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項，於是就有了本系列文章。開源地址：https://gitee.com/kwwwvagaa/net_winform_custom_control 如果覺得寫的還行，請點個 star 支持一下吧歡迎前來交流探討：企鵝群568015492 目錄 ...
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項，於是就有了本系列文章。
開源地址：https://gitee.com/kwwwvagaa/net_winform_custom_control
如果覺得寫的還行，請點個 star 支持一下吧
歡迎前來交流探討：企鵝群568015492
準備工作

終於到文本框了，文本框將包含原文本框擴展，透明文本框，數字輸入文本框，帶邊框文本框
本文將講解透明文本框
開始

這個用到的很少，直接看代碼吧
  1 // 版權所有  黃正輝  交流群：568015492   QQ：623128629
  2 // 文件名稱：TextBoxTransparent.cs
  3 // 創建日期：2019-08-15 16:03:49
  4 // 功能描述：TextBox
  5 // 項目地址：https://gitee.com/kwwwvagaa/net_winform_custom_control
  6 using System;
  7 using System.Collections;
  8 using System.ComponentModel;
  9 using System.Drawing;
 10 using System.Data;
 11 using System.Windows.Forms;
 12 
 13 using System.Drawing.Imaging;
 14 
 15 namespace HZH_Controls.Controls
 16 {
 17     public class TextBoxTransparent : TextBoxEx
 18     {
 19         #region private variables
 20 
 21         private uPictureBox myPictureBox;
 22         private bool myUpToDate = false;
 23         private bool myCaretUpToDate = false;
 24         private Bitmap myBitmap;
 25         private Bitmap myAlphaBitmap;
 26 
 27         private int myFontHeight = 10;
 28 
 29         private System.Windows.Forms.Timer myTimer1;
 30 
 31         private bool myCaretState = true;
 32 
 33         private bool myPaintedFirstTime = false;
 34 
 35         private Color myBackColor = Color.White;
 36         private int myBackAlpha = 10;
 37 
 38         /// <summary> 
 39         /// Required designer variable.
 40         /// </summary>
 41         private System.ComponentModel.Container components = null;
 42 
 43         #endregion // end private variables
 44 
 45 
 46         #region public methods and overrides
 47 
 48         public TextBoxTransparent()
 49         {
 50             // This call is required by the Windows.Forms Form Designer.
 51             InitializeComponent();
 52             // TODO: Add any initialization after the InitializeComponent call
 53 
 54             this.BackColor = myBackColor;
 55 
 56             this.SetStyle(ControlStyles.UserPaint, false);
 57             this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
 58             this.SetStyle(ControlStyles.DoubleBuffer, true);
 59 
 60 
 61             myPictureBox = new uPictureBox();
 62             this.Controls.Add(myPictureBox);
 63             myPictureBox.Dock = DockStyle.Fill;
 64         }
 65 
 66 
 67         protected override void OnResize(EventArgs e)
 68         {
 69 
 70             base.OnResize(e);
 71             this.myBitmap = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);//(this.Width,this.Height);
 72             this.myAlphaBitmap = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);//(this.Width,this.Height);
 73             myUpToDate = false;
 74             this.Invalidate();
 75         }
 76 
 77 
 78         //Some of these should be moved to the WndProc later
 79 
 80         protected override void OnKeyDown(KeyEventArgs e)
 81         {
 82             base.OnKeyDown(e);
 83             myUpToDate = false;
 84             this.Invalidate();
 85         }
 86 
 87         protected override void OnKeyUp(KeyEventArgs e)
 88         {
 89             base.OnKeyUp(e);
 90             myUpToDate = false;
 91             this.Invalidate();
 92 
 93         }
 94 
 95         protected override void OnKeyPress(KeyPressEventArgs e)
 96         {
 97             base.OnKeyPress(e);
 98             myUpToDate = false;
 99             this.Invalidate();
100         }
101 
102         protected override void OnMouseUp(MouseEventArgs e)
103         {
104             base.OnMouseUp(e);
105             this.Invalidate();
106         }
107 
108         protected override void OnGiveFeedback(GiveFeedbackEventArgs gfbevent)
109         {
110             base.OnGiveFeedback(gfbevent);
111             myUpToDate = false;
112             this.Invalidate();
113         }
114 
115 
116         protected override void OnMouseLeave(EventArgs e)
117         {
118             //found this code to find the current cursor location
119             //at http://www.syncfusion.com/FAQ/WinForms/FAQ_c50c.asp#q597q
120 
121             Point ptCursor = Cursor.Position;
122 
123             Form f = this.FindForm();
124             ptCursor = f.PointToClient(ptCursor);
125             if (!this.Bounds.Contains(ptCursor))
