C# CGContext.SetRGBFillColor方法代码示例

        protected void DrawStars(CGContext context)
        {
            context.SetRGBFillColor (1f, 0f, 0f, 1f);

            // save state so that as we translate (move the origin around,
            // it goes back to normal when we restore)
            context.SetRGBFillColor (0f, 0f, 0.329f, 1.0f);
            context.SaveState ();
            context.TranslateCTM (30, 300);
            DrawStar (context, 30);
            context.RestoreState ();

            context.SetRGBFillColor (1f, 0f, 0f, 1f);
            context.SaveState ();
            context.TranslateCTM (120, 200);
            DrawStar (context, 30);
            context.RestoreState ();
        }

	public override void DrawInContext (CGContext context)
	{
		// Drawing with a white stroke color
		context.SetRGBStrokeColor (1, 1, 1, 1);
		// And drawing with a blue fill color
		context.SetRGBFillColor (0, 0, 1, 1);
		// Draw them with a 2 stroke width so they are a bit more visible.
		context.SetLineWidth (2);
		
		// Add Rect to the current path, then stroke it
		context.AddRect (new RectangleF (30, 30, 60, 60));
		context.StrokePath ();
		
		// Stroke Rect convenience that is equivalent to above
		context.StrokeRect (new RectangleF (30, 120, 60, 60));
		
		// Stroke rect convenience equivalent to the above, plus a call to context.SetLineWidth ().
		context.StrokeRectWithWidth (new RectangleF (30, 210, 60, 60), 10);
		// Demonstate the stroke is on both sides of the path.
		context.SaveState ();
		context.SetRGBStrokeColor (1, 0, 0, 1);
		context.StrokeRectWithWidth (new RectangleF (30, 210, 60, 60), 2);
		context.RestoreState ();
		
		var rects = new RectangleF []
		{
			new RectangleF (120, 30, 60, 60),
			new RectangleF (120, 120, 60, 60),
			new RectangleF (120, 210, 60, 60),
		};
		// Bulk call to add rects to the current path.
		context.AddRects (rects);
		context.StrokePath ();
		
		// Create filled rectangles via two different paths.
		// Add/Fill path
		context.AddRect (new RectangleF (210, 30, 60, 60));
		context.FillPath ();
		// Fill convienience.
		context.FillRect (new RectangleF (210, 120, 60, 60));
	}	

	public override void DrawInContext (CGContext context)
	{
		var imageRect = new RectangleF (8, 8, 64, 64);
		
		// Note: The images are actually drawn upside down because Quartz image drawing expects
		// the coordinate system to have the origin in the lower-left corner, but a UIView
		// puts the origin in the upper-left corner. For the sake of brevity (and because
		// it likely would go unnoticed for the image used) this is not addressed here.
		// For the demonstration of PDF drawing however, it is addressed, as it would definately
		// be noticed, and one method of addressing it is shown there.
	
		// Draw the image in the upper left corner (0,0) with size 64x64
		context.DrawImage (imageRect, image);
		
		// Tile the same image across the bottom of the view
		// CGContextDrawTiledImage() will fill the entire clipping area with the image, so to avoid
		// filling the entire view, we'll clip the view to the rect below. This rect extends
		// past the region of the view, but since the view's rectangle has already been applied as a clip
		// to our drawing area, it will be intersected with this rect to form the final clipping area
		context.ClipToRect(new RectangleF (0, 80, Bounds.Width, Bounds.Height));
		
		// The origin of the image rect works similarly to the phase parameter for SetLineDash and
		// SetPatternPhase and specifies where in the coordinate system the "first" image is drawn.
		// The size (previously set to 64x64) specifies the size the image is scaled to before being tiled.
		imageRect.X = 32;
		imageRect.Y = 112;
		context.DrawTiledImage (imageRect, image);
		
		// Highlight the "first" image from the DrawTiledImage call.
		context.SetRGBFillColor (1, 0, 0, 0.5f);
		context.FillRect (imageRect);
		
