Localization in .NET MAUI DataForm (SfDataForm)

5 Jun 20236 minutes to read

Localization is translating the application resources into different languages for specific cultures. The SfDataForm can be localized by adding a resource file.

Localize the DataFormViewItem DisplayAttribute values and ValidationAttribute values by using the ResourceType property of the attribute or using the GenerateDataFormItem event when auto-generate true.

Setting CurrentUICulture to the application

Application culture can be changed by setting the CurrentUICulture in the App.xaml.cs file.

App.xaml.cs

using System.Globalization;

public partial class App : Application
{
    public App()
    {
        InitializeComponent();
        MainPage = new AppShell();
        var culture = new CultureInfo("fr");
        CultureInfo.CurrentUICulture = culture;
    }
}

NOTE

The required resx files with Build Action as EmbeddedResource (File name should contain culture code) into the Resources folder.

Add Localization resx file in sample level

Follow these steps to localize the DataForm based on the CurrentUICulture using the resource files.

1. Right-click on the Resources folder in the application.

   

2. Click Add and then NewItem.

3. In the Add New Item wizard, select the Resource File option and name the filename as DataFormLocalization.<culture name>.resx. For example, give the name DataFormLocalization.fr.resx for French culture.

   

4. The culture name indicates the name of the language and country.

5. Now, click Add to add the resource file in the Resources folder.

   

6. Add the Name or Value pair in the Resource Designer of the DataFormLocalization.fr.resx file and change its corresponding value to the corresponding culture.

   

Localizing data form display values

Here, the display attributes or data form item display values to get localized based on culture from the Localization Resource File (.Resx).

Using attribute

The ResourceType property of the Display attribute specifies the Resources File (.Resx), which is used to localize the values of the Name, ShortName, GroupName, Prompt and ItemsSource.

C#

[Display(Name = "FirstName", GroupName = "Name", Prompt = "PromptText", ResourceType = typeof(DataFormLocalization))]
public string FirstName {​ get; set; }​

Using event

Also, localize the DataFormItem’s LabelText, PlaceholderText, and GroupName in the GenerateDataFormItem event of the SfDataForm by using the Resources (.Resx) file.

Here, the string member of the .resx file will be accessed through the class (in resxFilename.Designer.cs), which will be auto-generated when the .resx file is created, and static string members get localized using the ResourceManager based on culture.

C#

[Display(Name = "First Name", GroupName = "Details", Prompt = "Type first name")]
public String FirstName { get; set; }

this.dataForm.GenerateDataFormItem += OnGenerateDataFormItem;

private void OnGenerateDataFormItem(object sender, GenerateDataFormItemEventArgs e)
{
    if (e.DataFormItem?.GroupName == "Details")
    {
        e.DataFormItem.GroupName = DataFormLocalization.GroupName;
    }

    if (e.DataFormItem.LabelText == "FirstName")
    {
        e.DataFormItem.LabelText = DataFormLocalization.FirstName;
        e.DataFormItem.PlaceholderText = DataFormLocalization.PromptText;
    }
}

Localizing validation error messages

Here, the ValidationAttribute values or data form error messages get localized based on culture from Localization Resource File (.Resx).

Using attribute

The ValidationAttribute error message can be localized using the ErrorMessageResourceType and ErrorMessageResourceName properties, which are used to get localized error messages from the Localization Resource File (.Resx) based on culture.

C#

[Display(Name = "FirstName", GroupName = "Name", Prompt = "PromptText", ResourceType = typeof(DataFormLocalization))]
[DataFormDisplayOptions(ValidMessage = "ValidMessage")]
[Required(ErrorMessage = "Value should not be empty", ErrorMessageResourceName = "ErrorMessage", ErrorMessageResourceType = typeof(DataFormLocalization))]
public string FirstName { get; set; }

Using event

Also, localize the data form error message and valid message in the ValidateProperty event of the SfDataForm by using the Resources (.Resx) file.

C#

[DataFormDisplayOptions(ValidMessage = "Text length is enough")]
[Required(ErrorMessage = "Enter proper name")]
[StringLength(15, ErrorMessage = "Enter proper name")]
public string LastName { get; set; }

this.dataForm.ValidateProperty += this.OnDataFormValidateProperty;

private void OnDataFormValidateProperty(object sender, DataFormValidatePropertyEventArgs e)
{
    if (e.PropertyName == nameof(LocalizationModel.LastName))
    {
        if (e.IsValid)
        {
            e.ValidMessage = DataFormLocalization.ValidMessage;
        }
        else
        {
            e.ErrorMessage = DataFormLocalization.ErrorMessage;
        }
    }
}

Localizing data form picker editors

Localize DataForm list items (Picker, AutoComplete, RadioGroup, ComboBox) ItemsSource using the ResourceType property of Display attribute.

C#

[Display(ResourceType = typeof(DataFormLocalization))]
public Gender Gender { get; set; }

this.dataForm.RegisterEditor("Gender", DataFormEditorType.RadioGroup);

public enum Gender
{
    Male,
    Female,
    Other
}

Here, the radio group items source gets localized based on culture from Localization Resource File (.Resx).

NOTE

View sample in GitHub