We use cookies to give you the best experience on our website. If you continue to browse, then you agree to our privacy policy and cookie policy. Image for the cookie policy date
Unfortunately, activation email could not send to your email. Please try again.
Syncfusion Feedback

How to add entered text to the dropdown collection in Xamarin.Forms DataForm (SfDataForm)

Platform: Xamarin.Forms |
Control: SfDataForm |
Published Date: April 15, 2020 |
Last Revised Date: April 15, 2020

You can add the entered text to the DropDown editor’s collection in Xamarin.Forms SfDataForm by using a custom editor.

You can create and add the custom editor to SfDataForm by overriding the DataFormEditor class, where the CustomDropDownEditor is inherited using DataFormDropDownEditor.

Refer to the online user guide documentation for creating a new custom editor in DataForm.

C#

DropDown editor modified by customizing DataFormDropDownEditor. When unfocused from dropdown entered text added to the collection.

public class CustomDropDownEditor : DataFormDropDownEditor
{
    DataFormDropDownItem dropDownItem;
    SfDataForm sfDataForm;
    public CustomDropDownEditor(SfDataForm dataForm) : base(dataForm)
    {
        this.sfDataForm = dataForm;
    }
    protected override void OnInitializeView(DataFormItem dataFormItem, SfComboBox view)
    {
        base.OnInitializeView(dataFormItem, view);
        view.IsEditableMode = true;
        view.Unfocused += View_Unfocused; 
        dropDownItem = dataFormItem as DataFormDropDownItem;
    }
    private void View_Unfocused(object sender, Xamarin.Forms.FocusEventArgs e)
    {
        var dropDown = sender as SfComboBox;
        var text = dropDown.Text;
    if (string.IsNullOrEmpty(text))
        return;
        var selectedItem = dropDown.SelectedItem;
        if (selectedItem == null || (selectedItem as Details)?.Name?.ToString() != text)
        {
            dropDownItem.ItemsSource.Add(new Details { Name = text });
            (DataForm.DataObject as Address).Country = text;
            sfDataForm.UpdateEditor("Country");
        }
    }
  protected override void OnUnWireEvents(SfComboBox view)
  {
     base.OnUnWireEvents(view);
     view.Unfocused -= View_Unfocused;
  }
}

Refer to the following code example for binding DataObject and register the editor using RegisterEditor as CustomDropDownEditor to make data form items as a custom editor in DataForm.

C#

Customized DropDown editors registered to DataForm.

public class DataFormBehavior : Behavior<ContentPage>
{
    SfDataForm dataForm;
    protected override void OnAttachedTo(ContentPage bindable)
    {
        base.OnAttachedTo(bindable);
        dataForm = bindable.FindByName<SfDataForm>("dataForm");
        dataForm.SourceProvider = new SourceProviderContactForm();
        dataForm.RegisterEditor("DropDown", new CustomDropDownEditor(dataForm));
        dataForm.RegisterEditor("Country", "DropDown");
        dataForm.AutoGeneratingDataFormItem += DataForm_AutoGeneratingDataFormItem;
    }
    private void DataForm_AutoGeneratingDataFormItem(object sender, AutoGeneratingDataFormItemEventArgs e)
    {
        if (e.DataFormItem != null)
        {
            if (e.DataFormItem.Name == "Country")
            {
                (e.DataFormItem as DataFormDropDownItem).DisplayMemberPath = "Name";
                (e.DataFormItem as DataFormDropDownItem).SelectedValuePath = "Name";
            }
        }
    }
    protected override void OnDetachingFrom(ContentPage bindable)
    {
        base.OnDetachingFrom(bindable);
        dataForm.AutoGeneratingDataFormItem -= DataForm_AutoGeneratingDataFormItem;
    }
}

Output

DropDownCollectionUpdate

View sample in GitHub

 

2X faster development

The ultimate Xamarin UI toolkit to boost your development speed.
ADD COMMENT
You must log in to leave a comment

Please sign in to access our KB

This page will automatically be redirected to the sign-in page in 10 seconds.

Up arrow icon

Warning Icon You are using an outdated version of Internet Explorer that may not display all features of this and other websites. Upgrade to Internet Explorer 8 or newer for a better experience.Close Icon

Live Chat Icon For mobile