		// And stroke the clipped area
		context.SetLineWidth (3);
		context.SetRGBStrokeColor (1, 0, 0, 1);
		context.StrokeRect (context.GetClipBoundingBox ());
	}

		public void DrawTextWithUTF8Fonts (CGContext mBmpContext, string text, float x, float y, string font_family, double text_size)
		{
			/*
			The problem is that CoreGraphics APIs for CGContext do not support rendering UTF8 code, and then ShowTextAtPoint() is limited to the text encoding in MacRoman.
			The fix is to use the UIKit function DrawString() instead.
			 */

			UIGraphics.PushContext (mBmpContext);
			mBmpContext.SetRGBFillColor(1f,1f,1f,1f);

			UIFont tfont = UIFont.FromName (font_family,(float)text_size);

			NSString nsstr = new NSString(text);
			SizeF sz = nsstr.StringSize(tfont);
			RectangleF rect = new RectangleF(x,y,sz.Width,sz.Height);
			nsstr.DrawString( rect, tfont);


			UIGraphics.PopContext ();
		}

			public override void DrawLayer (CALayer layer, CGContext context)
			{
				context.SaveState ();
				context.SetRGBFillColor (1.0f, 1.0f, 1.0f, 1.0f);
				context.FillRect (context.GetClipBoundingBox ());
				context.TranslateCTM (0.0f, layer.Bounds.Size.Height);
				context.ScaleCTM (1.0f, -1.0f);
				context.ConcatCTM (ParentController.PdfPage.GetDrawingTransform (CGPDFBox.Crop, layer.Bounds, 0, true));
				context.DrawPDFPage (ParentController.PdfPage);
				context.RestoreState ();
			}

		// This is a slightly more complicated draw pattern, but using it is just 
		// as easy as the previous one. To use this one, simply change "DrawPolkaDotPattern"
		// in line 54 above to "DrawStarPattern"
		protected void DrawStarPattern (CGContext context)
		{
			// declare vars
			float starDiameter = 16;
			// 144º
			float theta = 2 * (float)Math.PI * (2f / 5f);
			float radius = starDiameter / 2;
			
			// move up and over
			context.TranslateCTM (starDiameter / 2, starDiameter / 2);
			
			context.MoveTo (0, radius);
			for (int i = 1; i < 5; i++) {
				context.AddLineToPoint (radius * (float)Math.Sin (i * theta), radius * (float)Math.Cos (i * theta));
			}
			// fill our star as dark gray
			context.SetRGBFillColor (.3f, .3f, .3f, 1);
			context.ClosePath ();
			context.FillPath ();
		}

		// This is our pattern callback. it's called by coregraphics to create 
		// the pattern base.
		protected void DrawPolkaDotPattern (CGContext context)
		{
			context.SetRGBFillColor (.3f, .3f, .3f, 1);
			context.FillEllipseInRect (new RectangleF (4, 4, 8, 8));
		}

    static void DrawColored(CGContext context)
    {
        // Dark Blue
        context.SetRGBFillColor(29 / 255f, 156 / 255f, 215 / 255f, 10);
        context.FillRect(new RectangleF(0, 0, 8, 8));
        context.FillRect(new RectangleF(8, 8, 8, 8));

        // Light Blue
        context.SetRGBFillColor(204 / 255f, 224 / 255f, 244 / 255f, 10);
        context.FillRect(new RectangleF(8, 0, 8, 8));
        context.FillRect(new RectangleF(0, 8, 8, 8));
    }

		protected void DrawFlag (CGContext context)
		{
			// declare vars
			int i, j;
			
			// general sizes
			float flagWidth = Frame.Width * .8f;
			float flagHeight = (float)(flagWidth / 1.9);
			PointF flagOrigin = new PointF (Frame.Width * .1f, Frame.Height / 3);
			
			// stripe
			float stripeHeight = flagHeight / 13;
			float stripeSpacing = stripeHeight * 2;
			RectangleF stripeRect = new RectangleF (0, 0, flagWidth, stripeHeight);
			
