How to validate all the editors of Xamarin.Forms DataForm (SfDataform)

You can validate all the editors of Xamarin.Forms SfDataForm by using Validate method.

You can also refer the following article.

https://www.syncfusion.com/kb/11918/how-to-validate-all-the-editors-of-xamarin-forms-dataform-sfdataform

C#

You can validate all the properties using Validate inside the OnValidate command handler.

public DataFormViewModel()
{
    loginInfo = new DataFormModel();
    this.ValidateCommand = new Command<object>(this.OnValidate);
}
public Command<object> ValidateCommand { get; set; }
private void OnValidate(object dataForm)
{
    var dataFormLayout = dataForm as Syncfusion.XForms.DataForm.SfDataForm;
    dataFormLayout.Validate();
}

XMAL

ValidateCommand bind to Button form ViewModel

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="0.9*"/>
        <RowDefinition Height="0.1*"/>
    </Grid.RowDefinitions>
    <dataForm:SfDataForm x:Name="dataForm" DataObject="{Binding LoginInfo}" Grid.Row="0" ValidationMode="LostFocus" CommitMode="LostFocus"/>
    <Button x:Name="validateButton" Grid.Row="1"  Text="Submit" 
        Command="{Binding Path=BindingContext.ValidateCommand, 
        Source={x:Reference Name=dataForm}}"                                                   
        CommandParameter="{Binding Source={x:Reference Name=dataForm}}"/>
</Grid>

Output