item>();
allItems.Remove(listitem);
}
IMPORTANT : This would only delete the item from the bound collection. To delete it from the original list you need to use ObservableCollection

You can add all the toggled items to a list, suppose selectedItems. And when you click REJECT button, delete the selectedItems from the datasource of listview.
The full code is like this:
MainPage.xaml:
<StackLayout Orientation="Vertical">
<!-- Place new controls here -->
<Button Text="APPROVE"
HorizontalOptions="Center"
VerticalOptions="CenterAndExpand" />
<Button Text="REJECT"
HorizontalOptions="Center"
VerticalOptions="CenterAndExpand"
Clicked="reject"/>
<ListView x:Name="ProductsListView"
HasUnevenRows="True"
BackgroundColor="#ecf0f1"
SeparatorVisibility="None"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Vertical" Margin="6,4,6,4"
BackgroundColor="White">
<StackLayout Orientation="Horizontal">
<Label Text="{Binding name}" Margin="32,1,8,4" TextColor="Black" FontSize="Small" />
<Switch IsToggled="false" Margin="210,2,2,2" Toggled="Switch_Toggled" />
</StackLayout>
<StackLayout Orientation="Horizontal">
<Label Text="{Binding retail_modified_item_id}" Margin="25,10,4,4" TextColor="Black" FontSize="12" />
</StackLayout>
<StackLayout Orientation="Horizontal">
<Label Text="OldPrice" Margin="25,2,8,4" TextColor="Black" FontSize="Small"/>
<Label Text="{Binding old_price}" Margin="32,1,8,4" TextColor="Black" FontSize="Small" />
</StackLayout>
<StackLayout Orientation="Horizontal">
<Label Text="NewPrice" Margin="25,2,8,4" TextColor="Black" FontSize="Small" />
<Label Text="{Binding new_price}" Margin="32,1,8,4" TextColor="Black" FontSize="Small" />
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
MainPage.xaml.cs:
public partial class MainPage : ContentPage
{
ObservableCollection<ItemModel> allItems = new ObservableCollection<ItemModel>();
List<ItemModel> selectedItems = new List<ItemModel>();
public MainPage()
{
InitializeComponent();
InitializeData();
ProductsListView.ItemsSource = allItems;
}
private void reject(object sender, EventArgs e)
{
foreach (var v in selectedItems)
{
allItems.Remove(v);
}
DisplayAlert("Rejected", "Request Rejected!!", "OK");
}
private void Switch_Toggled(object sender, ToggledEventArgs e)
{
var switch1 = (Switch)sender;
var item = (ItemModel)switch1.BindingContext;
var isSelected = !item.selected;
if (isSelected)
{
selectedItems.Add(item);
}
else
{
selectedItems.Remove(item);
}
}
private void InitializeData() {
allItems.Add(new ItemModel { name = "Onion Rings, Medium",
retail_modified_item_id = 1000630,
old_price = 1.29,
new_price = 9.45,
selected = false
});
allItems.Add(new ItemModel
{
name = "Hashbrowns",
retail_modified_item_id = 1000739,
old_price = 0.99,
new_price = 8.5,
selected = false
});
allItems.Add(new ItemModel
{
name = "Amstel Light, Single",
retail_modified_item_id = 1002038,
old_price = 3.5,
new_price = 18,
selected = false
});
}
}
ItemModel.cs:
class ItemModel
{
public string name { get; set; }
public int retail_modified_item_id { get; set; }
public double old_price { get; set; }
public double new_price { get; set; }
public bool selected { get; set; }
}

Related

how to create and display item.cs while the program is running?

