DesignerGlyph.CanBeActivated 属性

定义

命名空间:

System.Workflow.ComponentModel.Design

程序集:

System.Workflow.ComponentModel.dll

获取一个值，该值指示 DesignerGlyph 能否在关联的 ActivityDesigner 上获取焦点。

public:
 virtual property bool CanBeActivated { bool get(); };

public virtual bool CanBeActivated { get; }

member this.CanBeActivated : bool

Public Overridable ReadOnly Property CanBeActivated As Boolean

属性值

Boolean

如果可以激活设计器标志符号，则为 true；否则为 false。 默认值为 false。

示例

下面的示例演示了 CanBeActivated 属性的实现。 此示例摘自“跟踪配置文件设计器”SDK 示例。 有关详细信息，请参阅 跟踪配置文件设计器示例。

/// <summary>
/// This glyph shows that the activity's track point is not correctly configured
/// </summary>
internal sealed class ErrorActivityGlyph : DesignerGlyph
{
    static Bitmap image = Resources.error;
    string errorMessage;

    internal ErrorActivityGlyph(string errorMessage)
    {
        this.errorMessage = errorMessage;
    }

    public override bool CanBeActivated
    {
        get
        {
            return true;
        }
    }

    /// <summary>
    /// Display an error message when this glyph is clicked
    /// </summary>
    /// <param name="designer"></param>
    protected override void OnActivate(ActivityDesigner designer)
    {
        MessageBox.Show(errorMessage);
    }

    public override Rectangle GetBounds(ActivityDesigner designer, bool activated)
    {
        Rectangle imageBounds = new Rectangle();
        if (image != null)
        {
            imageBounds.Size = image.Size;
            imageBounds.Location = new Point(designer.Bounds.Right - imageBounds.Size.Width / 4, designer.Bounds.Top - imageBounds.Size.Height / 2);
        }
        return imageBounds;
    }

    protected override void OnPaint(Graphics graphics, bool activated, AmbientTheme ambientTheme, ActivityDesigner designer)
    {
        image.MakeTransparent(Color.FromArgb(255, 255, 255));
        if (image != null)
        {
            graphics.DrawImage(image, GetBounds(designer, activated), new Rectangle(Point.Empty, image.Size), GraphicsUnit.Pixel);
        }
    }
}

' This glyph shows that the activity's track point is not correctly configured
Friend NotInheritable Class ErrorActivityGlyph
    Inherits DesignerGlyph

    Shared image As Bitmap = Resources.errorIcon
    Dim errorMessage As String

    Friend Sub New(ByVal errorMessage As String)
        Me.errorMessage = errorMessage
    End Sub

    Public Overrides ReadOnly Property CanBeActivated() As Boolean
        Get
            Return True
        End Get
    End Property

    ' Display an error message when this glyph is clicked
    Protected Overrides Sub OnActivate(ByVal designer As ActivityDesigner)
        MessageBox.Show(errorMessage)
    End Sub

    Public Overrides Function GetBounds(ByVal designer As ActivityDesigner, ByVal activated As Boolean) As Rectangle
        Dim imageBounds As New Rectangle()
        If image IsNot Nothing Then
            imageBounds.Size = image.Size
            imageBounds.Location = New Point(designer.Bounds.Right - imageBounds.Size.Width / 4, designer.Bounds.Top - imageBounds.Size.Height / 2)
        End If
        Return imageBounds
    End Function


    Protected Overrides Sub OnPaint(ByVal graphics As Graphics, ByVal activated As Boolean, ByVal ambientTheme As AmbientTheme, ByVal designer As ActivityDesigner)
        image.MakeTransparent(Color.FromArgb(255, 255, 255))
        If image IsNot Nothing Then
            graphics.DrawImage(image, GetBounds(designer, activated), New Rectangle(Point.Empty, image.Size), GraphicsUnit.Pixel)
        End If
    End Sub
End Class