126                 base.OnMouseLeave(e);
127         }
128 
129 
130         protected override void OnChangeUICues(UICuesEventArgs e)
131         {
132             base.OnChangeUICues(e);
133             myUpToDate = false;
134             this.Invalidate();
135         }
136 
137 
138         //--
139         protected override void OnGotFocus(EventArgs e)
140         {
141             base.OnGotFocus(e);
142             myCaretUpToDate = false;
143             myUpToDate = false;
144             this.Invalidate();
145 
146 
147             myTimer1 = new System.Windows.Forms.Timer(this.components);
148             myTimer1.Interval = (int)win32.GetCaretBlinkTime(); //  usually around 500;
149 
150             myTimer1.Tick += new EventHandler(myTimer1_Tick);
151             myTimer1.Enabled = true;
152 
153         }
154 
155         protected override void OnLostFocus(EventArgs e)
156         {
157             base.OnLostFocus(e);
158             myCaretUpToDate = false;
159             myUpToDate = false;
160             this.Invalidate();
161 
162             myTimer1.Dispose();
163         }
164 
165         //--        
166 
167         protected override void OnFontChanged(EventArgs e)
168         {
169             if (this.myPaintedFirstTime)
170                 this.SetStyle(ControlStyles.UserPaint, false);
171 
172             base.OnFontChanged(e);
173 
174             if (this.myPaintedFirstTime)
175                 this.SetStyle(ControlStyles.UserPaint, true);
176 
177 
178             myFontHeight = GetFontHeight();
179 
180 
181             myUpToDate = false;
182             this.Invalidate();
183         }
184 
185         protected override void OnTextChanged(EventArgs e)
186         {
187             base.OnTextChanged(e);
188             myUpToDate = false;
189             this.Invalidate();
190         }
191 
192 
193         protected override void WndProc(ref Message m)
194         {
195 
196             base.WndProc(ref m);
197 
198             // need to rewrite as a big switch
199 
200             if (m.Msg == win32.WM_PAINT)
201             {
202 
203                 myPaintedFirstTime = true;
204 
205                 if (!myUpToDate || !myCaretUpToDate)
206                     GetBitmaps();
207                 myUpToDate = true;
208                 myCaretUpToDate = true;
209 
210                 if (myPictureBox.Image != null) myPictureBox.Image.Dispose();
211 
212 
213                 if (string.IsNullOrEmpty(this.Text) && !string.IsNullOrEmpty(this.PromptText))
214                 {
215                     Bitmap bit = (Bitmap)myAlphaBitmap.Clone();
216                     Graphics g = Graphics.FromImage(bit);
217                     SizeF sizet1 = g.MeasureString(this.PromptText, this.PromptFont);
218                     g.DrawString(this.PromptText, this.PromptFont, new SolidBrush(PromptColor), new PointF(3, (bit.Height - sizet1.Height) / 2));
219                     g.Dispose();
220                     myPictureBox.Image = bit;
221                 }
222                 else
223                 {
224                     myPictureBox.Image = (Image)myAlphaBitmap.Clone();
225                 }
226             }
227 
228             else if (m.Msg == win32.WM_HSCROLL || m.Msg == win32.WM_VSCROLL)
229             {
230                 myUpToDate = false;
231                 this.Invalidate();
232             }
233 
234             else if (m.Msg == win32.WM_LBUTTONDOWN
235                 || m.Msg == win32.WM_RBUTTONDOWN
236                 || m.Msg == win32.WM_LBUTTONDBLCLK
237                 //  || m.Msg == win32.WM_MOUSELEAVE  ///****
238                 )
239             {
240                 myUpToDate = false;
241                 this.Invalidate();
242             }
243 
244             else if (m.Msg == win32.WM_MOUSEMOVE)
245             {
246                 if (m.WParam.ToInt32() != 0)  //shift key or other buttons
247                 {
248                     myUpToDate = false;
249                     this.Invalidate();
250                 }
251             }
252 
253             if (m.Msg == 15 || m.Msg == 7 || m.Msg == 8)
254             {
255                 base.OnPaint(null);
256             }
257 
258             //System.Diagnostics.Debug.WriteLine("Pro: " + m.Msg.ToString("X"));
259 
260         }
261 
262 
263         /// <summary> 
264         /// Clean up any resources being used.
