FindControl在列表视图中不起作用Null异常

protected void ListView1_ItemDataBound(object sender, ListViewItemEventArgs e)
{
    if (e.Item.ItemType == ListViewItemType.DataItem)
    {
        Label lbl = (Label)e.Item.FindControl("Label1");
        // 对控件进行操作
    }
}

public Control FindControlRecursive(Control root, string id)
{
    if (root.ID == id)
        return root;

    foreach (Control control in root.Controls)
    {
        Control foundControl = FindControlRecursive(control, id);
        if (foundControl != null)
            return foundControl;
    }

    return null;
}

// 在列表视图中使用递归查找控件
Label lbl = (Label)FindControlRecursive(ListView1, "Label1");

protected void ListView1_ItemDataBound(object sender, ListViewItemEventArgs e)
{
    if (e.Item.ItemType == ListViewItemType.DataItem)
    {
        ListViewDataItem dataItem = (ListViewDataItem)e.Item;
        Label lbl = (Label)dataItem.FindControl("Label1");
        // 对控件进行操作
    }
}