主题：内容不能为空再新增

Dim str1 As String = e.form.controls("TextBox1").Text

Dim str2 As String = e.form.controls("TextBox2").Text

Dim str3 As String = e.form.controls("TextBox3").Text

If e.keycode = keys.Enter andalso str1>"" andalso str2>"" andalso str3>"" Then