vb.net16进制浮点,vb浮点数

vb如何将浮点数的十六进制数转化为十进制数据

使用API函数CopyMemory来转换。

Option Explicit

    Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)

 

Private Sub Command1_Click()

    Dim BB(0 To 3) As Byte

    Dim se As Single

    BB(0) = H0

    BB(1) = H80

    BB(2) = H71

    BB(3) = H43

    CopyMemory se, ByVal VarPtr(BB(0)), 4

    Text1.Text = se

End Sub

具体参考：

怎么将4字节16进制转化成浮点数？

四字节16进制数可转换为四个二进制字节（Bytes），从而使用Api函数来处理成单精度浮点数。

以下用VB代码处理。

VB有专门的API函数CopyMemory能处理2-10进制浮点数转换和10-2进制浮点数转换。

下列代码演示了10进制Single（单精度浮点型转为16进制字符显示的浮点数和其相反运算：

Option Explicit

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)

Private Sub BinToSin_Click()

Dim sinStr As String

Dim sinSj As Single

Dim Buffer(3) As Byte

Dim i As Integer

sinStr = Text2

For i = 1 To Len(Text2) Step 2

Buffer((7 - i) / 2) = Val("H" Mid(sinStr, i, 2))

Next

CopyMemory ByVal VarPtr(sinSj), ByVal VarPtr(Buffer(0)), 4

Text3 = sinSj

End Sub

Private Sub SinToBin_Click()

Dim i As Integer

Dim hexData As String

Dim a As Single

Dim Buffer(3) As Byte

a = Val(Text1)

CopyMemory Buffer(0), a, 4

For i = 0 To 3

If Len(Hex(Buffer(i))) = 1 Then

hexData = "0" Hex(Buffer(i)) + hexData

Else

hexData = Hex(Buffer(i)) + hexData

End If

Next

Text2 = hexData

End Sub

需要注意的事项是这四字节的高低字节排序，不能搞错。

VB的Single 数据类型：

Single（单精度浮点型）变量存储为 IEEE 32 位（4 个字节）浮点数值的形式，它的范围在负数的时候是从 -3.402823E38 到 -1.401298E-45，而在正数的时候是从 1.401298E-45 到 3.402823E38。Single 的类型声明字符为感叹号 (!)。

在内存以32位二进制形式存在:

XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX

第1位为符号位；

第2-9位为阶码位；

第10-32位为2进制小数尾值；

即F2 ^ n * 1. XXXXXXX XXXXXXXX XXXXXXXX；

其中，F为正号或负号(首为为0正数,首位为1负数；

n为2-9位组成的BYTE数据值；

XXXXXXX XXXXXXXX XXXXXXXX为尾数。

参考：

如何用VB.NET将单精度16进制转换成浮点数

#读取上次检查到的行数

last_line=`cat ./mailinfo`

echo "上次行数："$last_line

#算出本次alert日志的行数

current_line=`wc -l $alert_log|awk '{print $1}'`

echo "本次行数："$current_line

#取上次行数和本次行数之间的alert日志内容，然后把ORA错误及上下三行放到mailinfo中

vb.net 4位十六进制 转浮点数

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Dim aa(3) As Byte

Dim f As Single

aa(0) = H0

aa(1) = H0

aa(2) = H80

aa(3) = H3F

'CopyMemory(f, aa, 4)

f = BitConverter.ToSingle(aa, 0)

TextBox1.Text = f

End Sub

End Class

vb.net 中2、8、10、16进制转换代码怎么写

Option Explicit

Dim Jz As Integer, K As Boolean

Private Sub Command1_Click()

Pic.Cls

If K Then Jz = Val(Qtjz.Text)

If Pd(Text1.Text, Jz) Then Pic.Print "选择的进制与数不符": Exit Sub

If Jz = 0 Then Pic.Print "请先输入进制" Else Pic.Print Zh(Text1.Text, Jz)

End Sub

Private Sub Command2_Click()

End

End Sub

Private Sub Frame1_DragDrop(Source As Control, X As Single, Y As Single)

End Sub

Private Sub Option1_Click(Index As Integer)

K = False

Select Case Index

Case 0

Jz = 2

Case 1

Jz = 8

Case 2

Jz = 10

Case 3

Jz = 16

Case 4

K = True

Qtjz.Text = ""

Qtjz.SetFocus

End Select

If Index 4 Then Command1.SetFocus

End Sub

Private Sub Qtjz_Click()

Qtjz.Text = ""

End Sub

Private Sub Text1_Click()

Text1.Text = ""

End Sub

Private Function Zh(a As String, b As Integer) As Integer

Dim c As String, i, d As Integer

a = LCase(a)

For i = 1 To Len(a)

c = Mid(a, Len(a) + 1 - i, 1)

If Asc(c) 96 Then d = Asc(c) - 87 Else d = Val(c)

Zh = Zh + d * b ^ (i - 1)

Next i

End Function

Private Function Pd(a As String, b As Integer) As Boolean

Dim c As String, i, d As Integer

Pd = False

For i = 1 To Len(a)

c = Mid(a, Len(a) + 1 - i, 1)

If Asc(c) 96 Then d = Asc(c) - 87 Else d = Val(c)

If d b - 1 Then Pd = True: Exit Function

Next i

End Function

VB把浮点数变为十六进制怎么办？

'//首先，在工程中加入心缘梦恋VB计算类模块“bMaths”'//'//全局定义Private B1 As New bMaths'//在窗体中写入自定义函数：Private Function HexToFloat(ByVal Hexadecimal As String) As Single

Dim tmp_B As String

tmp_B = B1.Bin(Text1(2).Text)

'

Dim Power As Integer, Effective As Long, s_Effective As String, PN As Byte

'//幂（Power）；Effective（有效数）；PN（正负定义）

Power = Val("H" B1.HexB(Mid(tmp_B, 2, 8))) - 127

s_Effective = Right(tmp_B, 23)

s_Effective = "1" s_Effective

Select Case Power

Case Is 0

Power = 0 - Power

Effective = Val("H" B1.HexB(s_Effective))

PN = Val(Left(tmp_B, 1))

HexToFloat = ((-1) ^ PN) * (Effective / (2 ^ (23 + Power)))

Case Is = 0

Dim s_Front As String, s_Follow As String

s_Front = Left(s_Effective, 1 + Power)

s_Follow = Right(s_Effective, 23 - Power)

PN = Val(Left(tmp_B, 1))

HexToFloat = ((-1) ^ PN) * (Val("H" B1.HexB(s_Front)) + Val("H" B1.HexB(s_Follow)) / (2 ^ (23 - Power)))

End Select

End Function'//'//调用函数HexToFloat，将十六进制数值转化为浮点型数据'//例如，将“43730000”转化为浮点型数据Private Sub Form_Load()

Debug.Print HexToFloat("43730000")

End Sub'//输出结果：“243”'//'//特别提醒：此段函数还没有考虑浮点数据的科学计数法。不过，这段函数在一般情况下已经够用了。如果还有好的建议，您可以加入我们的群（ID：18858430），一起探讨。