MonthCalendar.SelectionRange數據綁定示例

Question

如何針對MonthCalendar.SelectionRange屬性執行數據綁定？鑑於屬性類型是'SelectionRange'，這是一個類，我不知道該怎麼去做。任何例子將不勝感激。

Answer 1

嗯，似乎並沒有對這個任何明顯的事件，無論是在MonthCalendar或SelectionRange，也不工具INotifyPropertyChanged，所以它看起來像數據綁定可能無法在這裏。

更新：但是，它確實會引發DateChanged，因此您可以手動將某些內容鉤到一起，或者（更有用地）通過繼承控件以適合綁定的方式公開值和事件。注意Actual(...)是有用的，因爲最終（否則）是午夜前，而不是半夜本身...

using System; 
using System.Collections.Generic; 
using System.ComponentModel; 
using System.Diagnostics; 
using System.Windows.Forms; 
class Foo : INotifyPropertyChanged 
{ 
    public event PropertyChangedEventHandler PropertyChanged; 
    protected virtual void OnPropertyChanged(string propertyName) 
    { 
     var handler = PropertyChanged; 
     if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName)); 
     Debug.WriteLine(ToString()); 
    } 
    private void SetField<T>(ref T field, T value, string propertyName) 
    { 
     if (!EqualityComparer<T>.Default.Equals(field, value)) 
     { 
      field = value; 
      OnPropertyChanged(propertyName);    
     } 
    } 
    private DateTime start, end; 
    public DateTime Start { get { return start; } set { SetField(ref start, value, "Start"); } } 
    public DateTime End { get { return end; } set { SetField(ref end, value, "End"); } } 
} 

class BindableCalendar : MonthCalendar 
{ 
    public DateTime ActualSelectionStart 
    { 
     get { return SelectionRange.Start; } 
     set { if (ActualSelectionStart != value) { SetSelectionRange(value, ActualSelectionEnd); } } 
    } 
    public DateTime ActualSelectionEnd 
    { 
     get { return SelectionRange.End; } 
     set { if (ActualSelectionEnd != value) { SetSelectionRange(ActualSelectionStart, value); } } 
    } 
    // should really use EventHandlerList here... 
    public event EventHandler ActualSelectionStartChanged, ActualSelectionEndChanged; 

    DateTime lastKnownStart, lastKnownEnd; 
    protected override void OnDateChanged(DateRangeEventArgs drevent) 
    { 
     base.OnDateChanged(drevent); 
     if (lastKnownStart != drevent.Start) 
     { 
      if (ActualSelectionStartChanged != null) ActualSelectionStartChanged(this, EventArgs.Empty); 
      lastKnownStart = drevent.Start; 
     } 
     if (lastKnownEnd != drevent.End) 
     { 
      if (ActualSelectionEndChanged != null) ActualSelectionEndChanged(this, EventArgs.Empty); 
      lastKnownEnd = drevent.End; 
     } 
    } 

} 

static class Program 
{ 
    [STAThread] 
    static void Main() 
    { 

     Application.EnableVisualStyles(); 
     MonthCalendar cal; 
     Button btn; 
     using (Form form = new Form 
     { 
      Controls = { 
       (cal = new BindableCalendar { Dock = DockStyle.Fill, MaxSelectionCount = 10 }), 
       (btn = new Button { Dock = DockStyle.Bottom, Text = "thwack"}) 
      } 
     }) 
     { 
      Foo foo = new Foo { Start = DateTime.Today, End = DateTime.Today.AddDays(1) }; 
      cal.DataBindings.Add("ActualSelectionStart", foo, "Start").DataSourceUpdateMode = DataSourceUpdateMode.OnPropertyChanged; 
      cal.DataBindings.Add("ActualSelectionEnd", foo, "End").DataSourceUpdateMode = DataSourceUpdateMode.OnPropertyChanged; 
      btn.Click += delegate 
      { 
       foo.Start = foo.Start.AddDays(1); 
       foo.End = foo.End.AddDays(1); 
      }; 
      Application.Run(form); 
     } 
    } 
} 

Answer 2

對我來說，這似乎是很簡單的。我只綁定MonthCalendar組件的SelectionStart和SelectionEnd屬性。

this.Calendar1.DataBindings.Add(new System.Windows.Forms.Binding("SelectionStart", 
bindingSource, "DateField", true)); 
this.Calendar1.DataBindings.Add(new System.Windows.Forms.Binding("SelectionEnd", 
bindingSource, "DateField", true));