C# IGraphics.Clear方法代码示例

        private void Render(IGraphics ig)
        {
            string s = cbWhat.Text;

            if (s == "Clipping")
            {
                Pen pn = new Pen(Color.LightGray, 5);
                Pen pn2 = new Pen(Color.Yellow);

                ig.Clear(Color.Black);

                GraphicsContainer cnt = ig.BeginContainer();

                ig.SmoothingMode = SmoothingMode.HighQuality;

                ig.SetClip(new Rectangle(35,35,120,120));

                ig.DrawRectangle(pn, 5,5,45,70);
                ig.DrawRectangle(pn, 15,25,90,120);
                ig.DrawRectangle(pn, 50,30,100,170);
                ig.DrawRectangle(pn, 5,80,180,30);
                ig.DrawRectangle(pn, 75,10,40,160);

                ig.EndContainer(cnt);

                ig.DrawRectangle(pn2, 5,5,45,70);
                ig.DrawRectangle(pn2, 15,25,90,120);
                ig.DrawRectangle(pn2, 50,30,100,170);
                ig.DrawRectangle(pn2, 5,80,180,30);
                ig.DrawRectangle(pn2, 75,10,40,160);
            }
            else if (s == "Transforms")
            {

                ig.Clear(Color.Black);

                ig.RotateTransform(15);
                ig.DrawRectangle(new Pen(Color.Red,2), 260,80,50,40);
                ig.ResetTransform();
                ig.DrawRectangle(new Pen(Color.Red,2), 260,80,50,40);

                ig.TranslateTransform(15,-5);

                GraphicsContainer cnt = ig.BeginContainer();

                    ig.SmoothingMode = SmoothingMode.HighQuality;

                    ig.RotateTransform(5);
                    ig.FillEllipse(new SolidBrush(Color.Orange), 100,100,80,40);
                    ig.DrawRectangle(new Pen(Color.Orange,2), 60,80,40,40);

                    GraphicsContainer cnt2  = ig.BeginContainer();

                        ig.SmoothingMode = SmoothingMode.None;

                        ig.RotateTransform(5);
                        ig.ScaleTransform(1.1f, 1.2f);

                        ig.FillEllipse(new SolidBrush(Color.YellowGreen), 130,180,80,40);
                        ig.DrawRectangle(new Pen(Color.YellowGreen,2), 62,80,40,40);

                        GraphicsContainer cnt3  = ig.BeginContainer();

                            ig.SmoothingMode = SmoothingMode.HighQuality;

                            Matrix mm = new Matrix();
                            mm.Shear(0.3f, 0f);
                            ig.Transform = mm;

                            ig.FillEllipse(new SolidBrush(Color.Green), 180,120,80,40);
                            ig.DrawRectangle(new Pen(Color.Green,2), 62,84,40,40);

                        ig.EndContainer(cnt3);

                    ig.EndContainer(cnt2);

                    ig.FillEllipse(new SolidBrush(Color.Blue), 120,150,80,40);
                    ig.DrawRectangle(new Pen(Color.Blue,2), 64,80,40,40);

                ig.EndContainer(cnt);

                ig.FillEllipse(new SolidBrush(Color.Indigo), 80,210,80,40);
                ig.DrawRectangle(new Pen(Color.Indigo,2), 66,80,40,40);

                ig.DrawRectangle(new Pen(Color.White,2), 270,30,50,40);
                ig.ResetTransform();
                ig.DrawRectangle(new Pen(Color.White,2), 270,30,50,40);

            }
            else if (s == "Lines")
            {
                ig.SmoothingMode = SmoothingMode.AntiAlias;

                Pen ow = new Pen(Color.Purple, 12);
                ow.EndCap = LineCap.Round;
                ow.StartCap = LineCap.Round;
                ow.MiterLimit = 6f;
                ow.LineJoin = LineJoin.Miter;

                ig.SmoothingMode = SmoothingMode.None;
//.........这里部分代码省略.........

        /// <summary>
        /// Renders the map using the provided <see cref="IGraphics"/> object.
        /// </summary>
        /// <param name="g">the <see cref="IGraphics"/> object to use</param>
        /// <param name="layerCollectionType">the <see cref="LayerCollectionType"/> to use</param>
        /// <param name="drawMapDecorations">Set whether to draw map decorations on the map (if such are set)</param>
        /// <param name="drawTransparent">Set wether to draw with transparent background or with BackColor as background</param>
        /// <exception cref="ArgumentNullException">if <see cref="IGraphics"/> object is null.</exception>
        /// <exception cref="InvalidOperationException">if there are no layers to render.</exception>
        public void RenderMap(IGraphics g, LayerCollectionType layerCollectionType, bool drawMapDecorations, bool drawTransparent)
        {
            if (g == null)
                throw new ArgumentNullException("g", "Cannot render map with null graphics object!");

