制作只允許輸入數字的NumericTextBox(包括指定精確度,是否允許負數等)

一.設計時效果

二.運行時效果

三.簡單談談實現思路

該控件實現了控制粘貼,控制輸入有效精度,負數控制,整數控制等等操作,將為快速開發提供方便.

四.源代碼

 

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 ; //是否允許回車代替TAB
        private bool _isintegral  = false  ;//是否整數輸入
        private bool _EnPaste  = true  ;//是否允許粘貼
        private bool  _EnContextMenu  = true ; //是否允許現實右鍵菜單
        private int _PointNumber = -1 ;//為-1時允許輸入任意位小數
        private bool _isnegativenumber = false; //是否允許輸入負數
        public delegate void InputNumberTextBoxEvent();
        public event InputNumberTextBoxEvent PasteEvent;
        public JcsInputNum()
        ...{
            InitializeComponent();
        }
        /**//// <summary>
        /// 是否只讀
        /// </summary>
        [Category("JCS屬性"),Description("是否只讀。")]
        public bool Isreadonly
        ...{
            get ...{ return this._isreadonly; }
            set ...{ this._isreadonly = value; }
        }
        /**//// <summary>
        /// 是否是整數 
        /// </summary>
        [Category("JCS屬性"), Description("是否整數。")]
        public bool isintegral
        ...{
            get ...{ return this._isintegral; }
            set ...{ _isintegral = value; }
        }
   
        /**//// <summary>
        /// 是否允許輸入負數 
        /// </summary>
        [Category("JCS屬性"), Description("是否允許輸入負數。")]
        public bool IsNegativeNumber
        ...{
            get ...{ return _isnegativenumber; }
            set ...{ _isnegativenumber = value; }
        }
        /**//// <summary>
        /// 精度位數控制(即：允許輸入幾位小數控制) 
        /// </summary>
        [Category("JCS屬性"), Description("精度位數控制，-1時允許輸入任意位小數。")]
        public int PointNumber
        ...{
            get ...{ return _PointNumber; }
            set ...{ this._PointNumber = value; }
        }
        [Category("JCS屬性"), Description("是否允許粘貼。")]
        public bool EnablePaste
        ...{
            get ...{ return _EnPaste; }
            set
            ...{
                _EnPaste = value;
                this.Invalidate();
            }
        }
        /**//// <summary>
     &nbs /// 
        /// </summary>
        [Category("JCS屬性"), Description("是否右鍵菜單。")]
        public bool EnableContextMenu
        ...{

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


        "private and overrides function"#region "private and overrides function"
        /**//// <summary>
        /// 檢驗輸入
        /// </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)
            ...{
                case 8:
                case 13:
                    // Backspace, Enter 
                    break;
                // Allow entry 
                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 針對數字小數點精度的限制做了調整 
                    // Allow entry 
                    if (this._PointNumber != -1)
                    ...{
                        int index = this.Text.IndexOf(".");
                        if (index != -1)
                        ...{
                            int startindex = this.SelectionStart;
                            if (startindex >= index)
                            ...{
                                //如果光標位置在小數點右側，則要判斷是否已經輸入了有效位的數字 
                                int nUMLength = this.Text.Substring(index+1).Length + 1;
                                if (nUMLength > this._PointNumber & this.SelectionLength == 0)
                                ...{
                                    e.Handled = true;
                                    return; 
                                }
                            }
                            else
                            ...{
                                //如果光標位置在小數點左側，則允許輸入 
                            }
                        }
                    }

                    break;
                case 46:
                    //小數點
                    //是否整數
                    if (this._isintegral)
                    ...{
                        e.Handled = true;
                        return; // 
                    }

                    //小數點多於1個時 
                    if (this.Text.IndexOf( ".") != -1)
                    ...{
                        e.Handled = true;
                    }
                    else
                    ...{
        &n               //在起始位置時 
                        if (CurPos == 0)
                        ...{
                            this.Text = "0" + this.Text;
                            //Add a zero before it 
                            this.SelectionStart = 1;
                            //Set original cursor position光標在小數點後的位置 
                        }

                        else if (CurPos == 1 & this.Text.StartsWith("-"))
                        ...{
                            //負數 
                            this.Text = "-0." + this.Text.Substring(1);
                            //Add zero before decimal連接小數點後的內容 
                            this.SelectionStart = 3;
                            e.Handled = true;
                     }
                        else
                        ...{
                            this.Text = this.Text + ".00";
                            //Append Decimal and two zero''s 增添精確小數位數 
                            this.SelectionStart = CurPos + 1;
                            this.SelectionLength = 2;
                            //Highlight the zero''s 
                            e.Handled = true;
                        }
                    }

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

                    break;
                default:
                    e.Handled = true;

                    break;
            }
        }
        //Validate Input data for Numeric 
&nbs     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))
                    ...{
                        if (!IsNumeric(iData.ToString()))
                        ...{
                            return ;
                        }
                    }
                    else
                    ...{
                        return ;
                    }
                    if (PasteEvent != null)
                    ...{
                        PasteEvent();
                    }
                    break;
                case 123:
                    //contextmenu 
                    if (!_EnContextMenu)
                        return;
                    break;
                case 256:
                case 260:
                    //按下一個鍵,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);
        }
        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 


    }

}