539 lines
21 KiB
VB.net
539 lines
21 KiB
VB.net
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Imports System.Text
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Namespace Expression
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''' <summary>
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''' 字符算数表达式求和
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''' </summary>
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Public Class StringExpression
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''' <summary>精度</summary>
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Private Shared _doublePrecision As Double = 0.000001
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''' <summary>
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''' 替换占位符
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''' </summary>
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''' <param name="str">字符串表达式</param>
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''' <returns></returns>
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Public Shared Function UseMarkSymbolReplace(str As String) As String
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Dim destString As New StringBuilder
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str = str.Replace(" ", "")
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str = str.Replace(">>", "r") 'right move
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str = str.Replace("<<", "l") ' left move
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str = str.Replace("||", "o") 'or
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str = str.Replace("&&", "a") 'and
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str = str.Replace(">=", "g") 'greater equal
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str = str.Replace("<=", "s") 'small equal
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str = str.Replace("<>", "u") 'unequal
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str = str.Replace("!=", "u") 'unequal
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str = str.Replace("==", "e") 'equal
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For i As Integer = 0 To str.Length - 1 '替换负号
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If i = 0 Then
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If str.Chars(i) = "-"c Then
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destString.Append("0"c)
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End If
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destString.Append(str.Chars(i))
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ElseIf str.Chars(i) = "-"c AndAlso str.Chars(i - 1) = "("c Then
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destString.Append("0"c)
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destString.Append(str.Chars(i))
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Else
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destString.Append(str.Chars(i))
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End If
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Next
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Return destString.ToString()
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End Function
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''' <summary>
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''' 替换表达式式中的十六进制占位符为实际内容,例如替换B4为buf中的第4位即buf(4)的值
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''' </summary>
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''' <param name="buf"></param>
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''' <param name="expressionString"></param>
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''' <returns></returns>
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Public Shared Function ReplaceBytes(buf() As Byte, expressionString As String) As String
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Dim ch As Char
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Dim count As Integer = 0
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Dim str As String = ""
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Dim tmp As Integer
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For i As Integer = 0 To expressionString.Length - 1
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If expressionString.Chars(i) = "B"c Then
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ch = expressionString.Chars(i + count + 1)
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While IsNumeric(ch)
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count += 1
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If i + count + 1 >= expressionString.Length Then Exit While
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ch = expressionString.Chars(i + count + 1)
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End While
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If count <= 0 Then Return ""
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Dim st As String = Mid(expressionString, i + 1 + 1, count)
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tmp = Convert.ToInt32(st)
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If tmp > buf.Length - 1 Then Return ""
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str += buf(tmp).ToString
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i += count
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count = 0
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Else
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str += expressionString.Chars(i)
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End If
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Next
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Return str
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End Function
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''' <summary>
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''' 获取表达式转换后的结果是否为真,0、false、空字符为假，1，true为真, 其余为通过计算不为0判断真假
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''' </summary>
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''' <param name="exp"></param>
