C# Graphics.RectF类代码示例

		// If you would like to create a circle of the image set pixels to half the width of the image.
		internal static   Bitmap GetRoundedCornerBitmap(Bitmap bitmap, int pixels)
		{
			Bitmap output = null;

			try
			{
				output = Bitmap.CreateBitmap(bitmap.Width, bitmap.Height, Bitmap.Config.Argb8888);
				Canvas canvas = new Canvas(output);

				Color color = new Color(66, 66, 66);
				Paint paint = new Paint();
				Rect rect = new Rect(0, 0, bitmap.Width, bitmap.Height);
				RectF rectF = new RectF(rect);
				float roundPx = pixels;

				paint.AntiAlias = true;
				canvas.DrawARGB(0, 0, 0, 0);
				paint.Color = color;
				canvas.DrawRoundRect(rectF, roundPx, roundPx, paint);

				paint.SetXfermode(new PorterDuffXfermode(PorterDuff.Mode.SrcIn));
				canvas.DrawBitmap(bitmap, rect, rect, paint);
			}
			catch (System.Exception err)
			{
				System.Console.WriteLine ("GetRoundedCornerBitmap Error - " + err.Message);
			}

			return output;
		}

		public Transition GenerateNextTransition(RectF drawableBounds, RectF viewport)
		{
			bool firstTransition = _mLastGenTrans == null;
			bool drawableBoundsChanged = true;
			bool viewportRatioChanged = true;

			RectF srcRect = null;
			RectF dstRect = null;

			if (!firstTransition)
			{
				dstRect = _mLastGenTrans.GetDestinyRect();
				drawableBoundsChanged = !drawableBounds.Equals(_mLastDrawableBounds);
				viewportRatioChanged = !MathUtils.HaveSameAspectRatio(dstRect, viewport);
			}

			if (dstRect == null || drawableBoundsChanged || viewportRatioChanged)
			{
				srcRect = GenerateRandomRect(drawableBounds, viewport);
			}
			else
			{
				/* Sets the destiny rect of the last transition as the source one
				 if the current drawable has the same dimensions as the one of
				 the last transition. */
				srcRect = dstRect;
			}
			dstRect = GenerateRandomRect(drawableBounds, viewport);

			_mLastGenTrans = new Transition(srcRect, dstRect, _mTransitionDuration,
					_mTransitionIInterpolator);
			_mLastDrawableBounds = drawableBounds;

			return _mLastGenTrans;
		}

        public override void Draw(Android.Graphics.Canvas canvas)
        {
            base.Draw(canvas);

            var rect = new RectF(0,0,300,300);
            switch (TheShape)
            {
                case Shape.Circle:
                    canvas.DrawOval(rect, new Paint() { Color = Color.Aqua });
                    break;
                case Shape.Square:
                    canvas.DrawRect(rect, new Paint() { Color = Color.Red });
                    break;
                case Shape.Triangle:
                    var path = new Path();
                    path.MoveTo(rect.CenterX(), 0);
                    path.LineTo(0, rect.Height());
                    path.LineTo(rect.Width(), rect.Height());
                    path.Close();

                    var paint = new Paint() {Color = Color.Magenta};
                    paint.SetStyle(Paint.Style.Fill);
                    canvas.DrawPath(path, paint);
                    break;

                default:
                    throw new ArgumentOutOfRangeException();
            }
        }

        public override void Draw(Android.Graphics.Canvas canvas)
        {
            base.Draw (canvas);

            Paint mBgPaints = new Paint ();
            mBgPaints.AntiAlias = true;
            mBgPaints.SetStyle (Paint.Style.Fill);
            mBgPaints.Color = Color.Blue;
            mBgPaints.StrokeWidth = 0.5f;

            Paint tPaint = new Paint ();
            tPaint.Alpha = 0;
            canvas.DrawColor (tPaint.Color);

            RectF mOvals = new RectF (40, 40, layout.MeasuredWidth - 40, layout.MeasuredHeight - 40);

            decimal total = 0;
            foreach (SecuritiesViewModel.PieChartValue value in securitiesViewModel.DataForPieChart ()) {
                total += value.amount;
            }

            if (total == 0) {
                return;
            }

            decimal degressPerAmount = 360 / total;
            decimal currentAngle = 0;
            foreach (SecuritiesViewModel.PieChartValue value in securitiesViewModel.DataForPieChart ()) {
                canvas.DrawArc (mOvals, (float)currentAngle, (float)(degressPerAmount * value.amount), true, mBgPaints);
                currentAngle += (degressPerAmount * value.amount);
                mBgPaints.SetARGB (255, new Random ().Next (256), new Random ().Next (256), new Random ().Next (256));
            }
        }

