可编辑和拖动的文本框

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.Diagnostics;

namespace _SCREEN_CAPTURE
{
    public partial class MyInput : UserControl
    {
        private string Content = "";
        private int State = 1; //1:编辑 2:选中 3:透明文本       
        private Font m_font = new Font("宋体", 9);//字体格式
        private Color m_color = Color.Blue;       //字体颜色
        private Point m_downpoint = new Point();  //鼠标按下坐标
        private bool DragFlag = false;            //拖动标志
        Rectangle[] SmallRect = new Rectangle[8];
        private int FrameWidth = 6;               //边框宽度
        private Cursor m_cursor;

        enum HitDownSquare
        {
            HDS_NONE = 0,
            HDS_TOP = 1,
            HDS_RIGHT = 2,
            HDS_BOTTOM = 3,
            HDS_LEFT = 4,
            HDS_TOPLEFT = 5,
            HDS_TOPRIGHT = 6,
            HDS_BOTTOMLEFT = 7,
            HDS_BOTTOMRIGHT = 8
        }

        private HitDownSquare CurrHitPlace;

        public MyInput()
        {
            InitializeComponent();
        }

        void SetRectangles()
        {
            //定义8个小正方形的范围
            Rectangle baseRect = new Rectangle(FrameWidth, FrameWidth, this.Width - FrameWidth * 2, this.Height - FrameWidth * 2);
            Size Square = new Size(FrameWidth, FrameWidth);
            //左上
            SmallRect[0] = new Rectangle(new Point(baseRect.X - Square.Width, baseRect.Y - Square.Height), Square);
            //上中间
            SmallRect[4] = new Rectangle(new Point(baseRect.X + (baseRect.Width / 2) - (Square.Width / 2), baseRect.Y - Square.Height), Square);
            //右上
            SmallRect[1] = new Rectangle(new Point(baseRect.X + baseRect.Width, baseRect.Y - Square.Height), Square);
            //左下
            SmallRect[2] = new Rectangle(new Point(baseRect.X - Square.Width, baseRect.Y + baseRect.Height), Square);
            //下中间
            SmallRect[5] = new Rectangle(new Point(baseRect.X + (baseRect.Width / 2) - (Square.Width / 2), baseRect.Y + baseRect.Height), Square);
            //右下
            SmallRect[3] = new Rectangle(new Point(baseRect.X + baseRect.Width, baseRect.Y + baseRect.Height), Square);
            //左中间
            SmallRect[6] = new Rectangle(new Point(baseRect.X - Square.Width, baseRect.Y + (baseRect.Height / 2) - (Square.Height / 2)), Square);
            //右中间
            SmallRect[7] = new Rectangle(new Point(baseRect.X + baseRect.Width, baseRect.Y + (baseRect.Height / 2) - (Square.Height / 2)), Square);
        }

        private void MyInput_Paint(object sender, PaintEventArgs e)
        {
            Graphics gc_main = e.Graphics;

            if (State == 1)
            {
                if (m_input.Text == "")
                {
                    this.Size = new Size(4, 14);
                }
                gc_main.DrawRectangle(new Pen(Color.Blue, 2), 0, 0, this.Width, this.Height);
            }
            else if (State == 2)
            {
                gc_main.DrawRectangle(new Pen(Color.LightGray, FrameWidth * 2), 0, 0, this.Width, this.Height); //填充用于调整的边框的内部
                Rectangle StringRect = new Rectangle(FrameWidth + 1, FrameWidth + 1, this.Width - FrameWidth * 2, this.Height - FrameWidth * 2);
                gc_main.DrawString(Content, m_font, new SolidBrush(m_color), StringRect);
                SetRectangles();
                gc_main.FillRectangles(Brushes.Black, SmallRect); //填充8个锚点的内部
            }
            else if (State == 3)
            {
                Rectangle StringRect = new Rectangle(FrameWidth + 1, FrameWidth + 1, this.Width - FrameWidth * 2, this.Height - FrameWidth * 2);
                gc_main.DrawString(Content, m_font, new SolidBrush(m_color), StringRect);
            }
        }

        private void MyInput_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                m_downpoint = e.Location;
                DragFlag = true;
                if (State != 2)
                {
                    State = 2;
                    Invalidate();
                }
                this.Cursor = m_cursor;
            }
        }

