Styjun

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;