DataGridBoolColumn Class

Specifies a column in which each cell contains a check box for representing a Boolean value.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

'Declaration
Public Class DataGridBoolColumn
	Inherits DataGridColumnStyle
'Usage
Dim instance As DataGridBoolColumn

public class DataGridBoolColumn extends DataGridColumnStyle
public class DataGridBoolColumn extends DataGridColumnStyle

The DataGridBoolColumn derives from the abstract class DataGridColumnStyle. At run time, the DataGridBoolColumn contains check boxes in each cell that have three states by default: checked (true), unchecked (false), and Value. To use two-state check boxes, set the AllowNull property to false.

Properties added to the class include FalseValue, NullValue, and TrueValue. These properties specify the value underlying each of the column's states.

The following code example first creates a new DataGridBoolColumn and adds it to the GridColumnStylesCollection of a DataGridTableStyle.

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

Public Class MyForm
    Inherits System.Windows.Forms.Form
    Private components As System.ComponentModel.Container
    Private myTable As DataTable
    Private myGrid As DataGrid = New DataGrid()

    Public Shared Sub Main()
        Application.Run(New MyForm())
    End Sub

    Public Sub New()
        Try
            InitializeComponent()
            myTable = New DataTable("NamesTable")
            myTable.Columns.Add(New DataColumn("Name"))
            Dim column As DataColumn = New DataColumn _
            ("id", GetType(System.Int32))
            myTable.Columns.Add(column)
            myTable.Columns.Add(New DataColumn _
            ("calculatedField", GetType(Boolean)))
            Dim namesDataSet As DataSet = New DataSet("myDataSet")
            namesDataSet.Tables.Add(myTable)
            myGrid.SetDataBinding(namesDataSet, "NamesTable")
            AddData()
            AddTableStyle()

        Catch exc As System.Exception
            Console.WriteLine(exc.ToString)
        End Try
    End Sub

    Private Sub AddTableStyle()
        ' Map a new  TableStyle to the DataTable. Then 
        ' add DataGridColumnStyle objects to the collection
        ' of column styles with appropriate mappings.
        Dim dgt As DataGridTableStyle = New DataGridTableStyle()
        dgt.MappingName = "NamesTable"

        Dim dgtbc As DataGridTextBoxColumn = _
        New DataGridTextBoxColumn()
        dgtbc.MappingName = "Name"
        dgtbc.HeaderText = "Name"
        dgt.GridColumnStyles.Add(dgtbc)

        dgtbc = New DataGridTextBoxColumn()
        dgtbc.MappingName = "id"
        dgtbc.HeaderText = "id"
        dgt.GridColumnStyles.Add(dgtbc)

        Dim db As DataGridBoolColumnInherit = _
        New DataGridBoolColumnInherit()
        db.HeaderText = "less than 1000 = blue"
        db.Width = 150
        db.MappingName = "calculatedField"
        dgt.GridColumnStyles.Add(db)

        myGrid.TableStyles.Add(dgt)

        ' This expression instructs the grid to change
        ' the color of the inherited DataGridBoolColumn
        ' according to the value of the id field. If it's
        ' less than 1000, the row is blue. Otherwise,
        ' the color is yellow.
        db.Expression = "id < 1000"
    End Sub

    Private Sub AddData()

        ' Add data with varying numbers for the id field.
        ' If the number is over 1000, the cell will paint
        ' yellow. Otherwise, it will be blue.
        Dim dRow As DataRow

        dRow = myTable.NewRow()
        dRow("Name") = "name 1"
        dRow("id") = 999
        myTable.Rows.Add(dRow)

        dRow = myTable.NewRow()
        dRow("Name") = "name 2"
        dRow("id") = 2300
        myTable.Rows.Add(dRow)

        dRow = myTable.NewRow()
        dRow("Name") = "name 3"
        dRow("id") = 120
        myTable.Rows.Add(dRow)

        dRow = myTable.NewRow()
        dRow("Name") = "name 4"
        dRow("id") = 4023
        myTable.Rows.Add(dRow)

        dRow = myTable.NewRow()
        dRow("Name") = "name 5"
        dRow("id") = 2345
        myTable.Rows.Add(dRow)

        myTable.AcceptChanges()
    End Sub

    Private Sub InitializeComponent()
        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

End Class


Public Class DataGridBoolColumnInherit
    Inherits DataGridBoolColumn

    Private trueBrush As SolidBrush = Brushes.Blue
    Private falseBrush As SolidBrush = Brushes.Yellow
    Private expressionColumn As DataColumn = Nothing
    Shared count As Int32 = 0

    Public Property FalseColor() As Color
        Get
            Return falseBrush.Color
        End Get

        Set(ByVal Value As Color)

            falseBrush = New SolidBrush(Value)
            Invalidate()
        End Set
    End Property

    Public Property TrueColor() As Color
        Get
            Return trueBrush.Color
        End Get

