SelectedIndexChanged方法内的DataTable声明不起作用

Question

我正在尝试在dropdownchange方法中定义DataTable，如下所示：

protected void selectSegment_SelectedIndexChanged(object sender, EventArgs e)
{
    String query = "<View><Query><Where><Eq><FieldRef Name='Segment' /><Value Type='Lookup'>" + selectSegment.SelectedItem.Text + "</Value></Eq></Where></Query></View>";
    DataTable dt = SPCommon.GetFilteredItems("Approvers Info", "Business_x0020_Unit", "ID", query);
}

  

当我调试上面的代码时，我得到的错误为The name 'dt' does not exist in the current context

如果我在PageLoad上做同样的事情，可以正常工作：

protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {    
        DataTable Results = SPCommon.GetAllItems("Segments", "Title", "ID");
        System.Web.UI.WebControls.ListItem defalutListItem = new System.Web.UI.WebControls.ListItem();
        defalutListItem.Text = "Select";
        defalutListItem.Value = "-99";
        Common.populateDropdown(selectSegment, Results, "Title", "ID", defalutListItem);
        Results.Clear();
    }
}

请帮助理解为什么我无法在SelectedIndexChanged方法中声明新的DataTable变量？

Answer 1

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