vb.net FormatNumber用法

Title	Use the FormatNumber function in Visual Basic .NET
Description	This example shows how to use the FormatNumber function in Visual Basic .NET.
Keywords	FormatNumber,format number,VB.NET
Categories	Strings,VB.NET

The FormatNumber function returns a formatted string representation for a number. The Syntax is:

    FormatNumber(expression _
        [,digits_after_decimal] _
        [,include_leading_zero] _
        [,use_parens_if_negative] _
        [,groups_digits] )

Where:

expression: The numeric expression to format
digits_after_decimal: The number of digits to display after the decimal point
include_leading_zero: If the number is less than 1 and greater than -1,determines whether the number should have a leading 0 before the decimal point.
use_parens_if_negative: Determines whether negative numbers are surrounded with parentheses instead of using a minus sign.
groups_digits: Determines whether digits to the left of the decimal point are grouped with thousands separators (commas in the United States).

Examples:

Expression	Result
`FormatNumber(1.23456,2)`	`1.23`
`FormatNumber(0.123456,2,TriState.False)`	`.12`
`FormatNumber(0.123456,TriState.True)`	`0.12`
`FormatNumber(-12345.12,TriState.False)`	`-12,345.12`
`FormatNumber(-12345.12,TriState.True)`	`(12,345.12)`
`FormatNumber(-12345.12,TriState.True,TriState.False)`	`(12345.12)`

This example uses the following code to display these examples in a TextBox.

Private Sub Form1_Load(ByVal sender As System.Object,ByVal _
    e As System.EventArgs) Handles MyBase.Load
    Dim txt As String
    Dim x As Single

    x = 1.23456
    txt &= "FormatNumber(" & x.ToString() & ",2) = " & _
        FormatNumber(x,2) & vbCrLf
    x = 0.123456
    txt &= "FormatNumber(" & x.ToString() & "," & _
        "TriState.False) = " & FormatNumber(x,_
        TriState.False) & vbCrLf
    txt &= "FormatNumber(" & x.ToString() & "," & _
        "TriState.True) = " & FormatNumber(x,_
        TriState.True) & vbCrLf
    x = -12345.12345
    txt &= "FormatNumber(" & x.ToString() & ",_
        TriState.True) & vbCrLf
    txt &= "FormatNumber(" & x.ToString() & "," & _
        "TriState.True,TriState.False) = " & _
        FormatNumber(x,TriState.False) _
        & vbCrLf

    txtResult.Text = txt
    txtResult.Select(0,0)
End Sub

vb.net FormatNumber用法

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