DataGridColumnStyle Classe

Definição

public ref class DataGridColumnStyle abstract : System::ComponentModel::Component, System::Windows::Forms::IDataGridColumnStyleEditingNotificationService

public abstract class DataGridColumnStyle : System.ComponentModel.Component, System.Windows.Forms.IDataGridColumnStyleEditingNotificationService

type DataGridColumnStyle = class
    inherit Component
    interface IDataGridColumnStyleEditingNotificationService

Public MustInherit Class DataGridColumnStyle
Inherits Component
Implements IDataGridColumnStyleEditingNotificationService

Herança

Object

MarshalByRefObject

Component

DataGridColumnStyle

Derivado

System.Windows.Forms.DataGridBoolColumn

System.Windows.Forms.DataGridTextBoxColumn

Implementações

IDataGridColumnStyleEditingNotificationService

Exemplos

O seguinte exemplo de código cria um DataGridColumnStyle que hospeda um DateTimePicker controlo.

#using <System.dll>
#using <System.Data.dll>
#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>
#using <System.Xml.dll>

using namespace System;
using namespace System::Data;
using namespace System::Windows::Forms;
using namespace System::Drawing;
using namespace System::Security::Permissions;

// This example shows how to create your own column style that
// hosts a control, in this case, a DateTimePicker.

public ref class CustomDateTimePicker : public DateTimePicker
{
protected:
    [SecurityPermission(SecurityAction::Demand, Flags=SecurityPermissionFlag::UnmanagedCode)]
    virtual bool ProcessKeyMessage( Message% m ) override
    {
        // Keep all the keys for the DateTimePicker.
        return ProcessKeyEventArgs( m );
    }
};

public ref class DataGridTimePickerColumn : public DataGridColumnStyle
{
private:
   CustomDateTimePicker^ customDateTimePicker1;

   // The isEditing field tracks whether or not the user is
   // editing data with the hosted control.
   bool isEditing;

public:
   DataGridTimePickerColumn()
   {
      customDateTimePicker1 = gcnew CustomDateTimePicker;
      customDateTimePicker1->Visible = false;
   }

protected:
   virtual void Abort( int /*rowNum*/ ) override
   {
      isEditing = false;
      customDateTimePicker1->ValueChanged -=
         gcnew EventHandler( this, &DataGridTimePickerColumn::TimePickerValueChanged );
      Invalidate();
   }

   virtual bool Commit( CurrencyManager^ dataSource, int rowNum ) override
   {
      customDateTimePicker1->Bounds = Rectangle::Empty;

      customDateTimePicker1->ValueChanged -=
         gcnew EventHandler( this, &DataGridTimePickerColumn::TimePickerValueChanged );
      
      if (  !isEditing )
         return true;

      isEditing = false;

      try
      {
         DateTime value = customDateTimePicker1->Value;
         SetColumnValueAtRow( dataSource, rowNum, value );
      }
      catch ( Exception^ ) 
      {
         Abort( rowNum );
         return false;
      }

      Invalidate();
      return true;
   }

   virtual void Edit(
      CurrencyManager^ source,
      int rowNum,
      Rectangle bounds,
      bool /*readOnly*/,
      String^ /*displayText*/,
      bool cellIsVisible ) override
   {
      DateTime value =  (DateTime)
         GetColumnValueAtRow( source, rowNum );
      if ( cellIsVisible )
      {
         customDateTimePicker1->Bounds = Rectangle(
            bounds.X + 2, bounds.Y + 2,
            bounds.Width - 4, bounds.Height - 4 );
         customDateTimePicker1->Value = value;
         customDateTimePicker1->Visible = true;
         customDateTimePicker1->ValueChanged +=
            gcnew EventHandler( this, &DataGridTimePickerColumn::TimePickerValueChanged );
      }
      else
      {
         customDateTimePicker1->Value = value;
         customDateTimePicker1->Visible = false;
      }

      if ( customDateTimePicker1->Visible )
         DataGridTableStyle->DataGrid->Invalidate( bounds );

      customDateTimePicker1->Focus();
   }

   virtual System::Drawing::Size GetPreferredSize(
      Graphics^ /*g*/,
      Object^ /*value*/ ) override
   {
      return Size( 100, customDateTimePicker1->PreferredHeight + 4);
   }

