Winform 动态 画图 不闪

1 //--------------------------------------------------------------------------------------------------------------------
2 //<copyright file="PictureBoxEx.cs" company="hyl">
3 //hyl
4 //</copyright>
5 //<summary>
6 //用Action传画图方法。不闪。
7 //</summary>
8 //--------------------------------------------------------------------------------------------------------------------
9 
10 namespaceHYL
11 {
12     usingSystem;
13     usingSystem.Drawing;
14     usingSystem.Windows.Forms;
15 
16     public partial classPictureBoxEx : PictureBox
17 {
18         /// <summary>
19         ///画图方法
20         /// </summary>
21         private Action<Graphics>draw;
22 
23         publicPictureBoxEx()
24 {
26             this.InitializeComponent();
27 
28             //开双缓存（用这种方法，画图不太复杂的话，甚至不开也不闪。。。）
29             this.SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint, true);
30 }
31 
32         public void Rander(Action<Graphics>Draw)
33 {
34             this.Invalidate();
35             this.draw =Draw;
36 }
37 
38         protected override voidOnPaint(PaintEventArgs pe)
39 {
40             base.OnPaint(pe);
41 
42             //画图
43             this.draw?.Invoke(pe.Graphics);
44 }
45 }
46 }

1 namespaceHYL
2 {
3     usingSystem;
4     usingSystem.Collections.Generic;
5     usingSystem.Drawing;
6     usingSystem.Linq;
7     usingSystem.Windows.Forms;
8 
9     public partial classForm1 : Form
10 {
11         List<Line> lines = new List<Line>();
12 
13         private boolpainting;
14 
15         publicForm1()
16 {
17             this.InitializeComponent();
18 }
19 
20         private void panel1_MouseDown(objectsender, MouseEventArgs e)
21 {
22             if (e.Button ==MouseButtons.Left)
23 {
24                 //左键确定点
25                 if (this.btnLine.Checked)
26 {
27                     this.lines.Last().Points.Add(new LinePoint { IsTemp = false, Point =e.Location });
28                     this.painting = true;
29 }
30 }
31 
32             if (e.Button ==MouseButtons.Right)
33 {
34                 //右键停止画图
35                 if (this.btnLine.Checked)
36 {
37                     this.ClearEmptyLines();
38 }
39 
40                 this.painting = false;
41                 this.btnLine.Checked = false;
42 }
43 }
44 
45         private voidClearEmptyLines()
46 {
47             this.lines = this.lines.Where(l => l.Points.Count > 1).ToList();
48             if (this.lines.Count > 0)
49 {
50                 var lastLine = this.lines.Last();
51 lastLine.ClearTempPoints();
52 }
53 }
54 
55         private void panel1_MouseMove(objectsender, MouseEventArgs e)
56 {
57             if (this.painting)
58 {
59                 if (this.btnLine.Checked)
60 {
61                     this.PaintingLine(e);
62 }
63 
64                 this.Draw();
65 }
66 }
67 
68         private voidPaintingLine(MouseEventArgs e)
69 {
70             var lastLine = this.lines.Last();
71             var lastPoint =lastLine.Points.Last();
72 
73             if(lastPoint.IsTemp)
74 {
75 lastLine.Points.Remove(lastPoint);
76 }
77 
78             LinePoint newPoint = new LinePoint { IsTemp = true, Point =e.Location };
79 lastLine.Points.Add(newPoint);
80 }
81 
82         /// <summary>
83         ///画图
84         /// </summary>
85         private voidDraw()
86 {
87             Action<Graphics> draw = g =>
88 {
89                     Pen pen = new Pen(Color.Black, 2);
90                     g.SmoothingMode =System.Drawing.Drawing2D.SmoothingMode.HighQuality;
91                     g.PixelOffsetMode =System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
92 
93                     if (this.lines != null)
94 {
95                         foreach (Line line in this.lines)
96 {
97 g.DrawLines(pen, line.GetPoints().ToArray());
98 }
99 }
100 };
101 
102             this.pictureBoxEx1.Rander(draw);
103 }
104 
105         private void btnLine_CheckedChanged(objectsender, EventArgs e)
106 {
107             if (this.btnLine.Checked)
108 {
109                 this.lines.Add(newLine());
110 }
111             else
112 {
113                 this.ClearEmptyLines();
114                 this.painting = false;
115                 this.Draw();
116 }
117 }
118 }
119 
120     public classLine : ShapeElement
121 {
122         publicLine()
123 {
124             this.Points = new List<LinePoint>();
125 }
126 
127         //线里的点
128         public IList<LinePoint> Points { get; set; }
129 
130         //获取Point的集合
131         public IList<Point>GetPoints()
132 {
133             return this.Points.Select(p =>p.Point).ToList();
134 }
135 
136         //清理临时点
137         public voidClearTempPoints()
138 {
139             this.Points = this.Points.Where(p => !p.IsTemp).ToList();
140 }
141 }
142 
143     public classLinePoint
144 {
145         public Point Point { get; set; }
146 
147         //是否临时点
148         public bool IsTemp { get; set; }
149 }
150 }