C# Graphics.Clear方法代码示例

        public static void Run()
        {
            // ExStart:DrawingBezier
            // The path to the documents directory.
            string dataDir = RunExamples.GetDataDir_DrawingAndFormattingImages();

            // Creates an instance of FileStream
            using (FileStream stream = new FileStream(dataDir + "DrawingArc_out.bmp", FileMode.Create))
            {
                // Create an instance of BmpOptions and set its various properties
                BmpOptions saveOptions = new BmpOptions();
                saveOptions.BitsPerPixel = 32;

                // Set the Source for BmpOptions and create an instance of Image
                saveOptions.Source = new StreamSource(stream);               
                using (Image image = Image.Create(saveOptions, 100, 100))
                {
                    // Create and initialize an instance of Graphics class and clear Graphics surface
                    Graphics graphic = new Graphics(image);
                    graphic.Clear(Color.Yellow);

                    // Draw an arc shape by specifying the Pen object having red black color and coordinates, height, width, start & end angles                 
                    int width = 100;
                    int height = 200;
                    int startAngle = 45;
                    int sweepAngle = 270;

                    // Draw arc to screen and save all changes.
                    graphic.DrawArc(new Pen(Color.Black), 0, 0, width, height, startAngle, sweepAngle);
                    image.Save();
                }
                stream.Close();
            }
        }

        public static void Run()
        {
            // ExStart:DrawingEllipse
            // The path to the documents directory.
            string dataDir = RunExamples.GetDataDir_DrawingAndFormattingImages();

            // Creates an instance of FileStream
            using (FileStream stream = new FileStream(dataDir + "DrawingEllipse_out.bmp", FileMode.Create))
            {
                // Create an instance of BmpOptions and set its various properties
                BmpOptions saveOptions = new BmpOptions();
                saveOptions.BitsPerPixel = 32;
                saveOptions.Source = new StreamSource(stream);

                // Create an instance of Image
                using (Image image = Image.Create(saveOptions, 100, 100))
                {
                    // Create and initialize an instance of Graphics class and Clear Graphics surface                    
                    Graphics graphic = new Graphics(image);
                    graphic.Clear(Color.Yellow);

                    // Draw a dotted ellipse shape by specifying the Pen object having red color and a surrounding Rectangle
                    graphic.DrawEllipse(new Pen(Color.Red), new Rectangle(30, 10, 40, 80));

                    // Draw a continuous ellipse shape by specifying the Pen object having solid brush with blue color and a surrounding Rectangle
                    graphic.DrawEllipse(new Pen(new SolidBrush(Color.Blue)), new Rectangle(10, 30, 80, 40));
                    image.Save();
                }
                stream.Close();
            }
            // ExEnd:DrawingEllipse
        }

        public static void Run()
        {
            // ExStart:DrawingLines
            // The path to the documents directory.
            string dataDir = RunExamples.GetDataDir_DrawingAndFormattingImages() + "SolidLines_out.bmp";

            // Creates an instance of FileStream
            using (FileStream stream = new FileStream(dataDir, FileMode.Create))
            {
                // Create an instance of BmpOptions and set its various properties
                BmpOptions saveOptions = new BmpOptions();
                saveOptions.BitsPerPixel = 32;
                saveOptions.Source = new StreamSource(stream);

                // Create an instance of Image
                using (Image image = Image.Create(saveOptions, 100, 100))
                {
                    // Create and initialize an instance of Graphics class and Clear Graphics surface
                    Graphics graphic = new Graphics(image);
                    graphic.Clear(Color.Yellow);

                    // Draw two dotted diagonal lines by specifying the Pen object having blue color and co-ordinate Points
                    graphic.DrawLine(new Pen(Color.Blue), 9, 9, 90, 90);
                    graphic.DrawLine(new Pen(Color.Blue), 9, 90, 90, 9);

