官網
http://www.hzhcontrols.com
前提
入行已經7,8年了，一直想做一套漂亮點的自定義控制元件，于是就有了本系列文章，
GitHub：https://github.com/kwwwvagaa/NetWinformControl
碼云：https://gitee.com/kwwwvagaa/net_winform_custom_control.git
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NuGet
Install-Package HZH_Controls
目錄
https://www.cnblogs.com/bfyx/p/11364884.html
用處及效果
準備作業
GDI+畫圖，不了解先百度
開始
思路：
控制元件擴展屬性，在組件中對需要顯示倒影的控制元件的父控制元件添加Paint事件，在Paint事件中繪制控制元件，并旋轉180，然后畫到父控制元件上，然后再覆寫一層漸變色，完美，
添加一個類ShadowComponent 繼承Component，實作 IExtenderProvider介面，擴展屬性
代碼比較少，直接放上來了
1 /// <summary> 2 /// The m control cache 3 /// </summary> 4 Dictionary<Control, bool> m_controlCache = new Dictionary<Control, bool>(); 5 6 #region 建構式 English:Constructor 7 /// <summary> 8 /// Initializes a new instance of the <see cref="ShadowComponent" /> class. 9 /// </summary> 10 public ShadowComponent() 11 { 12 13 } 14 15 /// <summary> 16 /// Initializes a new instance of the <see cref="ShadowComponent" /> class. 17 /// </summary> 18 /// <param name="container">The container.</param> 19 public ShadowComponent(IContainer container) 20 : this() 21 { 22 container.Add(this); 23 } 24 #endregion 25 26 /// <summary> 27 /// 指定此物件是否可以將其擴展程式屬性提供給指定的物件， 28 /// </summary> 29 /// <param name="extendee">要接收擴展程式屬性的 <see cref="T:System.Object" />，</param> 30 /// <returns>如果此物件可以擴展程式屬性提供給指定物件，則為 true；否則為 false，</returns> 31 public bool CanExtend(object extendee) 32 { 33 if (extendee is Control && !(extendee is Form)) 34 return true; 35 return false; 36 } 37 38 /// <summary> 39 /// Gets the show shadow. 40 /// </summary> 41 /// <param name="control">The control.</param> 42 /// <returns><c>true</c> if XXXX, <c>false</c> otherwise.</returns> 43 [Browsable(true), Category("自定義屬性"), Description("是否顯示倒影"), DisplayName("ShowShadow"), Localizable(true)] 44 public bool GetShowShadow(Control control) 45 { 46 if (m_controlCache.ContainsKey(control)) 47 return m_controlCache[control]; 48 else 49 return false; 50 } 51 52 /// <summary> 53 /// Sets the show shadow. 54 /// </summary> 55 /// <param name="control">The control.</param> 56 /// <param name="isShowShadow">if set to <c>true</c> [is show shadow].</param> 57 public void SetShowShadow(Control control, bool isShowShadow) 58 { 59 control.ParentChanged += control_ParentChanged; 60 m_controlCache[control] = isShowShadow; 61 } 62 63 /// <summary> 64 /// Handles the ParentChanged event of the control control. 65 /// </summary> 66 /// <param name="sender">The source of the event.</param> 67 /// <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param> 68 void control_ParentChanged(object sender, EventArgs e) 69 { 70 Control control = sender as Control; 71 if (control.Parent != null && m_controlCache[control]) 72 { 73 if (!lstPaintEventControl.Contains(control.Parent)) 74 { 75 lstPaintEventControl.Add(control.Parent); 76 Type type = control.Parent.GetType(); 77 System.Reflection.PropertyInfo pi = type.GetProperty("DoubleBuffered", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic); 78 pi.SetValue(control.Parent, true, null); 79 control.Parent.Paint += Parent_Paint; 80 } 81 } 82 } 83 84 /// <summary> 85 /// The LST paint event control 86 /// </summary> 87 List<Control> lstPaintEventControl = new List<Control>(); 88 /// <summary> 89 /// The shadow height 90 /// </summary> 91 private float shadowHeight = 0.3f; 92 93 /// <summary> 94 /// Gets or sets the height of the shadow. 95 /// </summary> 96 /// <value>The height of the shadow.</value> 97 [Browsable(true), Category("自定義屬性"), Description("倒影高度，0-1"), Localizable(true)] 98 public float ShadowHeight 99 {100 get { return shadowHeight; }101 set { shadowHeight = value; }102 }103 /// <summary>104 /// The BLN loading105 /// </summary>106 bool blnLoading = false;107 /// <summary>108 /// Handles the Paint event of the Parent control.109 /// </summary>110 /// <param name="sender">The source of the event.</param>111 /// <param name="e">The <see cref="PaintEventArgs"/> instance containing the event data.</param>112 void Parent_Paint(object sender, PaintEventArgs e)113 {114 if (blnLoading)115 return; 116 if (shadowHeight > 0)117 {118 var control = sender as Control;119 var lst = m_controlCache.Where(p => p.Key.Parent == control && p.Value);120 if (lst != null && lst.Count() > 0)121 {122 blnLoading = true;123 e.Graphics.SetGDIHigh();124 foreach (var item in lst)125 {126 Control _control = item.Key;127 128 using (Bitmap bit = new Bitmap(_control.Width, _control.Height))129 {130 _control.DrawToBitmap(bit, _control.ClientRectangle);131 using (Bitmap bitNew = new Bitmap(bit.Width, (int)(bit.Height * shadowHeight)))132 {133 using (var g = Graphics.FromImage(bitNew))134 {135 g.DrawImage(bit, new RectangleF(0, 0, bitNew.Width, bitNew.Height), new RectangleF(0, bit.Height - bit.Height * shadowHeight, bit.Width, bit.Height * shadowHeight), GraphicsUnit.Pixel);136 }137 bitNew.RotateFlip(RotateFlipType.Rotate180FlipNone);138 e.Graphics.DrawImage(bitNew, new Point(_control.Location.X, _control.Location.Y + _control.Height + 1));139 Color bgColor = GetParentColor(_control);140 LinearGradientBrush lgb = new LinearGradientBrush(new Rectangle(_control.Location.X, _control.Location.Y + _control.Height + 1, bitNew.Width, bitNew.Height), Color.FromArgb(50, bgColor), bgColor, 90f); //75f 表示角度141 e.Graphics.FillRectangle(lgb, new Rectangle(new Point(_control.Location.X, _control.Location.Y + _control.Height + 1), bitNew.Size));142 }143 }144 }145 }146 }147 blnLoading = false;148 }149 150 /// <summary>151 /// Gets the color of the parent.152 /// </summary>153 /// <param name="c">The c.</param>154 /// <returns>Color.</returns>155 private Color GetParentColor(Control c)156 {157 if (c.Parent.BackColor != Color.Transparent)158 {159 return c.Parent.BackColor;160 }161 return GetParentColor(c.Parent);162 }
最后的話
如果你喜歡的話，請到 https://gitee.com/kwwwvagaa/net_winform_custom_control 點個星星吧
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標籤：WinForm