Detailed Guide to Drawing Circles and Ellipses with SkiaSharp

SkiaSharp is a powerful 2D graphics library that can be used to draw various shapes. This article will provide a detailed introduction on how to use SkiaSharp to draw circles and ellipses in WinForms applications.

Environment Setup

First, you need to install SkiaSharp related packages through NuGet Package Manager:

• SkiaSharp
• SkiaSharp.Views
• SkiaSharp.Views.WindowsForms

Basic Knowledge

In SkiaSharp:

• Use SKCanvas.DrawCircle() method to draw circles
• Use SKCanvas.DrawOval() method to draw ellipses
• Use SKPaint class to set drawing styles (color, line width, etc.)

SkiaSharp 是一个强大的 2D 图形库，可以用来绘制各种图形。本文将详细介绍如何使用 SkiaSharp 在 WinForms 应用程序中绘制圆形和椭圆。

环境准备

首先需要通过 NuGet 包管理器安装 SkiaSharp 相关包：

• SkiaSharp
• SkiaSharp.Views
• SkiaSharp.Views.WindowsForms

基础知识

在 SkiaSharp 中：

• 使用 SKCanvas.DrawCircle() 方法绘制圆形
• 使用 SKCanvas.DrawOval() 方法绘制椭圆
• 使用 SKPaint 类设置绘制样式（颜色、线宽等）

SkiaSharp is the .NET version of Google's Skia graphics engine, providing powerful 2D graphics processing capabilities. This article will provide a detailed introduction on how to use SkiaSharp to draw various rectangles in WinForm applications.

Environment Setup

First, you need to install the following packages through NuGet Package Manager:

• SkiaSharp
• SkiaSharp.Views
• SkiaSharp.Views.WindowsForms

Basic Example

Creating Basic Form

C#
using SkiaSharp;
using SkiaSharp.Views.Desktop;

namespace AppRectangle
{
    public partial class Form1 : Form
    {
        private SKControl skControl;

        public Form1()
        {
            InitializeComponent();

            // Create SKControl control
            skControl = new SKControl();
            skControl.Dock = DockStyle.Fill;
            skControl.PaintSurface += OnPaintSurface;
            this.Controls.Add(skControl);
        }

        // Paint event handler
        private void OnPaintSurface(object sender, SKPaintSurfaceEventArgs e)
        {
            // Get drawing canvas
            SKCanvas canvas = e.Surface.Canvas;

            // Clear canvas (using white background)
            canvas.Clear(SKColors.White);

            // Add drawing code here
            DrawRectangles(canvas);
        }

        private void DrawRectangles(SKCanvas canvas)
        {
            // Create paint brush
            using (var paint = new SKPaint())
            {
                // Enable anti-aliasing  
                paint.IsAntialias = true;

                // 1. Draw basic rectangle
                paint.Color = SKColors.Blue;        // Set color to blue
                paint.Style = SKPaintStyle.Fill;    // Set fill style
                canvas.DrawRect(50, 50, 200, 100, paint);

                // 2. Draw stroked rectangle
                paint.Color = SKColors.Red;         // Set color to red
                paint.Style = SKPaintStyle.Stroke;  // Set to stroke style
                paint.StrokeWidth = 3;             // Set stroke width
                canvas.DrawRect(50, 200, 200, 100, paint);

                // 3. Draw rounded rectangle
                paint.Color = SKColors.Green;       // Set color to green
                paint.Style = SKPaintStyle.Fill;    // Set fill style
                canvas.DrawRoundRect(50, 350, 200, 100, 20, 20, paint);
            }
        }
    }
}

SkiaSharp 是 Google's Skia 图形引擎的 .NET 版本，提供了强大的 2D 图形处理能力。本文将详细介绍如何在 WinForm 应用程序中使用 SkiaSharp 绘制各种矩形。

环境准备

首先需要通过 NuGet 包管理器安装以下包：

• SkiaSharp
• SkiaSharp.Views
• SkiaSharp.Views.WindowsForms

基础示例

创建基础窗体

C#
using SkiaSharp;
using SkiaSharp.Views.Desktop;

namespace AppRectangle
{
    public partial class Form1 : Form
    {
        private SKControl skControl;

        public Form1()
        {
            InitializeComponent();

            // 创建 SKControl 控件
            skControl = new SKControl();
            skControl.Dock = DockStyle.Fill;
            skControl.PaintSurface += OnPaintSurface;
            this.Controls.Add(skControl);
        }

        // 绘制事件处理
        private void OnPaintSurface(object sender, SKPaintSurfaceEventArgs e)
        {
            // 获取绘图画布
            SKCanvas canvas = e.Surface.Canvas;

            // 清空画布（使用白色背景）
            canvas.Clear(SKColors.White);

            // 在这里添加绘制代码
            DrawRectangles(canvas);
        }

        private void DrawRectangles(SKCanvas canvas)
        {
            // 创建画笔
            using (var paint = new SKPaint())
            {
                // 启用防锯齿  
                paint.IsAntialias = true;

                // 1. 绘制基础矩形
                paint.Color = SKColors.Blue;        // 设置颜色为蓝色
                paint.Style = SKPaintStyle.Fill;    // 设置填充样式
                canvas.DrawRect(50, 50, 200, 100, paint);

                // 2. 绘制描边矩形
                paint.Color = SKColors.Red;         // 设置颜色为红色
                paint.Style = SKPaintStyle.Stroke;  // 设置为描边样式
                paint.StrokeWidth = 3;             // 设置描边宽度
                canvas.DrawRect(50, 200, 200, 100, paint);

                // 3. 绘制圆角矩形
                paint.Color = SKColors.Green;       // 设置颜色为绿色
                paint.Style = SKPaintStyle.Fill;    // 设置填充样式
                canvas.DrawRoundRect(50, 350, 200, 100, 20, 20, paint);
            }
        }
    }
}

SkiaSharp is a powerful cross-platform 2D graphics drawing library derived from Google's Skia graphics library. This article will explore in depth how to use SkiaSharp to draw various types of lines.

Basic Line Drawing

C#
override protected void OnPaint(PaintEventArgs e)
{
    var info=new SKImageInfo(ClientSize.Width, ClientSize.Height);
    using (var surface = SKSurface.Create(info))
    {
        var canvas = surface.Canvas;
        canvas.Clear(SKColors.White);
        // Create Paint object
        using (var paint = new SKPaint())
        {
            // Set line color to blue
            paint.Color = SKColors.Blue;

            // Set line width
            paint.StrokeWidth = 5;

            // Set drawing mode to stroke
            paint.Style = SKPaintStyle.Stroke;

            // Draw a line from point (50, 50) to point (200, 200)
            canvas.DrawLine(50, 50, 200, 200, paint);
        }
        using(var view=new SKGLControl())
        {
            // Generate snapshot image from the drawing surface  
            var image = surface.Snapshot();
            // Generate SKBitmap from image  
            var bitmap = SKBitmap.FromImage(image);
            // Convert SKBitmap to GDI+ Bitmap and draw to Graphics object of PaintEventArgs  
            e.Graphics.DrawImage(bitmap.ToBitmap(), 0, 0);
        }
    }
}