How to access nested label via C#?

How to access nested label via C#? - c#

How to access ListViews item template element named TextButtonDetails to update its Text property?
i tried so -
TextButtonDetails.Text = AppResources.AppResources.MoreDetailsProduct;
and so
listView.FindByName<Label>("TextButtonDetails").Text = AppResources.AppResources.MoreDetailsProduct;
<ListView x:Name="listView" HorizontalOptions="FillAndExpand" HasUnevenRows="true" VerticalScrollBarVisibility="Default" Refreshing="Refresh" ItemSelected="Details">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Margin="20" VerticalOptions="StartAndExpand" Orientation="Vertical">
<Label Text="{Binding Title}" FontAttributes="Bold" VerticalTextAlignment="Start" HorizontalOptions="StartAndExpand" />
<Label Text="{Binding Text}" VerticalOptions="StartAndExpand" />
<Label VerticalTextAlignment="End" TextColor="#2196F3" x:Name="TextButtonDetails"></Label>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>

You can set your resource value in your view model:
public class YourItemViewModel
{
public YourItemViewModel()
{
Title = ...
Text = ...
MoreDetailsLabel = AppResources.AppResources.MoreDetailsProduct;
}
public string Title { get; }
public string Text { get; }
public string MoreDetailsLabel { get; }
}
or use the TranslateExtension markup extension from the xamarin forms docs: https://learn.microsoft.com/en-US/xamarin/xamarin-forms/app-fundamentals/localization/text?tabs=windows#localizing-xaml
It's a good idea to support localization.
You will be able to reference your resource value directly like this:
<?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="UsingResxLocalization.FirstPageXaml"
xmlns:i18n="clr-namespace:UsingResxLocalization;assembly=UsingResxLocalization">
<StackLayout Padding="0, 20, 0, 0">
<Label Text="{i18n:Translate NotesLabel}" />
<Entry Placeholder="{i18n:Translate NotesPlaceholder}" />
<Button Text="{i18n:Translate AddButton}" />
</StackLayout>
</ContentPage>

Related

Xamarin.Forms - Binding a command

I am using ToolKits Expander and I am trying to bind a command, this is what I got so far:
public partial class AssignTaskPage : ContentPage
{
public AssignTaskPage()
{
InitializeComponent();
GetMathSubCatgories = new Command(() => MathSubCatgoriesCommand());
}
public ICommand GetMathSubCatgories { get; private set; }
void MathSubCatgoriesCommand()
{
Console.Write("Here");
}
}
And in my view
<xct:Expander Command="{Binding GetMathSubCatgories}">
<xct:Expander.Header>
<Frame Padding="10" Margin="10" HasShadow="False" BorderColor="LightGray" VerticalOptions="CenterAndExpand">
<StackLayout Orientation="Horizontal">
<Image Source="{Binding icon}" WidthRequest="25" HeightRequest="25"></Image>
<Label Text="{Binding name}" TextColor="{Binding textColor}" FontSize="Large" FontAttributes="Bold" HeightRequest="35" VerticalOptions="CenterAndExpand"></Label>
</StackLayout>
</Frame>
</xct:Expander.Header>
<Grid Padding="10">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<ListView x:Name="SubCategories" ItemsSource="{Binding subCategories}" ItemSelected="SubCategories_ItemSelected">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout>
<Label Text="{Binding name}" TextColor="#02cc9d" FontAttributes="Bold" HeightRequest="35" VerticalOptions="CenterAndExpand"></Label>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</Grid>
</xct:Expander>
This does not work at all, (I put a break point on Console.Write("Here"); and its not hitting it)
So I did some digging and found this tutorial:
https://www.syncfusion.com/kb/12154/how-to-bind-command-to-expander-in-itemtemplate-of-xamarin-forms-listview-sflistview
and here is the sample in git.
https://github.com/SyncfusionExamples/command-to-expander-in-itemtemplate-listview-xamarin
I understand what I have to do here, the problem I am facing is when this Command is called, I was looking to get a value and use it in my AssignTaskPage, but what the tutorial is saying to have a ViewModel which is in a separate file. So should I setup a MessagingCenter in my AssignTaskPage and call it in the ViewModel to get the value I want and pass it to AssignTaskPage?