			// star field
			float starFieldHeight = 7 * stripeHeight;
			float starFieldWidth = flagWidth * (2f / 5f);
			RectangleF starField = new RectangleF (flagOrigin.X, flagOrigin.Y + (6 * stripeHeight), starFieldWidth, starFieldHeight);
			
			// stars
			float starDiameter = flagHeight * 0.0616f;
			float starHorizontalCenterSpacing = (starFieldWidth / 6);
			float starHorizontalPadding = (starHorizontalCenterSpacing / 4);
			float starVerticalCenterSpacing = (starFieldHeight / 5);
			float starVerticalPadding = (starVerticalCenterSpacing / 4);
			PointF firstStarOrigin = new PointF (flagOrigin.X + starHorizontalPadding, flagOrigin.Y + flagHeight - starVerticalPadding - (starVerticalCenterSpacing / 2));
			PointF secondRowFirstStarOrigin = new PointF (firstStarOrigin.X + (starHorizontalCenterSpacing / 2), firstStarOrigin.Y - (starVerticalCenterSpacing / 2));
			
			// white background + shadow
			context.SaveState ();
			// note: when drawing on-screen,the coord space for shadows doesn't get modified
			context.SetShadow (new SizeF (15, 15), 7);
			context.SetRGBFillColor (1, 1, 1, 1);
			context.FillRect (new RectangleF (flagOrigin.X, flagOrigin.Y, flagWidth, flagHeight));
			context.RestoreState ();
			
			// create a stripe layer
			using (CGLayer stripeLayer = CGLayer.Create (context, stripeRect.Size)) {
				
				// set red as the fill color
				// this works
				stripeLayer.Context.SetRGBFillColor (1f, 0f, 0f, 1f);
				// but this doesn't ????
				//stripeLayer.Context.SetFillColor (new float[] { 1f, 0f, 0f, 1f });
				// fill the stripe
				stripeLayer.Context.FillRect (stripeRect);
				
				// loop through the stripes and draw the layer
				context.SaveState ();
				for (i = 0; i < 7; i++) {
					Console.WriteLine ("drawing stripe layer");
					// draw the layer
					context.DrawLayer (stripeLayer, flagOrigin);
					// move the origin
					context.TranslateCTM (0, stripeSpacing);
				}
				context.RestoreState ();
			}
			
			// draw the star field
			//BUGBUG: apple bug - this only works on on-screen CGContext and CGLayer
			//context.SetFillColor (new float[] { 0f, 0f, 0.329f, 1.0f });
			context.SetRGBFillColor (0f, 0f, 0.329f, 1.0f);
			context.FillRect (starField);
			
			// create the star layer
			using (CGLayer starLayer = CGLayer.Create (context, starField.Size)) {
				
				// draw the stars
				DrawStar (starLayer.Context, starDiameter);
				
				// 6-star rows
				// save state so that as we translate (move the origin around, 
				// it goes back to normal when we restore)
				context.SaveState ();
				context.TranslateCTM (firstStarOrigin.X, firstStarOrigin.Y);
				// loop through each row
				for (j = 0; j < 5; j++) {
					
					// each star in the row
					for (i = 0; i < 6; i++) {
						
						// draw the star, then move the origin to the right
						context.DrawLayer (starLayer, new PointF (0f, 0f));
						context.TranslateCTM (starHorizontalCenterSpacing, 0f);
					}
					// move the row down, and then back left
					context.TranslateCTM ((-i * starHorizontalCenterSpacing), -starVerticalCenterSpacing);
				}
				context.RestoreState ();
				
				// 5-star rows			
				context.SaveState ();
				context.TranslateCTM (secondRowFirstStarOrigin.X, secondRowFirstStarOrigin.Y);
				// loop through each row
				for (j = 0; j < 4; j++) {
					
					// each star in the row
					for (i = 0; i < 5; i++) {
//.........这里部分代码省略.........