I want to create items in a ListView to be displayed in a View, how do I go about doing this?
Code-Behinds and the other View's ViewModel, are basically empty, except for a Binding Context and a manually created item in the ViewModel for viewing and testing stuff.
I have been trying for a while and this is basically me admitting defeat, I am sorry for literally copy-pasting my code, but I am getting desperate, if you can, please do explain the solution and thank you very much
Model - Item.cs is
{
public string Name { get; set; }
public string Description { get; set; }
public string Image { get; set; }
public int Quantity { get; set; }
public string TypeOfQuantity { get; set; }
}
Xaml for creating items V
<StackLayout BackgroundColor="AliceBlue" Padding="10">
<Button Text="Button"
Command="{Binding ButtonCommand}"
Clicked="Mover_Clicked"/>
<Grid BackgroundColor="Black"
ColumnSpacing="3"
RowSpacing="3"
Padding="3"
HeightRequest="200">
<Entry Placeholder="Enter Name"
BackgroundColor="AliceBlue" VerticalTextAlignment="Center" HorizontalTextAlignment="Center" Text="{Binding NewItem.Name}" />
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Grid.Column="1" BackgroundColor="AliceBlue" VerticalTextAlignment="Center" HorizontalTextAlignment="Center" Text="{Binding NewItem.Description}"/>
<Entry Placeholder="Enter Quantity"
Grid.Row="1" BackgroundColor="AliceBlue" VerticalTextAlignment="Center" HorizontalTextAlignment="Center" Text="{Binding NewItem.Quantity}"/>
<Entry Placeholder="Enter Type of Quantity"
Grid.Row="1" Grid.Column="1" BackgroundColor="AliceBlue" VerticalTextAlignment="Center" HorizontalTextAlignment="Center" Text="{Binding NewItem.TypeOfQuantity}"/>
</Grid>
</StackLayout>
</ContentPage.Content>
Xaml for Displaying items V
<viewmodels:ViewModelBase/>
</ContentPage.BindingContext>
<ListView
BackgroundColor="Transparent"
ItemsSource="{Binding Items}"
HasUnevenRows="True"
SeparatorVisibility="None">
<ListView.ItemTemplate>
<DataTemplate x:DataType="model:Item">
<ViewCell>
<ViewCell.ContextActions>
<MenuItem Text="Delete" ></MenuItem>
<MenuItem Text="Edit" ></MenuItem>
</ViewCell.ContextActions>
<Grid Padding="20">
<Frame CornerRadius="15">
<StackLayout Orientation="Horizontal">
<Frame BackgroundColor="AliceBlue">
<Image HeightRequest="90"
Source="{Binding Image}"/>
</Frame>
<StackLayout>
<Label
WidthRequest="150"
Text="{Binding Description}"
FontSize="Large"
VerticalTextAlignment="Center"/>
<Label
WidthRequest="150"
Text="{Binding Name}"
FontSize="Large"
VerticalTextAlignment="Center"/>
<Grid HeightRequest="50" WidthRequest=" 170" Padding="10" VerticalOptions="Start">
<Label
Text="{Binding Quantity}"
HorizontalOptions="End"
FontSize="Large"/>
<Label
Text="{Binding TypeOfQuantity}"
FontSize="Large" Grid.Column="1"/>
<Button HeightRequest="25"
WidthRequest="25"
Text="+"
FontSize="Large" Grid.Column="2"
BackgroundColor="OrangeRed"/>
<Button HeightRequest="25"
Text="-"
FontSize="Large" Grid.Column="3"/>
</Grid>
</StackLayout>
</StackLayout>
</Frame>
</Grid>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
<ListView.Header>
<Button x:Name="Mover" Clicked="Mover_Clicked" Text="Add new"></Button>
</ListView.Header>
</ListView>
</ContentPage>
ViewModelBase V
{
public ObservableRangeCollection<Item> Items { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public string Image { get; set; }
public int Quantity { get; set; }
public string TypeOfQuantity { get; set; }
public Item NewItem { get; set; }
public ViewModelBase()
{
Items = new ObservableRangeCollection<Item>();
}
}
ViewModel for item creation(which inherits ViewModelBase) V
{
public Command ButtonCommand { set; get; }
public ItemEntryPageViewModel()
{
ButtonCommand = new Command(AddItemCommand);
}
private void AddItemCommand(object obj)
{
Items.Add(NewItem);
}
} ```

Xamarin.Forms - Adjusting height of CollectionView to be minimum size to fit children

I have a CollectionView with a few items in it. I'm trying to adjust the size of the CollectionView to be just big enough to fit all of its children. Right now, it's much larger than the amount of children it has.
The Blue color represents the size of the CollectionView. As you can see, it's well beyond the size of it's children. I'd like it to fit them perfectly, or at the very least be closer to the same size.
I don't have any height requests on any of the elements on the page, including the CollectionView.
Here's my code. It's not particularly pretty at the moment, but it's a work in progress.
<StackLayout>
<CollectionView x:Name="assessmentsCollectionView"
BackgroundColor="Blue">
<CollectionView.ItemTemplate>
<DataTemplate>
<StackLayout Spacing="10"
Padding="5">
<Frame CornerRadius="5"
Padding="0"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand">
<StackLayout Orientation="Horizontal">
<Frame Padding="5"
CornerRadius="0"
WidthRequest="50">
<Label Text="{Binding TypeLetter}"
TextColor="#37474f"
FontSize="24"
VerticalTextAlignment="Center"
HorizontalTextAlignment="Center"/>
</Frame>
<StackLayout Padding="10">
<Label Text="{Binding Name}"
TextColor="Black"
FontSize="24"/>
<StackLayout Orientation="Horizontal">
<Image Source="calendarIcon.png"
WidthRequest="12"
HeightRequest="12"/>
<Label Text="{Binding Date}"
FontSize="12"
TextColor="Gray"/>
</StackLayout>
</StackLayout>
</StackLayout>
</Frame>
</StackLayout>
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
</StackLayout>