   virtual int GetMinimumHeight() override
   {
      return customDateTimePicker1->PreferredHeight + 4;
   }

   virtual int GetPreferredHeight( Graphics^ /*g*/,
      Object^ /*value*/ ) override
   {
      return customDateTimePicker1->PreferredHeight + 4;
   }

   virtual void Paint( Graphics^ g,
      Rectangle bounds,
      CurrencyManager^ source,
      int rowNum ) override
   {
      Paint( g, bounds, source, rowNum, false );
   }

   virtual void Paint(
      Graphics^ g,
      Rectangle bounds,
      CurrencyManager^ source,
      int rowNum,
      bool alignToRight ) override
   {
      Paint(
         g, bounds,
         source,
         rowNum,
         Brushes::Red,
         Brushes::Blue,
         alignToRight );
   }

   virtual void Paint(
      Graphics^ g,
      Rectangle bounds,
      CurrencyManager^ source,
      int rowNum,
      Brush^ backBrush,
      Brush^ foreBrush,
      bool /*alignToRight*/ ) override
   {
      DateTime date =  (DateTime)
         GetColumnValueAtRow( source, rowNum );
      Rectangle rect = bounds;
      g->FillRectangle( backBrush, rect );
      rect.Offset( 0, 2 );
      rect.Height -= 2;
      g->DrawString( date.ToString( "d" ),
         this->DataGridTableStyle->DataGrid->Font,
         foreBrush, rect );
   }

   virtual void SetDataGridInColumn( DataGrid^ value ) override
   {
      DataGridColumnStyle::SetDataGridInColumn( value );
      if ( customDateTimePicker1->Parent != nullptr )
      {
         customDateTimePicker1->Parent->Controls->Remove
            ( customDateTimePicker1 );
      }
      if ( value != nullptr )
      {
         value->Controls->Add( customDateTimePicker1 );
      }
   }

private:
   void TimePickerValueChanged( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      // Remove the handler to prevent it from being called twice in a row.
      customDateTimePicker1->ValueChanged -=
         gcnew EventHandler( this, &DataGridTimePickerColumn::TimePickerValueChanged );
      this->isEditing = true;
      DataGridColumnStyle::ColumnStartedEditing( customDateTimePicker1 );
   }
};

public ref class MyForm: public Form
{
private:
   DataTable^ namesDataTable;
   DataGrid^ grid;
public:
   MyForm()
   {
      grid = gcnew DataGrid;

      InitForm();

      namesDataTable = gcnew DataTable( "NamesTable" );
      namesDataTable->Columns->Add( gcnew DataColumn( "Name" ) );
      DataColumn^ dateColumn = gcnew DataColumn
         ( "Date",DateTime::typeid );
      dateColumn->DefaultValue = DateTime::Today;
      namesDataTable->Columns->Add( dateColumn );
      DataSet^ namesDataSet = gcnew DataSet;
      namesDataSet->Tables->Add( namesDataTable );
      grid->DataSource = namesDataSet;
      grid->DataMember = "NamesTable";
      AddGridStyle();
      AddData();
   }

private:
   void AddGridStyle()
   {
      DataGridTableStyle^ myGridStyle = gcnew DataGridTableStyle;
      myGridStyle->MappingName = "NamesTable";
      DataGridTextBoxColumn^ nameColumnStyle =
         gcnew DataGridTextBoxColumn;
      nameColumnStyle->MappingName = "Name";
      nameColumnStyle->HeaderText = "Name";
      myGridStyle->GridColumnStyles->Add( nameColumnStyle );

      DataGridTimePickerColumn^ timePickerColumnStyle =
         gcnew DataGridTimePickerColumn;
      timePickerColumnStyle->MappingName = "Date";
      timePickerColumnStyle->HeaderText = "Date";
      timePickerColumnStyle->Width = 100;
      myGridStyle->GridColumnStyles->Add( timePickerColumnStyle );

      grid->TableStyles->Add( myGridStyle );
   }

   void AddData()
   {
      DataRow^ dRow = namesDataTable->NewRow();
      dRow->default[ "Name" ] = "Name 1";
      dRow->default[ "Date" ] = DateTime(2001,12,01);
      namesDataTable->Rows->Add( dRow );

      dRow = namesDataTable->NewRow();
      dRow->default[ "Name" ] = "Name 2";
      dRow->default[ "Date" ] = DateTime(2001,12,04);
      namesDataTable->Rows->Add( dRow );

