vb.net输入数字,vb输入代码

如何在VB.NET 中限制文本框中只能输入数字

以下是只能输入数字和小数点，并且小数点只能输入一次

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles Textbox1.KeyPress

If Char.IsDigit(e.KeyChar) or e.KeyChar = Chr(8) or e.KeyChar = "." Then

If e.KeyChar = "." And InStr(TextBox1.Text, ".") 0 Then

e.Handled = True

Else

e.Handled = False

End If

Else

e.Handled = True

End If

End Sub

相关问答

Q1: VB.NET中的DATAGRIDVIEW怎样只能在表格中输入数字呢

第一部、先定义一个单元格操作变量，如下

Dim cellEdit As DataGridViewTextBoxEditingControl = Nothing

第二部、然后在在控件的EditingControlShowing事件中添加入下代码，参考如下：

Private Sub DataGridView3_EditingControlShowing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs) Handles DataGridView3.EditingControlShowing

cellEdit = CType(e.Control, DataGridViewTextBoxEditingControl)

cellEdit.SelectAll()

AddHandler cellEdit.KeyPress, AddressOf dataGridView3_KeyPress

End Sub

第三部：在要控制的列加入控件键盘按钮的代码，如下面ROLL列是要控制的列

Private Sub dataGridView3_KeyPress(ByVal sender As Object, ByVal e As KeyPressEventArgs) Handles DataGridView3.KeyPress

Dim i As Integer = DataGridView3.CurrentCellAddress.X

Dim ColumnName As String = DataGridView3.Columns(i).Name

If (ColumnName = "rollno") Then

If Not Char.IsDigit(e.KeyChar) And e.KeyChar Chr(8) Then

e.Handled = True

End If

End If

End Sub

Q2: VB.NET在简单组合框中输入数字字符（包含多位数且只能输入数字）按回车键后加入到组合框中

Private Sub ComboBox1_KeyUp(sender As Object, e As System.Windows.Forms.KeyEventArgs) Handles ComboBox1.KeyUp

Select Case e.KeyValue

Case 48 To 57

Case Keys.Enter

ComboBox1.Items.Add(ComboBox1.Text)

Case Else

ComboBox1.Text = ComboBox1.Text.Remove(ComboBox1.Text.Length - 1, 1)

ComboBox1.SelectionStart = ComboBox1.Text.Length

e.Handled = True

End Select

End Sub

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Q3: vb.net 输入一个小数 求能得到这个商的最小的整数除数和最小整数被除数

Option Explicit On

Option Strict On

Imports System

Module Program

Sub Main()

Dim s As String

Dim strs As String()

Dim fz,fm,n,m,t As Long

Console.Write("请输入一个小数：")

s=Console.ReadLine().Trim()

strs=s.Split("."C)

fz=CLng(strs(0))

fm=CLng(Math.Pow(10,strs(1).Length))

fz=fz*fm+CLng(strs(1))

n=fz

m=fm

While n Mod m0

t=n Mod m

n=m

m=t

End While

fz\=m

fm\=m

Console.WriteLine("{0}={1}/{2}",s,fz,fm)

Console.Write("Press any key to continue . . . ")

Console.ReadKey(True)

End Sub

End Module

Q4: 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