Question

好的，我有一个绑定到viewModel的ViewCell类。如果我创建了一个标签，我可以这样做：

        var taskName = new Label()
        {
            XAlign = TextAlignment.Start,
            YAlign = TextAlignment.Start,
            FontSize = Device.GetNamedSize(NamedSize.Medium, typeof(Label)),
            FontAttributes = FontAttributes.Bold,
            LineBreakMode = LineBreakMode.TailTruncation
        };

        taskName.SetBinding(Label.TextProperty, "CompanyName");

我想要做的是将对象的值绑定到tapGesture。

        var tapGesturePhone = new TapGestureRecognizer ();

        var phoneIcon = new Image {
            HorizontalOptions = LayoutOptions.Center,
            VerticalOptions = LayoutOptions.Center,
            Source = "phone.png"

        };

        phoneIcon.GestureRecognizers.Add (tapGesturePhone);

        tapGesturePhone.Tapped += (sender, e) => {
            var uri = new Uri("tel:" + );
            Device.OpenUri(uri);

        };

        //uri.setbinding("Uri.text", "PhoneNo")?

关于我如何做到这一点的任何想法？一个解决方案也可以。

我有一个名为ProjectContacts的模型，ProjectContactsViewModel设置为BindingContext。

我的ContentView如下所示：

public ProjectContactsView ()
    {
        //bind the view model to the context
        this.BindingContext = _viewModel;

        _list.ItemTemplate = new DataTemplate(typeof(ProjectContactsListCell));
        _list.IsGroupingEnabled = true;
        _list.GroupDisplayBinding = new Binding("Key");
        _list.GroupHeaderTemplate = new DataTemplate(typeof(ProjectContactsListHeaderCell));
        _list.HasUnevenRows = true;
    }

解决方案

感谢@Sten Petrov，我设法解决了这个问题。我最终不得不在我的ViewCell

中声明我的ProjectContactsViewModel的新实例

private TapGestureRecognizer tapGesturePhone = new TapGestureRecognizer ();
tapGesturePhone.BindingContext = new ProjectContactsViewModel ();

然后我以这种方式将我的TapGestureRecognizer绑定在ViewCell中：

tapGesturePhone.SetBinding<ProjectContactsViewModel> (TapGestureRecognizer.CommandProperty, vm => vm.DialPhoneCommand);
tapGesturePhone.SetBinding<ProjectContactsViewModel> (TapGestureRecognizer.CommandParameterProperty,vm => vm.PhoneNo);

从这里我只需要为ViewModel创建一个Setter and Getter并在构造函数中初始化Command：

 public Command DialPhoneCommand {get;set;}
 public string PhoneNo { get {return "http://google.com"; } set{ PhoneNo = value;}}
 public ProjectContactsViewModel ()
            {
                //Assign the dialcommand.
                DialPhoneCommand = new Command((phoneNo)=> 
                    Device.OpenUri(new Uri(phoneNo.ToString())));

            }

Answer 1

您可以在Command中创建ProjectContactsViewModel并将tapGesture.Command绑定到该地址。

与绑定相同的方式

 taskName.SetBinding(Label.TextProperty, "CompanyName");

你可以绑定轻击手势的命令

    var tapGesturePhone = new TapGestureRecognizer ();
      tapGesturePhone.SetBinding(TapGestureRecognizer.CommandProperty,"DialPhoneCommand");
tapGesturePhone.SetBinding(TapGestureRecognizer.CommandParameterProperty,"PhoneNo");

      var phoneIcon = new Image {
        HorizontalOptions = LayoutOptions.Center,
        VerticalOptions = LayoutOptions.Center,
        Source = "phone.png" 
      };

  phoneIcon.GestureRecognizers.Add (tapGesturePhone);

该命令可以在ProjectContactsViewModel中初始化（为简单起见）：

... ProjectContactsViewModel { 
  public string PhoneNo {get;set;} 
  public Command DialPhoneCommand {get;set;}
  ...
  public ProjectContactsViewModel(){
    DialPhoneCommand = new Command((phoneNo)=> 
      Device.OpenUri(new Uri("tel:" + phoneNo ));
    );
  }
}

TapMesture in Xamarin From Bound property

1 个答案: