c# - 如何在 Visual C# 中从 Active Directory 填充 gridview

Question

我目前正在使用 Visual C# 和 ASP.NET 框架，并且我正在尝试通过 DataTable 填充 GridView。正在从 Active Directory 获取信息。

我的 gridview 是这样声明的:

<asp:GridView ID="grdvList" runat="server" AutoGenerateColumns="False" Width="567px">
    <Columns>
        <asp:BoundField HeaderText="Name" ReadOnly="True" />
        <asp:BoundField HeaderText="Phone" ReadOnly="True" />
        <asp:BoundField HeaderText="Email" ReadOnly="True" />
    </Columns>
</asp:GridView>

我尝试填充 gridview 的代码如下:

DirectoryEntry entry = new DirectoryEntry(ConfigurationManager.AppSettings["LDAP"]);

DirectorySearcher search = new DirectorySearcher(entry)
        {
            SearchScope = SearchScope.Subtree,
            Filter = "(&(objectClass=user)(physicalDeliveryOfficeName=Dartmouth))"
        };

search.PropertiesToLoad.Add("sAMAccountName");

SearchResultCollection result = search.FindAll();

DataTable table = new DataTable();
DataRow dr = null;

//Add columns to DataTable
table.Columns.Add("Name", System.Type.GetType("System.String"));
table.Columns.Add("Phone", System.Type.GetType("System.String"));
table.Columns.Add("Email", System.Type.GetType("System.String"));

foreach (SearchResult sr in uList)
{
    dr = table.NewRow();

    DirectoryEntry DE = sr.GetDirectoryEntry();
    dr["Name"] = DE.Properties["givenName"].Value.ToString();
    dr["Phone"] = DE.Properties["telephoneNumber"].Value.ToString();
    dr["Email"] = DE.Properties["mail"].Value.ToString();

    table.Rows.Add(dr);
}

table.AcceptChanges();

grdvList.DataSource = table;
grdvList.DataBind();

目前当我运行它时，它会抛出一个

Object reference not set to an instance of an object error

在这一行:

dr["Phone"] = DE.Properties["telephoneNumber"].Value.ToString();

非常感谢任何帮助!

Answer 1

在您的场景中，您可以避免使用旧技术的DataTable 和DataSet。这些天来，我们尽量不使用它们，除非我们别无选择。

对于 NullReferenceException，您要确保 DE.Properties["mail"] 在获取其 Value 之前不为 null 。

例如，

DirectoryEntry entry = new DirectoryEntry(ConfigurationManager.AppSettings["LDAP"]);
DirectorySearcher search = new DirectorySearcher(entry)
{
    SearchScope = SearchScope.Subtree,
    Filter = "(&(objectClass=user)(physicalDeliveryOfficeName=Dartmouth))"
};
search.PropertiesToLoad.Add("sAMAccountName");
SearchResultCollection result = search.FindAll();

var users = result.Cast<SearchResult>().Select(sr => sr.GetDirectoryEntry())
    .Select(de => new 
    {
        Name = de.Properties["Name"] != null ? de.Properties["Name"].Value.ToString() : "",
        Phone = de.Properties["Phone"] != null ? de.Properties["Phone"].Value.ToString() : "",
        Email = de.Properties["Email"] != null ? de.Properties["Email"].Value.ToString() : "",
    }).ToList();

grdvList.DataSource = users;
grdvList.DataBind();