（七十七）c#Winform自定義控件-採樣控件

時間 2019-11-06

標籤七十七 c#winform winform 自定義控件採樣欄目 C# 简体版

原文原文鏈接

官網

http://www.hzhcontrols.comhtml

前提

入行已經7,8年了，一直想作一套漂亮點的自定義控件，因而就有了本系列文章。git

GitHub：https://github.com/kwwwvagaa/NetWinformControlgithub

碼雲：https://gitee.com/kwwwvagaa/net_winform_custom_control.git算法

若是以爲寫的還行，請點個 star 支持一下吧ide

歡迎前來交流探討：企鵝羣568015492 函數

來都來了，點個【推薦】再走吧，謝謝this

NuGet

Install-Package HZH_Controls

用處及效果

注意觀察各個控件交疊的地方，是否是發現他們沒有遮擋？這就是這個控件的妙處了。code

準備工做

先說明一下這個控件的做用，不少時候咱們須要一個圖片類型的控件，可是有須要密集的放在一塊兒，若是單純的設置背景圖或image的話交疊在一塊兒的部分就會存在遮擋現象，全部就有了這個控件。orm

該控件能夠根據設置的採樣圖片來裁剪有用的繪圖區域，這樣的好處就是在交疊的時候，無用區域不會遮擋。

這個用GDI+畫的，另外也用到了一點三角函數，不明白的話能夠先百度下

開始

添加一個類UCSampling ，繼承UserControl

添加屬性

 1   /// <summary>
 2         /// The sampling imag
 3         /// </summary>
 4         private Bitmap samplingImag = null;
 5         /// <summary>
 6         /// Gets or sets the sampling imag.
 7         /// </summary>
 8         /// <value>The sampling imag.</value>
 9         [Browsable(true), Category("自定義屬性"), Description("採樣圖片"), Localizable(true)]
10         public Bitmap SamplingImag
11         {
12             get { return samplingImag; }
13             set
14             {
15                 samplingImag = value;
16                 ResetBorderPath();
17                 Invalidate();
18             }
19         }
20 
21         /// <summary>
22         /// The transparent
23         /// </summary>
24         private Color? transparent = null;
25 
26         /// <summary>
27         /// Gets or sets the transparent.
28         /// </summary>
29         /// <value>The transparent.</value>
30         [Browsable(true), Category("自定義屬性"), Description("透明色，若是爲空，則使用0,0座標處的顏色"), Localizable(true)]
31         public Color? Transparent
32         {
33             get { return transparent; }
34             set
35             {
36                 transparent = value;
37                 ResetBorderPath();
38                 Invalidate();
39             }
40         }
41 
42         /// <summary>
43         /// The alpha
44         /// </summary>
45         private int alpha = 50;
46 
47         /// <summary>
48         /// Gets or sets the alpha.
49         /// </summary>
50         /// <value>The alpha.</value>
51         [Browsable(true), Category("自定義屬性"), Description("看成透明色的透明度，小於此透明度的顏色將被認定爲透明，0-255"), Localizable(true)]
52         public int Alpha
53         {
54             get { return alpha; }
55             set
56             {
57                 if (value < 0 || value > 255)
58                     return;
59                 alpha = value;
60                 ResetBorderPath();
61                 Invalidate();
62             }
63         }
64 
65         /// <summary>
66         /// The color threshold
67         /// </summary>
68         private int colorThreshold = 10;
69 
70         /// <summary>
71         /// Gets or sets the color threshold.
72         /// </summary>
73         /// <value>The color threshold.</value>
74         [Browsable(true), Category("自定義屬性"), Description("透明色顏色閥值"), Localizable(true)]
75         public int ColorThreshold
76         {
77             get { return colorThreshold; }
78             set
79             {
80                 colorThreshold = value;
81                 ResetBorderPath();
82                 Invalidate();
83             }
84         }
85 
86         /// <summary>
87         /// The bit cache
88         /// </summary>
89         private Bitmap _bitCache;

