C# アルファ透過が指定されている画像をビットマップに書くと汚くなる。

VisualStyleRenderer renderer =

	new VisualStyleRenderer(className,partNumber,stateNumber);



Bitmap image = new Bitmap(panel1.DisplayRectangle.Width,

                         panel1.DisplayRectangle.Height,

                        PixelFormat.Format32bppArgb);



using(Graphics g = Graphics.FromImage(image))

{

	// やってみただけ、画像の描画にはやっぱり関係ないらしい

	g.CompositingMode = CompositingMode.SourceOver;

	g.CompositingQuality = CompositingQuality.GammaCorrected;

	// ここまで

	

	// 描画

	renderer.DrawBackground(g,panel1.DisplayRectangle);

}

// パネルに描画

e.Graphics.DrawImage(image,panel1.DisplayRectangle);

/ <summary>
/// Get Selected Item Index from Point
/// </summary>
/// <param name="point"></param>
/// <returns></returns>
protected virtual int GetSelectedItemIndexFromPoint(Point point)
{
	if(shelf.ItemList.Count == 0)
		return -1;
	if(!GetBodyArea().Contains(point))
		return -1;
	
	int y = point.Y;
	if(!this.isReverseMode)
		y -= GetHeaderArea().Height;
	else
		y -= GetFooterArea().Height;
	
	y = y / shelf.ShelfListBaseTheme.ItemHeight;
	
	return y >= shelf.ItemList.Count ? -1 : y;
}

otected override void DrawBody(Graphics g)
{
	base.DrawBody(g);
				
	// Access shortcut
	int width = shelf.ShelfBaseTheme.Width;
	int height = shelf.ShelfListBaseTheme.ItemHeight;
	
	int offset = 0;
	
	for(int i=0;i<shelf.ItemList.Count;i++)
	{
		// Access shortcut
		IShelfListItem item = shelf.ItemList[i];
		ShelfListItemBaseTheme theme = GetSelectedItemTheme(i);
		
		// ItemArea
		Rectangle itemArea = new Rectangle(0,0,width,height);
		
		// Background
		Background.DirectDrawBackground(g,itemArea,theme.Background);
		
		// Icon
		g.DrawIcon(item.Icon,theme.IconArea);
		
		// Text
		Rhetoric.DrawText(g,item.Text,itemArea,theme.Text);
		
		// Incress offset
		g.TranslateTransform(0,height);
		offset += height;
	}
	g.TranslateTransform(0,-offset);
	
}

otected override void OnMouseMove(MouseEventArgs e)
{
	base.OnMouseMove(e);
	
	if(animationType != AnimationType.None)
		return;
	
	if(isOpen)
	{
		if(GetBodyArea().Contains(e.X,e.Y))
		{
			// Body
			
			#region Selecting Item Process
			if(!isDragOwner)
			{
				int selected = GetSelectedItemIndexFromPoint(new Point(e.X,e.Y));
				
				if(selected != -1)
				{
					if(e.Button == MouseButtons.Left)
						selectedItem = new SelectedItemInfo(selected,SelectedItemState.Active);
					else
						selectedItem = new SelectedItemInfo(selected,SelectedItemState.Hover);
				}
				else
					selectedItem = SelectedItemInfo.Empty;
				
				if(!previousSelectedItem.Equals(selectedItem))
				{
					// If different item is selected
					this.SetSize();
					this.Refresh();
				}
				previousSelectedItem = selectedItem;
			}
			#endregion
			
		}
	}
}

/ <summary>
/// Flip Surface
/// </summary>
public virtual void FlipSurface()
{
	FlipSurface(this.CreateGraphics());
}
public virtual void FlipSurface(Graphics g)
{
	#if(!BITMAP_DOUBLE_BUFFER)
	if(g == null)
		backSurface.Render();
	else
		backSurface.Render(g);
	#else
	g.DrawImage(backSurface,this.DisplayRectangle);
	#endif
}

public override void Refresh()
{
	Refresh(true);
}

public void Refresh(bool setregion)
{
	#if(!BITMAP_DOUBLE_BUFFER)
	Refresh(setregion,null);
	#else
	Refresh(setregion,this.CreateGraphics());
	#endif
}
public void Refresh(bool setregion,Graphics g)
{		
	#if(!BITMAP_DOUBLE_BUFFER)
	DrawOnSurface(backSurface.Graphics);
	#else
	using(Graphics grfx = Graphics.FromImage(backSurface))
		DrawOnSurface(grfx);
	#endif
	if(setregion)
		SetRegion();
	FlipSurface(g);
}

/// <summary>
/// SetRegion
/// </summary>
/// <description>Create Region from BackSurface and Form.TransparencyKey</description>
public void SetRegion()
{
	#if(!BITMAP_DOUBLE_BUFFER)
	Bitmap surface = new Bitmap(this.Width,this.Height);
	this.DrawToBitmap(surface,this.ClientRectangle);
	SetRegion(surface);
	#else
	SetRegion(backSurface);
	#endif
}
public virtual void SetRegion(Bitmap surface)
{
	this.Region = 
		WidgetHelper.CreateRegionFromBitmap(surface,this.TransparencyKey);
}