管理 DataView

可以使用 DataViewManager 管理 DataView中所有表的视图设置。 如果你有一个要绑定到多个表的控件,例如导航关系的网格,使用 DataViewManager 是理想的选择。

DataViewManager包含一组DataViewSetting对象,这些对象用于设置表中DataSet的视图设置。 对于数据集中的每个表,DataViewSettingCollection 都包含一个 DataViewSetting 对象。 可以使用引用表的 DataViewSetting 设置默认 ApplyDefaultSortSortRowStateFilter属性。 可以按名称或序号引用来引用 DataViewSetting 特定表,也可以传递对该特定表对象的引用。 可以通过使用DataViewSettings属性来访问DataViewManager中的DataViewSetting对象集合。

下面的代码示例在 DataSet 中填充了 SQL Server Northwind 数据库表 CustomersOrdersOrder Details,创建了表之间的关系,使用 DataViewManager 来设置默认 DataView,并将 DataGrid 绑定到 DataViewManager。 该示例将DataSet中所有表的默认设置为按表的主键进行排序(DataViewDataSettrue),然后修改Customers表的排序顺序为按CompanyName排序。

' Assumes connection is a valid SqlConnection to Northwind.
' Create a Connection, DataAdapters, and a DataSet.
Dim custDA As SqlDataAdapter = New SqlDataAdapter( _
  "SELECT CustomerID, CompanyName FROM Customers", connection)
Dim orderDA As SqlDataAdapter = New SqlDataAdapter( _
  "SELECT OrderID, CustomerID FROM Orders", connection)
Dim ordDetDA As SqlDataAdapter = New SqlDataAdapter( _
  "SELECT OrderID, ProductID, Quantity FROM [Order Details]", connection)

Dim custDS As DataSet = New DataSet()

' Open the Connection.
connection.Open()

    ' Fill the DataSet with schema information and data.
    custDA.MissingSchemaAction = MissingSchemaAction.AddWithKey
    orderDA.MissingSchemaAction = MissingSchemaAction.AddWithKey
    ordDetDA.MissingSchemaAction = MissingSchemaAction.AddWithKey

    custDA.Fill(custDS, "Customers")
    orderDA.Fill(custDS, "Orders")
    ordDetDA.Fill(custDS, "OrderDetails")

    ' Close the Connection.
    connection.Close()

    ' Create relationships.
    custDS.Relations.Add("CustomerOrders", _
          custDS.Tables("Customers").Columns("CustomerID"), _
          custDS.Tables("Orders").Columns("CustomerID"))

    custDS.Relations.Add("OrderDetails", _
          custDS.Tables("Orders").Columns("OrderID"), _
          custDS.Tables("OrderDetails").Columns("OrderID"))

' Create default DataView settings.
Dim viewManager As DataViewManager = New DataViewManager(custDS)

Dim viewSetting As DataViewSetting
For Each viewSetting In viewManager.DataViewSettings
  viewSetting.ApplyDefaultSort = True
Next

viewManager.DataViewSettings("Customers").Sort = "CompanyName"

' Bind to a DataGrid.
Dim grid As System.Windows.Forms.DataGrid = New System.Windows.Forms.DataGrid()
grid.SetDataBinding(viewManager, "Customers")
// Assumes connection is a valid SqlConnection to Northwind.
// Create a Connection, DataAdapters, and a DataSet.
SqlDataAdapter custDA = new SqlDataAdapter(
  "SELECT CustomerID, CompanyName FROM Customers", connection);
SqlDataAdapter orderDA = new SqlDataAdapter(
  "SELECT OrderID, CustomerID FROM Orders", connection);
SqlDataAdapter ordDetDA = new SqlDataAdapter(
  "SELECT OrderID, ProductID, Quantity FROM [Order Details]", connection);

DataSet custDS = new DataSet();

// Open the Connection.
connection.Open();

    // Fill the DataSet with schema information and data.
    custDA.MissingSchemaAction = MissingSchemaAction.AddWithKey;
    orderDA.MissingSchemaAction = MissingSchemaAction.AddWithKey;
    ordDetDA.MissingSchemaAction = MissingSchemaAction.AddWithKey;

    custDA.Fill(custDS, "Customers");
    orderDA.Fill(custDS, "Orders");
    ordDetDA.Fill(custDS, "OrderDetails");

    // Close the Connection.
    connection.Close();

    // Create relationships.
    custDS.Relations.Add("CustomerOrders",
          custDS.Tables["Customers"].Columns["CustomerID"],
          custDS.Tables["Orders"].Columns["CustomerID"]);

    custDS.Relations.Add("OrderDetails",
          custDS.Tables["Orders"].Columns["OrderID"],
          custDS.Tables["OrderDetails"].Columns["OrderID"]);

// Create default DataView settings.
DataViewManager viewManager = new DataViewManager(custDS);

foreach (DataViewSetting viewSetting in viewManager.DataViewSettings)
  viewSetting.ApplyDefaultSort = true;

viewManager.DataViewSettings["Customers"].Sort = "CompanyName";

// Bind to a DataGrid.
System.Windows.Forms.DataGrid grid = new System.Windows.Forms.DataGrid();
grid.SetDataBinding(viewManager, "Customers");

另请参阅