Vb.net Visual Basic(初学者)错误:对象引用未设置为对象的实例
我是初学者,所以请友善一点。我正在用Visual Basic制作货币兑换计算器,遇到了一个我似乎无法理解的错误:Vb.net Visual Basic(初学者)错误:对象引用未设置为对象的实例,vb.net,Vb.net,我是初学者,所以请友善一点。我正在用Visual Basic制作货币兑换计算器,遇到了一个我似乎无法理解的错误: 对象引用未设置为对象的实例 下面是我正在努力解决的代码: Dim Currency As Double Dim TextOther As String = Othertext.Text Dim TextGBP As String = GBPtext.Text Private Sub Calculate_Click(sender As Object, e As EventArgs
- 对象引用未设置为对象的实例
Dim Currency As Double
Dim TextOther As String = Othertext.Text
Dim TextGBP As String = GBPtext.Text
Private Sub Calculate_Click(sender As Object, e As EventArgs) Handles Calculate.Click
TextOther = Currency * Convert.ToDouble(TextGBP)
TextGBP = Currency * Convert.ToDouble(TextOther)
End Sub
提前谢谢。您需要将您的货币设置为某物并使用“.text”。在你的文本框之后 还可以在单击事件中设置变量
Dim Currency As Double
Dim TextOther As String
Dim TextGBP As String
Private Sub Calculate_Click(sender As Object, e As EventArgs) Handles Calculate.Click
currency = 10.0
TextOther = Othertext.Text
TextGBP = GBPtext.Text
TextOther.text = Currency * Convert.ToDouble(TextGBP)
TextGBP.text = Currency * Convert.ToDouble(TextOther)
End Sub
除了@Ando所说的之外,您得到
NullReferenceException
的原因是,在您声明变量TextOther
和TextGBP
时,表单实际上尚未创建。尝试为它们分配文本框的.text值(此时不存在)将导致空引用异常。哦,顺便说一句,您可能会发现养成标准命名约定的习惯很有用-看看这个-