I'm trying to remove items/rows from a ListView
but the difficulty is that I need to also pass in some delegate or fire some event or something, so when a person clicks a button to remove that row, my code handles some other logic, elsewhere (eg. remove the item from the DB or whatever).
I have a custom control I made:
public class SportsTeam : StackLayout { .. }
Inside this control, one of the elements is a ListView
which lists all the people in a sporting team.
var viewModel = teamMembers.Select(x => new SportsTeamViewModel(x));
return new ListView
{
HasUnevenRows = true,
ItemSource = viewModel,
ItemTemplate = new DataTemplate(typeof(SportsTeamViewCell));
};
Inside the SportsTeamViewCell
I have the following:
private Grid CreateContent()
{
var grid = new Grid();
// Setup row and column definitions.
// Add items to the Grid
grid.Children.Add(...);
var removeButton = RemoveButton;
grid.Children.Add(removeButton);
Grid.SetRowSpan(removeButton, 2);
return grid;
}
private Button RemoveButton
{
get
{
var button = new Button
{
Image = "Icons/remove.png"
};
return button;
}
}
From here, I don't know how to make it so that the button fires an event or some delete could be passed in via the constructor, so some custom logic is performed against the individual cell/row/item that is to be removed.
You can delete an item from ListView by the button loaded inside ItemTemplate in Xamarin. Forms. In VeiwModel command handler, removed the selected item from the collection.
Name the list in the Xaml and set the item source in C# as the MyList. Now in XAML create a ListView and give the name to your ContentPage and bind this with the Item Source Of the List. In the header add two buttons to add and delete a item.
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
Here is the full source code of the explained scenario - Handling Child Control Event in Listview using XAMARIN.FORMS.
Also the Tutorial - How to handle Row selection and delete Button in Row For Custom ListView using Xamarin.Forms explain deletion from a listview
as well.
I've found a similar approach and I want to share it. I filled the list with an ObservableCollection<MyObject>
. Then I filled the CommandParameter with just CommandParameter="{Binding .}"
. So I got the whole Object back. Then you can just cast the CommandParameter
to your Object and remove it from the ObservableCollection<MyObject>
List
XAML:
CommandParameter="{Binding .}"
Filling my List:
savingExpensesCollection = new ObservableCollection<SavingsExpensesEntry> ();
savingExpensesCollection .Add (new SavingsExpensesEntry ("1000 mAh Akku", "Dampfgarten", new DateTime (635808692400000000), 8.95));
savingExpensesCollection .Add (new SavingsExpensesEntry ("Cool-Mint Aroma", "Dampfgarten", new DateTime (635808692400000000), 3.95));
savingExpensesCollection .Add (new SavingsExpensesEntry ("Basis", "Dampfgarten", new DateTime (635808692400000000), 13.65));
savingExpensesList.ItemsSource = savingExpenses;
EventHandler:
void OnDelete(object sender, EventArgs e)
{
var menuItem = ((MenuItem)sender);
SavingsExpensesEntry see ((SavingsExpensesEntry)menuItem.CommandParameter);
savingExpensesCollection .Remove (see);
}
I've using a MenuItem
but it's the same approach with a Button
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