      dRow = namesDataTable->NewRow();
      dRow->default[ "Name" ] = "Name 3";
      dRow->default[ "Date" ] = DateTime(2001,12,29);
      namesDataTable->Rows->Add( dRow );

      dRow = namesDataTable->NewRow();
      dRow->default[ "Name" ] = "Name 4";
      dRow->default[ "Date" ] = DateTime(2001,12,13);
      namesDataTable->Rows->Add( dRow );

      dRow = namesDataTable->NewRow();
      dRow->default[ "Name" ] = "Name 5";
      dRow->default[ "Date" ] = DateTime(2001,12,21);
      namesDataTable->Rows->Add( dRow );

      namesDataTable->AcceptChanges();
   }

   void InitForm()
   {
      this->Size = System::Drawing::Size( 500, 500 );
      grid->Size = System::Drawing::Size( 350, 250 );
      grid->TabStop = true;
      grid->TabIndex = 1;
      this->StartPosition = FormStartPosition::CenterScreen;
      this->Controls->Add( grid );
   }
};

[STAThread]
int main()
{
   Application::Run( gcnew MyForm );
}

using System;
using System.Data;
using System.Windows.Forms;
using System.Drawing;

// This example shows how to create your own column style that
// hosts a control, in this case, a DateTimePicker.
public class DataGridTimePickerColumn : DataGridColumnStyle
{
    private CustomDateTimePicker customDateTimePicker1 = 
        new CustomDateTimePicker();

    // The isEditing field tracks whether or not the user is
    // editing data with the hosted control.
    private bool isEditing;

    public DataGridTimePickerColumn() : base()
    {
        customDateTimePicker1.Visible = false;
    }

    protected override void Abort(int rowNum)
    {
        isEditing = false;
        customDateTimePicker1.ValueChanged -=
            new EventHandler(TimePickerValueChanged);
        Invalidate();
    }

    protected override bool Commit
        (CurrencyManager dataSource, int rowNum)
    {
        customDateTimePicker1.Bounds = Rectangle.Empty;

        customDateTimePicker1.ValueChanged -=
            new EventHandler(TimePickerValueChanged);

        if (!isEditing)
            return true;

        isEditing = false;

        try
        {
            DateTime value = customDateTimePicker1.Value;
            SetColumnValueAtRow(dataSource, rowNum, value);
        }
        catch (Exception)
        {
            Abort(rowNum);
            return false;
        }

        Invalidate();
        return true;
    }

    protected override void Edit(
        CurrencyManager source,
        int rowNum,
        Rectangle bounds,
        bool readOnly,
        string displayText,
        bool cellIsVisible)
    {
        DateTime value = (DateTime)
            GetColumnValueAtRow(source, rowNum);
        if (cellIsVisible)
        {
            customDateTimePicker1.Bounds = new Rectangle
                (bounds.X + 2, bounds.Y + 2,
                bounds.Width - 4, bounds.Height - 4);
            customDateTimePicker1.Value = value;
            customDateTimePicker1.Visible = true;
            customDateTimePicker1.ValueChanged +=
                new EventHandler(TimePickerValueChanged);
        }
        else
        {
            customDateTimePicker1.Value = value;
            customDateTimePicker1.Visible = false;
        }

        if (customDateTimePicker1.Visible)
            DataGridTableStyle.DataGrid.Invalidate(bounds);

        customDateTimePicker1.Focus();
    }

    protected override Size GetPreferredSize(
        Graphics g,
        object value)
    {
        return new Size(100, customDateTimePicker1.PreferredHeight + 4);
    }

    protected override int GetMinimumHeight()
    {
        return customDateTimePicker1.PreferredHeight + 4;
    }

    protected override int GetPreferredHeight(Graphics g,
        object value)
    {
        return customDateTimePicker1.PreferredHeight + 4;
    }

    protected override void Paint(Graphics g,
        Rectangle bounds,
        CurrencyManager source,
        int rowNum)
    {
        Paint(g, bounds, source, rowNum, false);
    }

    protected override void Paint(
        Graphics g,
        Rectangle bounds,
        CurrencyManager source,
        int rowNum,
        bool alignToRight)
    {
        Paint(
            g, bounds,
            source,
            rowNum,
            Brushes.Red,
            Brushes.Blue,
            alignToRight);
    }