Because your command isn't defined in the ViewModel that you're binding to.You could bind the command which is defined in your AssignTaskPage,and then bind the viewmodel for the parent element of the expander.
For example :
public partial class AssignTaskPage : ContentPage
{
public AssignTaskPage()
{
InitializeComponent();
GetMathSubCatgories = new Command(() => MathSubCatgoriesCommand());
BindingContext = this;
}
public ICommand GetMathSubCatgories { get; private set; }
void MathSubCatgoriesCommand(object obj)
{
DisplayAlert("Alert!", "" + (obj as Contact).ContactName + "expanded", "Ok");
}
}
the xaml (here use the xaml codes of the above sample),the grid bind the viewmodel,and your expander bind the command of the root (your page):
<?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:local="clr-namespace:ExpanderXamarin"
x:Class="ExpanderXamarin.ExpandableListView"
x:Name="root"
xmlns:sflistview="clr-namespace:Syncfusion.ListView.XForms;assembly=Syncfusion.SfListView.XForms"
xmlns:expander="clr-namespace:Syncfusion.XForms.Expander;assembly=Syncfusion.Expander.XForms">
<ContentPage.Content>
<Grid x:Name="mainGrid" BackgroundColor="#F0F0F0" Padding="4">
<Grid.BindingContext>
<local:ViewModel />
</Grid.BindingContext>
<sflistview:SfListView x:Name="listView" AutoFitMode="DynamicHeight" ItemsSource="{Binding ContactsInfo}">
<sflistview:SfListView.ItemTemplate>
<DataTemplate>
<Frame x:Name="frame" CornerRadius="2" Padding="{OnPlatform Android=1, iOS=1, UWP=0}" Margin="{OnPlatform Android=1, iOS=1, UWP=0}" OutlineColor="White" HasShadow="{OnPlatform Android=true, iOS=false, UWP=true}">
<Grid Padding="{OnPlatform Android=2, iOS=2, UWP=0}" Margin="{OnPlatform Android=1, iOS=1, UWP=0}" BackgroundColor="White" >
<expander:SfExpander x:Name="expander" HeaderIconPosition="None">
<expander:SfExpander.Behaviors>
<local:EventToCommandBehavior Command="{Binding Path=BindingContext.GetMathSubCatgories, Source={x:Reference root}}" EventName="Expanding" CommandParameter="{Binding .}"/>
</expander:SfExpander.Behaviors>
<expander:SfExpander.Header>
...
</expander:SfExpander.Header>
<expander:SfExpander.Content>
..
</expander:SfExpander.Content>
</expander:SfExpander>
</Grid>
</Frame>
</DataTemplate>
</sflistview:SfListView.ItemTemplate>
</sflistview:SfListView>
</Grid>
</ContentPage.Content>
</ContentPage>
if you want get the parameters you could bind the CommandParameter like above.

Problem with Xamarin app while calling an API

I'm a beginner with C# and whole .NET (just wanted to mention at the beginning). So I'm learning Xamarin and APIs.
I've got the problem with fetching some data from API (https://jsonplaceholder.typicode.com/posts) to display inside the app. Once I execute the app, it gives me an error:
System.InvalidCastException: 'Specified cast is not valid'.
I also don't see where is it failing (after error, exception window is blank - like not showing where it stops).
using ExerciseApp.Models;
using Newtonsoft.Json;
using System.Collections.Generic;
using System.Net.Http;
using Xamarin.Forms;
namespace ExerciseApp
{
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
GetPosts();
}
private async void GetPosts()
{
HttpClient client = new HttpClient();
var response = await client.GetStringAsync("https://jsonplaceholder.typicode.com/posts");
var posts = JsonConvert.DeserializeObject<List<Posts>>(response);
PostsListView.ItemsSource = posts;
}
}
}
<?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="ExerciseApp.MainPage">
<StackLayout BackgroundColor="White">
<Frame BackgroundColor="#581845" Padding="10" CornerRadius="5" Margin="25">
<Label Text="ʕ•ᴥ•ʔ" HorizontalTextAlignment="Center" TextColor="White" FontSize="30"/>
</Frame>
<Label Text="Welcome to Exercise app with RESTAPI and NHibernate" TextColor="#581845" FontSize="Title" Padding="10" HorizontalTextAlignment="Center"/>
<Label FontSize="20" Padding="20" HorizontalTextAlignment="Center" TextColor="#581845">
<Label.FormattedText>
<FormattedString>
<FormattedString.Spans>
<Span Text="Here we will load some data"/>
</FormattedString.Spans>
</FormattedString>
</Label.FormattedText>
</Label>
<ListView x:Name="PostsListView">
<ListView.ItemTemplate>
<DataTemplate>
<StackLayout Orientation="Horizontal">
<Label Text="{Binding id}" TextColor="#581845"></Label>
<Label Text="{Binding title}" TextColor="#581845"></Label>
</StackLayout>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
</ContentPage>
namespace ExerciseApp.Models
{
public class Posts
{
public int userId { get; set; }
public int id { get; set; }
public string title { get; set; }
public string body { get; set; }
}
}

ListView must use a Cell type in their template. Adding a ViewCell into your XAML will fix this problem
<ListView x:Name="PostsListView">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal">
<Label Text="{Binding id}" TextColor="#581845"></Label>
<Label Text="{Binding title}" TextColor="#581845"></Label>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
alternately, you can use a CollectionView which allows you to create templates without the restriction of using a Cell

