主题：[求助]突然发现的错误，日期选择框代码

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点击日期选择框清除按钮时出现上面提示，项目文件停止运行，想死机一样

下面是日期输入框ValueChanged事件代码

Dim lst As WinForm.ComboBox = e.form.Controls("ComboBox1")

lst.items.Clear

e.Form.Controls("ComboBox1").Value = ""

Dim rq As String = e.form.Controls("DateTimePicker1").Value

Dim cmd As New SQLCommand

Dim dt As DataTable

dt = cmd.ExecuteReader

e.Form.Controls("ComboBox1").Combolist = dt.GetComboListString("BRXM")