    protected override void Paint(
        Graphics g,
        Rectangle bounds,
        CurrencyManager source,
        int rowNum,
        Brush backBrush,
        Brush foreBrush,
        bool alignToRight)
    {
        DateTime date = (DateTime)
            GetColumnValueAtRow(source, rowNum);
        Rectangle rect = bounds;
        g.FillRectangle(backBrush, rect);
        rect.Offset(0, 2);
        rect.Height -= 2;
        g.DrawString(date.ToString("d"),
            this.DataGridTableStyle.DataGrid.Font,
            foreBrush, rect);
    }

    protected override void SetDataGridInColumn(DataGrid value)
    {
        base.SetDataGridInColumn(value);
        if (customDateTimePicker1.Parent != null)
        {
            customDateTimePicker1.Parent.Controls.Remove
                (customDateTimePicker1);
        }
        if (value != null)
        {
            value.Controls.Add(customDateTimePicker1);
        }
    }

    private void TimePickerValueChanged(object sender, EventArgs e)
    {
        // Remove the handler to prevent it from being called twice in a row.
        customDateTimePicker1.ValueChanged -=
            new EventHandler(TimePickerValueChanged);
        this.isEditing = true;
        base.ColumnStartedEditing(customDateTimePicker1);
    }
}

public class CustomDateTimePicker : DateTimePicker
{
    protected override bool ProcessKeyMessage(ref Message m)
    {
        // Keep all the keys for the DateTimePicker.
        return ProcessKeyEventArgs(ref m);
    }
}

public class MyForm : Form
{
    private DataTable namesDataTable;
    private DataGrid grid = new DataGrid();
    public MyForm() : base()
    {
        InitForm();

        namesDataTable = new DataTable("NamesTable");
        namesDataTable.Columns.Add(new DataColumn("Name"));
        DataColumn dateColumn = new DataColumn
            ("Date", typeof(DateTime));
        dateColumn.DefaultValue = DateTime.Today;
        namesDataTable.Columns.Add(dateColumn);
        DataSet namesDataSet = new DataSet();
        namesDataSet.Tables.Add(namesDataTable);
        grid.DataSource = namesDataSet;
        grid.DataMember = "NamesTable";
        AddGridStyle();
        AddData();
    }

    private void AddGridStyle()
    {
        DataGridTableStyle myGridStyle = new DataGridTableStyle();
        myGridStyle.MappingName = "NamesTable";

        DataGridTextBoxColumn nameColumnStyle =
            new DataGridTextBoxColumn();
        nameColumnStyle.MappingName = "Name";
        nameColumnStyle.HeaderText = "Name";
        myGridStyle.GridColumnStyles.Add(nameColumnStyle);

        DataGridTimePickerColumn timePickerColumnStyle =
            new DataGridTimePickerColumn();
        timePickerColumnStyle.MappingName = "Date";
        timePickerColumnStyle.HeaderText = "Date";
        timePickerColumnStyle.Width = 100;
        myGridStyle.GridColumnStyles.Add(timePickerColumnStyle);

        grid.TableStyles.Add(myGridStyle);
    }

    private void AddData()
    {

        DataRow dRow = namesDataTable.NewRow();
        dRow["Name"] = "Name 1";
        dRow["Date"] = new DateTime(2001, 12, 01);
        namesDataTable.Rows.Add(dRow);

        dRow = namesDataTable.NewRow();
        dRow["Name"] = "Name 2";
        dRow["Date"] = new DateTime(2001, 12, 04);
        namesDataTable.Rows.Add(dRow);

        dRow = namesDataTable.NewRow();
        dRow["Name"] = "Name 3";
        dRow["Date"] = new DateTime(2001, 12, 29);
        namesDataTable.Rows.Add(dRow);

        dRow = namesDataTable.NewRow();
        dRow["Name"] = "Name 4";
        dRow["Date"] = new DateTime(2001, 12, 13);
        namesDataTable.Rows.Add(dRow);

        dRow = namesDataTable.NewRow();
        dRow["Name"] = "Name 5";
        dRow["Date"] = new DateTime(2001, 12, 21);
        namesDataTable.Rows.Add(dRow);

        namesDataTable.AcceptChanges();
    }

    private void InitForm()
    {
        this.Size = new Size(500, 500);
        grid.Size = new Size(350, 250);
        grid.TabStop = true;
        grid.TabIndex = 1;
        this.StartPosition = FormStartPosition.CenterScreen;
        this.Controls.Add(grid);
    }
 