        private void MyInput_MouseMove(object sender, MouseEventArgs e)
        {
            if (State == 2)
            {
                if (e.Button == MouseButtons.Left && DragFlag)
                {
                    switch (CurrHitPlace)
                    {
                        case HitDownSquare.HDS_NONE:
                            {
                                Point mousePos = Control.MousePosition; ;
                                Point p_chart = this.Parent.PointToClient(mousePos);
                                p_chart.Offset(-m_downpoint.X, -m_downpoint.Y);
                                if (p_chart.X > 0 && p_chart.X < ((Control)sender).Parent.Width && p_chart.Y > 0 && p_chart.Y < ((Control)sender).Parent.Height)
                                {
                                    ((Control)sender).Location = new Point(p_chart.X, p_chart.Y);
                                }
                            }
                            break;
                        default:
                            {
                                Mouse_Move(this, e); //调整位置或大小
                                m_downpoint = new Point(e.X, e.Y);
                                Invalidate();
                            }
                            break;
                    }
                }
                else
                {
                    Hit_Test(e.X, e.Y); //更新鼠标指针样式
                }
            }
            else
            {
                this.Cursor = Cursors.Default;
            }
        }

        public bool Hit_Test(int x, int y)
        {
            Point point = new Point(x, y);
            Rectangle ControlRect = new Rectangle(0, 0, this.Width, this.Height);
            if (!ControlRect.Contains(point))
            {
                Cursor.Current = Cursors.SizeAll;
                return false;
            }
            else if (SmallRect[0].Contains(point))
            {
                Cursor.Current = Cursors.SizeNWSE;
                CurrHitPlace = HitDownSquare.HDS_TOPLEFT;
            }
            else if (SmallRect[3].Contains(point))
            {
                Cursor.Current = Cursors.SizeNWSE;
                CurrHitPlace = HitDownSquare.HDS_BOTTOMRIGHT;
            }
            else if (SmallRect[1].Contains(point))
            {
                Cursor.Current = Cursors.SizeNESW;
                CurrHitPlace = HitDownSquare.HDS_TOPRIGHT;
            }
            else if (SmallRect[2].Contains(point))
            {
                Cursor.Current = Cursors.SizeNESW;
                CurrHitPlace = HitDownSquare.HDS_BOTTOMLEFT;
            }
            else if (SmallRect[4].Contains(point))
            {
                Cursor.Current = Cursors.SizeNS;
                CurrHitPlace = HitDownSquare.HDS_TOP;
            }
            else if (SmallRect[5].Contains(point))
            {
                Cursor.Current = Cursors.SizeNS;
                CurrHitPlace = HitDownSquare.HDS_BOTTOM;
            }
            else if (SmallRect[6].Contains(point))
            {
                Cursor.Current = Cursors.SizeWE;
                CurrHitPlace = HitDownSquare.HDS_LEFT;
            }
            else if (SmallRect[7].Contains(point))
            {
                Cursor.Current = Cursors.SizeWE;
                CurrHitPlace = HitDownSquare.HDS_RIGHT;
            }
            else if (ControlRect.Contains(point))
            {
                Cursor.Current = Cursors.SizeAll;
                CurrHitPlace = HitDownSquare.HDS_NONE;
            }
            m_cursor = Cursor.Current;
            return true;
        }

        public void Mouse_Move(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            //控件最小为 8x8
            if (this.Height < FrameWidth * 2 + 1)
            {
                this.Height = FrameWidth * 2 + 1;
                return;
            }
            else if (this.Width < FrameWidth * 2 + 1)
            {
                this.Width = FrameWidth * 2 + 1;
                return;
            }
            switch (this.CurrHitPlace)
            {
                case HitDownSquare.HDS_TOP:
                    this.Height = this.Height - e.Y + m_downpoint.Y;
                    if (this.Height > FrameWidth * 2 + 1)
                        this.Top = this.Top + e.Y - m_downpoint.Y;
                    break;
                case HitDownSquare.HDS_TOPLEFT:
                    this.Height = this.Height - e.Y + m_downpoint.Y;
                    if (this.Height > FrameWidth * 2 + 1)
                        this.Top = this.Top + e.Y - m_downpoint.Y;
                    this.Width = this.Width - e.X + m_downpoint.X;
                    if (this.Width > FrameWidth * 2 + 1)
                        this.Left = this.Left + e.X - m_downpoint.X;
                    break;
                case HitDownSquare.HDS_TOPRIGHT:
                    this.Height = this.Height - e.Y + m_downpoint.Y;
                    if (this.Height > FrameWidth * 2 + 1)
                        this.Top = this.Top + e.Y - m_downpoint.Y;
                    this.Width = this.Width + e.X - m_downpoint.X;
                    break;
                case HitDownSquare.HDS_RIGHT:
                    this.Width = this.Width + e.X - m_downpoint.X;
                    break;
                case HitDownSquare.HDS_BOTTOM:
                    this.Height = this.Height + e.Y - m_downpoint.Y;
                    break;
                case HitDownSquare.HDS_BOTTOMLEFT:
                    this.Height = this.Height + e.Y - m_downpoint.Y;
                    this.Width = this.Width - e.X + m_downpoint.X;
                    if (this.Width > FrameWidth * 2 + 1)
                        this.Left = this.Left + e.X - m_downpoint.X;
                    break;
                case HitDownSquare.HDS_BOTTOMRIGHT:
                    this.Height = this.Height + e.Y - m_downpoint.Y;
                    this.Width = this.Width + e.X - m_downpoint.X;
                    break;
                case HitDownSquare.HDS_LEFT:
                    this.Width = this.Width - e.X + m_downpoint.X;
                    if (this.Width > FrameWidth * 2 + 1)
                        this.Left = this.Left + e.X - m_downpoint.X;
                    break;
                case HitDownSquare.HDS_NONE:
                    this.Location.Offset(e.X - m_downpoint.X, e.Y - m_downpoint.Y);
                    break;
            }
        }

