WinForm 绑定到嵌套对象上的属性

WinFrom 绑定到嵌套对象上的属性

关键字: Windows Forms, DataBindings, Nested Class, 嵌套类

在 WinForm 中很早就已经支持数据绑定, 使用数据绑定可以大大减少更新界面和数据的代码.

一般情况下, 使用自定义的简单对象时数据绑定可以很好的工作, 当我们的对象越来越复杂, 一个对象中使用另一个对象作为属性时, 简单的数据绑定已经无法满足需求.

例如有下面两个对象:

/// <summary>
/// 外部实体
/// </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>
/// 内部实体
/// </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));
    }
}

数据绑定使用如下:

//初始化对象
var outer = new Outer();

//初始化绑定对象
var outerBindingSource = new BindingSource() { DataSource = outer };
var innerBindingSource = new BindingSource(outer, nameof(outer.Inner));

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

更新: ComboBox 绑定枚举. comboBox 选择项更改时, 绑定对象的枚举属性同样更改

//1. 设置 ComboBox 数据源
this.comboBox.DataSource = Enum.GetValues(typeof(CustomEnum));
this.comboBox.SelectedIndex = 0;

//2. 设置绑定
this.comboBox.DataBindings.Add(nameof(this.comboBox.SelectedItem), bindingSource, nameof(bindingSource.CustomEnumProperty));