ActivityDesigner.OnPaint(ActivityDesignerPaintEventArgs) Метод

Определение

Пространство имен:

System.Workflow.ComponentModel.Design

Сборка:

System.Workflow.ComponentModel.dll

Рисует визуальное представление операции во время разработки.

protected:
 virtual void OnPaint(System::Workflow::ComponentModel::Design::ActivityDesignerPaintEventArgs ^ e);

protected virtual void OnPaint (System.Workflow.ComponentModel.Design.ActivityDesignerPaintEventArgs e);

abstract member OnPaint : System.Workflow.ComponentModel.Design.ActivityDesignerPaintEventArgs -> unit
override this.OnPaint : System.Workflow.ComponentModel.Design.ActivityDesignerPaintEventArgs -> unit

Protected Overridable Sub OnPaint (e As ActivityDesignerPaintEventArgs)

Параметры

e

ActivityDesignerPaintEventArgs

Объект класса ActivityDesignerPaintEventArgs, содержащий данные события.

Исключения

ArgumentNullException

Параметр e содержит пустую ссылку (Nothing в Visual Basic).

Примеры

В следующем примере показан пользовательский объект класса ActivityDesigner, делегирующий обязанности по прорисовке базовому классу или самостоятельно прорисовывающий на основе на логического значения. Если параметр useBasePaint имеет значение false, пользовательское действие прорисовывает себя само, используя различные методы класса ActivityDesignerPaint.

private bool expanded = true;
private bool useBasePaint = false;

public bool UseBasePaint
{
    get { return this.useBasePaint; }
    set { this.useBasePaint = value; }
}

public bool Expanded
{
    get { return this.expanded; }
    set { this.expanded = value; }
}

protected override void OnPaint(ActivityDesignerPaintEventArgs e)
{
    if (this.UseBasePaint == true)
    {
        base.OnPaint(e);
        return;
    }

    DrawCustomActivity(e);
}

private void DrawCustomActivity(ActivityDesignerPaintEventArgs e)
{
    Graphics graphics = e.Graphics;

    CompositeDesignerTheme compositeDesignerTheme = (CompositeDesignerTheme)e.DesignerTheme;

    ActivityDesignerPaint.DrawRoundedRectangle(graphics, compositeDesignerTheme.BorderPen, this.Bounds, compositeDesignerTheme.BorderWidth);

    string text = this.Text;
    Rectangle textRectangle = this.TextRectangle;
    if (!string.IsNullOrEmpty(text) && !textRectangle.IsEmpty)
    {
        ActivityDesignerPaint.DrawText(graphics, compositeDesignerTheme.Font, text, textRectangle, StringAlignment.Center, e.AmbientTheme.TextQuality, compositeDesignerTheme.ForegroundBrush);
    }

    System.Drawing.Image image = this.Image;
    Rectangle imageRectangle = this.ImageRectangle;
    if (image != null && !imageRectangle.IsEmpty)
    {
        ActivityDesignerPaint.DrawImage(graphics, image, imageRectangle, DesignerContentAlignment.Fill);
    }

    ActivityDesignerPaint.DrawExpandButton(graphics,
        new Rectangle(this.Location.X, this.Location.Y, 10, 10),
        this.Expanded,
        compositeDesignerTheme);
}

Private expandedValue As Boolean = True
Private useBasePaintValue As Boolean = False

Public Property UseBasePaint() As Boolean
    Get
        Return Me.useBasePaintValue
    End Get

    Set(ByVal value As Boolean)
        Me.useBasePaintValue = value
    End Set
End Property

Public Property Expanded() As Boolean
    Get
        Return Me.expandedValue
    End Get
    Set(ByVal value As Boolean)
        Me.expandedValue = value
    End Set
End Property


Protected Overrides Sub OnPaint(ByVal e As ActivityDesignerPaintEventArgs)
    If Me.UseBasePaint = True Then
        MyBase.OnPaint(e)
        Return
    End If

    DrawCustomActivity(e)
End Sub

Private Sub DrawCustomActivity(ByVal e As ActivityDesignerPaintEventArgs)
    Dim graphics As Graphics = e.Graphics

    Dim compositeDesignerTheme As CompositeDesignerTheme = CType(e.DesignerTheme, CompositeDesignerTheme)

    ActivityDesignerPaint.DrawRoundedRectangle(graphics, compositeDesignerTheme.BorderPen, Me.Bounds, compositeDesignerTheme.BorderWidth)

    Dim text As String = Me.Text
    Dim TextRectangle As Rectangle = Me.TextRectangle
    If Not String.IsNullOrEmpty(text) And Not TextRectangle.IsEmpty Then
        ActivityDesignerPaint.DrawText(graphics, compositeDesignerTheme.Font, text, TextRectangle, StringAlignment.Center, e.AmbientTheme.TextQuality, compositeDesignerTheme.ForegroundBrush)
    End If

    Dim Image As System.Drawing.Image = Me.Image
    Dim ImageRectangle As Rectangle = Me.ImageRectangle
    If Image IsNot Nothing And Not ImageRectangle.IsEmpty Then
        ActivityDesignerPaint.DrawImage(graphics, Image, ImageRectangle, DesignerContentAlignment.Fill)
    End If

    ActivityDesignerPaint.DrawExpandButton(graphics, _
        New Rectangle(Me.Location.X, Me.Location.Y, 10, 10), _
        Me.Expanded, _
        compositeDesignerTheme)
End Sub