透明的textBox我看了网上的好几个的解决方案都是有问题，我把网上的几个解决方案都进行了验证，而且这些问题，我也没有想到解决方案，我发现了外国大神的一个解决方案，这个经过验证是可行的，希望对你们有所帮助。原文地址：https://www.codeproject.com/Articles/4390/AlphaBlendTextBox-A-transparent-translucent-textbo
using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
namespace ZBobb
{
/// <summary>
/// AlphaBlendTextBox: A .Net textbox that can be translucent to the background.
/// (C) 2003 Bob Bradley / [email protected]
/// </summary>
///
public class AlphaBlendTextBox : System.Windows.Forms.TextBox
{
#region private variables
private uPictureBox myPictureBox;
private bool myUpToDate = false;
private bool myCaretUpToDate = false;
private Bitmap myBitmap;
private Bitmap myAlphaBitmap;
private int myFontHeight = 10;
private System.Windows.Forms.Timer myTimer1;
private bool myCaretState = true;
private bool myPaintedFirstTime = false;
private Color myBackColor = Color.White;
private int myBackAlpha = 10;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
#endregion // end private variables
#region public methods and overrides
public AlphaBlendTextBox()
{
// This call is required by the Windows.Forms Form Designer.
InitializeComponent();
// TODO: Add any initialization after the InitializeComponent call
this.BackColor = myBackColor;
this.SetStyle(ControlStyles.UserPaint, false);
this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
this.SetStyle(ControlStyles.DoubleBuffer, true);
myPictureBox = new uPictureBox();
this.Controls.Add(myPictureBox);
myPictureBox.Dock = DockStyle.Fill;
}
protected override void OnResize(EventArgs e)
{
base.OnResize(e);
this.myBitmap = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);//(this.Width,this.Height);
this.myAlphaBitmap = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);//(this.Width,this.Height);
myUpToDate = false;
this.Invalidate();
}
//Some of these should be moved to the WndProc later
protected override void OnKeyDown(KeyEventArgs e)
{
base.OnKeyDown(e);
myUpToDate = false;
this.Invalidate();
}
protected override void OnKeyUp(KeyEventArgs e)
{
base.OnKeyUp(e);
myUpToDate = false;
this.Invalidate();
}
protected override void OnKeyPress(KeyPressEventArgs e)
{
base.OnKeyPress(e);
myUpToDate = false;
this.Invalidate();
}
protected override void OnMouseUp(MouseEventArgs e)
{
base.OnMouseUp(e);
this.Invalidate();
}
protected override void OnGiveFeedback(GiveFeedbackEventArgs gfbevent)
{
base.OnGiveFeedback(gfbevent);
myUpToDate = false;
this.Invalidate();
}
protected override void OnMouseLeave(EventArgs e)
{
//found this code to find the current cursor location
//at http://www.syncfusion.com/FAQ/WinForms/FAQ_c50c.asp#q597q
Point ptCursor = Cursor.Position;
Form f = this.FindForm();
ptCursor = f.PointToClient(ptCursor);
if (!this.Bounds.Contains(ptCursor))
base.OnMouseLeave(e);
}
protected override void OnChangeUICues(UICuesEventArgs e)
{
base.OnChangeUICues(e);
myUpToDate = false;
this.Invalidate();
}
//--
protected override void OnGotFocus(EventArgs e)
{
base.OnGotFocus(e);
myCaretUpToDate = false;
myUpToDate = false;
this.Invalidate();
myTimer1 = new System.Windows.Forms.Timer(this.components);
myTimer1.Interval = (int)win32.GetCaretBlinkTime(); // usually around 500;
myTimer1.Tick += new EventHandler(myTimer1_Tick);
myTimer1.Enabled = true;
}
protected override void OnLostFocus(EventArgs e)
{
base.OnLostFocus(e);
myCaretUpToDate = false;
myUpToDate = false;
this.Invalidate();
myTimer1.Dispose();
}
//--
protected override void OnFontChanged(EventArgs e)
{
if (this.myPaintedFirstTime)
this.SetStyle(ControlStyles.UserPaint, false);
base.OnFontChanged(e);
if (this.myPaintedFirstTime)
this.SetStyle(ControlStyles.UserPaint, true);
myFontHeight = GetFontHeight();
myUpToDate = false;
this.Invalidate();
}
protected override void OnTextChanged(EventArgs e)
{
base.OnTextChanged(e);
myUpToDate = false;
this.Invalidate();
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
// need to rewrite as a big switch