I changed CollectionView to FlexLayout with BindableLayout.ItemsSource and BindableLayout.ItemTemplate
What was previously
<CollectionView.ItemTemplate>
<DataTemplate>
...
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
What was done
<FlexLayout Direction="Column"
x:Name="MessagesList"
AutomationId="MessagesList"
BindableLayout.ItemsSource="{Binding Messages}" >
<BindableLayout.ItemTemplate>
<DataTemplate>
...
</DataTemplate>
</BindableLayout.ItemTemplate>
</FlexLayout>
For me works well, no need to set Height for item or FlexLayout, all are dynamic

If you have little rows in Collectionview, you can set a value to collectionView.HeightRequest. when item increase, the height will increase as well.
I create a property called.RowHeigth. If I add item in the CollectionView(with AddCommand), RowHeigth will increase.
<StackLayout>
<CollectionView
x:Name="assessmentsCollectionView"
BackgroundColor="Blue"
HeightRequest="{Binding rowHeigth}"
ItemsSource="{Binding letters}">
<CollectionView.ItemTemplate>
<DataTemplate>
<StackLayout Padding="5" Spacing="10">
<Frame
Padding="0"
CornerRadius="5"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand">
<StackLayout Orientation="Horizontal">
<Frame
Padding="5"
CornerRadius="0"
WidthRequest="50">
<Label
FontSize="24"
HorizontalTextAlignment="Center"
Text="{Binding TypeLetter}"
TextColor="#37474f"
VerticalTextAlignment="Center" />
</Frame>
<StackLayout Padding="10">
<Label
FontSize="24"
Text="{Binding Name}"
TextColor="Black" />
<StackLayout Orientation="Horizontal">
<Image
HeightRequest="12"
Source="c1.png"
WidthRequest="12" />
<Label
FontSize="12"
Text="{Binding Date}"
TextColor="Gray" />
</StackLayout>
</StackLayout>
</StackLayout>
</Frame>
</StackLayout>
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
<Button
x:Name="btn1"
Command="{Binding AddCommand}"
Text="btn1" />
</StackLayout>
public partial class Page4 : ContentPage
{
public Page4()
{
InitializeComponent();
this.BindingContext = new letterviewmodel(); ;
}
}
public class letterviewmodel: INotifyPropertyChanged
{
public ObservableCollection<lettermodel> letters { get; set; }
private int _rowHeigth;
public int rowHeigth
{
get { return _rowHeigth; }
set
{
_rowHeigth = value;
RaisePropertyChanged("rowHeigth");
}
}
public ICommand AddCommand { protected set; get; }
public letterviewmodel()
{
letters = new ObservableCollection<lettermodel>()
{
new lettermodel(){TypeLetter="A",Name="letter 1",Date="2021-01-01"},
new lettermodel(){TypeLetter="B",Name="letter 2",Date="2021-01-01"},
new lettermodel(){TypeLetter="C",Name="letter 3",Date="2021-01-01"}
};
rowHeigth = letters.Count * 100 ;
AddCommand = new Command<lettermodel>(async (key) => {
letters.Add(new lettermodel() { TypeLetter = "D", Name = "test letter ", Date = "2021-01-01" });
rowHeigth = letters.Count * 100 ;
});
}
public event PropertyChangedEventHandler PropertyChanged;
public void RaisePropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
public class lettermodel
{
public string TypeLetter { get; set; }
public string Name { get; set; }
public string Date { get; set; }
}
Don't forget toimplement INotifyPropertyChanged interface, to inotify data update.