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''' <returns></returns>
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Public Shared Function GetBooleanResult(exp As String) As Boolean
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If exp Is Nothing Then Return False
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If String.IsNullOrWhiteSpace(exp) Then Return False
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exp = exp.ToLower()
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If exp.Equals($"false") Then Return False
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If exp.Equals($"true") Then Return True
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exp = exp.Replace("false", "0"c)
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exp = exp.Replace("true", "1"c)
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Dim str As String = GetDoubleExpressionResult(exp).ToString()
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Console.WriteLine($"Result:{str}")
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Return Math.Abs(GetDoubleExpressionResult(exp) - 0) > _doublePrecision
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End Function
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''' <summary>
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''' 获取double类型运算式字符串后缀表达式
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''' </summary>
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''' <param name="str">字符串表达式</param>
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''' <returns></returns>
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Public Shared Function GetDoubleExpressionResult(str As String) As Double
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Dim isNum As Boolean
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Dim numStack As New Stack(Of Double)
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Dim operatorStack As New Stack(Of Char)
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Dim num1, num2 As Double
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Dim priority As Integer
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Dim ch As Char
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str = UseMarkSymbolReplace(str)
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For i As Integer = 0 To str.Length - 1
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ch = str.Chars(i)
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If ch >= "0"c AndAlso ch <= "9"c Then '数字处理
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Dim tmpStr As String = String.Empty
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Dim len As Integer = 1
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tmpStr += ch
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isNum = True
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While isNum
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If i + len >= str.Length Then Exit While
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ch = str.Chars(i + len)
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If ch >= "0"c AndAlso ch <= "9"c Then
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tmpStr += ch
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len += 1
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ElseIf ch = "."c Then
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tmpStr += ch
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len += 1
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Else
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isNum = False
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End If
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End While
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numStack.Push(Double.Parse(tmpStr))
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i += len - 1
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ElseIf CheckCharValidity(ch) = 1 Then '运算符号
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If operatorStack.Count = 0 Then
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operatorStack.Push(ch)
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Else
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priority = GetCharacterPriority(ch) '获取当前符号的优先级
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While operatorStack.Count > 0 AndAlso GetCharacterPriority(operatorStack.Peek) < 11 AndAlso priority <= GetCharacterPriority(operatorStack.Peek)
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num1 = numStack.Pop
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num2 = numStack.Pop
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numStack.Push(GetDoubleResult(num2, num1, operatorStack.Pop))
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End While
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If priority = 0 Then '为后半边括号
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operatorStack.Pop()
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Else '为前半边括号
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operatorStack.Push(ch)
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End If
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End If
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End If
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If i = str.Length - 1 Then
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priority = -1
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While operatorStack.Count > 0 AndAlso GetCharacterPriority(operatorStack.Peek) < 11 AndAlso priority <= GetCharacterPriority(operatorStack.Peek)
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num1 = numStack.Pop
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num2 = numStack.Pop
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numStack.Push(GetDoubleResult(num2, num1, operatorStack.Pop))
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End While
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End If
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Next
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Return Math.Round(numStack.Pop, 3) '计算保留小数位三位
