• C#透明TextBox


    1  using System;
      2  using System.Collections;
      3  using System.ComponentModel;
      4  using System.Drawing;
      5  using System.Data;
      6  using System.Windows.Forms;
      7  
      8  using System.Drawing.Imaging;
      9  
     10  namespace ZBobb
     11  {
     12      /// <summary>
     13      /// AlphaBlendTextBox: A .Net textbox that can be translucent to the background.
     14      /// (C) 2003 Bob Bradley / ZBobb@hotmail.com
     15      /// </summary>
     16      /// 
     17  
     18  
     19  
     20      public class AlphaBlendTextBox : System.Windows.Forms.TextBox
     21      {
     22          #region private variables
     23  
     24          private uPictureBox myPictureBox;
     25          private  bool   myUpToDate = false;
     26          private  bool   myCaretUpToDate = false;
     27          private  Bitmap myBitmap;
     28          private  Bitmap myAlphaBitmap;
     29  
     30          private int myFontHeight = 10;
     31  
     32          private System.Windows.Forms.Timer myTimer1;
     33  
     34          private bool myCaretState = true;
     35  
     36          private bool myPaintedFirstTime = false;
     37  
     38          private Color myBackColor = Color.White;
     39          private int myBackAlpha = 10;       
     40          
     41          /// <summary> 
     42          /// Required designer variable.
     43          /// </summary>
     44          private System.ComponentModel.Container components = null;
     45  
     46          #endregion // end private variables
     47  
     48  
     49          #region public methods and overrides
     50  
     51          public AlphaBlendTextBox()
     52          {
     53              // This call is required by the Windows.Forms Form Designer.
     54              InitializeComponent();
     55              // TODO: Add any initialization after the InitializeComponent call
     56  
     57              this.BackColor = myBackColor; 
     58  
     59              this.SetStyle(ControlStyles.UserPaint,false);
     60              this.SetStyle(ControlStyles.AllPaintingInWmPaint,true);
     61              this.SetStyle(ControlStyles.DoubleBuffer,true);
     62  
     63  
     64              myPictureBox = new uPictureBox();
     65              this.Controls.Add(myPictureBox);
     66              myPictureBox.Dock = DockStyle.Fill;
     67          }
     68  
     69  
     70          protected override void OnResize(EventArgs e)
     71          {
     72              
     73              base.OnResize (e);
     74              this.myBitmap = new Bitmap(this.ClientRectangle.Width,this.ClientRectangle.Height);//(this.Width,this.Height);
     75              this.myAlphaBitmap = new Bitmap(this.ClientRectangle.Width,this.ClientRectangle.Height);//(this.Width,this.Height);
     76              myUpToDate = false;
     77              this.Invalidate();
     78          }
     79  
     80  
     81          //Some of these should be moved to the WndProc later
     82  
     83          protected override void OnKeyDown(KeyEventArgs e)
     84          {
     85              base.OnKeyDown (e);
     86              myUpToDate = false;
     87              this.Invalidate();
     88          }
     89  
     90          protected override void OnKeyUp(KeyEventArgs e)
     91          {
     92              base.OnKeyUp (e);
     93              myUpToDate = false;
     94              this.Invalidate();
     95  
     96          }
     97  
     98          protected override void OnKeyPress(KeyPressEventArgs e)
     99          {
    100              base.OnKeyPress (e);
    101              myUpToDate = false;
    102              this.Invalidate();
    103          }
    104  
    105          protected override void OnMouseUp(MouseEventArgs e)
    106          {
    107              base.OnMouseUp (e);
    108              this.Invalidate();
    109          }
    110  
    111          protected override void OnGiveFeedback(GiveFeedbackEventArgs gfbevent)
    112          {
    113              base.OnGiveFeedback (gfbevent);
    114              myUpToDate = false;
    115              this.Invalidate();
    116          }
    117  
    118  
    119          protected override void OnMouseLeave(EventArgs e)
    120          {
    121              //found this code to find the current cursor location
    122              //at http://www.syncfusion.com/FAQ/WinForms/FAQ_c50c.asp#q597q
    123  
    124              Point ptCursor = Cursor.Position; 
    125              
    126              Form f = this.FindForm();
    127              ptCursor = f.PointToClient(ptCursor); 
    128              if( !this.Bounds.Contains(ptCursor) )  
    129                  base.OnMouseLeave (e);
    130          }       
    131          
    132                      
    133          protected override void OnChangeUICues(UICuesEventArgs e)
    134          {
    135              base.OnChangeUICues (e);
    136              myUpToDate = false;
    137              this.Invalidate();
    138          }
    139          
    140          
    141  //--
    142          protected override void OnGotFocus(EventArgs e)
    143          {
    144              base.OnGotFocus (e);
    145              myCaretUpToDate = false;
    146              myUpToDate = false;
    147              this.Invalidate();
    148              
    149  
    150              myTimer1 = new System.Windows.Forms.Timer(this.components);
