Using Fluent Bindings in MvvmCross is a powerful way to create data bindings between your views and view models. Here are some best practices to help you effectively utilize Fluent Bindings:
Understanding the Basics
- Target and Source: In MvvmCross, the Target refers to the property on your View that you want to bind, such as `Text`, `ItemsSource`, or `SelectedItem`. The Source is the property in your ViewModel that the View binds to[1].
- Fluent Binding Syntax: Fluent Bindings are created using a C# syntax, which is particularly useful on platforms like iOS where XML layout files are not as common. A typical Fluent Binding looks like this:
csharp
var set = this.CreateBindingSet();
set.Bind(someView)
.For(view => view.ViewProperty)
.To(viewModel => viewModel.ViewModelProperty);
Best Practices
1. Use the Correct Target**
When using Fluent Bindings, ensure that the Target is the actual View you want to bind to. Avoid using the `ContextOwnerType` (like `MvxViewController`) as the Target unless you are binding to a public property of that type[1].2. Expose Properties as Public**
For a property to be bound, it must be public. If you are trying to bind to a private field, you will need to expose it as a public property or use a different approach[1].3. Apply Bindings After Initialization**
Make sure to apply bindings after the View has been initialized. For iOS, this typically means after `ViewDidLoad()` has been called[3].4. Use Two-Way Bindings Wisely**
Two-way bindings are useful for updating both the View and ViewModel. However, they require a `TargetBinding` to handle updates from the View to the ViewModel. Use them when necessary, such as when editing form data[4].5. Utilize Value Converters**
Value converters are essential for converting data types between the View and ViewModel. For example, converting a float to an integer. Implement both `Convert` and `ConvertBack` methods for two-way conversions[2].6. Register Converters by Convention**
MvvmCross uses reflection to register converters by convention. You can also register them manually if needed. This allows you to reuse converters across your application[2].7. Call `Apply()` After Setting Bindings**
After defining all bindings, call `set.Apply()` to activate them. This ensures that the bindings are properly set up and start working as expected[3].8. Use Fluent Bindings for Complex Logic**
Fluent Bindings are particularly useful when you need more control over the binding process or when dealing with complex logic that cannot be easily expressed in XML or other binding formats[7].By following these best practices, you can effectively use Fluent Bindings in MvvmCross to create robust and maintainable cross-platform applications.
Citations:[1] https://blog.ostebaronen.dk/2018/01/mvvmcross-binding-target.html
[2] https://stackoverflow.com/questions/19712103/fluent-binding-and-conversions
[3] https://www.mvvmcross.com/documentation/tutorials/tipcalc/a-xamarinios-ui-project
[4] https://www.mvvmcross.com/documentation/fundamentals/data-binding
[5] https://www.mvvmcross.com/documentation/getting-started/getting-started
[6] https://diglib.tugraz.at/download.php?id=576a78335451d&location=browse
[7] https://crosscuttingconcerns.com/MvvmCross-Fluent-Databinding
[8] https://learn.microsoft.com/en-us/archive/msdn-magazine/2014/august/windows-phone-build-mvvm-apps-with-xamarin-and-mvvmcross
[9] http://wojosoftware.com/software/mvvmcross/