How autoclear a EntryCell in Xamarin.Forms? - xamarin

Question

I have a EntryCell that need to AutoClear each time the user select it. I know how do that on iOS directly but not with Xamarin.Forms.

Answer 1

If you mean clear the value when the Entry is Focused this can be accomplished in a few ways.
The easy way: Handling the Focused event.
<Entry Placeholder="Name" HorizontalOptions="FillAndExpand" Focused="Handle_Focused" />
and in code behind
void Handle_Focused(object sender, Xamarin.Forms.FocusEventArgs e)
{
((Entry)sender).Text = string.Empty;
}
note that you could also use ((Entry)sender).ClearValue(Entry.TextProperty); inside your Handle_Focused method.
Or with the still easy and cleaner way: Using a Behavior
namespace YourRootNamespace.Behaviors
{
public class EntryClearOnFocusBehavior : Behavior<Entry>
{
protected override void OnAttachedTo(Entry bindable)
{
if (bindable == null)
{
throw new InvalidOperationException("Entry was null. Behavior can only be atached to an Entry");
}
bindable.Focused += OnEntryFocused;
base.OnAttachedTo(bindable);
}
protected override void OnDetachingFrom(Entry bindable)
{
bindable.Focused -= OnEntryFocused;
base.OnDetachingFrom(bindable);
}
void OnEntryFocused(object sender, FocusEventArgs e)
{
((Entry)sender).ClearValue(Entry.TextProperty);
}
}
}
Then in your XAML you would:
Add this namespace in your ContentPage definition xmlns:behaviors="clr-namespace:YourRootNamespace.Behaviors"
and attach the behavior to your Entry (or Entries).
<Entry Placeholder="Last Name" HorizontalOptions="FillAndExpand">
<Entry.Behaviors>
<behaviors:EntryClearOnFocusBehavior />
</Entry.Behaviors>
</Entry>
This way is my favorite as it gives you reusability.
You can go one step further and create a Style with this Behavior so attaching the behavior would be as simple as adding an style. More about this here.
Hopes this helps.-

Answer 2

You can use trigger, It is very simple solution
<Entry Placeholder="enter name">
<Entry.Triggers>
<Trigger TargetType="Entry"
Property="IsFocused" Value="True">
<Setter
Property="Text"
Value="" />
</Trigger>
</Entry.Triggers>
</Entry>
For EntryCell:
XAML code
<ListView x:Name="listView" SeparatorVisibility="None" ItemsSource="{x:Static local:HomeViewModel.lights}">
<ListView.ItemTemplate>
<DataTemplate>
<EntryCell Label="{Binding comment}" Text="{Binding name}" Tapped="Item_Tapped" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Code behind
void Item_Tapped(object sender, System.EventArgs e)
{
((EntryCell)sender).Text = "";
}