    151              myTimer1.Interval = (int) win32.GetCaretBlinkTime(); //  usually around 500;
    152              
    153              myTimer1.Tick +=new EventHandler(myTimer1_Tick);
    154              myTimer1.Enabled = true;
    155                  
    156          }
    157  
    158          protected override void OnLostFocus(EventArgs e)
    159          {
    160              base.OnLostFocus (e);
    161              myCaretUpToDate = false;
    162              myUpToDate = false;
    163              this.Invalidate();
    164  
    165              myTimer1.Dispose();
    166          }
    167  
    168  //--        
    169  
    170          protected override void OnFontChanged(EventArgs e)
    171          {
    172              if (this.myPaintedFirstTime)
    173                  this.SetStyle(ControlStyles.UserPaint,false);
    174  
    175              base.OnFontChanged (e);
    176  
    177              if (this.myPaintedFirstTime)
    178                  this.SetStyle(ControlStyles.UserPaint,true);
    179  
    180                  
    181              myFontHeight = GetFontHeight();
    182  
    183  
    184              myUpToDate = false;
    185              this.Invalidate();
    186          }
    187  
    188          protected override void OnTextChanged(EventArgs e)
    189          {
    190              base.OnTextChanged (e);
    191              myUpToDate = false;
    192              this.Invalidate();
    193          }
    194  
    195          
    196          protected override void WndProc(ref Message m)
    197          {
    198  
    199              base.WndProc (ref m);
    200  
    201              // need to rewrite as a big switch
    202  
    203              if (m.Msg == win32.WM_PAINT)
    204              {
    205                  myPaintedFirstTime = true;
    206  
    207                  if (!myUpToDate || !myCaretUpToDate)
    208                      GetBitmaps();
    209                  myUpToDate = true;
    210                  myCaretUpToDate = true;
    211  
    212                  if (myPictureBox.Image != null) myPictureBox.Image.Dispose();
    213                  myPictureBox.Image = (Image)myAlphaBitmap.Clone();
    214  
    215              }
    216  
    217              else if (m.Msg ==  win32.WM_HSCROLL || m.Msg == win32.WM_VSCROLL)
    218              {
    219                  myUpToDate = false;
    220                  this.Invalidate();          
    221              }
    222  
    223              else if (m.Msg == win32.WM_LBUTTONDOWN 
    224                  || m.Msg == win32.WM_RBUTTONDOWN
    225                  || m.Msg == win32.WM_LBUTTONDBLCLK
    226                  //  || m.Msg == win32.WM_MOUSELEAVE  ///****
    227                  )
    228              {
    229                  myUpToDate = false;
    230                  this.Invalidate();          
    231              }
    232  
    233              else if (m.Msg == win32.WM_MOUSEMOVE )
    234              {
    235                  if (m.WParam.ToInt32() != 0)  //shift key or other buttons
    236                  {
    237                      myUpToDate = false;
    238                      this.Invalidate();          
    239                  }
    240              }
    241  
    242  
    243          
    244              //System.Diagnostics.Debug.WriteLine("Pro: " + m.Msg.ToString("X"));
    245  
    246          }
    247  
    248  
    249          /// <summary> 
    250          /// Clean up any resources being used.
    251          /// </summary>
    252          protected override void Dispose( bool disposing )
    253          {
    254              if( disposing )
    255              {
    256                  //this.BackColor = Color.Pink;
    257                  if(components != null)
    258                  {
    259                      components.Dispose();
    260                  }
    261              }
    262              base.Dispose( disposing );
    263          }
    264  
    265          #endregion      //end public method and overrides
    266  
    267  
    268          #region public property overrides
    269  
    270          public new BorderStyle BorderStyle
    271          {
    272              get {return base.BorderStyle;}
    273              set 
    274              {
    275                  if (this.myPaintedFirstTime)
    276                      this.SetStyle(ControlStyles.UserPaint,false);
    277  
    278                  base.BorderStyle = value;
    279                  
    280                  if (this.myPaintedFirstTime)
    281                      this.SetStyle(ControlStyles.UserPaint,true);
    282  
    283                  this.myBitmap = null;
    284                  this.myAlphaBitmap = null;
    285                  myUpToDate = false;
    286                  this.Invalidate();
    287              }
    288          }
    289  
    290          public  new Color BackColor
    291          {
    292              get
    293              {
    294                  return Color.FromArgb(base.BackColor.R, base.BackColor.G, base.BackColor.B);
    295              }
    296              set
    297              {
    298                  myBackColor = value;
    299                  base.BackColor = value;
    300                  myUpToDate = false;
    301              }
    302          }
    303          public override bool Multiline
    304          {
