Question

我在数据绑定项中遇到问题，从集合到网格内容视图。

请查看以下代码。这仅用于表示，它是完整逻辑的一部分。

查看模型类

  public class ViewModel : INotifyPropertyChanged
    {
        private ObservableCollection<ChildViewModel> myProperty;

        public ObservableCollection<ChildViewModel> MyProperty
        {
            get
            {
                return myProperty;
            }
            set
            {
                if (myProperty != value)
                {
                    myProperty = value;

                    if (PropertyChanged != null)
                    {
                        PropertyChanged(this,
                            new PropertyChangedEventArgs("MyProperty"));
                    }
                }
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }

    public class ChildViewModel : INotifyPropertyChanged
    {
        private string prop1;
        private string prop2;

        public string Prop1
        {
            get
            {
                return prop1;
            }
            set
            {
                if (prop1 != value)
                {
                    prop1 = value;

                    if (PropertyChanged != null)
                    {
                        PropertyChanged(this,
                            new PropertyChangedEventArgs("Prop1"));
                    }
                }
            }
        }
        public string Prop2
        {
            get
            {
                return prop2;
            }
            set
            {
                if (prop2 != value)
                {
                    prop2 = value;

                    if (PropertyChanged != null)
                    {
                        PropertyChanged(this,
                            new PropertyChangedEventArgs("Prop2"));
                    }
                }
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }

使用View Model Class

 ChildViewModel objChildViewModel1 = new ChildViewModel { Prop1 = "Prop1", Prop2 = "Prop2" };
        ChildViewModel objChildViewModel2 = new ChildViewModel { Prop1 = "Prop1", Prop2 = "Prop2" };

        ViewModel obj = new ViewModel
        {
            MyProperty = new ObservableCollection<ChildViewModel> { objChildViewModel1,objChildViewModel2}
        };

        //set binding context
        this.BindingContext = obj;

        var grid = new Grid();
        grid.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1, GridUnitType.Star) });
        grid.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1, GridUnitType.Star) });
        grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
        grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });

        var Label1 = new Label { };
        //how to databind obj.MyProperty[0].Prop1 to Label1 ???

        var Label2 = new Label { };
        //how to databind obj.MyProperty[1].Prop1 to Label2 ???

        var Entry1 = new Entry { };
        //how to databind obj.MyProperty[0].Prop2 to Entry1 ???

        var Entry2 = new Entry { };
        //how to databind obj.MyProperty[1].Prop2 to Entry2 ???

        grid.Children.Add(Label1, 0, 0);
        grid.Children.Add(Entry1, 0, 1);
        grid.Children.Add(Label2, 1, 0);
        grid.Children.Add(Entry2, 1, 1);

正如我在代码中所示，我想从LabelModel类的对象中为Label1，Label2，Entry1和Entry2进行数据绑定。我知道基本的数据绑定，其中只有绑定属性与名称以xamarin形式查看/控制，但在这里我无法绑定它。请帮助我。

Answer 1

grid.BindingContext=obj;


Label1.SetBinding (Label.TextProperty, "MyProperty[0].Prop1");
Label2.SetBinding (Label.TextProperty, "MyProperty[1].Prop1");
Entry1.SetBinding (Entry.TextProperty, "MyProperty[0].Prop2");
Entry2.SetBinding (Entry.TextProperty, "MyProperty[1].Prop2");

数据绑定项目以xamarin形式标记和文本视图

1 个答案: