C相当于XAML的commandParameter=“binding.”

在花了几乎几个小时的时间来应用各种排列和组合之后,以下是对我有用的“诀窍”:

Label lbl = new Label();
lbl.SetBinding(Label.TextProperty, modelProperty.Name, BindingMode.TwoWay);
TapGestureRecognizer tgr= new TapGestureRecognizer
{
  Command = BindingContext.CellClickedCommand,
};
tgr.SetBinding(TapGestureRecognizer.CommandParameterProperty, ".");
lbl.GestureRecognizers.Add(tgr);

我认为微软必须为Xamarin表单提供更好的文档,因为并非所有开发人员都一直在使用Xaml。而且,大多数文档都不使用MVVM。

下面是一个如何绑定 CommandParameterProperty A的 TapGestureRecognizer 到标签的 Text 使用C的属性#

public MainPage()
{
    var labelTappedGestureRecognizer = new TapGestureRecognizer
    {
        Command = new Command<string>(async labelText => await DisplayAlert("Label Tapped", labelText, "OK"))
    };

    var myLabel = new Label
    {
        Text = "This is my label",
        HorizontalOptions = LayoutOptions.Center,
        VerticalOptions = LayoutOptions.Center
    };

    myLabel.GestureRecognizers.Add(labelTappedGestureRecognizer);
    labelTappedGestureRecognizer.SetBinding(TapGestureRecognizer.CommandParameterProperty, new Binding(nameof(Label.Text), source: myLabel));

    Content = myLabel;
}

"{Binding .}" 简单等于 new Binding(".") . 但是 CommandParameter="{Binding .}" 等于'tapgesturerecognizer.setbinding(tapgesturerecognizer.commandParameterProperty,new binding(“.”)。