NativeActivity<TResult> 類別

定義

generic <typename TResult>
public ref class NativeActivity abstract : System::Activities::Activity<TResult>

public abstract class NativeActivity<TResult> : System.Activities.Activity<TResult>

type NativeActivity<'Result> = class
    inherit Activity<'Result>

Public MustInherit Class NativeActivity(Of TResult)
Inherits Activity(Of TResult)

類型參數

繼承

Object

Activity

ActivityWithResult

Activity<TResult>

NativeActivity<TResult>

衍生

System.Activities.Expressions.InvokeFunc<TResult>

System.Activities.Expressions.InvokeFunc<T1,T2,T3,T4,T5,T6,T7,T8,T9,TResult>

System.Activities.Expressions.InvokeFunc<T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,TResult>

System.Activities.Expressions.InvokeFunc<T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,TResult>

System.Activities.Expressions.InvokeFunc<T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,TResult>

更多…

範例

以下程式碼範例示範如何建立一個繼承自 NativeActivity<TResult>的類別。 這個範例來自 入門教學 [.NET Framework 4.5] 的 How to： Create an Activity 步驟。

public sealed class ReadInt : NativeActivity<int>
{
    [RequiredArgument]
    public InArgument<string> BookmarkName { get; set; }

    protected override void Execute(NativeActivityContext context)
    {
        string name = BookmarkName.Get(context);

        if (string.IsNullOrEmpty(name))
        {
            throw new ArgumentException("BookmarkName cannot be an Empty string.",
                "BookmarkName");
        }

        context.CreateBookmark(name, new BookmarkCallback(OnReadComplete));
    }

    // NativeActivity derived activities that do asynchronous operations by calling
    // one of the CreateBookmark overloads defined on System.Activities.NativeActivityContext
    // must override the CanInduceIdle property and return true.
    protected override bool CanInduceIdle
    {
        get { return true; }
    }

    void OnReadComplete(NativeActivityContext context, Bookmark bookmark, object state)
    {
        this.Result.Set(context, Convert.ToInt32(state));
    }
}

Public NotInheritable Class ReadInt
    Inherits NativeActivity(Of Integer)
    
    <RequiredArgument()>
    Property BookmarkName() As InArgument(Of String)

    Protected Overrides Sub Execute(ByVal context As NativeActivityContext)
        Dim name As String
        name = BookmarkName.Get(context)

        If name = String.Empty Then
            Throw New ArgumentException("BookmarkName cannot be an Empty string.",
                "BookmarkName")
        End If

        context.CreateBookmark(name, New BookmarkCallback(AddressOf OnReadComplete))
    End Sub

    ' NativeActivity derived activities that do asynchronous operations by calling 
    ' one of the CreateBookmark overloads defined on System.Activities.NativeActivityContext 
    ' must override the CanInduceIdle property and return True.
    Protected Overrides ReadOnly Property CanInduceIdle As Boolean
        Get
            Return True
        End Get
    End Property

    Sub OnReadComplete(ByVal context As NativeActivityContext, ByVal bookmark As Bookmark, ByVal state As Object)
        Result.Set(context, Convert.ToInt32(state))
    End Sub

End Class