Vb.net Visual basic小于0
我试图制作一个程序,当我把一个小于0的值放在一个标签中,比如“ 负数不能用我有这个Vb.net Visual basic小于0,vb.net,Vb.net,我试图制作一个程序,当我把一个小于0的值放在一个标签中,比如“ 负数不能用我有这个 Public Class Form1 'Sebastian roman. Perimeter, 10/1/2014 Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click Try D
Public Class Form1 'Sebastian roman. Perimeter, 10/1/2014
Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click
Try
Dim intSide1 As Integer = txtSide1.Text
Dim intSide2 As Integer = txtSide2.Text
Dim intSide3 As Integer = txtSide3.Text
Dim intSide4 As Integer = txtSide4.Text
Dim intTotal As Integer = intSide1 + intSide2 + intSide3 + intSide4
lblMessage.Text = intTotal.ToString("#,###.##")
Catch ex As Exception
MessageBox.Show("Incorrect Input. Enter a numeric value.")
End Try
End Sub
End Class
是的,我必须使用try-catch方法,我需要这方面的帮助整数可以是负数
Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click
Try
Dim intSide1 As Integer = txtSide1.Text
Dim intSide2 As Integer = txtSide2.Text
Dim intSide3 As Integer = txtSide3.Text
Dim intSide4 As Integer = txtSide4.Text
Dim intTotal As Integer = intSide1 + intSide2 + intSide3 + intSide4
lblMessage.Text = intTotal.ToString("#,###.##")
//New code
if intSide1 < 0 or intSide2 < 0 or intSide3 < 0 intSide4 < 0 Then
MessageBox.Show("Incorrect Input. Negative number not valid")
end if
Catch ex As Exception
MessageBox.Show("Incorrect Input. Enter a numeric value.")
End Try
End Sub
Private Sub btnCalculate\u Click(ByVal sender作为System.Object,ByVal e作为System.EventArgs)处理btnCalculate。单击
尝试
Dim intSide1作为整数=txtSide1.Text
Dim intSide2作为整数=txtSide2.Text
Dim intSide3作为整数=txtSide3.Text
Dim intSide4作为整数=txtSide4.Text
Dim intTotal为整数=intSide1+intSide2+intSide3+intSide4
lblMessage.Text=intTotal.ToString(“#,###.##”)
//新代码
如果intSide1<0或intSide2<0或intSide3<0,intSide4<0,则
MessageBox.Show(“输入错误,负数无效”)
如果结束
特例
MessageBox.Show(“输入不正确。请输入一个数值。”)
结束尝试
端接头
这听起来很像家庭作业,但您确实需要正确地转换整数,然后执行实际的比较
Public Class Form1 'Sebastian roman. Perimeter, 10/1/2014
Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click
Try
' Relies on the GetIntegerInput method to throw exceptions
' for invalid entries
Dim intSide1 As Integer = GetIntegerInput(txtSide1.Text)
Dim intSide2 As Integer = GetIntegerInput(txtSide2.Text)
Dim intSide3 As Integer = GetIntegerInput(txtSide3.Text)
Dim intSide4 As Integer = GetIntegerInput(txtSide4.Text)
Dim intTotal As Integer = intSide1 + intSide2 + intSide3 + intSide4
lblMessage.Text = intTotal.ToString("#,###.##")
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Private Function GetIntegerInput(ByVal input as String) As Integer)
Dim returnValue as Integer
' Will attempt a proper try parse. AndAlso will short circuit
' the comparison so a failure in TryParse will not perform the
' the second evaluation. In either case, an actual exception is
' thrown with your invalid numeric message
If (Not Int32.TryParse(input, returnValue) AndAlso returnValue < 0) Then
Throw New ArgumentException("Incorrect input. Enter a proper numeric value.")
End If
Return returnValue
End Function
End Class
公共类Form1'塞巴斯蒂安·罗曼周界,2014年1月10日
私有子BTNCalCalculate_Click(ByVal发送者作为System.Object,ByVal e作为System.EventArgs)处理btnCalculate。单击
尝试
'依赖GetIntegerInput方法引发异常
'用于无效条目
Dim intSide1 As Integer=GetIntegerInput(txtSide1.Text)
Dim intSide2 As Integer=GetIntegerInput(txtSide2.Text)
Dim intSide3 As Integer=GetIntegerInput(txtSide3.Text)
Dim intSide4 As Integer=GetIntegerInput(txtSide4.Text)
Dim intTotal为整数=intSide1+intSide2+intSide3+intSide4
lblMessage.Text=intTotal.ToString(“#,###.##”)
特例
MessageBox.Show(例如Message)
结束尝试
端接头
私有函数GetIntegerInput(ByVal输入为字符串)为整数)
将返回值设置为整数
'将尝试正确的try解析。并且还将短路
'进行比较,以便TryParse中的故障不会执行
'第二次求值。在任何一种情况下,都会出现实际异常
'与无效的数字消息一起抛出
如果(不是Int32.TryParse(输入,返回值)和同样返回值<0),则
抛出新ArgumentException(“输入不正确。请输入正确的数值。”)
如果结束
返回值
端函数
末级
这会阻止它,甚至在点击按钮之前:我不知道vb.net。但是你能给一个整数指定一个字符串吗(Dim intSide1 As Integer=txtSide1.Text
)?我想你需要一个Parse
或TryParse
@crashmstr:With选项Strict Off
它会为你执行隐式转换。谢谢兄弟帮我弄明白了:)我这么做了,但出于某种原因它对我不起作用,但谢谢