if (m.Msg == win32.WM_PAINT)
{
myPaintedFirstTime = true;
if (!myUpToDate || !myCaretUpToDate)
GetBitmaps();
myUpToDate = true;
myCaretUpToDate = true;
if (myPictureBox.Image != null) myPictureBox.Image.Dispose();
myPictureBox.Image = (Image)myAlphaBitmap.Clone();
}
else if (m.Msg == win32.WM_HSCROLL || m.Msg == win32.WM_VSCROLL)
{
myUpToDate = false;
this.Invalidate();
}
else if (m.Msg == win32.WM_LBUTTONDOWN
|| m.Msg == win32.WM_RBUTTONDOWN
|| m.Msg == win32.WM_LBUTTONDBLCLK
// || m.Msg == win32.WM_MOUSELEAVE ///****
)
{
myUpToDate = false;
this.Invalidate();
}
else if (m.Msg == win32.WM_MOUSEMOVE)
{
if (m.WParam.ToInt32() != 0) //shift key or other buttons
{
myUpToDate = false;
this.Invalidate();
}
}
//System.Diagnostics.Debug.WriteLine("Pro: " + m.Msg.ToString("X"));
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose(bool disposing)
{
if (disposing)
{
//this.BackColor = Color.Pink;
if (components != null)
{
components.Dispose();
}
}
base.Dispose(disposing);
}
#endregion //end public method and overrides
#region public property overrides
public new BorderStyle BorderStyle
{
get { return base.BorderStyle; }
set
{
if (this.myPaintedFirstTime)
this.SetStyle(ControlStyles.UserPaint, false);
base.BorderStyle = value;
if (this.myPaintedFirstTime)
this.SetStyle(ControlStyles.UserPaint, true);
this.myBitmap = null;
this.myAlphaBitmap = null;
myUpToDate = false;
this.Invalidate();
}
}
public new Color BackColor
{
get
{
return Color.FromArgb(base.BackColor.R, base.BackColor.G, base.BackColor.B);
}
set
{
myBackColor = value;
base.BackColor = value;
myUpToDate = false;
}
}
public override bool Multiline
{
get { return base.Multiline; }
set
{
if (this.myPaintedFirstTime)
this.SetStyle(ControlStyles.UserPaint, false);
base.Multiline = value;
if (this.myPaintedFirstTime)
this.SetStyle(ControlStyles.UserPaint, true);
this.myBitmap = null;
this.myAlphaBitmap = null;
myUpToDate = false;
this.Invalidate();
}
}
#endregion //end public property overrides
#region private functions and classes
private int GetFontHeight()
{
Graphics g = this.CreateGraphics();
SizeF sf_font = g.MeasureString("X", this.Font);
g.Dispose();
return (int)sf_font.Height;
}
private void GetBitmaps()
{
if (myBitmap == null
|| myAlphaBitmap == null
|| myBitmap.Width != Width
|| myBitmap.Height != Height
|| myAlphaBitmap.Width != Width
|| myAlphaBitmap.Height != Height)
{
myBitmap = null;
myAlphaBitmap = null;
}
if (myBitmap == null)
{
myBitmap = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);//(Width,Height);
myUpToDate = false;
}
if (!myUpToDate)
{
//Capture the TextBox control window
this.SetStyle(ControlStyles.UserPaint, false);
win32.CaptureWindow(this, ref myBitmap);
this.SetStyle(ControlStyles.UserPaint, true);
this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
this.BackColor = Color.FromArgb(myBackAlpha, myBackColor);
}
//--
Rectangle r2 = new Rectangle(0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height);
ImageAttributes tempImageAttr = new ImageAttributes();
//Found the color map code in the MS Help
ColorMap[] tempColorMap = new ColorMap[1];
tempColorMap[0] = new ColorMap();
tempColorMap[0].OldColor = Color.FromArgb(255, myBackColor);
tempColorMap[0].NewColor = Color.FromArgb(myBackAlpha, myBackColor);
tempImageAttr.SetRemapTable(tempColorMap);
if (myAlphaBitmap != null)
myAlphaBitmap.Dispose();
myAlphaBitmap = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);//(Width,Height);
Graphics tempGraphics1 = Graphics.FromImage(myAlphaBitmap);
tempGraphics1.DrawImage(myBitmap, r2, 0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height, GraphicsUnit.Pixel, tempImageAttr);
tempGraphics1.Dispose();
if (buttomBorder)
{
Pen borderPen = new Pen(Color.FromArgb(255, borderColor));
Graphics tempGraphics3 = Graphics.FromImage(myAlphaBitmap);
tempGraphics3.DrawLine(borderPen, new Point(0, this.ClientRectangle.Height - 1), new Point(this.ClientRectangle.Width, this.ClientRectangle.Height - 1));
