WinForm 綁定到嵌套對象上的屬性

WinFrom 綁定到嵌套對象上的屬性

關鍵字: Windows Forms, DataBindings, Nested Class, 嵌套類

在 WinForm 中很早就已經支持數據綁定, 使用數據綁定能夠大大減小更新界面和數據的代碼.

通常狀況下, 使用自定義的簡單對象時數據綁定能夠很好的工做, 當咱們的對象愈來愈複雜, 一個對象中使用另外一個對象做爲屬性時, 簡單的數據綁定已經沒法知足需求.

例若有下面兩個對象:

/// <summary>
/// 外部實體
/// </summary>
public class Outer : INotifyPropertyChanged
{
    #region - Private -
    private string _name;
    private Inner _inner;
    #endregion

    public event PropertyChangedEventHandler PropertyChanged;

    public string Name
    {
        get { return this._name; }
        set
        { 
            if(value != this._name)
            {
                this._name = value;
                RaisePropertyChanged();
            }
        }
    }

    public Inner Inner
    {
        get { return this._inner; }
        set
        {
            if(value != this._inner)
            {
                this._inner = value;
                RaisePropertyChanged();
            }
        }
    }

    private void RaisePropertyChanged([CallerMemberName]string propertyName = null)
    {
        this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

/// <summary>
/// 內部實體
/// </summary>
public class Inner : INotifyPropertyChanged
{
    #region - Private -
    private string _name;
    #endregion

    public event PropertyChangedEventHandler PropertyChanged;

    public string Name
    {
        get { return this._name; }
        set
        { 
            if(value != this._name)
            {
                this._name = value;
                RaisePropertyChanged();
            }
        }
    }

    private void RaisePropertyChanged([CallerMemberName]string propertyName = null)
    {
        this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

數據綁定使用以下:

//初始化對象
var outer = new Outer();

//初始化綁定對象
var outerBindingSource = new BindingSource() { DataSource = outer };
var innerBindingSource = new BindingSource(outer, nameof(outer.Inner));

//綁定到控件
this.textBoxName.DataBindings.Add("Text", outerBindingSource, nameof(outer.Name));
this.textBoxInnerName.DataBindings.Add("Text", innerBindingSource, nameof(outer.Inner.Name));

更新: ComboBox 綁定枚舉. comboBox 選擇項更改時, 綁定對象的枚舉屬性一樣更改

//1. 設置 ComboBox 數據源
this.comboBox.DataSource = Enum.GetValues(typeof(CustomEnum));
this.comboBox.SelectedIndex = 0;

//2. 設置綁定
this.comboBox.DataBindings.Add(nameof(this.comboBox.SelectedItem), bindingSource, nameof(bindingSource.CustomEnumProperty));