265         /// </summary>
266         protected override void Dispose(bool disposing)
267         {
268             if (disposing)
269             {
270                 //this.BackColor = Color.Pink;
271                 if (components != null)
272                 {
273                     components.Dispose();
274                 }
275             }
276             base.Dispose(disposing);
277         }
278 
279         #endregion        //end public method and overrides
280 
281 
282         #region public property overrides
283 
284         public new BorderStyle BorderStyle
285         {
286             get { return base.BorderStyle; }
287             set
288             {
289                 if (this.myPaintedFirstTime)
290                     this.SetStyle(ControlStyles.UserPaint, false);
291 
292                 base.BorderStyle = value;
293 
294                 if (this.myPaintedFirstTime)
295                     this.SetStyle(ControlStyles.UserPaint, true);
296 
297                 this.myBitmap = null;
298                 this.myAlphaBitmap = null;
299                 myUpToDate = false;
300                 this.Invalidate();
301             }
302         }
303 
304         public new Color BackColor
305         {
306             get
307             {
308                 return Color.FromArgb(base.BackColor.R, base.BackColor.G, base.BackColor.B);
309             }
310             set
311             {
312                 myBackColor = value;
313                 base.BackColor = value;
314                 myUpToDate = false;
315             }
316         }
317         public override bool Multiline
318         {
319             get { return base.Multiline; }
320             set
321             {
322                 if (this.myPaintedFirstTime)
323                     this.SetStyle(ControlStyles.UserPaint, false);
324 
325                 base.Multiline = value;
326 
327                 if (this.myPaintedFirstTime)
328                     this.SetStyle(ControlStyles.UserPaint, true);
329 
330                 this.myBitmap = null;
331                 this.myAlphaBitmap = null;
332                 myUpToDate = false;
333                 this.Invalidate();
334             }
335         }
336 
337 
338         #endregion    //end public property overrides
339 
340 
341         #region private functions and classes
342 
343         private int GetFontHeight()
344         {
345             Graphics g = this.CreateGraphics();
346             SizeF sf_font = g.MeasureString("X", this.Font);
347             g.Dispose();
348             return (int)sf_font.Height;
349         }
350 
351 
352         private void GetBitmaps()
353         {
354 
355             if (myBitmap == null
356                 || myAlphaBitmap == null
357                 || myBitmap.Width != Width
358                 || myBitmap.Height != Height
359                 || myAlphaBitmap.Width != Width
360                 || myAlphaBitmap.Height != Height)
361             {
362                 myBitmap = null;
363                 myAlphaBitmap = null;
364             }
365 
366 
367 
368             if (myBitmap == null)
369             {
370                 myBitmap = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);//(Width,Height);
371                 myUpToDate = false;
372             }
373 
374 
375             if (!myUpToDate)
376             {
377                 //Capture the TextBox control window
378 
379                 this.SetStyle(ControlStyles.UserPaint, false);
380 
381                 win32.CaptureWindow(this, ref myBitmap);
382 
383                 this.SetStyle(ControlStyles.UserPaint, true);
384                 this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
385                 this.BackColor = Color.FromArgb(myBackAlpha, myBackColor);
386 
387             }
388             //--
389 
390 
391 
392             Rectangle r2 = new Rectangle(0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height);
