Get each listview's row height

Question

Get each listview's row height

Dimitris Christoforidis 301

Hello and hope everyone doing well, i need to calculate each listview's row height. My listivew has uneven rows.
Or if it is possible to get all rows height by once. Thank you

Anonymous

2021-08-31T02:37:53.997+00:00

if it is possible to get all rows height by once.

I am afraid this answer is no. If rows do not appear in the screen, row cannot be rendered, so rows' height we cannot get it. I create a demo, I get the View height in the <ViewCell Appearing="ViewCell_Appearing" >, But I find I cannot get height when Row appear at the first time, but I can get height at the second time.

Dimitris Christoforidis 301

Thank you LeonLu. I tried view cell appearing but i am getting always height = -1.
Here is My code:

<StackLayout>
    <Button Clicked="Button_Clicked"/>
    <ListView x:Name="test" HasUnevenRows="True">
        <ListView.ItemTemplate>
            <DataTemplate>
                <ViewCell Appearing="ViewCell_Appearing">
                    <StackLayout >
                        <Label Text="{Binding Name}"/>
                    </StackLayout>
                </ViewCell>
            </DataTemplate>
        </ListView.ItemTemplate>
    </ListView>
</StackLayout>


 public class Customer
    {
        public string Name { get; set; }
    }
    private void Button_Clicked(object sender, EventArgs e)
    {
        var items = new ObservableCollection<Customer>();
        items.Add(new Customer { Name = "Dimitris" });

        test.ItemsSource = items;
    }
    private async void ViewCell_Appearing(object sender, EventArgs e)
    {
        var ss = sender as ViewCell;
        await DisplayAlert("", ss.Height.ToString(), "OK");
    }

Dimitris Christoforidis 301 Reputation points

2021-08-31T11:55:59.21+00:00
Or if it is possible to get each row height after appears in screen.
Example

foreach (var row in listView) { }

Anonymous

I set CachingStrategy="RecycleElement", then here is my onAppearing code. Please notice, when your row appear at the first time, the height value is -1, You can get the height value at the second appearing time,

private  void ViewCell_Appearing(object sender, EventArgs e)
        {
            var cell = sender as ViewCell;
            var myView=cell.View;
            var getHeight= myView.Height;
            Console.WriteLine("======"+ getHeight + "===========");     
        }

Dimitris Christoforidis 301 Reputation points

2021-09-01T08:20:37.123+00:00

ΤThank you LeonLu!! Is there any code which i can trigger Appearing event programmaticaly?
Anonymous

2021-09-02T09:27:21.34+00:00

I am afraid this answer is No, ViewCell's Appearing method is a lifecycle method, we can not use C# code to trigger it

Your answer

Anonymous

2021-08-31T02:37:53.997+00:00

if it is possible to get all rows height by once.

I am afraid this answer is no. If rows do not appear in the screen, row cannot be rendered, so rows' height we cannot get it. I create a demo, I get the View height in the <ViewCell Appearing="ViewCell_Appearing" >, But I find I cannot get height when Row appear at the first time, but I can get height at the second time.
Dimitris Christoforidis 301 Reputation points

2021-08-31T11:43:11.893+00:00

Thank you LeonLu. I tried view cell appearing but i am getting always height = -1.
Here is My code:

<StackLayout> <Button Clicked="Button_Clicked"/> <ListView x:Name="test" HasUnevenRows="True"> <ListView.ItemTemplate> <DataTemplate> <ViewCell Appearing="ViewCell_Appearing"> <StackLayout > <Label Text="{Binding Name}"/> </StackLayout> </ViewCell> </DataTemplate> </ListView.ItemTemplate> </ListView> </StackLayout> public class Customer { public string Name { get; set; } } private void Button_Clicked(object sender, EventArgs e) { var items = new ObservableCollection<Customer>(); items.Add(new Customer { Name = "Dimitris" }); test.ItemsSource = items; } private async void ViewCell_Appearing(object sender, EventArgs e) { var ss = sender as ViewCell; await DisplayAlert("", ss.Height.ToString(), "OK"); }
Dimitris Christoforidis 301 Reputation points

2021-08-31T11:55:59.21+00:00

Or if it is possible to get each row height after appears in screen.
Example

foreach (var row in listView) { }
Anonymous

2021-09-01T05:33:35.73+00:00

I set CachingStrategy="RecycleElement", then here is my onAppearing code. Please notice, when your row appear at the first time, the height value is -1, You can get the height value at the second appearing time,

private void ViewCell_Appearing(object sender, EventArgs e) { var cell = sender as ViewCell; var myView=cell.View; var getHeight= myView.Height; Console.WriteLine("======"+ getHeight + "==========="); }
Dimitris Christoforidis 301 Reputation points

2021-09-01T08:20:37.123+00:00

ΤThank you LeonLu!! Is there any code which i can trigger Appearing event programmaticaly?
Anonymous

2021-09-02T09:27:21.34+00:00

I am afraid this answer is No, ViewCell's Appearing method is a lifecycle method, we can not use C# code to trigger it

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Get each listview's row height

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