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End Function
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''' <summary>
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''' 获取小数类型运算结果
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''' </summary>
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''' <param name="num1">浮点型数1</param>
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''' <param name="num2">浮点型数2</param>
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''' <param name="c">运算符</param>
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''' <returns></returns>
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Public Shared Function GetDoubleResult(num1 As Double, num2 As Double, c As Char) As Double
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Dim result As Double
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Select Case c
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Case "*"c
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result = num1 * num2
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Case "/"c
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If Math.Abs(num2 - 0) < _doublePrecision Then Throw New Exception($"除数为0执行失败")
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result = num1 / num2
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Case "%"c
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result = num1 Mod num2
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Case "+"c
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result = num1 + num2
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Case "-"c
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result = num1 - num2
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Case "l"c '左移
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result = CInt(num1) << CInt(num2)
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Case "r"c '右移
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result = CInt(num1) >> CInt(num2)
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Case "&"c
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result = CInt(num1) And CInt(num2)
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Case "^"c
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result = CInt(num1) Xor CInt(num2)
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Case "|"c
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result = CInt(num1) Or CInt(num2)
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Case ">"c '大于等于
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result = CInt(IIf(num1 > num2, 1, 0))
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Case "<"c '大于等于
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result = CInt(IIf(num1 < num2, 1, 0))
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Case "="c '等于
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result = CInt(IIf(Math.Abs(num1 - num2) < _doublePrecision, 1, 0))
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Case "g"c '大于等于
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result = CInt(IIf(num1 >= num2, 1, 0))
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Case "s"c '小于等于
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result = CInt(IIf(num1 <= num2, 1, 0))
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Case "u"c '不等于
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result = CInt(IIf(Math.Abs(num1 - num2) > _doublePrecision, 1, 0))
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Case "e"c '等于
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result = CInt(IIf(Math.Abs(num1 - num2) < _doublePrecision, 1, 0))
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Case "a"c '逻辑与
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If num1 > 0 AndAlso num2 > 0 Then
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result = 1
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Else
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result = 0
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End If
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Case "o"c '逻辑或
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If num1 > 0 OrElse num2 > 0 Then
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result = 1
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Else
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result = 0
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End If
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Case Else
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Throw New Exception($"未知的操作符：[{c}]")
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End Select
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Return result
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End Function
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''' <summary>
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''' 获取符号的优先级
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''' </summary>
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''' <param name="c">运算符号</param>
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''' <returns></returns>
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Private Shared Function GetCharacterPriority(c As Char) As Integer
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Dim intNum As Integer
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Select Case c
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Case "("c
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intNum = 11
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Case "*"c, "/"c, "%"c
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intNum = 10
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Case "+"c, "-"c
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intNum = 9
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Case "l"c, "r"c
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intNum = 8
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Case ">"c, "<"c, "b"c, "s"c
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intNum = 7
