在網頁中通過div+css實現半透明效果不難，今天我們看看一種在winfrom中實現的方法：
效果圖如下，正常時：
顯示遮罩層時：
自定義遮罩層控件的源碼如下：
| 1 | using System; |
| 2 | using System.Drawing; |
| 3 | using System.Windows.Forms; |
| 4 | using System.ComponentModel; |
| 5 | |
| 6 | namespace MyOpaqueLayer |
| 7 | { |
| 8 | /// <summary> |
| 9 | /// 自定義控件:半透明控件 |
| 10 | /// </summary> |
| 11 | /* |
| 12 | * [ToolboxBitmap(typeof(MyOpaqueLayer))] |
| 13 | * 用於指定當把你做好的自定義控件添加到工具欄時，工具欄顯示的圖標。 |
| 14 | * 正確寫法應該是 |
| 15 | * [ToolboxBitmap(typeof(XXXXControl),"xxx.bmp")] |
| 16 | * 其中XXXXControl是你的自定義控件，"xxx.bmp"是你要用的圖標名稱。 |
| 17 | */ |
| 18 | [ToolboxBitmap(typeof(MyOpaqueLayer))] |
| 19 | public class MyOpaqueLayer : System.Windows.Forms.Control |
| 20 | { |
| 21 | private bool _transparentBG = true;//是否使用透明 |
| 22 | private int _alpha = 125;//設置透明度 |
| 23 | |
| 24 | private System.ComponentModel.Container components = new System.ComponentModel.Container(); |
| 25 | |
| 26 | public MyOpaqueLayer() |
| 27 | : this(125, true) |
| 28 | { |
| 29 | } |
| 30 | |
| 31 | public MyOpaqueLayer(int Alpha, bool IsShowLoadingImage) |
| 32 | { |
| 33 | SetStyle(System.Windows.Forms.ControlStyles.Opaque, true); |
| 34 | base.CreateControl(); |
| 35 | |
| 36 | this._alpha = Alpha; |
| 37 | if (IsShowLoadingImage) |
| 38 | { |
| 39 | PictureBox pictureBox_Loading = new PictureBox(); |
| 40 | pictureBox_Loading.BackColor = System.Drawing.Color.White; |
| 41 | pictureBox_Loading.Image = 加載中.Properties.Resources.loading; |
| 42 | pictureBox_Loading.Name = "pictureBox_Loading"; |
| 43 | pictureBox_Loading.Size = new System.Drawing.Size(48, 48); |
| 44 | pictureBox_Loading.SizeMode = System.Windows.Forms.PictureBoxSizeMode.AutoSize; |
| 45 | Point Location = new Point(this.Location.X + (this.Width - pictureBox_Loading.Width) / 2, this.Location.Y + (this.Height - pictureBox_Loading.Height) / 2);//居中 |
| 46 | pictureBox_Loading.Location = Location; |
| 47 | pictureBox_Loading.Anchor = AnchorStyles.None; |
| 48 | this.Controls.Add(pictureBox_Loading); |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | |
| 53 | protected override void Dispose(bool disposing) |
| 54 | { |
| 55 | if (disposing) |
| 56 | { |
| 57 | if (!((components == null))) |
| 58 | { |
| 59 | components.Dispose(); |
| 60 | } |
| 61 | } |
| 62 | base.Dispose(disposing); |
| 63 | } |
| 64 | |
| 65 | /// <summary> |
| 66 | /// 自定義繪制窗體 |
| 67 | /// </summary> |
| 68 | /// <param name="e"></param> |
| 69 | protected override void OnPaint(System.Windows.Forms.PaintEventArgs e) |
| 70 | { |
| 71 | float vlblControlWidth; |
| 72 | float vlblControlHeight; |
| 73 | |
| 74 | Pen labelBorderPen; |
| 75 | SolidBrush labelBackColorBrush; |
| 76 | |
| 77 | if (_transparentBG) |
| 78 | { |
| 79 | Color drawColor = Color.FromArgb(this._alpha, this.BackColor); |
| 80 | labelBorderPen = new Pen(drawColor, 0); |
| 81 | labelBackColorBrush = new SolidBrush(drawColor); |
| 82 | } |
| 83 | else |
| 84 | { |
| 85 | labelBorderPen = new Pen(this.BackColor, 0); |
| 86 | labelBackColorBrush = new SolidBrush(this.BackColor); |
| 87 | } |