Xamarin: ObservableCollection does't automatically update ListView

I have a ListView bounded to an ObservableCollection in the ViewModel.
In initialization the ListView items are displayed perfectly.
However, when I try to update a single value of an item of ObservableCollection at run-time, the linked item in the listview does not update automatically. It updates only if I scroll the listView. Why does it behave like this?
Here's the code:
XAML
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Frame Style="{StaticResource frameListView}" >
<StackLayout Margin="-15">
<Label Text="{Binding Articolo.Descrizione}"
Style="{StaticResource labelDescrizioneStyle}" />
<StackLayout Orientation="Horizontal"
HorizontalOptions="End" VerticalOptions="Center">
<Button x:Name="removeButton"
VerticalOptions="Center" HorizontalOptions="Center"
Text="-"
Font="20"
WidthRequest="45" FontAttributes="Bold"
Style="{StaticResource buttonNeutroStyle}"
Command="{Binding Source={x:Reference mieiAcquistiStack}, Path=BindingContext.AggiungiCommand}"
CommandParameter="{Binding .}" />
<StackLayout HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand" >
<Label Text="{Binding QtaEdit}"
TextColor="Black"
FontSize="18" FontAttributes="Bold"
WidthRequest="40"
HorizontalTextAlignment="Center" VerticalTextAlignment="Center"
VerticalOptions="FillAndExpand"/>
</StackLayout>
<Button x:Name="addButton"
VerticalOptions="Center" HorizontalOptions="Center"
Text="+"
WidthRequest="45" FontAttributes="Bold"
Style="{StaticResource buttonNeutroStyle}"
Command="{Binding Source={x:Reference mieiAcquistiStack}, Path=BindingContext.AggiungiCommand}"
CommandParameter="{Binding .}" />
</StackLayout>
</StackLayout>
</Frame>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
ViewModel
public static ObservableCollection<RigaStoricoModel> acquistiList;
public ObservableCollection<RigaStoricoModel> AcquistiList
{
get { return acquistiList; }
set
{
if (acquistiList != value)
{
acquistiList = value;
OnPropertyChanged();
}
}
}
private void AggiungiArticolo(RigaStoricoModel prodotto, ParametriUM parametriUM)
{
double esistenzaUMPredef = parametriUM.EsistenzaUMPredef.GetValueOrDefault(0);
if (esistenzaUMPredef > 0)
{
double qtaMinima = parametriUM.QtaMinima.GetValueOrDefault(1);
if (prodotto.QtaEdit + qtaMinima <= esistenzaUMPredef)
{
prodotto.QtaEdit += qtaMinima; // <-- here the update not working
}
}

Do you want to achieve the result like following GIF?
If so, you should achieve the INotifyPropertyChanged interface in your RigaStoricoModel as Silvermind's said.
Here is MyViewModel.cs code.
public class RigaStoricoModel: INotifyPropertyChanged
{
private double _qtaEdit;
public double QtaEdit
{
set
{
_qtaEdit = value;
OnPropertyChanged("QtaEdit");
}
get => _qtaEdit;
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
I used AggiungiCommand to make a test(decrease or increase).
public class MyViewModel
{
public static ObservableCollection<RigaStoricoModel> acquistiList;
public ObservableCollection<RigaStoricoModel> AcquistiList
{
get { return acquistiList; }
set
{
if (acquistiList != value)
{
acquistiList = value;
// OnPropertyChanged();
}
}
}
public ICommand AggiungiCommand { protected set; get; }
public ICommand AggiungiCommand2 { protected set; get; }
// public int MyProperty { get; set; }
public MyViewModel()
{
AcquistiList = new ObservableCollection<RigaStoricoModel>();
AcquistiList.Add(new RigaStoricoModel() { QtaEdit=0.28 });
AcquistiList.Add(new RigaStoricoModel() { QtaEdit = 0.38 });
AcquistiList.Add(new RigaStoricoModel() { QtaEdit = 0.48 });
AcquistiList.Add(new RigaStoricoModel() { QtaEdit = 0.58 });
AcquistiList.Add(new RigaStoricoModel() { QtaEdit = 0.68 });
AggiungiCommand2=new Command(async (key) =>
{
RigaStoricoModel model = key as RigaStoricoModel;
model.QtaEdit += 0.1;
});
AggiungiCommand = new Command(async (key) =>
{
RigaStoricoModel model= key as RigaStoricoModel;
model.QtaEdit -= 0.1;
});
}
}
}
Here is layout.xaml(I do not have this style, for testing,I delete them and adjust this layout).
<StackLayout>
<!-- Place new controls here -->
<ListView ItemsSource="{Binding AcquistiList}" x:Name="mieiAcquistiStack" HasUnevenRows="True" >
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Frame >
<StackLayout Margin="-15" HorizontalOptions="CenterAndExpand" VerticalOptions="CenterAndExpand">
<Label Text="{Binding Articolo.Descrizione}"
/>
<StackLayout Orientation="Horizontal"
HorizontalOptions="End" VerticalOptions="Center">
<Button x:Name="removeButton"
VerticalOptions="Center" HorizontalOptions="Center"
Text="-"
Font="20"
WidthRequest="45" FontAttributes="Bold"
Command="{Binding Source={x:Reference mieiAcquistiStack}, Path=BindingContext.AggiungiCommand}"
CommandParameter="{Binding .}" />
<StackLayout HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand" >
<Label Text="{Binding QtaEdit}"
TextColor="Black"
FontSize="18" FontAttributes="Bold"
WidthRequest="40"
HorizontalTextAlignment="Center" VerticalTextAlignment="Center"
VerticalOptions="FillAndExpand"/>
</StackLayout>
<Button x:Name="addButton"
VerticalOptions="Center" HorizontalOptions="Center"
Text="+"
WidthRequest="45" FontAttributes="Bold"
Command="{Binding Source={x:Reference mieiAcquistiStack}, Path=BindingContext.AggiungiCommand2}"
CommandParameter="{Binding .}" />
</StackLayout>
</StackLayout>
</Frame>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
Here is layout background code.
public MainPage()
{
InitializeComponent();
this.BindingContext = new MyViewModel();
}