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Case "="c, "u"c, "e"c
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intNum = 6
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Case "&"c
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intNum = 5
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Case "^"c
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intNum = 4
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Case "|"c
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intNum = 3
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Case "a"c
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intNum = 2
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Case "o"c
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intNum = 1
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Case ")"c
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intNum = 0
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Case Else
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Throw New Exception($"未知的操作符：[{c}]")
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End Select
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Return intNum
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End Function
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''' <summary>
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''' 校验字符合法性，0为数字，1为运算符，-1为未使用的运算符
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''' </summary>
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''' <param name="c">需要校验的字符</param>
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''' <returns></returns>
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Private Shared Function CheckCharValidity(c As Char) As Integer
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Select Case c
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Case "1"c, "2"c, "3"c, "4"c, "5"c, "6"c, "7"c, "8"c, "9"c, "0"c
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Return 0
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Case "+"c, "-"c, "*"c, "/"c, "%"c, "^"c, "|"c, "&"c, "("c, ")"c, "o"c, "a"c, "l"c, "r"c, "."c,
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"u"c, "g"c, "s"c, "<"c, ">"c, "="c, "e"c
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Return 1
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Case Else
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Return -1
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End Select
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End Function
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''' <summary>
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''' 校验运算式字符串合法性(todo:待进一步完善检测逻辑)
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''' </summary>
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''' <param name="str">需要校验的字符串</param>
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''' <returns></returns>
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Public Shared Function CheckExpressionString(str As String) As Boolean
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str = str.Replace(" ", "")
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For i As Integer = 0 To str.Length - 1
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If CheckCharValidity(str.Chars(i)) = -1 Then
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Return False
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End If
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Next
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Return True
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End Function
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'''' <summary>
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'''' 获取int类型运算式字符串后缀表达式
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'''' </summary>
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'''' <param name="str">字符串表达式</param>
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'''' <returns></returns>
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'Public Shared Function GetIntegerExpressionResult(str As String) As Integer
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' Dim isNum As Boolean
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' Dim numberStack As New Stack(Of Integer)
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' Dim operatorStack As New Stack(Of Char)
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' Dim num1, num2, priority As Integer
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' str = UseMarkSymbolReplace(str, False)
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' For Each c As Char In str
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' If c >= "0"c AndAlso c <= "9"c Then
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' If isNum Then
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' Dim tmp As Integer = numberStack.Pop
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' tmp = tmp * 10 + Integer.Parse(c.ToString)
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' numberStack.Push(tmp)
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' Else
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' numberStack.Push(Integer.Parse(c.ToString))
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' isNum = True
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' End If
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' ElseIf CheckCharValidity(c) = 1 Then
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' isNum = False
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' If operatorStack.Count = 0 Then
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' operatorStack.Push(c)
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' Else
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' priority = GetCharacterPriority(c)
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' While operatorStack.Count > 0 AndAlso GetCharacterPriority(operatorStack.Peek) < 11 AndAlso priority <= GetCharacterPriority(operatorStack.Peek)
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' num1 = numberStack.Pop
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' num2 = numberStack.Pop
