VS.NET - ASP.NET - ASP.NET Numeric Textbox control

ASP.NET Numeric Textbox control that handles pasting.

Synopsis:

A common need I've had when working with ASP.NET is for a numeric only textbox control. The standard control doesn't offer such features. I had been using a Numeric control from Excentrics World, but even this didn't handle pasting exactly as I wanted, nor is it available for download now (for the time being at least.). To do this I used a validation script on mredkj and bundled it into a custom control that inherits from the textbox control and adds a few properties to set parameters used for the javascript. For more information about the javascript to allow only numbers go here: JavaScript validate 'as you type'

Solution:

Download : Dll and Code



Option Explicit On 
Imports System.ComponentModel
Imports System.Web.UI

Public Class NumericTextBox
    Inherits System.Web.UI.WebControls.TextBox

    Private _DecimalPlaces As Int32 = -1
    Private _AllowDecimal As Boolean
    Private _AllowNegative As Boolean
    Private js As String = "<script language='javascript'>// created: 2005-08-30" & vbCrLf & _
        "// updated: 2005-08-31" & vbCrLf & _
        "// mredkj.com" & vbCrLf & _
        "function extractNumber(obj, decimalPlaces, allowNegative)" & vbCrLf & _
        "{" & vbCrLf & _
        "	var temp = obj.value;" & vbCrLf & _
        "	" & vbCrLf & _
        "	// avoid changing things if already formatted correctly" & vbCrLf & _
        "	var reg0Str = '[0-9]*';" & vbCrLf & _
        "	if (decimalPlaces > 0) {" & vbCrLf & _
        "       reg0Str += '\\.?[0-9]{0,' + decimalPlaces + '}';" & vbCrLf & _
        "   } else if (decimalPlaces < 0) {" & vbCrLf & _
        "       reg0Str += '\\.?[0-9]*';" & vbCrLf & _
        "   }" & vbCrLf & _
        "	reg0Str = allowNegative ? '^-?' + reg0Str : '^' + reg0Str;" & vbCrLf & _
        "	reg0Str = reg0Str + '$';" & vbCrLf & _
        "	var reg0 = new RegExp(reg0Str);" & vbCrLf & _
        "	if (reg0.test(temp)) return true;" & vbCrLf & _
        "" & vbCrLf & _
        "	// first replace all non numbers" & vbCrLf & _
        "	var reg1Str = '[^0-9' + (decimalPlaces != 0 ? '.' : '') " & _
 	"+ (allowNegative ? '-' : '') + ']';" & vbCrLf & _
        "	var reg1 = new RegExp(reg1Str, 'g');" & vbCrLf & _
        "	temp = temp.replace(reg1, '');" & vbCrLf & _
        "" & vbCrLf & _
        "	if (allowNegative) {" & vbCrLf & _
        "		// replace extra negative" & vbCrLf & _
        "		var hasNegative = temp.length > 0 && temp.charAt(0) == '-';" & vbCrLf & _
        "		var reg2 = /-/g;" & vbCrLf & _
        "		temp = temp.replace(reg2, '');" & vbCrLf & _
        "		if (hasNegative) temp = '-' + temp;" & vbCrLf & _
        "	}" & vbCrLf & _
        "	" & vbCrLf & _
        "	if (decimalPlaces != 0) {" & vbCrLf & _
        "		var reg3 = /\./g;" & vbCrLf & _
        "       var reg3Array = reg3.exec(temp);" & vbCrLf & _
        "       if (reg3Array != null) {" & vbCrLf & _
        "		    // keep only first occurrence of . " & vbCrLf & _
        "   	    //  and the number of places specified by decimalPlaces " & _
        "or the entire string if decimalPlaces < 0" & vbCrLf & _
        "	        var reg3Right = temp.substring(reg3Array.index " & _
        "+ reg3Array[0].length);" & vbCrLf & _
        "	        reg3Right = reg3Right.replace(reg3, '');" & vbCrLf & _
        "	        reg3Right = decimalPlaces > 0 ? reg3Right.substring(0, decimalPlaces) : reg3Right;" & vbCrLf & _
        "	        temp = temp.substring(0,reg3Array.index) + '.' + reg3Right;" & vbCrLf & _
        "       }" & vbCrLf & _
        "   }" & vbCrLf & _
        "	" & vbCrLf & _
        "	obj.value = temp;" & vbCrLf & _
        "}" & vbCrLf & _
        "function blockNonNumbers(obj, e, allowDecimal, allowNegative)" & vbCrLf & _
        "{" & vbCrLf & _
        "	var key;" & vbCrLf & _
        "	var isCtrl = false;" & vbCrLf & _
        "	var keychar;" & vbCrLf & _
        "	var reg;" & vbCrLf & _
        "	" & vbCrLf & _
        "	if(window.event) {" & vbCrLf & _
        "		key = e.keyCode;" & vbCrLf & _
        "		isCtrl = window.event.ctrlKey" & vbCrLf & _
        "	}" & vbCrLf & _
        "	else if(e.which) {" & vbCrLf & _
        "		key = e.which;" & vbCrLf & _
        "		isCtrl = e.ctrlKey;" & vbCrLf & _
        "	}" & vbCrLf & _
        "	" & vbCrLf & _
        "	if (isNaN(key)) return true;" & vbCrLf & _
        "	" & vbCrLf & _
        "	keychar = String.fromCharCode(key);" & vbCrLf & _
        "		" & vbCrLf & _
        "	// check for backspace or delete, or if Ctrl was pressed" & vbCrLf & _
        "	if (key == 8 || isCtrl)" & vbCrLf & _
        "	{" & vbCrLf & _
        "		return true;" & vbCrLf & _
        "	}" & vbCrLf & _
        "	reg = /\d/;" & vbCrLf & _
        "	var isFirstN = allowNegative ? keychar == '-' && obj.value.indexOf('-') == -1 : false;" & vbCrLf & _
        "	var isFirstD = allowDecimal ? keychar == '.' && obj.value.indexOf('.') == -1 : false;" & vbCrLf & _
        "	" & vbCrLf & _
        "	return isFirstN || isFirstD || reg.test(keychar);" & vbCrLf & _
        "}</script>"


    Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
        MyBase.OnPreRender(e)
        Dim decPlaces As Int32
        If _AllowDecimal Then
            decPlaces = _DecimalPlaces
        End If
        Me.Page.RegisterClientScriptBlock("NumericValidation", js)
        Me.Attributes.Add("onblur", "extractNumber(this," & _
   decPlaces & "," & _AllowNegative.ToString.ToLower & ");")
        Me.Attributes.Add("onkeyup", "extractNumber(this," & _
  decPlaces & "," & _AllowNegative.ToString.ToLower & ");")
        Me.Attributes.Add("onkeypress", "return blockNonNumbers(this, event," & _
   _AllowDecimal.ToString.ToLower & "," & _AllowNegative.ToString.ToLower & ");")

    End Sub

    Public Property DecimalPlaces() As Int32
        Get
            Return _DecimalPlaces
        End Get
        Set(ByVal Value As Int32)
            _DecimalPlaces = Value
        End Set
    End Property

    Public Property AllowDecimal() As Boolean
        Get
            Return _AllowDecimal
        End Get
        Set(ByVal Value As Boolean)
            _AllowDecimal = Value
        End Set
    End Property

    Public Property AllowNegative() As Boolean
        Get
            Return _AllowNegative
        End Get
        Set(ByVal Value As Boolean)
            _AllowNegative = Value
        End Set
    End Property
End Class

Examples of Use:

	NumericTextBox1.AllowDecimal = True
        NumericTextBox1.AllowNegative = False
	NumericTextBox1.DecimalPlaces = 2

Additional Information:
A DecimalPlaces value of -1 = unlimited numbers after the decimal point