如何把DataTable对象添加到 DataSet 中

通过帮助，我们可以查出如下代码实现

示例
[ C#] 以下示例创建两个 DataTable 对象和一个 DataRelation 对象，并将这些新对象添加到 DataSet 中。然后通过调用 DataGrid.SetDataBinding 方法在 DataGrid 控件中显示这些表。 
  [C#]
// Put the next line into the Declarations section.
 private System.Data.DataSet myDataSet;
 
 private void MakeDataTables(){
    // Run all of the functions.
    MakeParentTable();
    MakeChildTable();
    MakeDataRelation();
    BindToDataGrid();
 }
 
 private void MakeParentTable(){
    // Create a new DataTable.
    System.Data.DataTable myDataTable = new DataTable("ParentTable");
    // Declare variables for DataColumn and DataRow objects.
    DataColumn myDataColumn;
    DataRow myDataRow;
 
    // Create new DataColumn, set DataType, ColumnName and add to DataTable.   
    myDataColumn = new DataColumn();
    myDataColumn.DataType = System.Type.GetType("System.Int32");
    myDataColumn.ColumnName = "id";
    myDataColumn.ReadOnly = true;
    myDataColumn.Unique = true;
    // Add the Column to the DataColumnCollection.
    myDataTable.Columns.Add(myDataColumn);
 
    // Create second column.
    myDataColumn = new DataColumn();
    myDataColumn.DataType = System.Type.GetType("System.String");
    myDataColumn.ColumnName = "ParentItem";
    myDataColumn.AutoIncrement = false;
    myDataColumn.Caption = "ParentItem";
    myDataColumn.ReadOnly = false;
    myDataColumn.Unique = false;
    // Add the column to the table.
    myDataTable.Columns.Add(myDataColumn);
 
    // Make the ID column the primary key column.
    DataColumn[] PrimaryKeyColumns = new DataColumn[1];
    PrimaryKeyColumns[0] = myDataTable.Columns["id"];
    myDataTable.PrimaryKey = PrimaryKeyColumns;
 
    // Instantiate the DataSet variable.
    myDataSet = new DataSet();
    // Add the new DataTable to the DataSet.
    myDataSet.Tables.Add(myDataTable);
 
    // Create three new DataRow objects and add them to the DataTable
    for (int i = 0; i<= 2; i++){
       myDataRow = myDataTable.NewRow();
       myDataRow["id"] = i;
       myDataRow["ParentItem"] = "ParentItem " + i;
       myDataTable.Rows.Add(myDataRow);
    }
 }
 
 private void MakeChildTable(){
    // Create a new DataTable.
    DataTable myDataTable = new DataTable("childTable");
    DataColumn myDataColumn;
    DataRow myDataRow;
 
    // Create first column and add to the DataTable.
    myDataColumn = new DataColumn();
    myDataColumn.DataType= System.Type.GetType("System.Int32");
    myDataColumn.ColumnName = "ChildID";
    myDataColumn.AutoIncrement = true;
    myDataColumn.Caption = "ID";
    myDataColumn.ReadOnly = true;
    myDataColumn.Unique = true;
    // Add the column to the DataColumnCollection.
    myDataTable.Columns.Add(myDataColumn);
 
    // Create second column.
    myDataColumn = new DataColumn();
    myDataColumn.DataType= System.Type.GetType("System.String");
    myDataColumn.ColumnName = "ChildItem";
    myDataColumn.AutoIncrement = false;
    myDataColumn.Caption = "ChildItem";
    myDataColumn.ReadOnly = false;
    myDataColumn.Unique = false;
    myDataTable.Columns.Add(myDataColumn);
 
    // Create third column.
    myDataColumn = new DataColumn();
    myDataColumn.DataType= System.Type.GetType("System.Int32");
    myDataColumn.ColumnName = "ParentID";
    myDataColumn.AutoIncrement = false;
    myDataColumn.Caption = "ParentID";
    myDataColumn.ReadOnly = false;
    myDataColumn.Unique = false;
    myDataTable.Columns.Add(myDataColumn);
 
    myDataSet.Tables.Add(myDataTable);
    // Create three sets of DataRow objects, five rows each, and add to DataTable.
    for(int i = 0; i <= 4; i ++){
       myDataRow = myDataTable.NewRow();
       myDataRow["childID"] = i;
       myDataRow["ChildItem"] = "Item " + i;
       myDataRow["ParentID"] = 0 ;
       myDataTable.Rows.Add(myDataRow);
    }
    for(int i = 0; i <= 4; i ++){
       myDataRow = myDataTable.NewRow();
       myDataRow["childID"] = i + 5;
       myDataRow["ChildItem"] = "Item " + i;
       myDataRow["ParentID"] = 1 ;
       myDataTable.Rows.Add(myDataRow);
    }
    for(int i = 0; i <= 4; i ++){
       myDataRow = myDataTable.NewRow();
       myDataRow["childID"] = i + 10;
       myDataRow["ChildItem"] = "Item " + i;
       myDataRow["ParentID"] = 2 ;
       myDataTable.Rows.Add(myDataRow);
    }
 }
 
 private void MakeDataRelation(){
    // DataRelation requires two DataColumn (parent and child) and a name.
    DataRelation myDataRelation;
    DataColumn parentColumn;
    DataColumn childColumn;
    parentColumn = myDataSet.Tables["ParentTable"].Columns["id"];
    childColumn = myDataSet.Tables["ChildTable"].Columns["ParentID"];
    myDataRelation = new DataRelation("parent2Child", parentColumn, childColumn);
    myDataSet.Tables["ChildTable"].ParentRelations.Add(myDataRelation);
 }
 
 private void BindToDataGrid(){
    // Instruct the DataGrid to bind to the DataSet, with the
    // ParentTable as the topmost DataTable.
    dataGrid1.SetDataBinding(myDataSet,"ParentTable");
 }


但是在实际的开发过程中，我们一般是通过数据库读取数据，然后放到DataSet中，下面我使用演示如何通过连接数据实现

private DataSet myds;
myds=new DataSet();
   SqlDataBase  SqlDB=new SqlDataBase(DSN);
   string strsql=" select * from A ";
   System.Data.DataSet ds=SqlDB.CreateSet(strsql,"A");
            DataTable dt;
   dt=ds.Tables[0].Clone();
   myds.Tables.Add(dt);
   string strsql1=" select * from B";
   System.Data.DataSet ds1=SqlDB.CreateSet(strsql1,"B");
            DataTable dt1;
   dt1=ds1.Tables[0].Clone();
   myds.Tables.Add(dt1);
   SqlDB.CloseConnection();
   myds.Merge(ds.Tables[0]);
   myds.Merge(ds1.Tables[0]);
   this.DataGrid1.DataSource=myds;
  
   this.DataGrid1.DataBind();
   this.DataGrid2.DataSource=myds.Tables[1];
   this.DataGrid2.DataBind();