修正--NumericTextBox

一.修正说明

主要是针对0在控件中的输入情况做出了调整.在selectionstart = 0的时候,如果text.length ! =0,那么将限制对0的输入.同样,对于类似0.19,中光标位于0后边的情况，同样不允许输入0.

二.源代码

 

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

namespace JcsExpLibary.Numeric_Textbox
...{
    public partial class JcsInputNum : TextBox 
    ...{
        private bool _isreadonly  = true ; //是否允许回车代替TAB
        private bool _isintegral  = false  ;//是否整数输入
        private bool _EnPaste  = true  ;//是否允许粘贴
        private bool  _EnContextMenu  = true ; //是否允许现实右键菜单
        private int _PointNumber = -1 ;//为-1时允许输入任意位小数
        private bool _isnegativenumber = false; //是否允许输入负数
        public delegate void InputNumberTextBoxEvent();
        public event InputNumberTextBoxEvent PasteEvent;
        public JcsInputNum()
        ...{
            InitializeComponent();
        }
        /**//// <summary>
        /// 是否只读
        /// </summary>
        [Category("JCS属性"),Description("是否只读。")]
        public bool Isreadonly
        ...{
            get ...{ return this._isreadonly; }
            set ...{ this._isreadonly = value; }
        }
        /**//// <summary>
        /// 是否是整数 
        /// </summary>
        [Category("JCS属性"), Description("是否整数。")]
        public bool isintegral
        ...{
            get ...{ return this._isintegral; }
            set ...{ _isintegral = value; }
        }
   
        /**//// <summary>
        /// 是否允许输入负数 
        /// </summary>
        [Category("JCS属性"), Description("是否允许输入负数。")]
        public bool IsNegativeNumber
        ...{
            get ...{ return _isnegativenumber; }
            set ...{ _isnegativenumber = value; }
        }
        /**//// <summary>
        /// 精度位数控制(即：允许输入几位小数控制) 
        /// </summary>
        [Category("JCS属性"), Description("精度位数控制，-1时允许输入任意位小数。")]
        public int PointNumber
        ...{
            get ...{ return _PointNumber; }
            set ...{ this._PointNumber = value; }
        }
        [Category("JCS属性"), Description("是否允许粘贴。")]
        public bool EnablePaste
        ...{
            get ...{ return _EnPaste; }
            set
            ...{
                _EnPaste = value;
                this.Invalidate();
            }
        }
        /**//// <summary>
        /// 
        /// </summary>
        [Category("JCS属性"), Description("是否右键菜单。")]
        public bool EnableContextMenu
        ...{

            get ...{ return _EnContextMenu; }
            set
            ...{
                _EnContextMenu = value;
                this.Invalidate();
            }
        }


        "private and overrides function"#region "private and overrides function"
        /**//// <summary>
        /// 检验输入
        /// </summary>
        /// <param name="e"></param>
        /// <param name="KeyAsc"></param>
        /// <param name="CurPos"></param>
        private void ValidNumeric(System.Windows.Forms.KeyPressEventArgs e, int KeyAsc, int CurPos)
        ...{
            switch (KeyAsc)
            ...{
                // Backspace, Enter 
                case 8:
                case 13:
                    break;
                case 22:
                    if (!_EnPaste)
                        e.Handled = true;
                    break;
                case 48:
                case 49:
                case 50:
                case 51:
                case 52:
                case 53:
                case 54:
                case 55:
                case 56:
                case 57:
                    //0-9 modified by jcs 2007-02-28 针对数字小数点精度的限制做了调整 
                    // Allow entry 
                    if (this._PointNumber != -1)
                    ...{
                        int startindex = this.SelectionStart;
                        int index = this.Text.IndexOf(".");
                        if (index != -1)
                        ...{
                            if (startindex > index)
                            ...{
                                //如果光标位置在小数点右侧，则要判断是否已经输入了有效位的数字 
                                int numlength = this.Text.Substring(index + 1).Length + 1;
                                if (numlength > this._PointNumber & this.SelectionLength == 0)
                                ...{
                                    e.Handled = true;
                                    return;
                                }
                            }
                            //else if (startindex = index)
                            //{

                            //}
                            else if(KeyAsc ==48)
                            ...{
                                //如果光标位置在小数点左侧，则允许输入 
                                //判断是否0在最左侧或者前面的字符是第1个字符，而且也是0
                                if (startindex == 0 )
                                ...{
                                    e.Handled = true;
                                }
                                if (startindex == 1 && this.Text.Substring(0, 1) == "0")
                                ...{
                                    e.Handled = true;
                                }

