C#绘制三角形并填充，使用winform实现qq聊天气泡

首先是需求，需要制作一个聊天气泡， 但是winform中有没有类似Android的.9图，只有自己设计图形拼接气泡。

第一种是绘制空心三角形，第二种是绘制三角形区域，可以指定RGB颜色。

private void Form1_Paint(object sender, PaintEventArgs e)
        {
            Pen pen = new Pen(Color.Red, 1);            
            e.Graphics.DrawLine(pen, 10, 10, 50, 10);
            e.Graphics.DrawLine(pen, 10, 10, 50, 50);
            e.Graphics.DrawLine(pen, 50, 10, 50, 50);

            Color color = System.Drawing.Color.FromArgb(((int)(((byte)(34)))), ((int)(((byte)(54)))), ((int)(((byte)(82)))));
            Brush brushes = new SolidBrush(color);
            Point[] point new Point[3];
            point[0] = new Point(50,100);
            point[1] = new Point(100,50);
            point[2] = new Point(100,100);
            e.Graphics.FillPolygon(brushes, point);
        }

 效果：

可以作为气泡中的箭头，另外四个角用椭圆：

 

Winform仿制QQ微信聊天窗口气泡 

绘制圆角矩形的代码：

//窗口圆角   
private void Main_Paint(object sender, PaintEventArgs e)
        {
            List<Point> list = new List<Point>();
            int width = this.Width;
            int height = this.Height;

            #region 四个圆角

            //左上  
            list.Add(new Point(0, 47));
            list.Add(new Point(1, 42));
            list.Add(new Point(2, 38));
            list.Add(new Point(3, 36));
            list.Add(new Point(4, 33));
            list.Add(new Point(5, 32));
            list.Add(new Point(6, 29));
            list.Add(new Point(7, 27));
            list.Add(new Point(8, 26));
            list.Add(new Point(9, 24));
            list.Add(new Point(10, 22));
            list.Add(new Point(11, 21));
            list.Add(new Point(12, 20));
            list.Add(new Point(13, 19));
            list.Add(new Point(14, 17));
            list.Add(new Point(15, 16));
            list.Add(new Point(16, 15));
            list.Add(new Point(17, 14));
            list.Add(new Point(19, 13));
            list.Add(new Point(20, 12));
            list.Add(new Point(21, 11));
            list.Add(new Point(22, 10));
            list.Add(new Point(24, 9));
            list.Add(new Point(26, 8));
            list.Add(new Point(27, 7));
            list.Add(new Point(29, 6));
            list.Add(new Point(32, 5));
            list.Add(new Point(33, 4));
            list.Add(new Point(36, 3));
            list.Add(new Point(38, 2));
            list.Add(new Point(42, 1));
            list.Add(new Point(47, 0));

            //右上  
            list.Add(new Point(width - 47, 0));
            list.Add(new Point(width - 42, 1));
            list.Add(new Point(width - 38, 2));
            list.Add(new Point(width - 36, 3));
            list.Add(new Point(width - 33, 4));
            list.Add(new Point(width - 32, 5));
            list.Add(new Point(width - 29, 6));
            list.Add(new Point(width - 27, 7));
            list.Add(new Point(width - 26, 8));
            list.Add(new Point(width - 24, 9));
            list.Add(new Point(width - 22, 10));
            list.Add(new Point(width - 21, 11));
            list.Add(new Point(width - 20, 12));
            list.Add(new Point(width - 19, 13));
            list.Add(new Point(width - 17, 14));
            list.Add(new Point(width - 16, 15));
            list.Add(new Point(width - 15, 16));
            list.Add(new Point(width - 14, 17));
            list.Add(new Point(width - 13, 19));
            list.Add(new Point(width - 12, 20));
            list.Add(new Point(width - 11, 21));
            list.Add(new Point(width - 10, 22));
            list.Add(new Point(width - 9, 24));
            list.Add(new Point(width - 8, 26));
            list.Add(new Point(width - 7, 27));
            list.Add(new Point(width - 6, 29));
            list.Add(new Point(width - 5, 32));
            list.Add(new Point(width - 4, 33));
            list.Add(new Point(width - 3, 36));
            list.Add(new Point(width - 2, 38));
            list.Add(new Point(width - 1, 42));
            list.Add(new Point(width - 0, 47));

            //右下  
            list.Add(new Point(width - 0, height - 47));
            list.Add(new Point(width - 1, height - 42));
            list.Add(new Point(width - 2, height - 38));
            list.Add(new Point(width - 3, height - 36));
            list.Add(new Point(width - 4, height - 33));
            list.Add(new Point(width - 5, height - 32));
            list.Add(new Point(width - 6, height - 29));
            list.Add(new Point(width - 7, height - 27));
            list.Add(new Point(width - 8, height - 26));
            list.Add(new Point(width - 9, height - 24));
            list.Add(new Point(width - 10, height - 22));
            list.Add(new Point(width - 11, height - 21));
            list.Add(new Point(width - 12, height - 20));
            list.Add(new Point(width - 13, height - 19));
            list.Add(new Point(width - 14, height - 17));
            list.Add(new Point(width - 15, height - 16));
            list.Add(new Point(width - 16, height - 15));
            list.Add(new Point(width - 17, height - 14));
            list.Add(new Point(width - 19, height - 13));
            list.Add(new Point(width - 20, height - 12));
            list.Add(new Point(width - 21, height - 11));
            list.Add(new Point(width - 22, height - 10));
            list.Add(new Point(width - 24, height - 9));
            list.Add(new Point(width - 26, height - 8));
            list.Add(new Point(width - 27, height - 7));
            list.Add(new Point(width - 29, height - 6));
            list.Add(new Point(width - 32, height - 5));
            list.Add(new Point(width - 33, height - 4));
            list.Add(new Point(width - 36, height - 3));
            list.Add(new Point(width - 38, height - 2));
            list.Add(new Point(width - 42, height - 1));
            list.Add(new Point(width - 47, height - 0));

            //左下  
            list.Add(new Point(47, height - 0));
            list.Add(new Point(42, height - 1));
            list.Add(new Point(38, height - 2));
            list.Add(new Point(36, height - 3));
            list.Add(new Point(33, height - 4));
            list.Add(new Point(32, height - 5));
            list.Add(new Point(29, height - 6));
            list.Add(new Point(27, height - 7));
            list.Add(new Point(26, height - 8));
            list.Add(new Point(24, height - 9));
            list.Add(new Point(22, height - 10));
            list.Add(new Point(21, height - 11));
            list.Add(new Point(20, height - 12));
            list.Add(new Point(19, height - 13));
            list.Add(new Point(17, height - 14));
            list.Add(new Point(16, height - 15));
            list.Add(new Point(15, height - 16));
            list.Add(new Point(14, height - 17));
            list.Add(new Point(13, height - 19));
            list.Add(new Point(12, height - 20));
            list.Add(new Point(11, height - 21));
            list.Add(new Point(10, height - 22));
            list.Add(new Point(9, height - 24));
            list.Add(new Point(8, height - 26));
            list.Add(new Point(7, height - 27));
            list.Add(new Point(6, height - 29));
            list.Add(new Point(5, height - 32));
            list.Add(new Point(4, height - 33));
            list.Add(new Point(3, height - 36));
            list.Add(new Point(2, height - 38));
            list.Add(new Point(1, height - 42));
            list.Add(new Point(0, height - 47));

            #endregion

            Point[] points = list.ToArray();

            GraphicsPath shape = new GraphicsPath();
            shape.AddPolygon(points);

            this.Region = new System.Drawing.Region(shape);

        }