C# Questions about the binding model structure

*DataModel Class

public DataModel()
            {
                this.MeasureA = new BindingList<MiddleMeasure>()
                {
                    new MiddleMeasure()
                    {
                        
                    }
                };  
            }
    
    
            public event PropertyChangedEventHandler PropertyChanged;
            void OnPropertyChanged(string propertyName)
            {
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
            }
        }

*MiddleMeasure Class

public class MiddleMeasure 
    {
        public BindingList<MeasureData> MeasureB
        {
            get; set;
        } = new BindingList<MeasureData>();


        public MiddleMeasure()
        {
            MeasureB.Add(new MeasureData()
            {
                Title = "500",
                Title2 = 500,
                Data = 10,
            });

            MeasureB.Add(new MeasureData()
            {
                Title = "501",
                Title2 = 501,
                Data = 20,
            });


            MeasureB.Add(new MeasureData()
            {
                Title = "503",
                Title2 = 503,
                Data = 30,
            });

            MeasureB.Add(new MeasureData()
            {
                Title = "504",
                Title2 = 504,
                Data = 40,
            });
        } 
    }

• MeasureData Class

  public class MeasureData : INotifyPropertyChanged
  {
  private string m_Title;
  private double m_Title2;
  private double m_Data;

            public MeasureData()
            {
  
            }
  
            public MeasureData(double title, double data)
            {
                this.Title2 = title;
                this.Title = title.ToString();
                this.Data = data;
            }
  
  
            public string Title
            {
                get => this.m_Title;
                set 
                {
                    this.m_Title = value;
                    OnPropertyChanged(nameof(Title));
                }
            }
  
            public double Title2
            {
                get => this.m_Title2;
                set
                {
                    this.m_Title2 = value;
                    OnPropertyChanged(nameof(Title2));
                }
            }
  
  
            public double Data
            {
                get => this.m_Data;
                set
                {
                    this.m_Data = value;
                    OnPropertyChanged(nameof(Data));
                }
            }
  
  
  
            public event PropertyChangedEventHandler PropertyChanged;
            void OnPropertyChanged(string propertyName)
            {
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
            }
        }
  

It is a structure with MiddleMeasure in DataModel and MeasureData class in it.

The class to bind to the itemsource is the MeasureData class.

this.xDataGrid.ItemsSource = this.m_Model.MeasureA;
If you try this, it won't bind.

Binding like this.m_Model.MeasureA[0].MeasureB is possible, but not what I want. All MeasureB in MeasureA must be bound.

how can i solve it?

Maybe you misunderstand the binding value in your code.

> this.xDataGrid.ItemsSource = this.m_Model.MeasureA; If you try this, it won't bind.

this.xDataGrid.ItemsSource = this.m_Model.MeasureA: this line set the itemsource as the BindingList<MiddleMeasure>() which just have one item(MiddleMeasure) in it. Just like the this.xDataGrid.ItemsSource = BindingList<MiddleMeasure>(){ new MiddleMeasure() }. So the ItemSource just have one item. And there is only a BindingList<MeasureData> property on the only item.

> Binding like this.m_Model.MeasureA[0].MeasureB is possible, but not what I want. All MeasureB in MeasureA must be bound

The value of the this.m_Model.MeasureA[0].MeasureB is BindingList<MeasureData>. So you bind successfully when you set it as the itemsource.

> The class to bind to the itemsource is the MeasureData class

The the value of the this.xDataGrid.ItemsSource must be BindingList<MeasureData>. But you said all MeasureB in MeasureA must be bound. So you need to declare a variable( type of BindingList<MeasureData> ) to get MeasureA's every item's MeasureB.

If so, the MiddleMeasure class has no meanings.You can just let the MeasureA be type of BindingList<MeasureData>.