ListViewItem.Group 属性

public:
 property System::Windows::Forms::ListViewGroup ^ Group { System::Windows::Forms::ListViewGroup ^ get(); void set(System::Windows::Forms::ListViewGroup ^ value); };

public System.Windows.Forms.ListViewGroup Group { get; set; }

public System.Windows.Forms.ListViewGroup? Group { get; set; }

member this.Group : System.Windows.Forms.ListViewGroup with get, set

Public Property Group As ListViewGroup

属性值

为其 ListViewGroup 分配项。

示例

下面的代码示例演示如何 Group 在按子项值在详细信息视图中组织 ListView 项的应用程序中使用该属性。 这种分组形式类似于 Windows 资源管理器中使用的分组。 在此示例中，组是动态创建的。 对于每个子项列，为每个唯一子项值创建一个组。 对于父项列，为每个唯一的初始字母创建一个组。 为每个列创建的组存储在哈希表中，以及子项文本或首字母。 单击列标题时，将检索与该列对应的哈希表。 接下来，该列的子项文本值用作哈希表键，以检索每个项的正确组。 然后，使用属性将该项分配给组 Group 。

此代码示例是为属性提供的大型示例的 ListView.Groups 一部分。

   // Sets myListView to the groups created for the specified column.
private:
   void SetGroups(int column)
   {
      // Remove the current groups.
      myListView->Groups->Clear();

      // Retrieve the hash table corresponding to the column.
      Hashtable^ groups = dynamic_cast<Hashtable^>(groupTables[column]);

      // Copy the groups for the column to an array.
      array<ListViewGroup^>^ groupsArray = gcnew array<ListViewGroup^>(groups->Count);
      groups->Values->CopyTo(groupsArray, 0);

      // Sort the groups and add them to myListView.
      Array::Sort(groupsArray, gcnew ListViewGroupSorter(myListView->Sorting));
      myListView->Groups->AddRange(groupsArray);

      // Iterate through the items in myListView, assigning each 
      // one to the appropriate group.
      IEnumerator^ myEnum = myListView->Items->GetEnumerator();
      while (myEnum->MoveNext())
      {
         ListViewItem^ item = safe_cast<ListViewItem^>(myEnum->Current);
         // Retrieve the subitem text corresponding to the column.
         String^ subItemText = item->SubItems[column]->Text;

         // For the Title column, use only the first letter.
         if (column == 0) 
         {
            subItemText = subItemText->Substring(0, 1);
         }

         // Assign the item to the matching group.
         item->Group = dynamic_cast<ListViewGroup^>(groups[subItemText]);
      }
   }

// Sets myListView to the groups created for the specified column.
private void SetGroups(int column)
{
    // Remove the current groups.
    myListView.Groups.Clear();

    // Retrieve the hash table corresponding to the column.
    Hashtable groups = (Hashtable)groupTables[column];

    // Copy the groups for the column to an array.
    ListViewGroup[] groupsArray = new ListViewGroup[groups.Count];
    groups.Values.CopyTo(groupsArray, 0);

    // Sort the groups and add them to myListView.
    Array.Sort(groupsArray, new ListViewGroupSorter(myListView.Sorting));
    myListView.Groups.AddRange(groupsArray);

    // Iterate through the items in myListView, assigning each 
    // one to the appropriate group.
    foreach (ListViewItem item in myListView.Items)
    {
        // Retrieve the subitem text corresponding to the column.
        string subItemText = item.SubItems[column].Text;

        // For the Title column, use only the first letter.
        if (column == 0) 
        {
            subItemText = subItemText.Substring(0, 1);
        }

        // Assign the item to the matching group.
        item.Group = (ListViewGroup)groups[subItemText];
    }
}

' Sets myListView to the groups created for the specified column.
Private Sub SetGroups(column As Integer)
    ' Remove the current groups.
    myListView.Groups.Clear()
    
    ' Retrieve the hash table corresponding to the column.
    Dim groups As Hashtable = CType(groupTables(column), Hashtable)
    
    ' Copy the groups for the column to an array.
    Dim groupsArray(groups.Count - 1) As ListViewGroup
    groups.Values.CopyTo(groupsArray, 0)
    
    ' Sort the groups and add them to myListView.
    Array.Sort(groupsArray, New ListViewGroupSorter(myListView.Sorting))
    myListView.Groups.AddRange(groupsArray)
    
    ' Iterate through the items in myListView, assigning each 
    ' one to the appropriate group.
    Dim item As ListViewItem
    For Each item In myListView.Items
        ' Retrieve the subitem text corresponding to the column.
        Dim subItemText As String = item.SubItems(column).Text
        
        ' For the Title column, use only the first letter.
        If column = 0 Then
            subItemText = subItemText.Substring(0, 1)
        End If 

        ' Assign the item to the matching group.
        item.Group = CType(groups(subItemText), ListViewGroup)
    Next item
End Sub

注解

使用此属性可设置项所属的组。 还可以在 ListViewItem 构造函数中设置组，也可以使用此属性在运行时修改组成员身份。 如果将此属性 null 设置为集合中有 ListView.Groups 组，则该项将显示在默认组中，该组的标题标签为“DefaultGroupSystem.Windows.Forms”。 默认组不包含在 ListView.Groups 集合中，不能更改。 它主要用于调试，以确保所有项都已正确添加到组。

另请参阅

• ListViewGroup