Question

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged, TextBox2.TextChanged
If String.IsNullOrEmpty(TextBox1.Text) OrElse String.IsNullOrEmpty(TextBox2.Text) Then Exit Sub
If Not IsNumeric(TextBox1.Text) OrElse Not IsNumeric(TextBox2.Text) Then Exit Sub
TextBox3.Text = CDbl(TextBox1.Text) + CDbl(TextBox2.Text)
End Sub

此代码适用于我，但当我删除文本框的两个值时，总数仍然存在...我的问题的任何解决方案？

Answer 1

当清除输入TextBoxes（TextBox1和TextBox2）时，没有代码可以从输出TextBox（TextBox3）中删除值。您可以在TextChanged事件处理程序的开头清除TextBox3。

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged, TextBox2.TextChanged
    TextBox3.Text = ""
    If String.IsNullOrEmpty(TextBox1.Text) OrElse String.IsNullOrEmpty(TextBox2.Text) Then Exit Sub
    If Not IsNumeric(TextBox1.Text) OrElse Not IsNumeric(TextBox2.Text) Then Exit Sub
    TextBox3.Text = (CDbl(TextBox1.Text) + CDbl(TextBox2.Text)).ToString
End Sub

自动计算

1 个答案: