vb.net只输入数字 vb输入任何字符都只显示

VB.NET下,让textbox只能输入数字,小数点,和负号,我的代码哪里有错?private str as string 'str最好定义到外面
Private Sub TextBox1_KeyUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyUp
Dim d As Double
If Double.TryParse(TextBox1.Text, d) Or TextBox1.Text = "-" Or TextBox1.Text.Trim() = "" Then
str = TextBox1.Text
Else
TextBox1.Text = str
TextBox1.SelectionStart = TextBox1.Text.Length
TextBox1.Focus()
End If
End Sub
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vb.net只输入数字,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
【vb.net只输入数字 vb输入任何字符都只显示】End Sub
vb.net 让相应的textbox中只能输入“中文字符、英文、数字”每个textbox都有KeyPress事件(event)vb.net只输入数字 , 每次用户输入一个字符时检测vb.net只输入数字,如不满足则清空
我现在不在vs下,vb.net只输入数字你可以找到这个面板 , 绑定相应的函数
比如只能显示数字
Private Sub NumBox_KeyPress(KeyAscii As Integer)
If Not IsNumeric(NumBox.Text) Then
NumBox.Text = ""
End If
End Sub
只能显示英语(a-z 97-122; A-Z 65-90; 8(退格)和13(换行))
Private Sub EngBox_KeyPress(KeyAscii As Integer)
If Not (KeyAscii = 97 And KeyAscii=122) Or (KeyAscii = 90 And KeyAscii=65) Or = 8 Then
EngBox.Text = ""
End If
End Sub
只能显示汉字(汉字的ASCII值要么小于0 , 要么是8(退格)和13(换行))
Private Sub ChineseBox_KeyPress(KeyAscii As Integer)
If Not KeyAscii0 Or KeyAscii = 8 Or KeyAscii = 13 Then
ChineseBox.Text=""
End If
End Sub
做vb.net只输入数字了一些小修改,不明白请及时追问,满意敬请采纳,O(∩_∩)O谢谢
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.KeyCharChr(8) Then
e.Handled = True
End If
End If
End Sub
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