Xamarin Forms 清除所有条目

Question

Is there a way to clear all entries in an Xamarin.Forms app? I checked this link here but it did not help.

Answer 1

I have used @Bassies code, modified to clear entries from layout dynamically. So, you do not need to add reference in code behind. This method will loop through each items and clear text. So, while comparing @Bassies way, this dynamic method will take little more time to process. But it will be negligible time as single page view will not contain huge amount of views (like 10000 or more)

 public partial class MainPage : ContentPage
    {
        public MainPage()
        {
            InitializeComponent();
        }

        private void Button_Clicked(object sender, EventArgs e)
        {
            var child = this.Content as Layout;
            if (child != null)
            {
                ProcessLayoutChildren(child);
            }
        }

        public void ProcessLayoutChildren(Layout child)
        {
            foreach (var item in child.Children)
            {
                var layout = item as Layout;
                if (layout != null)
                {
                    ProcessLayoutChildren(layout);
                }
                else
                {
                    ClearEntry(item);
                }
            }

            void ClearEntry(Element entryElement)
            {
                var entry = entryElement as Entry;
                if (entry != null)
                {
                    entry.Text = string.Empty;
                }
            }
        }
    }

Answer 2

I haven't tested this but it should work

You can iterate through all the child views in your layout and clear the entries inside of it.

If you are using XAML, give your layout a name so you could access it in the backend code

<StackLayout x:Name="MyForm">
    <Label Text="Anything"/>
    <Entry />
    <Entry />
    <Entry />
    <Button Text="Clear" x:Name="Clear" Clicked="Clear_Clicked" />

</StackLayout>

Then in your Backend:

private void Clear_Clicked(object sender, EventArgs e)
{
    foreach (View view in MyForm.Children)
    {

        if(view is Entry)
        {
            (view as Entry).Text = String.Empty;
        }
    }

}

Answer 3

Maybe not the right way but an example how it works on 1 Page.

You might want to change it, but give's an idea how it works

<StackLayout>
    <Frame BackgroundColor="#2196F3" Padding="24" CornerRadius="0">
        <Label Text="Clear All" HorizontalTextAlignment="Center" TextColor="White" FontSize="36"/>
    </Frame>

    <Entry x:Name="Nr1" />
    <Entry x:Name="Nr2" />
    <Entry x:Name="Nr3" />
    <Button Text="Clear" Clicked="Button_Clicked" />

</StackLayout>

And Make a List and give the Entry's a Name, i use Nr1, Nr2 and Nr3 but only for example.

public partial class MainPage : ContentPage
{
    List<Entry> entry = new List<Entry>();
    public MainPage()
    {
        InitializeComponent();
        entry.Clear();
        entry.Add(Nr1);
        entry.Add(Nr2);
        entry.Add(Nr3);

    }

    private void Button_Clicked(object sender, EventArgs e)
    {
        foreach (var entry in entry)
        {

            entry.Text = "";
        }

    }
}