Xamarin forms Activity Indicator Not Showing on Button click Even when Binding is true

I have a Activity Indicator and have no issues with how it looks or anything like that, i just can't get it to to display on the button click.
There's a Lengthy Process that i need to go threw when Checking items out on the cart.
The Method Structure:
Button Clicked => Api Calls
=> await IsinStock()
=> Fetch Products
=> await SingleCheck() || await VariableCheck()
=> No Errors => AddOrder || Errors Display Error
My Indicators are being set to Active before API calls and Ends after checks are complete and it returns to add or show errors.
But it's just not displaying.
<?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:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
xmlns:o="clr-namespace:Octane.Xamarin.Forms.VideoPlayer;assembly=Octane.Xamarin.Forms.VideoPlayer"
xmlns:local="clr-namespace:Ecombeta"
xmlns:ffimageloading="clr-namespace:FFImageLoading.Forms;assembly=FFImageLoading.Forms"
x:Class="Ecombeta.Views.Cart">
<ContentPage.Content>
<AbsoluteLayout>
<Grid
RowSpacing="0"
AbsoluteLayout.LayoutFlags="All"
AbsoluteLayout.LayoutBounds="0,0,1,1">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<!--My Beautiful Ui Mark up here-->
</Grid>
<!--Loading Indicator-->
<AbsoluteLayout IsVisible="{Binding running}" AbsoluteLayout.LayoutFlags="All"
AbsoluteLayout.LayoutBounds="0,0,1,1">
<BoxView
BackgroundColor="#80000000"
AbsoluteLayout.LayoutFlags="All"
AbsoluteLayout.LayoutBounds="0,0,1,1" />
<StackLayout
AbsoluteLayout.LayoutFlags="PositionProportional"
AbsoluteLayout.LayoutBounds="0.5,0.5,-1,-1">
<Frame Padding="20,15"
CornerRadius="7"
VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand"
BackgroundColor="Black"
HasShadow="false">
<StackLayout VerticalOptions="Center"
HorizontalOptions="Center">
<ActivityIndicator
IsRunning="{Binding running}"
HorizontalOptions="Center"
VerticalOptions="Center"
Color="White" />
<Label Text="{Binding LoadingIndicatorMessage}"
x:Name="lblLoadingText"
HorizontalOptions="Center"
VerticalOptions="Center"
TextColor="White" />
</StackLayout>
</Frame>
</StackLayout>
</AbsoluteLayout>
<StackLayout Padding="5" AbsoluteLayout.LayoutBounds="0,0,1,1"
AbsoluteLayout.LayoutFlags="All" BackgroundColor="White">
<ListView x:Name="cartView"
HasUnevenRows="True"
SeparatorColor="Black"
VerticalOptions="FillAndExpand"
HorizontalOptions="FillAndExpand"
SeparatorVisibility="Default"
IsPullToRefreshEnabled="True"
ItemSelected="EvetClicked">
<ListView.Resources>
<ResourceDictionary>
<local:BgConverter x:Key="BgConverter" />
</ResourceDictionary>
</ListView.Resources>
<ListView.Header>
<Label Text="Shopping List" HorizontalOptions="Center" VerticalOptions="Center"
HorizontalTextAlignment="Center" Margin="0,0,0,15" TextColor="Black"
FontAttributes="Bold" FontSize="Title" />
</ListView.Header>
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<ViewCell.View>
<StackLayout Orientation="Vertical">
<Label TextColor="Black" x:Name="something" HorizontalOptions="CenterAndExpand"
Text="{Binding ProductName}" FontSize="Subtitle" />
<ffimageloading:CachedImage
HeightRequest="150"