                    // Draw a four continuous line by specifying the Pen object having Solid Brush with red color and two point structures
                    graphic.DrawLine(new Pen(new SolidBrush(Color.Red)), new Point(9, 9), new Point(9, 90));
                    graphic.DrawLine(new Pen(new SolidBrush(Color.Aqua)), new Point(9, 90), new Point(90, 90));
                    graphic.DrawLine(new Pen(new SolidBrush(Color.Black)), new Point(90, 90), new Point(90, 9));
                    graphic.DrawLine(new Pen(new SolidBrush(Color.White)), new Point(90, 9), new Point(9, 9));
                    image.Save();
                }
            }
            // ExEnd:DrawingLines
        }

        public static void Run()
        {
            // ExStart:DrawingRectangle
            // The path to the documents directory.
            string dataDir = RunExamples.GetDataDir_DrawingAndFormattingImages() + "SampleRectangle_out.bmp";

            // Creates an instance of FileStream
            using (FileStream stream = new FileStream(dataDir, FileMode.Create))
            {
                // Create an instance of BmpOptions and set its various properties
                BmpOptions saveOptions = new BmpOptions();
                saveOptions.BitsPerPixel = 32;

                // Set the Source for BmpOptions and Create an instance of Image
                saveOptions.Source = new StreamSource(stream);
                using (Image image = Image.Create(saveOptions, 100, 100))
                {
                    // Create and initialize an instance of Graphics class,  Clear Graphics surface, Draw a rectangle shapes and  save all changes.
                    Graphics graphic = new Graphics(image);
                    graphic.Clear(Color.Yellow);
                    graphic.DrawRectangle(new Pen(Color.Red), new Rectangle(30, 10, 40, 80));
                    graphic.DrawRectangle(new Pen(new SolidBrush(Color.Blue)), new Rectangle(10, 30, 80, 40));
                    image.Save();
                }
            }
            // ExEnd:DrawingRectangle
        }

        public static void Run()
        {
            // ExStart:DrawingUsingGraphics
            // The path to the documents directory.
            string dataDir = RunExamples.GetDataDir_DrawingAndFormattingImages() + "SampleImage_out.bmp";

            // Create an instance of BmpOptions and set its various properties
            BmpOptions imageOptions = new BmpOptions();
            imageOptions.BitsPerPixel = 24;

            // Create an instance of FileCreateSource and assign it to Source property 
            imageOptions.Source = new FileCreateSource(dataDir, false);
            using (var image =  Image.Create(imageOptions, 500, 500))
            {
                var graphics = new Graphics(image);

                // Clear the image surface with white color and Create and initialize a Pen object with blue color
                graphics.Clear(Color.White);                
                var pen = new Pen(Color.Blue);

                // Draw Ellipse by defining the bounding rectangle of width 150 and height 100 also Draw a polygon using the LinearGradientBrush
                graphics.DrawEllipse(pen, new Rectangle(10, 10, 150, 100));
                using (var linearGradientBrush = new LinearGradientBrush(image.Bounds, Color.Red, Color.White, 45f))
                {
                    graphics.FillPolygon(linearGradientBrush, new[] { new Point(200, 200), new Point(400, 200), new Point(250, 350) });
                }
                image.Save();
            }
            // ExEnd:DrawingUsingGraphics
        }

            public static void PaintDocumentGradientBackground(Graphics graphics, Rectangle rectangle)
            {
                LinearGradientBrush BackgroundBrush = new LinearGradientBrush(rectangle, DefaultGradientUpper, DefaultGradientLower, LinearGradientMode.Vertical);

                graphics.Clear(DefaultGradientUpper);
                graphics.FillRectangle(BackgroundBrush, rectangle);
                BackgroundBrush.Dispose();
            }

 //Graphics g_,Graphics g1_)
 public arm()
 {
     //g = g_;
     //g1 = g1_;
     armBmp = new Bitmap(800, 400);
     drawBmp = new Bitmap(400,400);
     g = Graphics.FromImage(armBmp);
     g.Clear(Color.White);
     g1 = Graphics.FromImage(drawBmp);
     g1.Clear(Color.White);
 }

    protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
    {
        G = e.Graphics;
        G.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;

        G.Clear(BackColor);
        G.SmoothingMode = SmoothingMode.AntiAlias;

