Cint 小数部分超过0.5的部分都进位，不分正负

例如：

Cint（2.51）=3

Cint（-2.51）=-3

小于等于0.5的部分都舍去，不分正负

例如：

Cint(2.49)=2

Cint(-2.49)=-2

Cint(2.5)=2

Cint(-2.5)=-2

Int取到的是小于这个数的最大整数

例如:

Int(2.49)=2

Int(2.50)=2

Int(2.51)=2

Int(-2.49)=-3

Int(-2.50)=-3

Int(-2.51)=-3

Round 确定好保留的位数后，后面的直接四舍五入

例如：

Round(2.459,2)=2.46

Round(2.454,2)=2.45

Round(-2.459)=-2.46

Round(-2.454,2)=-2.45

Fix省略小数位，即直接截走小数位

例如

Fix(2.51)=2 Fix(2.49)=2

Fix(-2.49)=-2 Fix(-2.51)=-2

在实际操作中验证：

Private Sub Command1_Click()

List1.AddItem "Cint(2.49)=" & CStr(CInt(2.49))

List1.AddItem "Cint(-2.49)=" & CStr(CInt(-2.49))

List1.AddItem "Cint(2.50)=" & CStr(CInt(2.5))

List1.AddItem "Cint(-2.50)=" & CStr(CInt(-2.5))

List1.AddItem "Cint(2.12)=" & CStr(CInt(2.12))

List1.AddItem "Cint(-2.12)=" & CStr(CInt(-2.12))

List1.AddItem "Cint(2.51)=" & CStr(CInt(2.51))

List1.AddItem "Cint(-2.51)=" & CStr(CInt(-2.51))

List1.AddItem " "

List1.AddItem "Int(2.49)=" & CStr(Int(2.49))

List1.AddItem "Int(-2.49)=" & CStr(Int(-2.49))

List1.AddItem "Int(2.50)=" & CStr(Int(2.5))

List1.AddItem "Int(-2.50)=" & CStr(Int(-2.5))

List1.AddItem "Int(2.12)=" & CStr(Int(2.12))

List1.AddItem "Int(-2.12)=" & CStr(Int(-2.12))

List1.AddItem "Int(2.51)=" & CStr(Int(2.51))

List1.AddItem "Int(-2.51)=" & CStr(Int(-2.51))

List1.AddItem "Int(-0.51)=" & CStr(Int(-0.51))

List1.AddItem "Int(0.51)=" & CStr(Int(0.51))

List1.AddItem " "

List1.AddItem "Round(2.459,2)=" & CStr(Round(2.459, 2))

List1.AddItem "Round(-2.459,2)=" & CStr(Round(-2.459, 2))

List1.AddItem "Round(2.454,2)=" & CStr(Round(2.454, 2))

List1.AddItem "Round(-2.454,2)=" & CStr(Round(-2.454, 2))

List1.AddItem " "

List1.AddItem "fix(2.45)=" & CStr(Fix(2.45))

List1.AddItem "fix(2.51)=" & CStr(Fix(2.51))

List1.AddItem "fix(-2.49)=" & CStr(Fix(-2.49))

List1.AddItem "fix(-2.51)=" & CStr(Fix(-2.51))

End Sub