在大小改變或圖片改變時從新計算邊界

 1  /// <summary>
 2         /// The m border path
 3         /// </summary>
 4         GraphicsPath m_borderPath = new GraphicsPath();
 5 
 6         /// <summary>
 7         /// Handles the SizeChanged event of the UCSampling control.
 8         /// </summary>
 9         /// <param name="sender">The source of the event.</param>
10         /// <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
11         void UCSampling_SizeChanged(object sender, EventArgs e)
12         {
13             ResetBorderPath();
14         }
15 
16         /// <summary>
17         /// Resets the border path.
18         /// </summary>
19         private void ResetBorderPath()
20         {
21             if (samplingImag == null)
22             {
23                 m_borderPath = this.ClientRectangle.CreateRoundedRectanglePath(5);
24             }
25             else
26             {
27                 var bit = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);
28                 using (var bitg = Graphics.FromImage(bit))
29                 {
30                     bitg.DrawImage(samplingImag, this.ClientRectangle, 0, 0, samplingImag.Width, samplingImag.Height, GraphicsUnit.Pixel);
31                 }
32                 _bitCache = bit;
33                 m_borderPath = new GraphicsPath();
34                 List<PointF> lstPoints = GetBorderPoints(bit, transparent ?? samplingImag.GetPixel(0, 0));
35                 m_borderPath.AddLines(lstPoints.ToArray());
36                 m_borderPath.CloseAllFigures();
37             }
38         }
39 
40         /// <summary>
41         /// Gets the border points.
42         /// </summary>
43         /// <param name="bit">The bit.</param>
44         /// <param name="transparent">The transparent.</param>
45         /// <returns>List&lt;PointF&gt;.</returns>
46         private List<PointF> GetBorderPoints(Bitmap bit, Color transparent)
47         {
48             float diameter = (float)Math.Sqrt(bit.Width * bit.Width + bit.Height * bit.Height);
49             int intSplit = 0;
50             intSplit = (int)(7 - (diameter - 200) / 100);
51             if (intSplit < 1)
52                 intSplit = 1;
53             List<PointF> lstPoint = new List<PointF>();
54             for (int i = 0; i < 360; i += intSplit)
55             {
56                 for (int j = (int)diameter / 2; j > 5; j--)
57                 {
58                     Point p = GetPointByAngle(i, j, new PointF(bit.Width / 2, bit.Height / 2));
59                     if (p.X < 0 || p.Y < 0 || p.X >= bit.Width || p.Y >= bit.Height)
60                         continue;
61                     Color _color = bit.GetPixel(p.X, p.Y);
62                     if (!(((int)_color.A) <= alpha || IsLikeColor(_color, transparent)))
63                     {
64                         if (!lstPoint.Contains(p))
65                         {
66                             lstPoint.Add(p);
67                         }
68                         break;
69                     }
70                 }
71             }
72             return lstPoint;
73         }
74 
75         /// <summary>
76         /// Determines whether [is like color] [the specified color1].
77         /// </summary>
78         /// <param name="color1">The color1.</param>
79         /// <param name="color2">The color2.</param>
80         /// <returns><c>true</c> if [is like color] [the specified color1]; otherwise, <c>false</c>.</returns>
81         private bool IsLikeColor(Color color1, Color color2)
82         {
83             var cv = Math.Sqrt(Math.Pow((color1.R - color2.R), 2) + Math.Pow((color1.G - color2.G), 2) + Math.Pow((color1.B - color2.B), 2));
84             if (cv <= colorThreshold)
85                 return true;
86             else
87                 return false;
88         }

 1  #region 根據角度獲得座標    English:Get coordinates from angles
 2         /// <summary>
 3         /// 功能描述:根據角度獲得座標    English:Get coordinates from angles
 4         /// 做　　者:HZH
 5         /// 建立日期:2019-09-28 11:56:25
 6         /// 任務編號:POS
 7         /// </summary>
 8         /// <param name="angle">angle</param>
 9         /// <param name="radius">radius</param>
10         /// <param name="origin">origin</param>
11         /// <returns>返回值</returns>
12         private Point GetPointByAngle(float angle, float radius, PointF origin)
13         {
14             float y = origin.Y + (float)Math.Sin(Math.PI * (angle / 180.00F)) * radius;
15             float x = origin.X + (float)Math.Cos(Math.PI * (angle / 180.00F)) * radius;
16             return new Point((int)x, (int)y);
17         }
18         #endregion

取邊界的思路以下：

1，以控件中心爲原點，按照必定的角度順時針依次進行旋轉，

二、每次旋轉後，按照此角度從外向內，找到第一個不是透明的點記錄下來，這就是外邊界點

這個取邊界算法感受並非太好，若是哪位小夥伴有更好的算法，但願能夠探討一下

重繪

 1   protected override void OnPaint(PaintEventArgs e)
 2         {
 3             base.OnPaint(e);
 4             e.Graphics.SetGDIHigh();
 5 
 6             this.Region = new System.Drawing.Region(m_borderPath);
 7            
 8             if (_bitCache != null)
 9                 e.Graphics.DrawImage(_bitCache, 0, 0);
10            
11         }