        GP1 = ThemeModule.CreateRound(0, 0, Width - 1, Height - 1, 7);
        GP2 = ThemeModule.CreateRound(1, 1, Width - 3, Height - 3, 7);

        if (IsMouseDown)
        {
            PB1 = new PathGradientBrush(GP1);
            PB1.CenterColor = Color.FromArgb(60, 60, 60);
            PB1.SurroundColors = new Color[] { Color.FromArgb(55, 55, 55) };
            PB1.FocusScales = new PointF(0.8f, 0.5f);

            G.FillPath(PB1, GP1);
        }
        else
        {
            GB1 = new LinearGradientBrush(ClientRectangle, Color.FromArgb(60, 60, 60), Color.FromArgb(55, 55, 55), 90f);
            G.FillPath(GB1, GP1);
        }

        G.DrawPath(P1, GP1);
        G.DrawPath(P2, GP2);

        SZ1 = G.MeasureString(Text, Font);
        PT1 = new PointF(5, Height / 2 - SZ1.Height / 2);

        if (IsMouseDown)
        {
            PT1.X += 1f;
            PT1.Y += 1f;
        }

        G.DrawString(Text, Font, Brushes.Black, PT1.X + 1, PT1.Y + 1);
        G.DrawString(Text, Font, Brushes.White, PT1);
    }

        public static void Run()
        {
            // ExStart:DrawingBezier
            // The path to the documents directory.
            string dataDir = RunExamples.GetDataDir_DrawingAndFormattingImages();
 
            // Creates an instance of FileStream
            using (FileStream stream = new FileStream(dataDir + "DrawingBezier_out.bmp", FileMode.Create))
            {
                // Create an instance of BmpOptions and set its various properties
                BmpOptions saveOptions = new BmpOptions();
                saveOptions.BitsPerPixel = 32;

                // Set the Source for BmpOptions and Create an instance of Image
                saveOptions.Source = new StreamSource(stream);
                using (Image image = Image.Create(saveOptions, 100, 100))
                {
                    // Create and initialize an instance of Graphics class and clear Graphics surface
                    Graphics graphic = new Graphics(image);
                    graphic.Clear(Color.Yellow);

                    // Initializes the instance of PEN class with black color and width
                    Pen BlackPen = new Pen(Color.Black, 3);
                    float startX = 10;
                    float startY = 25;
                    float controlX1 = 20;
                    float controlY1 = 5;
                    float controlX2 = 55;
                    float controlY2 = 10;
                    float endX = 90;
                    float endY = 25;

                    // Draw a Bezier shape by specifying the Pen object having black color and co-ordinate Points and save all changes.
                    graphic.DrawBezier(BlackPen, startX, startY, controlX1, controlY1, controlX2, controlY2, endX, endY);
                    image.Save();
                }
            }
            // ExEnd:DrawingBezier
        }

        public static void Run()
        {
            // ExStart:DrawingUsingGraphicsPath
            // The path to the documents directory.
            string dataDir = RunExamples.GetDataDir_DrawingAndFormattingImages();

            // Create an instance of BmpOptions and set its various properties
            BmpOptions ImageOptions = new BmpOptions();
            ImageOptions.BitsPerPixel = 24;

            // Create an instance of FileCreateSource and assign it to Source property
            ImageOptions.Source = new FileCreateSource(dataDir + "sample_1.bmp", false);

            // Create an instance of Image and initialize an instance of Graphics
            using (Image image = Image.Create(ImageOptions, 500, 500))
            {
                Graphics graphics = new Graphics(image);
                graphics.Clear(Color.White);

                // Create an instance of GraphicsPath and Instance of Figure, add EllipseShape, RectangleShape and TextShape to the figure
                GraphicsPath graphicspath = new GraphicsPath();
                Figure figure = new Figure();
                figure.AddShape(new EllipseShape(new RectangleF(0, 0, 499, 499)));
                figure.AddShape(new RectangleShape(new RectangleF(0, 0, 499, 499)));
                figure.AddShape(new TextShape("Aspose.Imaging", new RectangleF(170, 225, 170, 100), new Font("Arial", 20), StringFormat.GenericTypographic));
                graphicspath.AddFigures(new[] { figure });
                graphics.DrawPath(new Pen(Color.Blue), graphicspath);

