正文
vb.net位数 vbnet dir
提示：扫一扫查出行【扫一扫了解最新限行尾号】
复制提示
vb.net 怎样使计算结果只保留四位小数？
用这个函数把
Math.Round 方法 (Decimal, Int32)
将小数值舍入到指定精度。
命名空间： System
程序集： mscorlib（在 mscorlib.dll 中）
语法
Visual Basic（用法）
Dim d As Decimal
Dim decimals As Integer
Dim returnValue As Decimal
returnValue = Math.Round(d, decimals)
参数
d
类型：System.Decimal
要舍入的小数。
decimals
类型：System.Int32
返回值中的小数位数（精度）。
返回值
类型：System.Decimal
精度等于 decimals，最接近 d 的数字。
Math.Round(3.4666666, 4) 结果是 3.4667.
相关问答
Q1: VB.NET设置屏幕分辨率、颜色位数、刷新率 实例代码
这篇文章介绍了VB.NET设置屏幕分辨率、颜色位数、刷新率
实例代码，有需要的朋友可以参考一下
复制代码
代码如下:
Private
Declare
Function
GetDeviceCaps
Lib
"gdi32"
(ByVal
hdc
As
Long,
ByVal
nIndex
As
Long)
As
Long
Private
Declare
Function
ChangeDisplaySettings
Lib
"user32"
Alias
"ChangeDisplaySettingsA"
(lpDevMode
As
Any,
ByVal
dwflags
As
Long)
As
Long
Private
Const
CCDEVICENAME
As
Long
=
32
Private
Const
CCFORMNAME
As
Long
=
32
Private
Const
DM_BITSPERPEL
As
Long
=
H40000
Private
Const
DM_PELSWIDTH
As
Long
=
H80000
Private
Const
DM_PELSHEIGHT
As
Long
=
H100000
Private
Const
DM_DISPLAYFLAGS
As
Long
=
H200000
Private
Const
DM_DISPLAYFREQUENCY
=
H400000
Private
Const
CDS_FORCE
As
Long
=
H80000000
Private
Const
BITSPIXEL
As
Long
=
12
Private
Const
HORZRES
As
Long
=
8
Private
Const
VERTRES
As
Long
=
10
Private
Const
VREFRESH
=
116
Private
Type
DEVMODE
dmDeviceName
As
String
*
CCDEVICENAME
dmSpecVersion
As
Integer
dmDriverVersion
As
Integer
dmSize
As
Integer
dmDriverExtra
As
Integer
dmFields
As
Long
dmOrientation
As
Integer
dmPaperSize
As
Integer
dmPaperLength
As
Integer
dmPaperWidth
As
Integer
dmScale
As
Integer
dmCopies
As
Integer
dmDefaultSource
As
Integer
dmPrintQuality
As
Integer
dmColor
As
Integer
dmDuplex
As
Integer
dmYResolution
As
Integer
dmTTOption
As
Integer
dmCollate
As
Integer
dmFormName
As
String
*
CCFORMNAME
dmUnusedPadding
As
Integer
dmBitsPerPel
As
Integer
dmPelsWidth
As
Long
dmPelsHeight
As
Long
dmDisplayFlags
As
Long
dmDisplayFrequency
As
Long
End
Type
Private
Sub
cmdChangeDesktopMode_Click()
Dim
DM
As
DEVMODE
With
DM
.dmPelsWidth
=
CInt(txtNewWidth.Text)
.dmPelsHeight
=
CInt(txtNewHeight.Text)
.dmBitsPerPel
=
CInt(txtNewColor.Text)
.dmDisplayFrequency
=
CInt(txtNewFreq.Text)
.dmFields
=
DM_PELSWIDTH
Or
DM_PELSHEIGHT
Or
DM_BITSPERPEL
Or
DM_DISPLAYFREQUENCY
.dmSize
=
LenB(DM)
End
With
If
ChangeDisplaySettings(DM,
CDS_FORCE)
Then
MsgBox
"错误!不支持此模式！"
End
If
End
Sub
Private
Sub
Form_Load()
txtOldWidth.Text
=
GetDeviceCaps(Me.hdc,
HORZRES)
txtOldHeight.Text
=
GetDeviceCaps(Me.hdc,
VERTRES)
txtOldColor.Text
=
GetDeviceCaps(Me.hdc,
BITSPIXEL)
txtOldFreq.Text
=
GetDeviceCaps(Me.hdc,
VREFRESH)
End
Sub
Q2: VB.NET ，文本框限制输入数字个数。例如不低于5位数而不大于11位数。违反则有提示。
input type="text" maxlength="11" /这是控制最大输入字数至于不能少于11个字，需要在点击保存按钮时，通过.length来控制
Q3: 怎么在VB.NET中，提取系统日期中的后的 月和日 的位数
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim a As Short = Date.Now.Month
Dim b As Short = Date.Now.Day
MessageBox.Show(a)
MessageBox.Show(b)
End Sub
上面是获取月份以及天数
'======================
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim a As Short = Date.Now.Month
Dim b As Short = Date.Now.Day
Dim c, d As String
If a 0 AndAlso a 10 Then
c = "1位数"
Else
c = "2位数"
End If
If b 0 AndAlso b 10 Then
d = "1位数"
Else
d = "2位数"
End If
MessageBox.Show(c)
MessageBox.Show(d)
End Sub
这个是获取位数的
Q4: vb.net怎么设置数字保留小数点位数
举个例子
Dim a As Decimal = 1.999
Dim b As Decimal = Math.Round(a, 2)
结果为b = 2.00
四舍五入保留两位
Q5: vb.net 获得CPU位数的代码？
CPU位数获取不了vb.net位数，核心数可以，能够用程序侦测出的，可以点vb.net位数我的电脑，右键属性
vb.net位数的介绍就聊到这里吧，感谢你花时间阅读本站内容，更多关于vbnet dir、vb.net位数的信息别忘了在本站进行查找喔。