                            }
                        }
                        else
                        ...{
                            if (startindex == 0 && this.Text.Length !=0)
                            ...{
                                e.Handled = true;
                            }
                        }
                    }
                    else if (KeyAsc ==48) //对精度无控制时对输入0的限制
                    ...{
                        int startindex = this.SelectionStart;
                        int index = this.Text.IndexOf(".");
                        if (index != -1)
                        ...{
                            //如果第1个字符是0，则不允许在0后面再次输入0
                            if (startindex == 1 && Text.Substring(0, 1) == "0")
                            ...{
                                e.Handled = true;
                            }
                            else
                            ...{
                                //判断在最左侧输入时，或者前面的字符是第1个字符，而且也是0
                                if (startindex == 0 && this.Text.Substring(0, 1) != ".")
                                ...{
                                    e.Handled = true;
                                }
                            }
                        }
                        else
                        ...{
                            if (KeyAsc == 48)
                            ...{
                                //如果字符长度不为空，并且在最左侧输入，0将被限制
                                if (startindex == 0 && this.Text.Length != 0)
                                ...{
                                    e.Handled = true;
                                }
                                else
                                ...{
                                    if (startindex == 0)
                                    ...{
                                        this.Text = "0.0";
                                        this.SelectionStart = 2;
                                        this.SelectionLength = 1;
                                        e.Handled = true;
                                    }
                                }
                            }
                        }
                    }

                    break;
                case 46:
                    //小数点
                    //是否整数
                    if (this._isintegral)
                    ...{
                        e.Handled = true;
                        return; // 
                    }

                    //小数点多于1个时 
                    if (this.Text.IndexOf( ".") != -1)
                    ...{
                        e.Handled = true;
                    }
                    else
                    ...{
                        //在起始位置时 
                        if (CurPos == 0)
                        ...{
                            this.Text = "0" + this.Text;
                            //Add a zero before it 
                            this.SelectionStart = 1;
                            //Set original cursor position光标在小数点后的位置 
                        }

                        else if (CurPos == 1 & this.Text.StartsWith("-"))
                        ...{
                            //负数 
                            this.Text = "-0." + this.Text.Substring(1);
                            //Add zero before decimal连接小数点后的内容 
                            this.SelectionStart = 3;
                            e.Handled = true;
                        }
                        else
                        ...{
                            this.Text = this.Text + ".00";
                            //Append Decimal and two zero's 增添精确小数位数 
                            this.SelectionStart = CurPos + 1;
                            this.SelectionLength = 2;
                            //Highlight the zero's 
                            e.Handled = true;
                        }
                    }

                    break;
                case 45:
                    //负号 
                    if (!this._isnegativenumber)
                    ...{
                        e.Handled = true;
                        return; 
                    }
                    else
                    ...{
                        if (CurPos != 0)
                        ...{
                            //开始位置 
                            e.Handled = true;
                            return;  
                        }
                    }

                    break;
                default:
                    e.Handled = true;

                    break;
            }
        }
        //Validate Input data for Numeric 
        protected override void OnKeyPress(System.Windows.Forms.KeyPressEventArgs e)
        ...{

            int KeyAsc;
            //Ascii code of character 
            int CurPos;
            //Cursor position 

            KeyAsc = Convert.ToInt32(e.KeyChar);
            CurPos = this.SelectionStart;

            ValidNumeric(e, KeyAsc, CurPos);

        }
        protected override void OnKeyDown(System.Windows.Forms.KeyEventArgs e)
        ...{
            if (_isreadonly)
            ...{
                if (e.KeyCode == System.Windows.Forms.Keys.Enter)
                ...{
                    SendKeys.Send("{TAB}");
                }
            }
        }

        protected override void OnGotFocus(System.EventArgs e)
        ...{
            this.Select();
            this.SelectAll();
        }
        protected override void WndProc(ref System.Windows.Forms.Message m)
        ...{
            switch (m.Msg)
            ...{
                case 770:
                    //paste 
                    
                    if (!_EnPaste)
                        return;
                    IDataObject iData = Clipboard.GetDataObject();
                    if (iData.GetDataPresent(DataFormats.Text))
                    ...{
                        string s = (string)iData.GetData(typeof(string));
                        if (!IsNumeric(s))
                        ...{
                            return ;
                        }
                    }
                    else
                    ...{
                        return ;
                    }
                    if (PasteEvent != null)
                    ...{
                        PasteEvent();
                    }
                    break;
                case 123:
                    //contextmenu 
                    if (!_EnContextMenu)
                        return;
                    break;
                case 256:
                case 260:
                    //按下一个键,WM_KEYDOWN；WM_SYSKEYDOWN 
                    //switch (m.WParam.ToInt32)
                    //{
                    //    case Keys.Enter:
                    //        SendKeys.Send("{tab}");
                    //        break;
                    //    case Keys.Left:

                    //        return;
                    //    case Keys.Right:

                    //        return;
                    //    case Keys.Up:

                    //        return;
                    //    case Keys.Down:

                    //        return;
                    //    case Keys.Shift + Keys.Tab:
                    //        return;
                    //    case Keys.Tab:
                    //        break;

                    //}
                    break;

            }
            base.WndProc(ref m);
        }
        /**//// <summary>
        /// 
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public bool IsNumeric(string str)
        ...{
            char[] ch = new char[str.Length];
            ch = str.ToCharArray();
            for (int i = 0; i < ch.Length; i++)
            ...{
                if (ch[i] < 48 || ch[i] > 57)
                    return false;
            }
            return true;
        }   

        #endregion 


    }

}