        private void MyInput_MouseUp(object sender, MouseEventArgs e)
        {
            if (State == 2)
            {
                if (e.Button == MouseButtons.Left)
                {
                    DragFlag = false;
                }
                else if (e.Button == MouseButtons.Right)
                {
                    InputMenu.Show(PointToScreen(e.Location));
                }
            }
        }

        private void MyInput_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                m_input.Visible = true;
                m_input.Font = m_font;
                m_input.Focus();
                State = 1;
                Invalidate();
            }
        }

        private void MyInput_LostFocus(object sender, EventArgs e)
        {
            if (State == 2)
            {
                State = 3;
                Invalidate();
            }
        }

        private Font GetFont(Size s, string P_String)
        {
            string sFontName = "宋体";
            Bitmap _bitmap = new Bitmap(s.Width, s.Height);
            Graphics _graphics = Graphics.FromImage(_bitmap);
            float fontsize = 0.1f;
            for (Size _size = new Size(); _size.Width < s.Width && _size.Height < s.Height; fontsize += 0.1f)
            {
                Font font_1 = new Font(sFontName, fontsize);
                _size = _graphics.MeasureString(P_String, font_1).ToSize();
            }
            return new Font(sFontName, fontsize - 0.2f);
        }

        private void m_input_TextChanged(object sender, EventArgs e)
        {
            Graphics gc = this.CreateGraphics();

            SizeF TextSize = gc.MeasureString(m_input.Text.ToString(), m_font);
            TextSize.Width += FrameWidth * 2 + 2;
            TextSize.Height += FrameWidth * 2 + 2;
            this.Size = TextSize.ToSize();

            Invalidate();
        }

        private void m_input_KeyUp(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                this.Focus();
            }
        }

        private void m_input_LostFocus(object sender, EventArgs e)
        {
            if (m_input.Text == "")
            {
                Dispose();
                return;
            }
            Content = m_input.Text;
            m_input.Visible = false;
            State = 3;
            Invalidate();
        }

        private void input_delete_Click(object sender, EventArgs e)
        {
            this.Dispose();
        }

        private void input_property_Click(object sender, EventArgs e)
        {
            //InputProperties m_pop = new InputProperties();
            //m_pop.FontInfo = m_font;
            //m_pop.ColorInfo = m_color;
            //if (m_pop.ShowDialog() == DialogResult.OK)
            //{
            //    m_font = m_pop.FontInfo;
            //    m_color = m_pop.ColorInfo;
            //    Invalidate();
            //}

            EnhanceFontDialog f = new EnhanceFontDialog();
            f.SelectedFontColorFromArgb = m_color;
            f.SelectedFontStyles = m_font.Style;
            f.SelectedFontSize = m_font.Size;
            try
            {
                if (f.ShowDialog(this) == DialogResult.OK)
                {
                    MessageBox.Show(f.SelectedFontColorFromArgb.ToString() + "\n"
                        + f.SelectedFontName.ToString() + "\n"
                        + f.SelectedFontStyles.ToString() + "\n"
                        + f.SelectedFontSize.ToString() + "\n"
                        + f.SelectedFontUnit.ToString() + "\n"
                        , "字体");
                    m_font = new Font(f.SelectedFontName, f.SelectedFontSize);
                    m_color = f.SelectedFontColorFromArgb;
                    Invalidate();
                }
            }
            catch (Exception exc)
            {
                //handle ur exception
                MessageBox.Show("发生错误：" + exc.Message);
            }
            finally
            {
                f.Dispose();
            }
        }

        private void MyInput_KeyUp(object sender, KeyEventArgs e)
        {
            if (State == 2)
            {
                if (e.KeyCode == Keys.Delete)
                {
                    this.Dispose();
                }
            }
        }
    }
}