Chỉnh sửa

Chia sẻ qua

Managing DataViews

  • Bài viết

You can use a DataViewManager to manage view settings for all the tables in a DataView. If you have a control that you want to bind to multiple tables, such as a grid that navigates relationships, a DataViewManager is ideal.

The DataViewManager contains a collection of DataViewSetting objects that are used to set the view setting of the tables in the DataSet. The DataViewSettingCollection contains one DataViewSetting object for each table in a DataSet. You can set the default ApplyDefaultSort, Sort, RowFilter, and RowStateFilter properties of the referenced table by using its DataViewSetting. You can reference the DataViewSetting for a particular table by name or ordinal reference, or by passing a reference to that specific table object. You can access the collection of DataViewSetting objects in a DataViewManager by using the DataViewSettings property.

The following code example fills a DataSet with the SQL Server Northwind database tables Customers, Orders, and Order Details, creates the relationships between the tables, uses a DataViewManager to set default DataView settings, and binds a DataGrid to the DataViewManager. The example sets the default DataView settings for all tables in the DataSet to sort by the primary key of the table (ApplyDefaultSort = true), and then modifies the sort order of the Customers table to sort by CompanyName.

' 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");

See also