Xamarin.iOS中使用MvvmLight框架

Xamarin.iOS中使用MvvmLight框架

如何在Xamarin.iOS 中使用MvvmLight框架：

1. 通过NuGet包管理器安装MvvmLight包

2. 创建对应的ViewModel

3. 在Controller中使用ViewModel（需要在Controller中添加引用：using GalaSoft.MvvmLight.Helpers 才能使用binding技术）

UpdateTargetTrigger方法已经不被推荐使用，推荐使用ObserveTargetEvent。

ViewModel：

public class TextViewModel : ViewModelBase
{
    private string text;
 
    public string Text
    {
        get { return text; }
        set { 
　　　　　　　　if (value != _text)
             {
                 _text= value;
                 RaisePropertyChanged("Text");
             } 
　　　　　　}
    }
}

UIViewController:

需要在Controller中添加引用：

using GalaSoft.MvvmLight.Helpers;

public class TextViewController : UIViewController
    {
        private TextViewModel textViewModel;
 
        private Binding<string, string> textFieldBinding;
        private UITextField textField;
 
        private UITextField TextField
        {
            get { return textField; }
        }
 
        private TextViewModel TextViewModel
        {
            get { return textViewModel; }
        }
 
        public override void ViewDidLoad()
        {
            base.ViewDidLoad();
            textViewModel = new TextViewModel();
 
            textField = new UITextField(new CoreGraphics.CGRect(20, 75, 280, 40));
            textField.BackgroundColor = UIColor.White;
 
            textFieldBinding = this.SetBinding(
                () => TextViewModel.Text,
                () => TextField.Text,
                BindingMode.TwoWay)
                .ObserveTargetEvent(nameof(UITextField.EditingChanged));
 
            View.AddSubview(textField);
        }
    }

 UISlider:

 this.SetBinding(() => mDetailViewModel.PasswordLength, () => SliderCount.Value, BindingMode.TwoWay).ObserveTargetEvent(nameof(UISlider.ValueChanged));

BEMCheckBox:

this.SetBinding(() => mDetailViewModel.CheckLower, () => CheckBoxContainer.CheckBoxLower.On, BindingMode.TwoWay).ObserveTargetEvent(nameof(BEMCheckBox.AnimationDidStopForCheckBox));