| 88 | base.OnPaint(e); |
| 89 | vlblControlWidth = this.Size.Width; |
| 90 | vlblControlHeight = this.Size.Height; |
| 91 | e.Graphics.DrawRectangle(labelBorderPen, 0, 0, vlblControlWidth, vlblControlHeight); |
| 92 | e.Graphics.FillRectangle(labelBackColorBrush, 0, 0, vlblControlWidth, vlblControlHeight); |
| 93 | } |
| 94 | |
| 95 | |
| 96 | protected override CreateParams CreateParams//v1.10 |
| 97 | { |
| 98 | get |
| 99 | { |
| 100 | CreateParams cp = base.CreateParams; |
| 101 | cp.ExStyle |= 0x00000020; //0x20; // 開啟 WS_EX_TRANSPARENT,使控件支持透明 |
| 102 | return cp; |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | /* |
| 107 | * [Category("myOpaqueLayer"), Description("是否使用透明,默認為True")] |
| 108 | * 一般用於說明你自定義控件的屬性（Property）。 |
| 109 | * Category用於說明該屬性屬於哪個分類，Description自然就是該屬性的含義解釋。 |
| 110 | */ |
| 111 | [Category("MyOpaqueLayer"), Description("是否使用透明,默認為True")] |
| 112 | public bool TransparentBG |
| 113 | { |
| 114 | get |
| 115 | { |
| 116 | return _transparentBG; |
| 117 | } |
| 118 | set |
| 119 | { |
| 120 | _transparentBG = value; |
| 121 | this.Invalidate(); |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | [Category("MyOpaqueLayer"), Description("設置透明度")] |
| 126 | public int Alpha |
| 127 | { |
| 128 | get |
| 129 | { |
| 130 | return _alpha; |
| 131 | } |
| 132 | set |
| 133 | { |
| 134 | _alpha = value; |
| 135 | this.Invalidate(); |
| 136 | } |
| 137 | } |
| 138 | } |
| 139 | } |
OpaqueCommand的方法：ShowOpaqueLayer(顯示遮罩層)和HideOpaqueLayer(隱藏遮罩層)
| 1 | using System; |
| 2 | using System.Windows.Forms; |
| 3 | |
| 4 | namespace 加載中 |
| 5 | { |
| 6 | class OpaqueCommand |
| 7 | { |
| 8 | private MyOpaqueLayer.MyOpaqueLayer m_OpaqueLayer = null;//半透明蒙板層 |
| 9 | |
| 10 | /// <summary> |
| 11 | /// 顯示遮罩層 |
| 12 | /// </summary> |
| 13 | /// <param name="control">控件</param> |
| 14 | /// <param name="alpha">透明度</param> |
| 15 | /// <param name="isShowLoadingImage">是否顯示圖標</param> |
| 16 | public void ShowOpaqueLayer(Control control, int alpha, bool isShowLoadingImage) |
| 17 | { |
| 18 | try |
| 19 | { |
| 20 | if (this.m_OpaqueLayer == null) |
| 21 | { |
| 22 | this.m_OpaqueLayer = new MyOpaqueLayer.MyOpaqueLayer(alpha, isShowLoadingImage); |
| 23 | control.Controls.Add(this.m_OpaqueLayer); |
| 24 | this.m_OpaqueLayer.Dock = DockStyle.Fill; |
| 25 | this.m_OpaqueLayer.BringToFront(); |
| 26 | } |
| 27 | this.m_OpaqueLayer.Enabled = true; |
| 28 | this.m_OpaqueLayer.Visible = true; |
| 29 | } |
| 30 | catch { } |
| 31 | } |
| 32 | |
| 33 | /// <summary> |
| 34 | /// 隱藏遮罩層 |
| 35 | /// </summary> |
| 36 | public void HideOpaqueLayer() |
| 37 | { |
| 38 | try |
| 39 | { |
| 40 | if (this.m_OpaqueLayer != null) |
| 41 | { |
| 42 | this.m_OpaqueLayer.Visible = false; |
| 43 | this.m_OpaqueLayer.Enabled = false; |
| 44 | } |
| 45 | } |
| 46 | catch(Exception ex) |
| 47 | { |
| 48 | //MessageBox.Show(ex.Message); |
| 49 | } |
| 50 | } |
| 51 | } |
| 52 | } |
自定義半透明遮罩層源碼下載：
files.cnblogs.com/JuneZhang/%E8%87%AA%E5%AE%9A%E4%B9%89%E5%8D%8A%E9%80%8F%E6%98%8E%E9%81%AE%E7%BD%A9%E5%B1%82-%E6%BA%90%E7%A0%81.rar