自由设置好友

本节的内容可以参考CaseStudy目录下的文件: 内置验证QQServer.Table，内置验证QQClient.Table

上一节讲到，使用内置身份验证时，虽然可以根据用户分组或角色选择好友， 但局限性比较大，不够灵活。

你可以自行扩展服务器项目，让服务端管理人员可以给登录者自由选择好友。

设计步骤

1、首先在服务端项目增加一个名为“好友”的表，这个表有两列，分别是“用户名”和“好友”，前者是字符型，后者是备注型：

提示：

上表的好友列，可以包括单个的用户名，也可以包括分组名，其中分组名用方括号括起来。
例如上表中董燕的好友包括贺辉、周明、杨刚，以及所有分组为员工的用户。

2、然后设计一个下图所示的窗口：

窗口的AfterLoad事件代码为：

Dim trv1 As WinForm.TreeView = e.Form.Controls("TreeView1")
Dim trv2 As WinForm.TreeView = e.Form.Controls("TreeView2")
Dim trvs() As WinForm.TreeView = {trv1,trv2}
For Each trv As WinForm.TreeView In trvs
    For Each u As UserInfo In Users
        If u.Type = UserTypeEnum.User Then
            If trv.Nodes.Contains(u.Group) = False Then
                trv.Nodes.Add(u.Group)
            End If
            trv.Nodes(u.Group).Nodes.Add(u.Name)
        End If
    Next
Next
trv2.CheckBoxes = True '右边目录树显示复选框

左边目录树的AfterSelectNode事件代码设置为：

Dim trv1 As WinForm.TreeView = e.Form.Controls("TreeView1")
Dim trv2 As WinForm.TreeView = e.Form.Controls("TreeView2")
Dim dr As DataRow
If e.node.Level = 1 Then
    dr = DataTables("好友").Find("员工 = '" & e.Node.Name & "'")
End If
Dim nms As New List(of String)
If dr IsNot Nothing AndAlso dr.IsNull("好友") = False
    nms.AddRange(dr("好友").Split(","))
End If
For Each nd As WinForm.TreeNode In trv2.AllNodes
    If nd.Level = 0 Then
        nd.Checked = nms.Contains("[" &nd.Name & "]")
    Else
        nd.Checked = nms.Contains(nd.Name)
    End If
Next
trv2.Enabled = (e.node.Level = 1)

右边目录树的AfterCheckNode事件代码设置为：

Dim trv1 As WinForm.TreeView = e.Form.Controls("TreeView1")
Dim trv2 As WinForm.TreeView = e.Form.Controls("TreeView2")
Dim nd1 As WinForm.TreeNode = trv1.SelectedNode
If nd1.Level = 0 Then
    Return
End If
Dim dr As DataRow
If e.Node.ParentNode IsNot Nothing Then '取消父节点的选中标记,因为选中子节点,就不要选中父节点了
    e.Node.ParentNode.Checked = False
End If
For Each cnd As WinForm.TreeNode In e.Node.Nodes '取消子节点的选中标记,因为选中父节点,就不要选中子节点了
    cnd.Checked = False
Next
dr = DataTables("好友").Find("员工 = '" & nd1.Name & "'")
If dr Is Nothing  Then
    dr = DataTables("好友").AddNew()
    dr("员工") = nd1.Name
End If
Dim nms As String
For Each nd2 As WinForm.TreeNode In trv2.Nodes '先添加分组
    If nd2.Checked Then
        nms  = nms & ",[" &  nd2.Name & "]"  '分组名用方括号括起来,表示这是一个分组.
    End If
Next
For Each nd2 As WinForm.TreeNode In trv2.AllNodes '然后是普通用户
    If nd2.Level = 1 AndAlso nd2.Checked AndAlso nd1.Name <> nd2.Name Then
        nms = nms & "," &  nd2.Name
    End If
Next
If nms > "" Then
    dr("好友") = nms.Trim(",")
Else
    dr("好友") = Nothing
End If

4、最后将QQserver的UserLogging事件代码设置为：

If e.User Is Nothing Then
    Return
Else
    e.Success = True
End If
Dim dr As DataRow
dr = DataTables("好友").Find("员工 = '" & e.User.Name & "'")
If dr IsNot Nothing Then
    Dim nms As New List(of String)
    nms.AddRange(dr("好友").Split(","))
    For Each u As UserInfo In Users
        If u.Name <> e.User.Name Then
            If nms.Contains(u.Name) OrElse nms.Contains("[" & u.Group & "]")
                If u.Group > ""  Then
                    e.Buddies.Add(u.Group & "." & u.Name)
                Else
                    e.Buddies.Add(u.Name)
                End If
            End If
        End If
    Next
Else
    For Each u As UserInfo In Users
        If u.Name <> e.User.Name  Then
            If u.Group > ""  Then
                e.Buddies.Add(u.Group & "." & u.Name)
            Else
                e.Buddies.Add(u.Name)
            End If
        End If
    Next
End If