How would one implement INotifyPropertyChanged for use in an F# type? Thanks!
It's basically the same as in any other language:
open System.ComponentModel
type MyType() =
let ev = new Event<_,_>()
let mutable str = ""
member x.StringProp
with get() = str
and set(str') =
str <- str'
ev.Trigger(x, PropertyChangedEventArgs("StringProp"))
interface INotifyPropertyChanged with
[<CLIEvent>]
member x.PropertyChanged = ev.Publish
https://github.com/Fody/PropertyChanged https://github.com/Fody/PropertyChanged/issues/280
In practice
You can use fody proeprty changed to automatically implement it
public abstract class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
}
Then you can use it like this
type ViewModelTest() =
inherit ViewModelBase()
/// two way binding
member val Hello = 6 with get, set
/// one way binding
member x.Yes = x.Hello + 1
The generated Decompiled codes are
using System;
using Microsoft.FSharp.Core;
namespace Shrimp.UI.Forms.FSharp
{
// Token: 0x02000002 RID: 2
[CompilationMapping(3)]
[Serializable]
public class ViewModelTest : ViewModelBase
{
// Token: 0x06000001 RID: 1 RVA: 0x00002050 File Offset: 0x00000250
public ViewModelTest() : this()
{
this.Hello@ = 6;
}
// Token: 0x17000001 RID: 1
// (get) Token: 0x06000002 RID: 2 RVA: 0x00002061 File Offset: 0x00000261
// (set) Token: 0x06000003 RID: 3 RVA: 0x0000206C File Offset: 0x0000026C
public int Hello
{
get
{
return this.Hello@;
}
set
{
if (this.Hello@ == value)
{
return;
}
this.Hello@ = value;
this.<>OnPropertyChanged(<>PropertyChangedEventArgs.Yes);
this.<>OnPropertyChanged(<>PropertyChangedEventArgs.Hello);
}
}
// Token: 0x17000002 RID: 2
// (get) Token: 0x06000004 RID: 4 RVA: 0x000020A4 File Offset: 0x000002A4
public int Yes
{
get
{
return this.Hello + 1;
}
}
// Token: 0x04000001 RID: 1
internal int Hello@;
}
}
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