    305              get{return base.Multiline;}
    306              set
    307              {
    308                  if (this.myPaintedFirstTime)
    309                      this.SetStyle(ControlStyles.UserPaint,false);
    310                  
    311                  base.Multiline = value;
    312  
    313                  if (this.myPaintedFirstTime)
    314                      this.SetStyle(ControlStyles.UserPaint,true);
    315  
    316                  this.myBitmap = null;
    317                  this.myAlphaBitmap = null;
    318                  myUpToDate = false;
    319                  this.Invalidate();
    320              }
    321          }
    322  
    323          
    324          #endregion    //end public property overrides
    325  
    326  
    327          #region private functions and classes
    328  
    329          private int GetFontHeight()
    330          {
    331              Graphics g = this.CreateGraphics();
    332              SizeF sf_font = g.MeasureString("X",this.Font);
    333              g.Dispose();
    334              return  (int) sf_font.Height;
    335          }
    336          
    337          
    338          private void GetBitmaps()
    339          {
    340  
    341              if (myBitmap == null
    342                  || myAlphaBitmap == null
    343                  || myBitmap.Width != Width 
    344                  || myBitmap.Height != Height        
    345                  || myAlphaBitmap.Width != Width 
    346                  || myAlphaBitmap.Height != Height)
    347              {
    348                  myBitmap = null;
    349                  myAlphaBitmap = null;
    350              }
    351  
    352  
    353  
    354          if (myBitmap == null)
    355              {
    356                  myBitmap = new Bitmap(this.ClientRectangle.Width,this.ClientRectangle.Height);//(Width,Height);
    357                  myUpToDate = false;
    358              }
    359  
    360  
    361              if (!myUpToDate)
    362              {
    363                  //Capture the TextBox control window
    364  
    365                  this.SetStyle(ControlStyles.UserPaint,false);
    366                  
    367                  win32.CaptureWindow(this,ref myBitmap);
    368  
    369                  this.SetStyle(ControlStyles.UserPaint,true);
    370                  this.SetStyle(ControlStyles.SupportsTransparentBackColor,true);
    371                  this.BackColor = Color.FromArgb(myBackAlpha,myBackColor);
    372  
    373              }
    374              //--
    375              
    376  
    377          
    378              Rectangle r2 = new Rectangle(0,0,this.ClientRectangle.Width,this.ClientRectangle.Height);
    379              ImageAttributes tempImageAttr = new ImageAttributes();
    380                          
    381  
    382              //Found the color map code in the MS Help
    383  
    384              ColorMap[] tempColorMap = new ColorMap[1];
    385              tempColorMap[0] = new ColorMap();
    386              tempColorMap[0].OldColor = Color.FromArgb(255,myBackColor); 
    387              tempColorMap[0].NewColor = Color.FromArgb(myBackAlpha,myBackColor);
    388  
    389              tempImageAttr.SetRemapTable(tempColorMap);
    390  
    391              if (myAlphaBitmap != null)
    392                  myAlphaBitmap.Dispose();
    393                      
    394                      
    395              myAlphaBitmap = new Bitmap(this.ClientRectangle.Width,this.ClientRectangle.Height);//(Width,Height);
    396  
    397              Graphics tempGraphics1 = Graphics.FromImage(myAlphaBitmap);
    398  
    399              tempGraphics1.DrawImage(myBitmap,r2,0,0,this.ClientRectangle.Width,this.ClientRectangle.Height,GraphicsUnit.Pixel,tempImageAttr);
    400  
    401              tempGraphics1.Dispose();
    402              
    403  //----
    404  
    405              if (this.Focused && (this.SelectionLength == 0))
    406              {
    407                  Graphics tempGraphics2 = Graphics.FromImage(myAlphaBitmap);
    408                  if (myCaretState)
    409                  {
    410                      //Draw the caret
    411                      Point caret = this.findCaret();
    412                      Pen p = new Pen(this.ForeColor,3);
    413                      tempGraphics2.DrawLine(p,caret.X,caret.Y + 0,caret.X,caret.Y + myFontHeight);
    414                      tempGraphics2.Dispose();
    415                  }
    416                          
    417              }
    418  
    419  
    420  
    421          }
    422  
    423  
    424  
    425          private Point findCaret() 
    426          {
    427              /*  Find the caret translated from code at 
    428               * http://www.vb-helper.com/howto_track_textbox_caret.html
    429               * 
    430               * and 
    431               * 
    432               * http://www.microbion.co.uk/developers/csharp/textpos2.htm
    433               * 
    434               * Changed to EM_POSFROMCHAR
    435               * 
    436               * This code still needs to be cleaned up and debugged
    437               * */
    438  
    439              Point pointCaret = new Point(0);
    440              int i_char_loc = this.SelectionStart;
    441              IntPtr pi_char_loc = new IntPtr(i_char_loc);
    442  