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' numberStack.Push(GetIntegerResult(num2, num1, operatorStack.Pop))
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' End While
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' If priority = 0 Then
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' operatorStack.Pop()
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' Else
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' operatorStack.Push(c)
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' End If
|
|||
|
|
' End If
|
|||
|
|
' End If
|
|||
|
|
|
|||
|
|
' If c = str.Chars(str.Length - 1) Then
|
|||
|
|
' priority = GetCharacterPriority(c)
|
|||
|
|
' While operatorStack.Count > 0 AndAlso GetCharacterPriority(operatorStack.Peek) < 11 AndAlso priority <= GetCharacterPriority(operatorStack.Peek)
|
|||
|
|
' num1 = numberStack.Pop
|
|||
|
|
' num2 = numberStack.Pop
|
|||
|
|
' numberStack.Push(GetIntegerResult(num2, num1, operatorStack.Pop))
|
|||
|
|
' End While
|
|||
|
|
' End If
|
|||
|
|
' Next
|
|||
|
|
|
|||
|
|
' Return numberStack.Pop
|
|||
|
|
'End Function
|
|||
|
|
|
|||
|
|
'''' <summary>
|
|||
|
|
'''' 获取整形的运算结果
|
|||
|
|
'''' </summary>
|
|||
|
|
'''' <param name="num1">整数1</param>
|
|||
|
|
'''' <param name="num2">整数2</param>
|
|||
|
|
'''' <param name="c">运算符</param>
|
|||
|
|
'''' <returns>预算结果</returns>
|
|||
|
|
'Public Shared Function GetIntegerResult(num1 As Integer, num2 As Integer, c As Char) As Integer
|
|||
|
|
' Dim result As Integer
|
|||
|
|
' Select Case c
|
|||
|
|
' Case "*"c
|
|||
|
|
' result = num1 * num2
|
|||
|
|
' Case "/"c
|
|||
|
|
' result = num1 \ num2
|
|||
|
|
' Case "%"c
|
|||
|
|
' result = num1 Mod num2
|
|||
|
|
' Case "+"c
|
|||
|
|
' result = num1 + num2
|
|||
|
|
' Case "-"c
|
|||
|
|
' result = num1 - num2
|
|||
|
|
' Case "L"c
|
|||
|
|
' result = num1 << num2
|
|||
|
|
' Case "R"c
|
|||
|
|
' result = num1 >> num2
|
|||
|
|
' Case "&"c
|
|||
|
|
' result = num1 And num2
|
|||
|
|
' Case "^"c
|
|||
|
|
' result = num1 Xor num2
|
|||
|
|
' Case "|"c
|
|||
|
|
' result = num1 Or num2
|
|||
|
|
|
|||
|
|
' Case ">"c '大于等于
|
|||
|
|
' result = CInt(IIf(num1 > num2, 1, 0))
|
|||
|
|
' Case "<"c '大于等于
|
|||
|
|
' result = CInt(IIf(num1 < num2, 1, 0))
|
|||
|
|
' Case "="c '等于
|
|||
|
|
' result = CInt(IIf(num1 = num2, 1, 0))
|
|||
|
|
' Case "g"c '大于等于
|
|||
|
|
' result = CInt(IIf(num1 >= num2, 1, 0))
|
|||
|
|
' Case "l"c '小于等于
|
|||
|
|
' result = CInt(IIf(num1 <= num2, 1, 0))
|
|||
|
|
' Case "u"c '不等于
|
|||
|
|
' result = CInt(IIf(num1 <> num2, 1, 0))
|
|||
|
|
' Case "e"c '等于
|
|||
|
|
' result = CInt(IIf(num1 = num2, 1, 0))
|
|||
|
|
|
|||
|
|
' Case "A"c
|
|||
|
|
' If num1 > 0 AndAlso num2 > 0 Then
|
|||
|
|
' result = 1
|
|||
|
|
' Else
|
|||
|
|
' result = 0
|
|||
|
|
' End If
|
|||
|
|
' Case "O"c
|
|||
|
|
' If num1 > 0 OrElse num2 > 0 Then
|
|||
|
|
' result = 1
|
|||
|
|
' Else
|
|||
|
|
' result = 0
|
|||
|
|
' End If
|
|||
|
|
' Case Else
|
|||
|
|
' Throw New Exception($"未知的操作符：[{c}]")
|
|||
|
|
' End Select
|
|||
|
|
' Return result
|
|||
|
|
'End Function
|
|||
|
|
|
|||
|
|
|
|||
|
|
' Private Shared ReadOnly _operateList As New List(Of Char) From {"+"c, "*"c, "/"c, "%"c, "-"c, "^"c, "|"c, "&"c}
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
'Private Shared Function CheckDoubleResultChar(exp As String) As Boolean
|
|||
|
|
' For i As Integer = 0 To exp.Length - 1
|
|||
|
|
' If exp.Chars(i) > "0"c AndAlso exp.Chars(i) < "9"c Then
|
|||
|
|
' '有效数字
|
|||
|
|
' Continue For
|
|||
|
|
' End If
|
|||
|
|
|
|||
|
|
|
|||
|
|
' Select Case exp.Chars(i)
|
|||
|
|
' Case "-"c
|
|||
|
|
' '减运算符前不能为运算符
|
|||
|
|
|
|||
|
|
|
|||
|
|
' Case "+"c, "*"c, "/"c, "%"c
|
|||
|
|
' '运算符前后位必须为数字
|
|||
|
|
' If i = 0 Then Return False '不能为开头
|
|||
|
|
' If i = exp.Length - 1 Then Return False '不能为结尾
|
|||
|
|
' ' If exp.Chars(i + 1) Then Return False'下一位不能
|
|||
|
|
|
|||
|
|
' Case "!"c'是否应该支持
|
|||
|
|
' '按位操作前后须有数字
|
|||
|
|
|
|||
|
|
' Case "^"c
|
|||
|
|
' '按位操作前后须有数字
|
|||
|
|
|
|||
|
|
' Case "|"c
|
|||
|
|
' '按位操作前后须有数字
|
|||
|
|
|
|||
|
|
' '逻辑操作前后须有数字
|
|||
|
|
|
|||
|
|
|
|||
|
|
' '确定是否为逻辑操作
|
|||
|
|
|
|||
|
|
' Case "&"c
|
|||
|
|
' '按位操作前后须有数字
|
|||
|
|
|
|||
|
|
' '逻辑操作前后须有数字
|
|||
|
|
|
|||
|
|
|
|||
|
|
' '确定是否为逻辑操作
|
|||
|
|
|
|||
|
|
' Case ">"c
|
|||
|
|
' '判断逻辑符或是组合符号
|
|||
|
|
|
|||
|
|
' Case "<"c
|
|||
|
|
' '判断逻辑符或是组合符号
|
|||
|
|
|
|||
|
|
' Case "="c
|
|||
|
|
|
|||
|
|
' '判断逻辑符或是组合符号
|
|||
|
|
|
|||
|
|
' Case "."c
|
|||
|
|
' '前后必为数字
|
|||
|
|
|
|||
|
|
' Case "("c
|
|||
|
|
' '括号必须匹配
|
|||
|
|
|
|||
|
|
' Case ")"c
|
|||
|
|
' '括号必须匹配
|
|||
|
|
|
|||
|
|
' Case " "c
|
|||
|
|
' '空格忽略
|
|||
|
|
|
|||
|
|
' Case Else
|
|||
|
|
|
|||
|
|
|
|||
|
|
' End Select
|
|||
|
|
' Next
|
|||
|
|
|
|||
|
|
|
|||
|
|
' Return False
|
|||
|
|
'End Function
|
|||
|
|
|
|||
|
|
|
|||
|
|
''' <summary>
|
|||
|
|
''' 返回表达式的值 'Momo 2022-11-10 增加 、Momo 2023-12-15 错误时抛出错误而不是弹窗
|
|||
|
|
''' </summary>
|
|||
|
|
''' <returns></returns>
|
|||
|
|
Public Shared Function ExecuteLimit(ByVal strExpression As String, ByRef dblResult As String) As Boolean
|
|||
|
|
'检测有无需要计算的表达式
|
|||
|
|
If String.IsNullOrWhiteSpace(strExpression) Then
|
|||
|
|
'’MsgBox(strExpression & " 是空白值或表达式，执行失败！")
|
|||
|
|
'Throw New Exception(strExpression & " 是空白值或表达式，执行失败！") 'Momo 2023-12-15 错误时抛出错误而不是弹窗
|
|||
|
|
Return False
|
|||
|
|
End If
|
|||
|
|
|
|||
|
|
'检测表达式的有效性
|
|||
|
|
If StringExpression.CheckExpressionString(strExpression) = False Then
|
|||
|
|
'’MsgBox(strExpression & " 是无效值或表达式，执行失败！")
|
|||
|
|
'Throw New Exception(strExpression & " 是无效值或表达式，执行失败！") 'Momo 2023-12-15 错误时抛出错误而不是弹窗
|
|||
|
|
Return False
|
|||
|
|
End If
|
|||
|
|
|
|||
|
|
Try
|
|||
|
|
dblResult = StringExpression.GetDoubleExpressionResult(strExpression).ToString()
|
|||
|
|
Return True
|
|||
|
|
Catch ex As Exception
|
|||
|
|
'’MsgBox(strExpression & " 表达式计算失败，执行失败！")
|
|||
|
|
'Throw New Exception(strExpression & " 表达式计算失败，执行失败！") 'Momo 2023-12-15 错误时抛出错误而不是弹窗
|
|||
|
|
Return False
|
|||
|
|
End Try
|
|||
|
|
|
|||
|
|
End Function
|
|||
|
|
|
|||
|
|
|
|||
|
|
End Class
|
|||
|
|
End Namespace
|