        protected override void OnDraw(Android.Graphics.Canvas canvas)
        {
            var rect = new RectF(0, 0, 300, 300);
            switch (Shape)
            {
                case Shape.Circle:
                    canvas.DrawOval(rect, new Paint() { Color = Color.CornflowerBlue });
                    break;
                case Shape.Square:
                    canvas.DrawRect(rect, new Paint() { Color = Color.Crimson });
                    break;
                case Shape.Triangle:

                    var path = new Path();
                    path.MoveTo(rect.CenterX(), rect.Top);
                    path.LineTo(rect.Left, rect.Bottom);
                    path.LineTo(rect.Right, rect.Bottom);
                    path.Close();
                    var paint = new Paint() {Color = Color.Crimson};
                    paint.Color = Color.Gold;
                    paint.SetStyle(Paint.Style.Fill);
                    canvas.DrawPath(path, paint);
                    break;
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }

		public static void parse(SVGProperties pSVGProperties, Canvas pCanvas, SVGPaint pSVGPaint, RectF pRect) {
			float? centerX = pSVGProperties.getFloatAttribute(SVGConstants.ATTRIBUTE_CENTER_X);
			float? centerY = pSVGProperties.getFloatAttribute(SVGConstants.ATTRIBUTE_CENTER_Y);
			float? radiusX = pSVGProperties.getFloatAttribute(SVGConstants.ATTRIBUTE_RADIUS_X);
			float? radiusY = pSVGProperties.getFloatAttribute(SVGConstants.ATTRIBUTE_RADIUS_Y);
			if (centerX != null && centerY != null && radiusX != null && radiusY != null) {
				pRect.Set(centerX.Value - radiusX.Value,
				          centerY.Value - radiusY.Value,
				          centerX.Value + radiusX.Value,
				          centerY.Value + radiusY.Value);

				bool fill = pSVGPaint.setFill(pSVGProperties);
				if (fill) {
					pCanvas.DrawOval(pRect, pSVGPaint.getPaint());
				}

				bool stroke = pSVGPaint.setStroke(pSVGProperties);
				if (stroke) {
					pCanvas.DrawOval(pRect, pSVGPaint.getPaint());
				}

				if(fill || stroke) {
					pSVGPaint.ensureComputedBoundsInclude(centerX.Value - radiusX.Value, centerY.Value - radiusY.Value);
					pSVGPaint.ensureComputedBoundsInclude(centerX.Value + radiusX.Value, centerY.Value + radiusY.Value);
				}
			}
		}

 protected override void OnDraw(Canvas canvas)
 {
     Android.Graphics.Drawable.Drawable drawable = GetDrawable();
     if (drawable is BitmapDrawable)
     {
         RectF rectF = new RectF(drawable.GetBounds());
         int restoreCount = canvas.SaveLayer(rectF, null, Canvas.AllSaveFlag);
         GetImageMatrix().MapRect(rectF);
         Paint paint = ((BitmapDrawable)drawable).GetPaint();
         paint.SetAntiAlias(true);
         paint.SetColor(unchecked((int)(0xff000000)));
         canvas.DrawARGB(0, 0, 0, 0);
         canvas.DrawRoundRect(rectF, Radius, Radius, paint);
         Xfermode restoreMode = paint.GetXfermode();
         paint.SetXfermode(new PorterDuffXfermode(PorterDuff.Mode.SrcIn));
         base.OnDraw(canvas);
         // Restore paint and canvas
         paint.SetXfermode(restoreMode);
         canvas.RestoreToCount(restoreCount);
     }
     else
     {
         base.OnDraw(canvas);
     }
 }

        public static Bitmap ToRounded(Bitmap source, float rad)
        {
            int size = Math.Min(source.Width, source.Height);

            int dx = (source.Width - size) / 2;
            int dy = (source.Height - size) / 2;

            Bitmap bitmap = Bitmap.CreateBitmap(size, size, Bitmap.Config.Argb8888);

            using (Canvas canvas = new Canvas(bitmap))
            using (Paint paint = new Paint())
            using (BitmapShader shader = new BitmapShader(source, Shader.TileMode.Clamp, Shader.TileMode.Clamp))
            using (Matrix matrix = new Matrix())
            {
                if (dx != 0 || dy != 0)
                {
                    // source isn't square, move viewport to centre
                    matrix.SetTranslate(-dx, -dy);
                    shader.SetLocalMatrix(matrix);
                }
                paint.SetShader(shader);
                paint.AntiAlias = true;