    443              int i_point = win32.SendMessage(this.Handle,win32.EM_POSFROMCHAR,pi_char_loc,IntPtr.Zero);
    444              pointCaret = new Point(i_point);
    445  
    446              if (i_char_loc == 0) 
    447              {
    448                  pointCaret = new Point(0);
    449              }
    450              else if (i_char_loc >= this.Text.Length)
    451              {
    452                  pi_char_loc = new IntPtr(i_char_loc - 1);
    453                  i_point = win32.SendMessage(this.Handle,win32.EM_POSFROMCHAR,pi_char_loc,IntPtr.Zero);
    454                  pointCaret = new Point(i_point);
    455  
    456                  Graphics g = this.CreateGraphics();
    457                  String t1 = this.Text.Substring(this.Text.Length-1,1) + "X";
    458                  SizeF sizet1 = g.MeasureString(t1,this.Font);
    459                  SizeF sizex  = g.MeasureString("X",this.Font);
    460                  g.Dispose();
    461                  int xoffset = (int)(sizet1.Width - sizex.Width);
    462                  pointCaret.X = pointCaret.X + xoffset;
    463  
    464                  if (i_char_loc == this.Text.Length)
    465                  {
    466                      String slast = this.Text.Substring(Text.Length-1,1);
    467                      if (slast == "
    ")
    468                      {
    469                          pointCaret.X = 1;
    470                          pointCaret.Y = pointCaret.Y + myFontHeight;
    471                      }
    472                  }
    473  
    474              }
    475  
    476  
    477  
    478              return pointCaret;
    479          }
    480  
    481  
    482          private void myTimer1_Tick(object sender, EventArgs e)
    483          {
    484              //Timer used to turn caret on and off for focused control
    485  
    486              myCaretState = !myCaretState;
    487              myCaretUpToDate = false;
    488              this.Invalidate();
    489          }
    490  
    491  
    492          private class uPictureBox : PictureBox 
    493          {
    494              public uPictureBox() 
    495              {
    496                  this.SetStyle(ControlStyles.Selectable,false);
    497                  this.SetStyle(ControlStyles.UserPaint,true);
    498                  this.SetStyle(ControlStyles.AllPaintingInWmPaint,true);
    499                  this.SetStyle(ControlStyles.DoubleBuffer,true);
    500  
    501                  this.Cursor = null;
    502                  this.Enabled = true; 
    503                  this.SizeMode = PictureBoxSizeMode.Normal;
    504                  
    505              }
    506  
    507  
    508  
    509  
    510              //uPictureBox
    511              protected override void WndProc(ref Message m)
    512              {
    513                  if (m.Msg == win32.WM_LBUTTONDOWN 
    514                      || m.Msg == win32.WM_RBUTTONDOWN
    515                      || m.Msg == win32.WM_LBUTTONDBLCLK
    516                      || m.Msg == win32.WM_MOUSELEAVE
    517                      || m.Msg == win32.WM_MOUSEMOVE )
    518                  {
    519                      //Send the above messages back to the parent control
    520                      win32.PostMessage(this.Parent.Handle,(uint) m.Msg,m.WParam,m.LParam);
    521                  }
    522  
    523                  else if (m.Msg == win32.WM_LBUTTONUP)
    524                  {
    525                      //??  for selects and such
    526                      this.Parent.Invalidate();
    527                  }
    528  
    529  
    530                  base.WndProc (ref m);
    531              }
    532  
    533  
    534          }   // End uPictureBox Class
    535  
    536  
    537          #endregion  // end private functions and classes
    538  
    539  
    540          #region Component Designer generated code
    541          /// <summary> 
    542          /// Required method for Designer support - do not modify 
    543          /// the contents of this method with the code editor.
    544          /// </summary>
    545          private void InitializeComponent()
    546          {
    547              components = new System.ComponentModel.Container();
    548          }
    549          #endregion
    550  
    551  
    552          #region New Public Properties
    553  
    554          [
    555          Category("Appearance"),
    556          Description("The alpha value used to blend the control's background. Valid values are 0 through 255."),
    557          Browsable(true),
    558          DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)
    559  
    560          ]
    561          public int BackAlpha
    562          {
    563              get { return myBackAlpha; }
    564              set 
    565              {
    566                  int v = value;
    567                  if (v > 255)
    568                      v = 255;
    569                  myBackAlpha = v;
    570                  myUpToDate = false; 
    571                  Invalidate();
    572              }
    573          }
    574  
    575          #endregion
    576  
    577  
    578  
    579      }  // End AlphaTextBox Class
    580  
    581  
    582  }  // End namespace ZBobb
    583  
    584  
    585  //----
    586  
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  • 原文地址:https://www.cnblogs.com/blogpro/p/11463111.html
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