WidthRequest="150"
HorizontalOptions="CenterAndExpand"
VerticalOptions="CenterAndExpand"
DownsampleToViewSize="true"
Source="{Binding ImgSource}" />
<Label IsVisible="{Binding _virtual}" HorizontalTextAlignment="Center"
TextColor="Black">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding CartAtribKey }" FontAttributes="Bold" />
<Span Text="{Binding CartAtribValue , StringFormat=' {0}' }"
FontSize="Small" />
</FormattedString>
</Label.FormattedText>
</Label>
<Label IsVisible="{Binding _virtual}" HorizontalTextAlignment="Center"
TextColor="Black">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding CartAtribKey1 }" FontAttributes="Bold" />
<Span Text="{ Binding CartAtribValue1, StringFormat=' {0}'}"
FontSize="Small" />
</FormattedString>
</Label.FormattedText>
</Label>
<!--<Label HorizontalOptions="EndAndExpand" VerticalOptions="StartAndExpand" Text="{Binding PId, StringFormat='SKU {0:F0}'}" FontSize="Medium"></Label> -->
<Label FontSize="Large" VerticalOptions="CenterAndExpand" TextColor="Black"
HorizontalOptions="CenterAndExpand"
Text="{Binding TotalDynamicPrice, StringFormat='Total R:{0,5:#,0.00}' }"
FontAttributes="Bold" />
<Label HorizontalOptions="CenterAndExpand" TextColor="Black"
FontAttributes="Bold"
Text="{Binding Source={x:Reference stepper}, Path=Value, StringFormat='Quantity {0:F0}'}"
FontSize="Medium" />
<StackLayout Orientation="Horizontal">
<ImageButton HorizontalOptions="Center" VerticalOptions="Center"
HeightRequest="30" WidthRequest="30"
Source="https://mm-app.co.za/wp-content/uploads/2020/01/icons8-remove-64.png"
BindingContext="{Binding PId}" Clicked="Removevalue_Clicked" />
<Stepper x:Name="stepper" Maximum="{Binding StockQuantity}"
Value="{Binding ProductQuantity}"
Minimum="{Binding MinQ}"
ClassId="{Binding PId}"
TabIndex="{Binding VariationId}"
HorizontalOptions="CenterAndExpand"
VerticalOptions="CenterAndExpand"
Increment="{Binding IncrementQ}"
ValueChanged="stepper_ValueChanged" />
</StackLayout>
</StackLayout>
</ViewCell.View>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<StackLayout Padding="0" Orientation="Horizontal" BackgroundColor="White">
<Button Margin="2" TextColor="white" BorderColor="#0088d3" BackgroundColor="#0088d3"
CornerRadius="10" Padding="10" VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand" Text="Buy Now!" Clicked="ImageButton_Clicked" />
</StackLayout>
</StackLayout>
</AbsoluteLayout>
</ContentPage.Content>
</ContentPage>
private async void ImageButton_Clicked(object sender, EventArgs e)
{
running = true;
try
{
//You cant checkout if your not logged in There are no Guest Checkouts(I can But would rather not)
if (Users.LoggedIn && _spamClick == false)
{
if (_orderlineitems == null)
_orderlineitems = new List<OrderLineItem>();
RestAPI rest = new RestAPI("http://xxxx/wp-json/wc/v2/","xxxxxxxxx","cs_xxxxxxxxxxx");
var wc = new WCObject(rest);
await IsInStock();
}
running = false;
}
(...)
}
public partial class Cart : ContentPage, INotifyPropertyChanged
private bool _running;
public bool running
{
get => _running;
set
{
if (_running == value)
return;
_running = value;
RaisePropertyChanged();
}
}
Any Ideas?