    [STAThread]
    public static void Main()
    {
        Application.Run(new MyForm());
    }
}

Imports System.Data
Imports System.Windows.Forms
Imports System.Drawing
Imports System.ComponentModel
Imports System.Security.Permissions

' This example shows how to create your own column style that
' hosts a control, in this case, a DateTimePicker.
Public Class DataGridTimePickerColumn
    Inherits DataGridColumnStyle

    Private customDateTimePicker1 As New CustomDateTimePicker()

    ' The isEditing field tracks whether or not the user is
    ' editing data with the hosted control.
    Private isEditing As Boolean

    Public Sub New()
        customDateTimePicker1.Visible = False
    End Sub

    Protected Overrides Sub Abort(ByVal rowNum As Integer)
        isEditing = False
        RemoveHandler customDateTimePicker1.ValueChanged, _
            AddressOf TimePickerValueChanged
        Invalidate()
    End Sub

    Protected Overrides Function Commit _
        (ByVal dataSource As CurrencyManager, ByVal rowNum As Integer) _
        As Boolean

        customDateTimePicker1.Bounds = Rectangle.Empty

        RemoveHandler customDateTimePicker1.ValueChanged, _
            AddressOf TimePickerValueChanged

        If Not isEditing Then
            Return True
        End If
        isEditing = False

        Try
            Dim value As DateTime = customDateTimePicker1.Value
            SetColumnValueAtRow(dataSource, rowNum, value)
        Catch
        End Try

        Invalidate()
        Return True
    End Function

    Protected Overloads Overrides Sub Edit( _
        ByVal [source] As CurrencyManager, _
        ByVal rowNum As Integer, _
        ByVal bounds As Rectangle, _
        ByVal [readOnly] As Boolean, _
        ByVal displayText As String, _
        ByVal cellIsVisible As Boolean)

        Dim value As DateTime = _
        CType(GetColumnValueAtRow([source], rowNum), DateTime)
        If cellIsVisible Then
            customDateTimePicker1.Bounds = New Rectangle _
            (bounds.X + 2, bounds.Y + 2, bounds.Width - 4, _
            bounds.Height - 4)

            customDateTimePicker1.Value = value
            customDateTimePicker1.Visible = True
            AddHandler customDateTimePicker1.ValueChanged, _
            AddressOf TimePickerValueChanged
        Else
            customDateTimePicker1.Value = value
            customDateTimePicker1.Visible = False
        End If

        If customDateTimePicker1.Visible Then
            DataGridTableStyle.DataGrid.Invalidate(bounds)
        End If

        customDateTimePicker1.Focus()

    End Sub

    Protected Overrides Function GetPreferredSize( _
        ByVal g As Graphics, _
        ByVal value As Object) As Size

        Return New Size(100, customDateTimePicker1.PreferredHeight + 4)

    End Function

    Protected Overrides Function GetMinimumHeight() As Integer
        Return customDateTimePicker1.PreferredHeight + 4
    End Function

    Protected Overrides Function GetPreferredHeight( _
        ByVal g As Graphics, ByVal value As Object) As Integer

        Return customDateTimePicker1.PreferredHeight + 4

    End Function

    Protected Overloads Overrides Sub Paint( _
        ByVal g As Graphics, ByVal bounds As Rectangle, _
        ByVal [source] As CurrencyManager, ByVal rowNum As Integer)

        Paint(g, bounds, [source], rowNum, False)

    End Sub

    Protected Overloads Overrides Sub Paint(ByVal g As Graphics, _
        ByVal bounds As Rectangle, ByVal [source] As CurrencyManager, _
        ByVal rowNum As Integer, ByVal alignToRight As Boolean)

        Paint(g, bounds, [source], rowNum, Brushes.Red, _
            Brushes.Blue, alignToRight)

    End Sub

    Protected Overloads Overrides Sub Paint(ByVal g As Graphics, _
        ByVal bounds As Rectangle, ByVal [source] As CurrencyManager, _
        ByVal rowNum As Integer, ByVal backBrush As Brush, _
        ByVal foreBrush As Brush, ByVal alignToRight As Boolean)