                RectF rectF = new RectF(0, 0, size, size);
                canvas.DrawRoundRect(rectF, rad, rad, paint);

                return bitmap;
            }
        }

		protected virtual void HandleShapeDraw (Canvas canvas)
		{
			// We need to account for offsetting the coordinates based on the padding
			var x = GetX () + Resize (this.ShapeView.Padding.Left);
			var y = GetY () + Resize (this.ShapeView.Padding.Top);

			switch (ShapeView.ShapeType) {
			case ShapeType.Box:
				HandleStandardDraw (canvas, p => {
					var rect = new RectF (x, y, x + this.Width, y + this.Height);
					if (ShapeView.CornerRadius > 0) {
						var cr = Resize (ShapeView.CornerRadius);
						canvas.DrawRoundRect (rect, cr, cr, p);
					} else {
						canvas.DrawRect (rect, p);
					}
				});
				break;
			case ShapeType.Circle:
				HandleStandardDraw (canvas, p => canvas.DrawCircle (x + this.Width / 2, y + this.Height / 2, (this.Width - 10) / 2, p));
				break;
			case ShapeType.CircleIndicator:
				HandleStandardDraw (canvas, p => canvas.DrawCircle (x + this.Width / 2, y + this.Height / 2, (this.Width - 10) / 2, p), drawFill: false);
				HandleStandardDraw (canvas, p => canvas.DrawArc (new RectF (x, y, x + this.Width, y + this.Height), QuarterTurnCounterClockwise, 360 * (ShapeView.IndicatorPercentage / 100), false, p), ShapeView.StrokeWidth + 3, false);
				break;
			}
		}

        protected override void OnDraw(Canvas canvas)
        {
            base.OnDraw (canvas);

            var stokewidth = TapUtil.dptodx (this.stokewidthdp);
            var progresswidth = TapUtil.dptodx (this.progresswidthdp);
            //draw border
            int center = Width / 2;
            nn_paint.SetStyle(Paint.Style.Stroke);
            nn_paint.Color=nn_outcolor;
            nn_paint.StrokeWidth = stokewidth;
            canvas.DrawCircle(center,center, nn_radius-stokewidth, nn_paint);

            //draw remainingsection of progress
            nn_paint.SetStyle (Paint.Style.Fill);
            nn_paint.Color=nn_progressremainingcolor;
            //RectF position is relative toparent
            canvas.DrawCircle(center,center, nn_radius-stokewidth*2, nn_paint);

            //draw progress
            nn_paint.SetStyle (Paint.Style.Stroke);
            nn_paint.Color=nn_progresscolor;
            nn_paint.StrokeWidth = progresswidthdp*2;
            //RectF position is relative toparent
            RectF oval = new RectF (0+(stokewidth*2)+Convert.ToSingle(progresswidthdp*1.5),0+(stokewidth*2)+Convert.ToSingle(progresswidthdp*1.5),nn_radius*2-(stokewidth*2)-Convert.ToSingle(progresswidthdp*1.5),nn_radius*2-(stokewidth*2)-Convert.ToSingle(progresswidthdp*1.5));
            canvas.DrawArc(oval, progresssstartangle, progresssendangle, false, nn_paint);

            //draw avatarcontainer (innercircle)
            nn_paint.SetStyle(Paint.Style.Fill);
            nn_paint.Color=nn_innercontainercolor;
            canvas.DrawCircle(center,center, nn_radius-progresswidth-stokewidth*2, nn_paint);
        }

 public CircleDrawable(Bitmap bmp)
 {
     this.bmp = bmp;
     this.bmpShader = new BitmapShader(bmp, Shader.TileMode.Clamp, Shader.TileMode.Clamp);
     this.paint = new Paint() { AntiAlias = true };
     this.paint.SetShader(bmpShader);
     this.oval = new RectF();
 }

 private static void DrawOutline(Canvas canvas, IStyle style, RectF destination)
 {
     var vectorStyle = (style as VectorStyle);
     if (vectorStyle == null) return;
     if (vectorStyle.Outline == null) return;
     if (vectorStyle.Outline.Color == null) return;
     DrawRectangle(canvas, destination, vectorStyle.Outline.Color);
 }

 private static void DrawRectangle(Canvas canvas, RectF destination, Styles.Color outlineColor)
 {
     var paint = new Paint();
     paint.SetStyle(Paint.Style.Stroke);
     paint.Color = new AndroidColor(outlineColor.R, outlineColor.G, outlineColor.B, outlineColor.A);
     paint.StrokeWidth = 4;
     canvas.DrawRect(destination, paint);
 }

 public override void DrawRectBounds( FastColour colour, float lineWidth, int x, int y, int width, int height )
 {
     RectF rec = new RectF( x, y, x + width, y + height );
     Paint brush = GetOrCreateBrush( colour );
     brush.SetStyle( Paint.Style.Stroke );
     c.DrawRect( rec, brush );
     brush.SetStyle( Paint.Style.FillAndStroke );
 }

 public override void Clear( FastColour colour, int x, int y, int width, int height )
 {
     RectF rec = new RectF( x, y, x + width, y + height );
     Paint brush = GetOrCreateBrush( colour );
     brush.AntiAlias = false;
     c.DrawRect( rec, brush );
     brush.AntiAlias = true;
 }