                // Create an instance of HatchBrush and set its properties also Fill path by supplying the brush and GraphicsPath objects
                HatchBrush hatchbrush = new HatchBrush();
                hatchbrush.BackgroundColor = Color.Brown;
                hatchbrush.ForegroundColor = Color.Blue;
                hatchbrush.HatchStyle = HatchStyle.Vertical;
                graphics.FillPath(hatchbrush, graphicspath);
                image.Save();
                Console.WriteLine("Processing completed successfully.");
            }
            // ExEnd:DrawingUsingGraphicsPath
        }

        public static void Run()
        {
            // ExStart:CombineImages
            // The path to the documents directory.
            string dataDir = RunExamples.GetDataDir_DrawingAndFormattingImages();

            // Create an instance of JpegOptions and set its various properties
            JpegOptions imageOptions = new JpegOptions();

            // Create an instance of FileCreateSource and assign it to Source property
            imageOptions.Source = new FileCreateSource(dataDir + "Two_images_result_out.bmp", false);

            // Create an instance of Image and define canvas size
            using (var image = Image.Create(imageOptions, 600, 600))
            {
                // Create and initialize an instance of Graphics, Clear the image surface with white color and Draw Image
                var graphics = new Graphics(image);
                graphics.Clear(Color.White);
                graphics.DrawImage(Image.Load(dataDir + "sample_1.bmp"), 0, 0, 600, 300);
                graphics.DrawImage(Image.Load(dataDir + "File1.bmp"), 0, 300, 600, 300);
                image.Save();
            }
            // ExEnd:CombineImages
        }

    protected override void OnPaint(PaintEventArgs e)
    {
        G = e.Graphics;

        G.Clear(BackColor);
        G.SmoothingMode = SmoothingMode.AntiAlias;

        GP1 = ThemeModule.CreateRound(0, 0, Width - 1, Height - 1, 7);
        GP2 = ThemeModule.CreateRound(1, 1, Width - 3, Height - 3, 7);

        PB1 = new PathGradientBrush(GP1);
        PB1.CenterColor = Color.FromArgb(50, 50, 50);
        PB1.SurroundColors = new Color[] { Color.FromArgb(45, 45, 45) };
        PB1.FocusScales = new PointF(0.9f, 0.5f);

        G.FillPath(PB1, GP1);

        G.DrawPath(P1, GP1);
        G.DrawPath(P2, GP2);

        G.SmoothingMode = SmoothingMode.None;

        for (int I = 0; I <= Table.Length - 1; I++)
        {
            int C = Math.Max(Table[I], (byte)75);

            int X = ((I % RowSize) * ItemSize) + WA.X;
            int Y = ((I / RowSize) * ItemSize) + WA.Y;

            B2 = new SolidBrush(Color.FromArgb(C, C, C));

            G.FillRectangle(B1, X + 1, Y + 1, DrawSize, DrawSize);
            G.FillRectangle(B2, X, Y, DrawSize, DrawSize);

            B2.Dispose();
        }

    }

    private void UpdateGraphics(Graphics g)
    {
        g.Clear(Color.FromArgb (255, 255, 255, 255));
        g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
        Pen p = new Pen (new SolidBrush (Color.Black));
        SolidBrush r = new SolidBrush (Color.Red);
        renderer.Polygon demoObject = CreateTestPolygon ();
        demoObject.Draw2D (p, g);
        LineTest (testLine1, g, 0);
        LineTest (testLine2, g, Math.PI/100);
        try
        {
            Console.Write(testLine1.FindLineLineIntersection (testLine2));
            testLine1.DrawPoint(g, testLine1.FindLineLineIntersection (testLine2), new SolidBrush(Color.Purple));
        }
        catch (ArgumentException e) {
            Console.WriteLine ("Invalid arguments");
        }

        foreach (Node element in nodeList)
        {
            element.Draw(g);
        }
    }