According to your description, I remember you posted a similar question a few days ago, but you deleted this question.
You said that you wanted to display ActivityIndicator when Button click, I test your code and find that there are two StackLayouts, one contains ActivityIndicator, another contains ListView, I suggest you can swap the positions of two stacklayouts, like this:
<AbsoluteLayout>
<StackLayout
Padding="5"
AbsoluteLayout.LayoutBounds="0,0,1,1"
AbsoluteLayout.LayoutFlags="All"
BackgroundColor="White">
<ListView
x:Name="cartView"
HasUnevenRows="True"
HorizontalOptions="FillAndExpand"
IsPullToRefreshEnabled="True"
ItemsSource="{Binding products}"
SeparatorColor="Black"
SeparatorVisibility="Default"
VerticalOptions="FillAndExpand">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Vertical">
<Label
x:Name="something"
HorizontalOptions="CenterAndExpand"
Text="{Binding ProductName}"
TextColor="Black" />
<Image
HeightRequest="150"
HorizontalOptions="CenterAndExpand"
Source="{Binding ImgSource}"
VerticalOptions="CenterAndExpand"
WidthRequest="150" />
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Button
x:Name="getproduct"
Clicked="Getproduct_Clicked"
Text="load product" />
</StackLayout>
<StackLayout
x:Name="LoadingOverlay"
AbsoluteLayout.LayoutBounds="0,0,1,1"
AbsoluteLayout.LayoutFlags="All"
BackgroundColor="White"
HorizontalOptions="FillAndExpand"
IsVisible="{Binding loading}"
Opacity="0.5"
VerticalOptions="FillAndExpand">
<ActivityIndicator
x:Name="TaskLoader"
HorizontalOptions="CenterAndExpand"
IsRunning="{Binding running}"
IsVisible="{Binding running}"
Scale="4"
VerticalOptions="CenterAndExpand"
Color="Red" />
</StackLayout>
</AbsoluteLayout>
public partial class Page5 : ContentPage, INotifyPropertyChanged
{
public ObservableCollection<product> products { get; set; }
private bool _loading;
public bool loading
{
get { return _loading; }
set
{
_loading = value;
RaisePropertyChanged("loading");
}
}
private bool _running;
public bool running
{
get { return _running; }
set
{
_running = value;
RaisePropertyChanged("running");
}
}
public Page5()
{
InitializeComponent();
products = new ObservableCollection<product>();
loading = false;
running = false;
this.BindingContext = this;
}
private void loaddata()
{
products.Add(new product() { ProductName = "product 1", ImgSource = "a5.jpg" });
products.Add(new product() { ProductName = "product 2", ImgSource = "a6.jpg" });
products.Add(new product() { ProductName = "product 3", ImgSource = "a7.jpg" });
products.Add(new product() { ProductName = "product 4", ImgSource = "a8.jpg" });
products.Add(new product() { ProductName = "product 1", ImgSource = "a5.jpg" });
products.Add(new product() { ProductName = "product 2", ImgSource = "a6.jpg" });
products.Add(new product() { ProductName = "product 3", ImgSource = "a7.jpg" });
products.Add(new product() { ProductName = "product 4", ImgSource = "a8.jpg" });
}
public event PropertyChangedEventHandler PropertyChanged;
public void RaisePropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
private async void Getproduct_Clicked(object sender, EventArgs e)
{
loading = true;
running = true;
await Task.Delay(5000);
loaddata();
loading = false;
running = false;
}
}
public class product
{
public string ProductName { get; set; }
public string ImgSource { get; set; }
}
There is screenshot:

