ActivityDesigner.OnPaint(ActivityDesignerPaintEventArgs) 方法

定義

命名空間:

System.Workflow.ComponentModel.Design

組件:

System.Workflow.ComponentModel.dll

在設計階段繪製活動的視覺化表示。

C#

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

參數

e

ActivityDesignerPaintEventArgs

包含事件資料的 ActivityDesignerPaintEventArgs。

例外狀況

ArgumentNullException

e 包含 null 參考 (在 Visual Basic 中為 Nothing)。

範例

下列範例示範自訂的 ActivityDesigner，它會委派繪製責任給基底類別或根據布林值繪製本身。 如果 useBasePaint 為 false，自訂活動將會使用 ActivityDesignerPaint 類別的各種方法來繪製本身。

C#

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);
}

適用於