            VariableLayerCollection.Pause = true;

            LayerCollection lc = null;
            switch (layerCollectionType)
            {
                case LayerCollectionType.Static:
                    lc = Layers;
                    break;
                case LayerCollectionType.Variable:
                    lc = VariableLayers;
                    break;
                case LayerCollectionType.Background:
                    lc = BackgroundLayer;
                    break;
            }

            if (lc == null || lc.Count == 0)
                throw new InvalidOperationException("No layers to render");

            Matrix transform = g.Transform;
            lock (MapTransform)
            {
                g.Transform = MapTransform.Clone();
            }
            if (!drawTransparent)
                g.Clear(BackColor);

            g.PageUnit = GraphicsUnitType.Pixel;

            LayerCollectionRenderer.AllowParallel = true;
            using (var lcr = new LayerCollectionRenderer(lc))
            {
                lcr.Render(g, this);
            }

            /*
            var layerList = new ILayer[lc.Count];
            lc.CopyTo(layerList, 0);

            foreach (ILayer layer in layerList)
            {
                if (layer.Enabled && layer.MaxVisible >= Zoom && layer.MinVisible < Zoom)
                    layer.Render(g, this);
            }

             */

            if (drawTransparent)


                g.Transform = transform;
            if (layerCollectionType == LayerCollectionType.Static)
            {
#pragma warning disable 612,618
                RenderDisclaimer(g);
#pragma warning restore 612,618
                if (drawMapDecorations)
                {
                    foreach (var mapDecoration in Decorations)
                    {
                        mapDecoration.Render(g, this);
                    }
                }
            }



            VariableLayerCollection.Pause = false;

        }

        void Draw(IGraphics g, DrawingMode mode)
        {
            g.SmoothingMode = checkBoxAntialiasing.Checked ? SmoothingMode.HighQuality : SmoothingMode.None;
            g.Clear(Color.White);

            DrawMillimeterGridInPixels(g, tabControl1.SelectedTab.Controls[0].ClientRectangle);

            g.PageUnit = GraphicsUnit.Millimeter;

            var points = _noisePoints;

            DrawLines(g, points, mode);

            g.ResetTransform();

            var path = CreateRoundedRectanglePath(new RectangleF(10, 10, 100, 40), 10);

            g.FillPath(new SolidBrush(Color.FromArgb(120, Color.LightSlateGray)), path);
            g.DrawPath(new Pen(Color.LightSlateGray, 0.0f), path);

            g.FillPie(new SolidBrush(Color.FromArgb(120, Color.CadetBlue)), new Rectangle(30, 20, 100, 100), 45.0f, 90.0f);
            g.DrawPie(new Pen(Color.CadetBlue, 0.0f), new Rectangle(30, 20, 100, 100), 45.0f, 90.0f);

            //GLGraphics gl = g as GLGraphics;
            //if (gl != null)
            //    gl.FillTextBackground = gl.FillTextBackground_glReadPixels;

            g.PageUnit = GraphicsUnit.Pixel;
            RectangleF rect = new RectangleF(30.0f, 15.0f, _testImage.Width, _testImage.Height);
            g.DrawImage(_testImage, rect);
            g.DrawRectangle(Pens.Black, rect.X, rect.Y, rect.Width, rect.Height);

            g.PageUnit = GraphicsUnit.Millimeter;

            g.HintTextBackgroundAction((gdi, textLocation, textRect) =>
            {
                _millimeterGridBrush.ResetTransform();
                _millimeterGridBrush.TranslateTransform(-textLocation.X, -textLocation.Y);
                gdi.FillRectangle(_millimeterGridBrush, textRect);
            });

            g.DrawString("Testovací řetězec pro odzkoušení správné implementace IGraphics - metody DrawString.",
                new Font("Arial", 12.0f), Brushes.Black, new PointF(100.0f, 58.0f));
        }

        /// <summary>
        /// Draws the sprites
        /// </summary>
        /// <param name="gameTime">Game time</param>
        /// <param name="renderer">Graphics</param>
        public void Draw(GameTime gameTime, IGraphics renderer)
        {
            // Draw the walls to the map buffer
            this.mapGraphics.DrawImage(this.mapImage, 0, 0, this.mapImage.Width, this.mapImage.Height);

            // Draw all objects to the map buffer
            foreach (Sprite sprite in this.allObjects)
            {
                sprite.Draw(this.mapGraphics, gameTime);
            }

            // Clear the screen background (because it is larger than the map)
            renderer.Clear(Color.Black);

            // Draw the map to the screen buffer
            renderer.DrawImage(this.mapBuffer, MapXoffset, MapYoffset, this.mapBuffer.Width, this.mapBuffer.Height);

            // Draw the text messages to the screen buffer
            this.DrawMessages(gameTime, renderer);
        }