INotifyPropertyChanged ListView

I am new to Xamarin Forms and trying to implement Infinite Loop Functionality in my app. The sample code that i followed is working fine and i have managed to integrate it into my app successfully.
The problem is that i am unable to find out how to change the source of the listview from the code.
I intend to have buttons above my listview (As in the following Image) and upon click the source of the listView should change.
This is how my code looks like
<ContentPage.BindingContext>
<local:MainViewModel />
</ContentPage.BindingContext>
<StackLayout>
<ListView x:Name="tyres_listview" ItemsSource="{Binding Items}"
HasUnevenRows="True" SeparatorVisibility="None" >
<ListView.Behaviors>
<extended:InfiniteScrollBehavior IsLoadingMore="{Binding IsBusy}" />
</ListView.Behaviors>
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout>
<Grid Margin="10" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="0.25*"></ColumnDefinition>
<ColumnDefinition Width="0.75*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<StackLayout Grid.Column="0" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" Margin="5,5,5,10">
<Image Source="{Binding image_url}" >
</Image>
</StackLayout>
<StackLayout Grid.Column="1" Spacing="0" >
<Label Text="{Binding name}" FontAttributes="Bold" FontSize="Small" Margin="0,5,5,0" VerticalOptions="Center" ></Label>
<Label Text="{Binding brand}" VerticalOptions="Center" FontSize="Micro" ></Label>
<Label Text="{Binding item_id}" VerticalOptions="Center" FontSize="Micro" ></Label>
<StackLayout Orientation="Horizontal" x:Name="sl_db" >
<Image Source="fuel.png" ></Image>
<Label Text="{Binding fuel_type}"></Label>
<Image Source="weather.png"></Image>
<Label Text="{Binding wheather_type }"></Label>
<Image Source="volume.png" ></Image>
<Label Text="{Binding noise}"></Label>
<Label Text="dB"></Label>
</StackLayout>
<StackLayout Orientation="Horizontal">
<Image></Image>
<Label Text="{Binding rated_count }"></Label>
</StackLayout>
<StackLayout Orientation="Horizontal">
<Label Text="Price: " VerticalOptions="Center"></Label>
<Label Text="{Binding price }" VerticalOptions="Center" TextColor="Green"></Label>
<Label Text=" EUR" VerticalOptions="Center"></Label>
</StackLayout>
<StackLayout Orientation="Horizontal">
<StackLayout.GestureRecognizers>
<TapGestureRecognizer Tapped="TapGestureRecognizer_Tapped_1" >
</TapGestureRecognizer>
</StackLayout.GestureRecognizers>
<StackLayout BackgroundColor="Red" Orientation="Horizontal" Margin="5" >
<Image Source="shoppingcart.png" Margin="10,0,0,0"></Image>
<Label Text="Add to Cart" VerticalOptions="Center" HorizontalOptions="EndAndExpand" Margin="0,0,10,0" ></Label>
</StackLayout>
<Image x:Name="button_info" Source="info.png" >
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="button_info_Clicked"></TapGestureRecognizer>
</Image.GestureRecognizers>
</Image>
</StackLayout>
</StackLayout>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
<ListView.Footer>
<Grid Padding="6" IsVisible="{Binding IsBusy}">
<!-- set the footer to have a zero height when invisible -->
<Grid.Triggers>
<Trigger TargetType="Grid" Property="IsVisible" Value="False">
<Setter Property="HeightRequest" Value="0" />
</Trigger>
</Grid.Triggers>
<!-- the loading content -->
<Label Text="Loading..." TextColor="DeepPink" FontSize="20" FontAttributes="Bold" VerticalOptions="Center" HorizontalOptions="Center" />
</Grid>
</ListView.Footer>
</ListView>
<Button Clicked="button_Change_Order_Clicked"></Button>
</StackLayout>
public class MainViewModel : INotifyPropertyChanged
{
private bool _isBusy;
private const int PageSize = 10;
readonly DataService _dataService = new DataService();
public InfiniteScrollCollection<Product_Search> Items { get; }
public bool IsBusy
{
get => _isBusy;
set
{
_isBusy = value;
OnPropertyChanged();
}
}
public MainViewModel()
{
Items = new InfiniteScrollCollection<Product_Search>
{
OnLoadMore = async () =>
{
IsBusy = true;
// load the next page
var page = Items.Count / PageSize;
var items = await _dataService.GetItemsAsync(page, PageSize);
IsBusy = false;
// return the items that need to be added
return items;
},
OnCanLoadMore = () =>
{
return Items.Count < 44;
}
};
DownloadDataAsync();
}
private async Task DownloadDataAsync()
{
var items = await _dataService.GetItemsAsync(pageIndex: 0, pageSize: PageSize);
Items.AddRange(items);
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
}
Any help would be of great importance.

Your ListView.Items property is already bound to your MainViewModel.Items property, a PropertyChanged event needs to be triggered to signal a change on the property value (corresponding to the property itself or its content if InfiniteScrollCollection<> is an Observable collection).
When you would want to replace the Items source you can give it a new value, signal it has changed and your ListView might be refreshed:
private InfiniteScrollCollection<Product_Search> _items;
public InfiniteScrollCollection<Product_Search> Items
{
get { return _items; }
set
{
_items = value;
OnPropertyChanged();
}
}

Develop Reference

C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.

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