        Dim [date] As DateTime = _
        CType(GetColumnValueAtRow([source], rowNum), DateTime)
        Dim rect As Rectangle = bounds
        g.FillRectangle(backBrush, rect)
        rect.Offset(0, 2)
        rect.Height -= 2
        g.DrawString([date].ToString("d"), _
            Me.DataGridTableStyle.DataGrid.Font, foreBrush, _
            RectangleF.FromLTRB(rect.X, rect.Y, rect.Right, rect.Bottom))

    End Sub

    Protected Overrides Sub SetDataGridInColumn(ByVal value As DataGrid)
        MyBase.SetDataGridInColumn(value)
        If (customDateTimePicker1.Parent IsNot Nothing) Then
            customDateTimePicker1.Parent.Controls.Remove(customDateTimePicker1)
        End If
        If (value IsNot Nothing) Then
            value.Controls.Add(customDateTimePicker1)
        End If
    End Sub

    Private Sub TimePickerValueChanged( _
        ByVal sender As Object, ByVal e As EventArgs)

        ' Remove the handler to prevent it from being called twice in a row.
        RemoveHandler customDateTimePicker1.ValueChanged, _
            AddressOf TimePickerValueChanged
        Me.isEditing = True
        MyBase.ColumnStartedEditing(customDateTimePicker1)

    End Sub

End Class

Public Class CustomDateTimePicker
    Inherits DateTimePicker

    <SecurityPermissionAttribute( _
    SecurityAction.LinkDemand, Flags := SecurityPermissionFlag.UnmanagedCode)> _
    Protected Overrides Function ProcessKeyMessage(ByRef m As Message) As Boolean
        ' Keep all the keys for the DateTimePicker.
        Return ProcessKeyEventArgs(m)
    End Function

End Class

Public Class MyForm
    Inherits Form

    Private namesDataTable As DataTable
    Private myGrid As DataGrid = New DataGrid()

    Public Sub New()

        InitForm()

        namesDataTable = New DataTable("NamesTable")
        namesDataTable.Columns.Add(New DataColumn("Name"))
        Dim dateColumn As DataColumn = _
             New DataColumn("Date", GetType(DateTime))
        dateColumn.DefaultValue = DateTime.Today
        namesDataTable.Columns.Add(dateColumn)
        Dim namesDataSet As DataSet = New DataSet()
        namesDataSet.Tables.Add(namesDataTable)
        myGrid.DataSource = namesDataSet
        myGrid.DataMember = "NamesTable"
        AddGridStyle()
        AddData()

    End Sub

    Private Sub AddGridStyle()
        Dim myGridStyle As DataGridTableStyle = _
                    New DataGridTableStyle()
        myGridStyle.MappingName = "NamesTable"

        Dim nameColumnStyle As DataGridTextBoxColumn = _
            New DataGridTextBoxColumn()
        nameColumnStyle.MappingName = "Name"
        nameColumnStyle.HeaderText = "Name"
        myGridStyle.GridColumnStyles.Add(nameColumnStyle)

        Dim customDateTimePicker1ColumnStyle As DataGridTimePickerColumn = _
            New DataGridTimePickerColumn()
        customDateTimePicker1ColumnStyle.MappingName = "Date"
        customDateTimePicker1ColumnStyle.HeaderText = "Date"
        customDateTimePicker1ColumnStyle.Width = 100
        myGridStyle.GridColumnStyles.Add(customDateTimePicker1ColumnStyle)

        myGrid.TableStyles.Add(myGridStyle)
    End Sub

    Private Sub AddData()
        Dim dRow As DataRow = namesDataTable.NewRow()
        dRow("Name") = "Name 1"
        dRow("Date") = New DateTime(2001, 12, 1)
        namesDataTable.Rows.Add(dRow)

        dRow = namesDataTable.NewRow()
        dRow("Name") = "Name 2"
        dRow("Date") = New DateTime(2001, 12, 4)
        namesDataTable.Rows.Add(dRow)

        dRow = namesDataTable.NewRow()
        dRow("Name") = "Name 3"
        dRow("Date") = New DateTime(2001, 12, 29)
        namesDataTable.Rows.Add(dRow)

        dRow = namesDataTable.NewRow()
        dRow("Name") = "Name 4"
        dRow("Date") = New DateTime(2001, 12, 13)
        namesDataTable.Rows.Add(dRow)

        dRow = namesDataTable.NewRow()
        dRow("Name") = "Name 5"
        dRow("Date") = New DateTime(2001, 12, 21)
        namesDataTable.Rows.Add(dRow)

        namesDataTable.AcceptChanges()
    End Sub

    Private Sub InitForm()
        Me.Size = New Size(500, 500)
        myGrid.Size = New Size(350, 250)
        myGrid.TabStop = True
        myGrid.TabIndex = 1
        Me.StartPosition = FormStartPosition.CenterScreen
        Me.Controls.Add(myGrid)
    End Sub