393             ImageAttributes tempImageAttr = new ImageAttributes();
394 
395 
396             //Found the color map code in the MS Help
397 
398             ColorMap[] tempColorMap = new ColorMap[1];
399             tempColorMap[0] = new ColorMap();
400             tempColorMap[0].OldColor = Color.FromArgb(255, myBackColor);
401             tempColorMap[0].NewColor = Color.FromArgb(myBackAlpha, myBackColor);
402 
403             tempImageAttr.SetRemapTable(tempColorMap);
404 
405             if (myAlphaBitmap != null)
406                 myAlphaBitmap.Dispose();
407 
408 
409             myAlphaBitmap = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);//(Width,Height);
410 
411             Graphics tempGraphics1 = Graphics.FromImage(myAlphaBitmap);
412 
413             tempGraphics1.DrawImage(myBitmap, r2, 0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height, GraphicsUnit.Pixel, tempImageAttr);
414 
415             tempGraphics1.Dispose();
416 
417             //----
418 
419             if (this.Focused && (this.SelectionLength == 0))
420             {
421                 Graphics tempGraphics2 = Graphics.FromImage(myAlphaBitmap);
422                 if (myCaretState)
423                 {
424                     //Draw the caret
425                     Point caret = this.findCaret();
426                     Pen p = new Pen(this.ForeColor, 3);
427                     tempGraphics2.DrawLine(p, caret.X + 2, caret.Y + 0, caret.X + 2, caret.Y + myFontHeight);
428                     tempGraphics2.Dispose();
429                 }
430 
431             }
432 
433 
434 
435         }
436 
437 
438 
439         private Point findCaret()
440         {
441             /*  Find the caret translated from code at 
442              * http://www.vb-helper.com/howto_track_textbox_caret.html
443              * 
444              * and 
445              * 
446              * http://www.microbion.co.uk/developers/csharp/textpos2.htm
447              * 
448              * Changed to EM_POSFROMCHAR
449              * 
450              * This code still needs to be cleaned up and debugged
451              * */
452 
453             Point pointCaret = new Point(0);
454             int i_char_loc = this.SelectionStart;
455             IntPtr pi_char_loc = new IntPtr(i_char_loc);
456 
457             int i_point = win32.SendMessage(this.Handle, win32.EM_POSFROMCHAR, pi_char_loc, IntPtr.Zero);
458             pointCaret = new Point(i_point);
459 
460             if (i_char_loc == 0)
461             {
462                 pointCaret = new Point(0);
463             }
464             else if (i_char_loc >= this.Text.Length)
465             {
466                 pi_char_loc = new IntPtr(i_char_loc - 1);
467                 i_point = win32.SendMessage(this.Handle, win32.EM_POSFROMCHAR, pi_char_loc, IntPtr.Zero);
468                 pointCaret = new Point(i_point);
469 
470                 Graphics g = this.CreateGraphics();
471                 String t1 = this.Text.Substring(this.Text.Length - 1, 1) + "X";
472                 SizeF sizet1 = g.MeasureString(t1, this.Font);
473                 SizeF sizex = g.MeasureString("X", this.Font);
474                 g.Dispose();
475                 int xoffset = (int)(sizet1.Width - sizex.Width);
476                 pointCaret.X = pointCaret.X + xoffset;
477 
478                 if (i_char_loc == this.Text.Length)
479                 {
480                     String slast = this.Text.Substring(Text.Length - 1, 1);
481                     if (slast == "\n")
482                     {
483                         pointCaret.X = 1;
484                         pointCaret.Y = pointCaret.Y + myFontHeight;
485                     }
486                 }
487 
488             }
489 
490 
491 
492             return pointCaret;
493         }
494 
495 
496         private void myTimer1_Tick(
（二十九）c#Winform自定義控制項-文本框（二）

前提

目錄

準備工作

開始
