Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.ClickDim aa, bb, cc, dd As Double
aa = CDbl(TextBox1.Text)
bb = CDbl(TextBox2.Text)
cc = CDbl(TextBox3.Text)
dd = CDbl(TextBox4.Text)
If dd = aa + bb + cc Then
MessageBox.Show("相等。")
Else
MessageBox.Show("不相等。")
End If
End Sub
当：TextBox1.Text=1.1
TextBox2.Text=1.1
TextBox3.Text=1.1
TextBox4.Text=3.3时
MessageBox.Show("不相等。")
这是哪里不对，怎样改正?