Winform之TextBox边框底色重绘实例

TextBox边框及底色重绘实例本实例通过继承TextBox类对TextBox边框及底色进行重绘，本实例实现了TextBox四个边的边框重绘，其他单边的重绘可依照此方式进行扩展。

先来看一下具体效果。

1.设计时TextBox边框线。

2.新增的属性用于对边框底色及边框宽度进行设置，FocusHotTrack=false时不对TextBox进行重绘，即此时就是MS提供的TextBox。

3.运行时效果界面具体代码如下：Windows API ：[DllImport("User32.dll")]public static extern IntPtr GetWindowDC(IntPtr hWnd);[DllImport("User32.dll")]public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hdc);注：此处API可用可不用。

实现类：说明：重绘TextBox边框实现过程是：将TextBox加入到一个Panel中，当获取焦点时在Panel 上绘制一个矩形框，同时绘制一个1像素的TextBox边框。

添加Panel的用途是为TextBox绘制外边框，因为当TextBox边框线大于1像素的时候，会覆盖编辑区，引起绘制的边框的变形，为了能根据需要设定边框线的宽度，使用Panel来添加外边框线。

using System;using System.Collections.Generic;using ponentModel;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace Sam.WinUI.Controls{/// <summary>/// </summary>public class RTextBox : System.Windows.Forms.TextBox{/// <summary>/// 是否启用焦点,默认不启用/// </summary>private bool _IsFocusHotTrack = true;/// <summary>/// 获取焦点时背景色/// </summary>private Color _FocusBackColor = Color.MistyRose;/// <summary>/// 获取焦点时边框色/// </summary>private Color _FocusBorderColor = Color.DarkOrange;/// <summary>/// 失去焦点背景色/// </summary>private Color _LostBackColor;/// <summary>/// 失去焦点边框色/// </summary>private Color _LostBorderColor = Color.Transparent;/// <summary>/// 边框线宽度/// </summary>private int _BorderWidth = 1;/// <summary>/// 组件的父容器/// </summary>private Panel _ParentContainer = null;/// <summary>/// 是否启用热点/// </summary>[Category("行为"),Description("获得或设置一个值，指示当鼠标经过控件时控件边框是否发生变化。

只在控件的BorderStyle为FixedSingle时有效"),DefaultValue(true)]public bool FocusHotTrack{get { return _IsFocusHotTrack; }set{this._IsFocusHotTrack = value;//在该值发生变化时重绘控件，下同//在设计模式下，更改该属性时，如果不调用该语句，//则不能立即看到设计试图中该控件相应的变化this.Invalidate();}}/// <summary>/// 获取焦点时背景色/// </summary>public Color HotBackColor{get { return this._FocusBackColor; }set{this._FocusBackColor = value;this.Invalidate();}}/// <summary>/// 获取焦点时边框色/// </summary>public Color HotBorderColor{get { return this._FocusBorderColor; }set{this._FocusBorderColor = value;this.Invalidate();}}/// <summary>/// 失去焦点时背景色/// </summary>public Color LostBackColor{get { return this._LostBackColor; }set{this._LostBackColor = value;this.Invalidate();}}/// <summary>/// 失去焦点时背景色/// </summary>public Color LostBorderColor{get { return this._LostBorderColor; }set{this._LostBorderColor = value;this.Invalidate();}}/// <summary>/// 边框线宽度/// </summary>[DefaultValue(1)]//[EditorBrowsable(EditorBrowsableState.Never),Browsable(false)] public int BorderWidth{get { return this._BorderWidth; }set{this._BorderWidth = value;this.Invalidate();}}public RTextBox():base(){this.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;this._LostBackColor = this.BackColor;this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true);this.SetParentContainer();}/// <summary>/// 设置TextBox添加父容器/// </summary>private void SetParentContainer(){this._ParentContainer = new Panel();this._ParentContainer.Controls.Add(this);}/// <summary>/// Windows消息处理函数/// </summary>/// <param name="m"></param>protected override void WndProc(ref Message m){base.WndProc(ref m);//0xf:WM_PRINT 0x133:WM_CTLCOLOREDITif (m.Msg == 0xf || m.Msg == 0x133){ResetBorderColor(m.HWnd);}}/// <summary>/// 重绘边框/// </summary>/// <param name="hWnd"></param>internal void ResetBorderColor(IntPtr hWnd){//根据颜色和边框像素取得一条线System.Drawing.Pen pen = new Pen(this._LostBackColor, this._BorderWidth);//得到当前的句柄IntPtr hdc = Win32.GetWindowDC(hWnd);if (hdc.ToInt32() == 0){return;}if (pen != null){if (_IsFocusHotTrack){if (this.Focused){pen.Color = this._FocusBorderColor;this.BackColor = this._FocusBackColor;}else{pen.Color = this._LostBorderColor;this.BackColor = this._LostBackColor;}//绘制边框System.Drawing.Graphics g = this.Parent.CreateGraphics();g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;g.DrawRectangle(pen,this.Location.X-1,this.Location.Y-1,this.Size.Width+1, this.Size.Height+1);this.CreateGraphics().DrawRectangle(new Pen(pen.Color,1), 0, 0, this.Size.Width - 1, this.Size.Height - 1);pen.Dispose();}}//释放Win32.ReleaseDC(hWnd, hdc);}/// <summary>/// 获取焦点/// </summary>/// <param name="e"></param>protected override void OnGotFocus(EventArgs e){if(this._IsFocusHotTrack){this.Parent.Invalidate();}base.OnGotFocus(e);}/// <summary>/// 失去焦点/// </summary>/// <param name="e"></param>protected override void OnLostFocus(EventArgs e){if(this._IsFocusHotTrack){this.Parent.Invalidate();}base.OnLostFocus(e);}/// <summary>/// 鼠标进入控件编辑区/// </summary>/// <param name="e"></param>protected override void OnMouseEnter(EventArgs e){if (this.Focused){this.Parent.Invalidate();this.Invalidate();}base.OnMouseEnter(e);}/// <summary>/// 鼠标离开编辑区/// </summary>/// <param name="e"></param>protected override void OnMouseLeave(EventArgs e){if (this.Focused){this.Parent.Invalidate();}base.OnMouseLeave(e);}}}。