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 Forms Command Binding inside ListView is not working

i'm trying to bind a command to a button inside a listView, but without success. I follow all other answers posted here, like this one:
Xamarin Forms Button Command binding inside a ListView
The actual result is that nothing happens. A thing that i notice is that visual studio, when i type after x:Reference suggests me just GridWebcam, like if it doesn't see other reference elements. What can i do?
Here my code:
<ContentPage
...
x:Name="WebcamList">
<ContentPage.Resources>
...
<ContentPage.Content>
<ListView ItemsSource="{Binding ListOfWebcam}"
SeparatorVisibility="None"
CachingStrategy="RecycleElement"
RowHeight="250"
VerticalOptions="FillAndExpand"
x:Name="ListWebcam">
<ListView.Header>
<StackLayout x:Name="HeaderStackLayout"
Padding="5,25,0,30"
Orientation="Horizontal"
HorizontalOptions="FillAndExpand">
<Label x:Name="LabelHeader"
Text="Webcam:"
FontSize="Large"
FontAttributes="Bold"
TextColor="{x:Static statics:Palette.PrimaryColor}"
VerticalOptions="Center"
HorizontalOptions="Start" Margin="10,0,0,0"/>
</StackLayout>
</ListView.Header>
<ListView.ItemTemplate>
<DataTemplate>
<controls:ExtendedViewCell IsEnabled="False">
<controls:ExtendedViewCell.View>
<Grid x:Name="GridWebcam">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Frame Grid.Column="1"
Grid.RowSpan="2"
CornerRadius="20"
BackgroundColor="{x:Static statics:Palette.PrimaryColor}"
VerticalOptions="FillAndExpand"
HorizontalOptions="FillAndExpand"
HasShadow="True"
Margin="5,10">
<StackLayout>
<Label Text="{Binding t_str_vid,Converter={StaticResource WebcamNameConverter}}"
FontSize="Medium"
TextColor="White"
FontAttributes="Bold"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand">
</Label>
<Label TextColor="White"
FontSize="Medium"
Text="{Binding direzione,Converter={StaticResource DirectionToStringConverter}}"/>
<StackLayout Orientation="Horizontal">
<ffimageloading:CachedImage LoadingPlaceholder="Rolling.gif"
DownsampleToViewSize="False"
VerticalOptions="FillAndExpand"
HorizontalOptions="StartAndExpand"
Source="{Binding image1}"/>
<iconize:IconButton Text="fas-play-circle"
FontSize="50"
HorizontalOptions="EndAndExpand"
VerticalOptions="EndAndExpand"
TextColor="White"
Command="{Binding BindingContext.OpenVideoWebcamCommand, Source={x:Reference WebcamList}}"
CommandParameter="{Binding .}"
BackgroundColor="Transparent"/>
</StackLayout>
</StackLayout>
</Frame>
</Grid>
</controls:ExtendedViewCell.View>
</controls:ExtendedViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</ContentPage.Content>
</ContentPage>
```
public class WebcamListViewModel : BaseViewModel
{
public ICommand OpenVideoWebcamCommand { set; get; }
private List<Webcam> _ListOfWebcam { get; set; }
public List<Webcam> ListOfWebcam
{
get { return _ListOfWebcam; }
set
{
_ListOfWebcam = value;
OnPropertyChanged();
}
}
private Task DownloadFramesTask;
CancellationTokenSource tokenSourceDownloadFrames = new CancellationTokenSource();
CancellationToken cancellationTokenDownloadFrames;
public WebcamListViewModel(INavigationService navigationService, IApiAutostradeManagerFactory apiAutostradeManagerFactory) : base(navigationService,apiAutostradeManagerFactory)
{
OpenVideoWebcamCommand = new Command<Webcam>(async (webcam) => {
await navigationService.NavigateAsync(Locator.WebcamVideoPopUpPage);
Messenger.Default.Send(new InfoWebcamVideoMessage(webcam.c_mpr, webcam.c_uuid, webcam.t_str_vid));
});
}

Well it could be related to this mysterious controls:ExtendedViewCell of yours :)
Also did you disable the ListView selection: <ListView ... SelectionMode="None" /> ?

As Roubachof said that I don't know if it is related to controls:ExtendedViewCell,please check if you have binding BindingContext, then you can take a look the following code:
<StackLayout>
<ListView x:Name="listview1" ItemsSource="{Binding persons}">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal">
<Label Text="{Binding Id}" />
<Label Text="{Binding name}" />
<Button
Command="{Binding BindingContext.command, Source={x:Reference listview1}}"
CommandParameter="{Binding Id}"
Text="Delete item" />
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
public partial class Page1 : ContentPage
{
public ObservableCollection<person> persons { get; set; }
public RelayCommand1 command { get; set; }
public Page1 ()
{
InitializeComponent ();
persons = new ObservableCollection<person>();
for(int i =0;i<20;i++)
{
person p = new person()
{
Id = i,
name = "cherry" + i
};
persons.Add(p);
command = new RelayCommand1(obj => method1((int)obj));
}
this.BindingContext = this;
}
public void method1(int Id)
{
persons.RemoveAt(Id);
//IEnumerable<person> list = persons.Where(x => x.Id == Id);
//foreach (person m in list)
//{
//}
}
}
public class person
{
public int Id { get; set; }
public string name { get; set; }
}

Listview does not contain a definition for selecteditems

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; }
}

Develop Reference

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

How to access nested label via C#? - c#

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