tempGraphics3.Dispose();
}
//----
if (this.Focused && (this.SelectionLength == 0))
{
Graphics tempGraphics2 = Graphics.FromImage(myAlphaBitmap);
if (myCaretState)
{
//Draw the caret
Point caret = this.findCaret();
Pen p = new Pen(this.ForeColor,2);
tempGraphics2.DrawLine(p, caret.X, caret.Y + 0, caret.X, caret.Y + myFontHeight);
tempGraphics2.Dispose();
}
}
}
private Point findCaret()
{
/* Find the caret translated from code at
* http://www.vb-helper.com/howto_track_textbox_caret.html
*
* and
*
* http://www.microbion.co.uk/developers/csharp/textpos2.htm
*
* Changed to EM_POSFROMCHAR
*
* This code still needs to be cleaned up and debugged
* */
Point pointCaret = new Point(0);
int i_char_loc = this.SelectionStart;
IntPtr pi_char_loc = new IntPtr(i_char_loc);
int i_point = win32.SendMessage(this.Handle, win32.EM_POSFROMCHAR, pi_char_loc, IntPtr.Zero);
pointCaret = new Point(i_point);
if (i_char_loc == 0)
{
pointCaret = new Point(0);
}
else if (i_char_loc >= this.Text.Length)
{
pi_char_loc = new IntPtr(i_char_loc - 1);
i_point = win32.SendMessage(this.Handle, win32.EM_POSFROMCHAR, pi_char_loc, IntPtr.Zero);
pointCaret = new Point(i_point);
Graphics g = this.CreateGraphics();
String t1 = this.Text.Substring(this.Text.Length - 1, 1) + "X";
SizeF sizet1 = g.MeasureString(t1, this.Font);
SizeF sizex = g.MeasureString("X", this.Font);
g.Dispose();
int xoffset = (int)(sizet1.Width - sizex.Width);
pointCaret.X = pointCaret.X + xoffset;
if (i_char_loc == this.Text.Length)
{
String slast = this.Text.Substring(Text.Length - 1, 1);
if (slast == "\n")
{
pointCaret.X = 1;
pointCaret.Y = pointCaret.Y + myFontHeight;
}
}
}
return pointCaret;
}
private void myTimer1_Tick(object sender, EventArgs e)
{
//Timer used to turn caret on and off for focused control
myCaretState = !myCaretState;
myCaretUpToDate = false;
this.Invalidate();
}
private class uPictureBox : PictureBox
{
public uPictureBox()
{
this.SetStyle(ControlStyles.Selectable, false);
this.SetStyle(ControlStyles.UserPaint, true);
this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
this.SetStyle(ControlStyles.DoubleBuffer, true);
this.Cursor = null;
this.Enabled = true;
this.SizeMode = PictureBoxSizeMode.Normal;
}
//uPictureBox
protected override void WndProc(ref Message m)
{
if (m.Msg == win32.WM_LBUTTONDOWN
|| m.Msg == win32.WM_RBUTTONDOWN
|| m.Msg == win32.WM_LBUTTONDBLCLK
|| m.Msg == win32.WM_MOUSELEAVE
|| m.Msg == win32.WM_MOUSEMOVE)
{
//Send the above messages back to the parent control
win32.PostMessage(this.Parent.Handle, (uint)m.Msg, m.WParam, m.LParam);
}
else if (m.Msg == win32.WM_LBUTTONUP)
{
//?? for selects and such
this.Parent.Invalidate();
}
base.WndProc(ref m);
}
} // End uPictureBox Class
#endregion // end private functions and classes
#region Component Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
components = new System.ComponentModel.Container();
}
#endregion
#region New Public Properties
[
Category("Appearance"),
Description("The alpha value used to blend the control's background. Valid values are 0 through 255."),
Browsable(true),
DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)
]
public int BackAlpha
{
get { return myBackAlpha; }
set
{
int v = value;
if (v > 255)
v = 255;
myBackAlpha = v;
myUpToDate = false;
Invalidate();
}
}
private Color borderColor;
[CategoryAttribute("Appearance"), Description("设置边框颜色！")]
public Color BorderColor
{
get { return borderColor; }
set
{
if (borderColor == value) return;
borderColor = value;
this.Invalidate();
}
}
private bool buttomBorder = false;
[CategoryAttribute("Appearance"), Description("是否有底部边框！")]
public bool ButtomBorder
{
get { return buttomBorder; }
set
{
buttomBorder = value;
this.Invalidate();
}
}
#endregion
} // End AlphaTextBox Class
} // End namespace ZBobb
//----
using System;
using System.Runtime.InteropServices;
using System.Drawing;
namespace ZBobb
{
/// <summary>
/// Win32 support code.
