DataTable Classe

Definição

public ref class DataTable : System::ComponentModel::MarshalByValueComponent, System::ComponentModel::IListSource, System::ComponentModel::ISupportInitialize, System::Runtime::Serialization::ISerializable

public ref class DataTable : System::ComponentModel::MarshalByValueComponent, System::ComponentModel::IListSource, System::ComponentModel::ISupportInitializeNotification, System::Runtime::Serialization::ISerializable, System::Xml::Serialization::IXmlSerializable

[System.Serializable]
public class DataTable : System.ComponentModel.MarshalByValueComponent, System.ComponentModel.IListSource, System.ComponentModel.ISupportInitialize, System.Runtime.Serialization.ISerializable

[System.Serializable]
public class DataTable : System.ComponentModel.MarshalByValueComponent, System.ComponentModel.IListSource, System.ComponentModel.ISupportInitializeNotification, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable

public class DataTable : System.ComponentModel.MarshalByValueComponent, System.ComponentModel.IListSource, System.ComponentModel.ISupportInitializeNotification, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable

[<System.Serializable>]
type DataTable = class
    inherit MarshalByValueComponent
    interface IListSource
    interface ISupportInitialize
    interface ISerializable

[<System.Serializable>]
type DataTable = class
    inherit MarshalByValueComponent
    interface IListSource
    interface ISupportInitializeNotification
    interface ISupportInitialize
    interface ISerializable
    interface IXmlSerializable

type DataTable = class
    inherit MarshalByValueComponent
    interface IListSource
    interface ISupportInitialize
    interface ISupportInitializeNotification
    interface ISerializable
    interface IXmlSerializable

Public Class DataTable
Inherits MarshalByValueComponent
Implements IListSource, ISerializable, ISupportInitialize

Public Class DataTable
Inherits MarshalByValueComponent
Implements IListSource, ISerializable, ISupportInitializeNotification, IXmlSerializable

Herança

Object

MarshalByValueComponent

DataTable

Derivado

System.Data.TypedTableBase<T>

Atributos

SerializableAttribute

Implementações

IListSource ISupportInitialize ISerializable ISupportInitializeNotification IXmlSerializable

Exemplos

O exemplo seguinte cria dois DataTable objetos e um DataRelation objeto, e adiciona os novos objetos a um DataSet. As tabelas são então apresentadas num DataGridView controlo.

// Put the next line into the Declarations section.
private System.Data.DataSet dataSet;

private void MakeDataTables()
{
    // Run all of the functions.
    MakeParentTable();
    MakeChildTable();
    MakeDataRelation();
    BindToDataGrid();
}

private void MakeParentTable()
{
    // Create a new DataTable.
    System.Data.DataTable table = new DataTable("ParentTable");
    // Declare variables for DataColumn and DataRow objects.
    DataColumn column;
    DataRow row;

    // Create new DataColumn, set DataType,
    // ColumnName and add to DataTable.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.Int32");
    column.ColumnName = "id";
    column.ReadOnly = true;
    column.Unique = true;
    // Add the Column to the DataColumnCollection.
    table.Columns.Add(column);

    // Create second column.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.String");
    column.ColumnName = "ParentItem";
    column.AutoIncrement = false;
    column.Caption = "ParentItem";
    column.ReadOnly = false;
    column.Unique = false;
    // Add the column to the table.
    table.Columns.Add(column);

    // Make the ID column the primary key column.
    DataColumn[] PrimaryKeyColumns = new DataColumn[1];
    PrimaryKeyColumns[0] = table.Columns["id"];
    table.PrimaryKey = PrimaryKeyColumns;

    // Instantiate the DataSet variable.
    dataSet = new DataSet();
    // Add the new DataTable to the DataSet.
    dataSet.Tables.Add(table);

    // Create three new DataRow objects and add
    // them to the DataTable
    for (int i = 0; i <= 2; i++)
    {
        row = table.NewRow();
        row["id"] = i;
        row["ParentItem"] = "ParentItem " + i;
        table.Rows.Add(row);
    }
}

private void MakeChildTable()
{
    // Create a new DataTable.
    DataTable table = new DataTable("childTable");
    DataColumn column;
    DataRow row;

    // Create first column and add to the DataTable.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.Int32");
    column.ColumnName = "ChildID";
    column.AutoIncrement = true;
    column.Caption = "ID";
    column.ReadOnly = true;
    column.Unique = true;

    // Add the column to the DataColumnCollection.
    table.Columns.Add(column);

    // Create second column.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.String");
    column.ColumnName = "ChildItem";
    column.AutoIncrement = false;
    column.Caption = "ChildItem";
    column.ReadOnly = false;
    column.Unique = false;
    table.Columns.Add(column);

    // Create third column.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.Int32");
    column.ColumnName = "ParentID";
    column.AutoIncrement = false;
    column.Caption = "ParentID";
    column.ReadOnly = false;
    column.Unique = false;
    table.Columns.Add(column);

    dataSet.Tables.Add(table);

    // Create three sets of DataRow objects,
    // five rows each, and add to DataTable.
    for (int i = 0; i <= 4; i++)
    {
        row = table.NewRow();
        row["childID"] = i;
        row["ChildItem"] = "Item " + i;
        row["ParentID"] = 0;
        table.Rows.Add(row);
    }
    for (int i = 0; i <= 4; i++)
    {
        row = table.NewRow();
        row["childID"] = i + 5;
        row["ChildItem"] = "Item " + i;
        row["ParentID"] = 1;
        table.Rows.Add(row);
    }
    for (int i = 0; i <= 4; i++)
    {
        row = table.NewRow();
        row["childID"] = i + 10;
        row["ChildItem"] = "Item " + i;
        row["ParentID"] = 2;
        table.Rows.Add(row);
    }
}

private void MakeDataRelation()
{
    // DataRelation requires two DataColumn
    // (parent and child) and a name.
    DataColumn parentColumn =
        dataSet.Tables["ParentTable"].Columns["id"];
    DataColumn childColumn =
        dataSet.Tables["ChildTable"].Columns["ParentID"];
    DataRelation relation = new
        DataRelation("parent2Child", parentColumn, childColumn);
    dataSet.Tables["ChildTable"].ParentRelations.Add(relation);
}

private void BindToDataGrid()
{
    // Instruct the DataGrid to bind to the DataSet, with the
    // ParentTable as the topmost DataTable.
    DataGrid1.SetDataBinding(dataSet, "ParentTable");
}

' Put the next line into the Declarations section.
private dataSet As DataSet 
 
Private Sub MakeDataTables()
    ' Run all of the functions. 
    MakeParentTable()
    MakeChildTable()
    MakeDataRelation()
    BindToDataGrid()
End Sub
 
Private Sub MakeParentTable()
    ' Create a new DataTable.
    Dim table As New DataTable("ParentTable")

    ' Declare variables for DataColumn and DataRow objects.
    Dim column As DataColumn 
    Dim row As DataRow 
 
    ' Create new DataColumn, set DataType, ColumnName 
    ' and add to DataTable.    
    column = New DataColumn()
    column.DataType = System.Type.GetType("System.Int32")
    column.ColumnName = "id"
    column.ReadOnly = True
    column.Unique = True

    ' Add the Column to the DataColumnCollection.
    table.Columns.Add(column)
 
    ' Create second column.
    column = New DataColumn()
    column.DataType = System.Type.GetType("System.String")
    column.ColumnName = "ParentItem"
    column.AutoIncrement = False
    column.Caption = "ParentItem"
    column.ReadOnly = False
    column.Unique = False

    ' Add the column to the table.
    table.Columns.Add(column)
 
    ' Make the ID column the primary key column.
    Dim PrimaryKeyColumns(0) As DataColumn
    PrimaryKeyColumns(0)= table.Columns("id")
    table.PrimaryKey = PrimaryKeyColumns
 
    ' Instantiate the DataSet variable.
    dataSet = New DataSet()

    ' Add the new DataTable to the DataSet.
    dataSet.Tables.Add(table)
 
    ' Create three new DataRow objects and add 
    ' them to the DataTable
    Dim i As Integer
    For i = 0 to 2
       row = table.NewRow()
       row("id") = i
       row("ParentItem") = "ParentItem " + i.ToString()
       table.Rows.Add(row)
    Next i
End Sub
 
Private Sub MakeChildTable()
    ' Create a new DataTable.
    Dim table As New DataTable("childTable")
    Dim column As DataColumn 
    Dim row As DataRow 
 
    ' Create first column and add to the DataTable.
    column = New DataColumn()
    column.DataType= System.Type.GetType("System.Int32")
    column.ColumnName = "ChildID"
    column.AutoIncrement = True
    column.Caption = "ID"
    column.ReadOnly = True
    column.Unique = True

    ' Add the column to the DataColumnCollection.
    table.Columns.Add(column)
 
    ' Create second column.
    column = New DataColumn()
    column.DataType= System.Type.GetType("System.String")
    column.ColumnName = "ChildItem"
    column.AutoIncrement = False
    column.Caption = "ChildItem"
    column.ReadOnly = False
    column.Unique = False
    table.Columns.Add(column)
 
    ' Create third column.
    column = New DataColumn()
    column.DataType= System.Type.GetType("System.Int32")
    column.ColumnName = "ParentID"
    column.AutoIncrement = False
    column.Caption = "ParentID"
    column.ReadOnly = False
    column.Unique = False
    table.Columns.Add(column)
 
    dataSet.Tables.Add(table)

    ' Create three sets of DataRow objects, five rows each, 
    ' and add to DataTable.
    Dim i As Integer
    For i = 0 to 4
       row = table.NewRow()
       row("childID") = i
       row("ChildItem") = "Item " + i.ToString()
       row("ParentID") = 0 
       table.Rows.Add(row)
    Next i
    For i = 0 to 4
       row = table.NewRow()
       row("childID") = i + 5
       row("ChildItem") = "Item " + i.ToString()
       row("ParentID") = 1 
       table.Rows.Add(row)
    Next i
    For i = 0 to 4
       row = table.NewRow()
       row("childID") = i + 10
       row("ChildItem") = "Item " + i.ToString()
       row("ParentID") = 2 
       table.Rows.Add(row)
    Next i
End Sub
 
Private Sub MakeDataRelation()
    ' DataRelation requires two DataColumn 
    ' (parent and child) and a name.
    Dim parentColumn As DataColumn = _
        dataSet.Tables("ParentTable").Columns("id")
    Dim childColumn As DataColumn = _
        dataSet.Tables("ChildTable").Columns("ParentID")
    Dim relation As DataRelation = new _
        DataRelation("parent2Child", parentColumn, childColumn)
    dataSet.Tables("ChildTable").ParentRelations.Add(relation)
End Sub
 
Private Sub BindToDataGrid()
    ' Instruct the DataGrid to bind to the DataSet, with the 
    ' ParentTable as the topmost DataTable.
    DataGrid1.SetDataBinding(dataSet,"ParentTable")
End Sub

Observações

Para mais informações sobre esta API, consulte Observações suplementares da API para DataTable.

Segurança de Thread

Este tipo é seguro para operações de leitura multithread. Tem de sincronizar quaisquer operações de escrita.

Ver também

• Tabelas de dados