    <STAThread()> _
    Public Shared Sub Main()
        Application.Run(New MyForm())
    End Sub

End Class

Observações

A coleção de objetos DataGridColumnStyle (o GridColumnStylesCollection) é acedida através da propriedade TableStyles do controlo System.Windows.Forms.DataGrid.

O controlo System.Windows.Forms.DataGrid cria automaticamente uma coleção de objetos DataGridColumnStyle para si quando define a propriedade DataSource para uma fonte de dados apropriada. Os objetos criados são, na verdade, instâncias de uma das seguintes classes que herdam de DataGridColumnStyle: DataGridBoolColumn ou DataGridTextBoxColumn classe.

Para formatar a visualização dos dados, defina a Format propriedade da DataGridTextBoxColumn classe para um dos valores de formatação. Para mais informações sobre valores de formatação válidos, consulte Tipos de Formatação e Cadeias de Formatação Personalizadas de Data e Hora.

Também pode criar o seu próprio conjunto de DataGridColumnStyle objetos e adicioná-los ao GridColumnStylesCollection. Ao fazê-lo, deve definir o MappingName estilo de cada coluna para ColumnName o de a DataColumn para sincronizar a apresentação das colunas com os dados reais.

Quando uma das classes derivadas é instanciada por um controlo System.Windows.Forms.DataGrid, a classe criada depende do DataType do objeto DataColumn associado ao objeto DataGridColumnStyle. Por exemplo, um DataColumn com o seu DataType conjunto em System.Boolean será associado a um DataGridBoolColumn. Para determinar o tipo de qualquer DataGridColumnStyle, use o GetType método.

Para criar as suas próprias classes de coluna, pode herdar de DataGridColumnStyle. Pode querer fazer isto para criar colunas especiais que hospedam controlos, como exemplificado pela DataGridTextBox classe que hospeda o TextBox controlo. Por exemplo, pode hospedar um Image controlo para mostrar imagens nas colunas, ou pode criar o seu próprio controlo de utilizador para hospedar na coluna.

A funcionalidade do DataGridColumnStyle não deve ser confundida com a do DataColumn. Enquanto o DataColumn contém as propriedades e métodos apropriados para criar o esquema de uma tabela de dados, o DataGridColumnStyle contém as propriedades e métodos relacionados com o aparecimento de uma coluna individual no ecrã.

Se uma linha contiver um DBNull.Value, o texto apresentado na coluna pode ser definido com a NullText propriedade.

A DataGridColumnStyle classe também permite especificar o comportamento de uma coluna enquanto os seus dados estão a ser alterados. Os BeginUpdate métodos e EndUpdate suspendem temporariamente o desenho da coluna enquanto grandes atualizações são feitas aos dados da coluna. Sem esta funcionalidade, cada alteração em cada célula da grelha seria imediatamente desenhada; Isto pode ser distrativo para o utilizador e um risco de desempenho.

Vários métodos permitem monitorizar a coluna à medida que é editada pelo utilizador, incluindo os Edit eventos and (e Commit eventos).

A maioria das propriedades e métodos da classe é adaptada para controlar a aparência de uma coluna. Mas algumas, como o GetColumnValueAtRow e SetColumnValueAtRow permitem-lhe examinar e alterar o valor numa célula específica.

Notas para Implementadores

Quando herdas de DataGridColumnStyle, deves sobrepor os seguintes elementos: Abort(Int32), Commit(CurrencyManager, Int32), Edit(CurrencyManager, Int32, Rectangle, Boolean), e Paint(Graphics, Rectangle, CurrencyManager, Int32) (duas vezes).

Ver também

• DataColumn
• DataGrid
• DataGridBoolColumn
• DataGridTextBox
• DataGridTableStyle
• DataView
• GridColumnStylesCollection