/// (C) 2003 Bob Bradley / [email protected]
/// </summary>
public class win32
{
public const int WM_MOUSEMOVE = 0x0200;
public const int WM_LBUTTONDOWN = 0x0201;
public const int WM_LBUTTONUP = 0x0202;
public const int WM_RBUTTONDOWN = 0x0204;
public const int WM_LBUTTONDBLCLK = 0x0203;
public const int WM_MOUSELEAVE = 0x02A3;
public const int WM_PAINT = 0x000F;
public const int WM_ERASEBKGND = 0x0014;
public const int WM_PRINT = 0x0317;
//const int EN_HSCROLL = 0x0601;
//const int EN_VSCROLL = 0x0602;
public const int WM_HSCROLL = 0x0114;
public const int WM_VSCROLL = 0x0115;
public const int EM_GETSEL = 0x00B0;
public const int EM_LINEINDEX = 0x00BB;
public const int EM_LINEFROMCHAR = 0x00C9;
public const int EM_POSFROMCHAR = 0x00D6;
[DllImport("USER32.DLL", EntryPoint = "PostMessage")]
public static extern bool PostMessage(IntPtr hwnd, uint msg,
IntPtr wParam, IntPtr lParam);
/*
BOOL PostMessage( HWND hWnd,
UINT Msg,
WPARAM wParam,
LPARAM lParam
);
*/
// Put this declaration in your class //IntPtr
[DllImport("USER32.DLL", EntryPoint = "SendMessage")]
public static extern int SendMessage(IntPtr hwnd, int msg, IntPtr wParam,
IntPtr lParam);
[DllImport("USER32.DLL", EntryPoint = "GetCaretBlinkTime")]
public static extern uint GetCaretBlinkTime();
const int WM_PRINTCLIENT = 0x0318;
const long PRF_CHECKVISIBLE = 0x00000001L;
const long PRF_NONCLIENT = 0x00000002L;
const long PRF_CLIENT = 0x00000004L;
const long PRF_ERASEBKGND = 0x00000008L;
const long PRF_CHILDREN = 0x00000010L;
const long PRF_OWNED = 0x00000020L;
/* Will clean this up later doing something like this
enum CaptureOptions : long
{
PRF_CHECKVISIBLE= 0x00000001L,
PRF_NONCLIENT = 0x00000002L,
PRF_CLIENT = 0x00000004L,
PRF_ERASEBKGND = 0x00000008L,
PRF_CHILDREN = 0x00000010L,
PRF_OWNED = 0x00000020L
}
*/
public static bool CaptureWindow(System.Windows.Forms.Control control,
ref System.Drawing.Bitmap bitmap)
{
//This function captures the contents of a window or control
Graphics g2 = Graphics.FromImage(bitmap);
//PRF_CHILDREN // PRF_NONCLIENT
int meint = (int)(PRF_CLIENT | PRF_ERASEBKGND); //| PRF_OWNED ); // );
System.IntPtr meptr = new System.IntPtr(meint);
System.IntPtr hdc = g2.GetHdc();
win32.SendMessage(control.Handle, win32.WM_PRINT, hdc, meptr);
g2.ReleaseHdc(hdc);
g2.Dispose();
return true;
}
}
}