        Set(ByVal Value As Color)

            trueBrush = New SolidBrush(Value)
            Invalidate()
        End Set
    End Property

    Public Sub New()
        count += 1
    End Sub

    ' This will work only with a DataSet or DataTable.
    ' The code is not compatible with IBindingList implementations.
    Public Property Expression() As String
        Get
            If Me.expressionColumn Is Nothing Then
                Return String.Empty
            Else
                Return Me.expressionColumn.Expression
            End If
        End Get
        Set(ByVal Value As String)
            If expressionColumn Is Nothing Then
                AddExpressionColumn(Value)
            Else
                expressionColumn.Expression = Value
            End If
            If Not (expressionColumn Is Nothing) And expressionColumn.Expression.Equals(Value) Then
                Return
            End If
            Invalidate()
        End Set
    End Property

    Private Sub AddExpressionColumn(ByVal value As String)
        ' Get the grid's data source. First check for a null 
        ' table or data grid.
        If Me.DataGridTableStyle Is Nothing Or _
        Me.DataGridTableStyle.DataGrid Is Nothing Then
            Return
        End If

        Dim dg As DataGrid = Me.DataGridTableStyle.DataGrid
        Dim dv As DataView = CType(dg.BindingContext(dg.DataSource, dg.DataMember), CurrencyManager).List

        ' This works only with System.Data.DataTable.
        If dv Is Nothing Then
            Return
        End If

        ' If the user already added a column with the name 
        ' then exit. Otherwise, add the column and set the 
        ' expression to the value passed to this function.
        Dim col As DataColumn = dv.Table.Columns("__Computed__Column__")
        If Not (col Is Nothing) Then
            Return
        End If
        col = New DataColumn("__Computed__Column__" + count.ToString())

        dv.Table.Columns.Add(col)

        col.Expression = value
        expressionColumn = col
    End Sub


    ' Override the OnPaint method to paint the cell based on the expression.
    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 trueExpression As Boolean = False
        Dim hasExpression As Boolean = False
        Dim drv As DataRowView = [source].List(rowNum)
        hasExpression = Not (Me.expressionColumn Is Nothing) And Not (Me.expressionColumn.Expression Is Nothing) And Not Me.expressionColumn.Expression.Equals([String].Empty)

        ' Get the value from the expression column.
        ' For simplicity, we assume a True/False value for the 
        ' expression column.
        If hasExpression Then
            Dim expr As Object = drv.Row(expressionColumn.ColumnName)
            trueExpression = expr.Equals("True")
        End If

        ' Let the DataGridBoolColumn do the painting.
        If Not hasExpression Then
            MyBase.Paint(g, bounds, [source], rowNum, backBrush, foreBrush, alignToRight)
        End If

        ' Paint using the expression color for true or false, as calculated.
        If trueExpression Then
            MyBase.Paint(g, bounds, [source], rowNum, trueBrush, foreBrush, alignToRight)
        Else
            MyBase.Paint(g, bounds, [source], rowNum, falseBrush, foreBrush, alignToRight)
        End If
    End Sub
End Class

import System.*;
import System.Data.*;
import System.Windows.Forms.*;
import System.Drawing.*;
import System.ComponentModel.*;

public class MyForm extends Form
{
    private DataTable myTable;
    private DataGrid myGrid = new DataGrid();

    public MyForm()
    {
        try {
            InitializeComponent();
            myTable = new DataTable("NamesTable");
            myTable.get_Columns().Add(new DataColumn("Name"));

            DataColumn column = 
                new DataColumn("id", System.Int32.class.ToType());

            myTable.get_Columns().Add(column);
            myTable.get_Columns().Add(new DataColumn("calculatedField", 
                boolean.class.ToType()));

            DataSet namesDataSet = new DataSet();

            namesDataSet.get_Tables().Add(myTable);
            myGrid.SetDataBinding(namesDataSet, "NamesTable");
            AddTableStyle();
            AddData();
        }
        catch(System.Exception exc) {
            Console.WriteLine(exc.ToString());
        }
    } //MyForm

    private void gridEnter(Object sender, EventArgs e)
    {
        myGrid.set_CurrentCell(new DataGridCell(2, 2));
    } //gridEnter

    private void AddTableStyle()
    {
        // Map a new  TableStyle to the DataTable. Then 
        // add DataGridColumnStyle objects to the collection
        // of column styles with appropriate mappings.
        DataGridTableStyle dgt = new DataGridTableStyle();

        dgt.set_MappingName("NamesTable");

        DataGridTextBoxColumn dgtbc = new DataGridTextBoxColumn();

        dgtbc.set_MappingName("Name");
        dgtbc.set_HeaderText("Name");
        dgt.get_GridColumnStyles().Add(dgtbc);
        dgtbc = new DataGridTextBoxColumn();
        dgtbc.set_MappingName("id");
        dgtbc.set_HeaderText("id");
        dgt.get_GridColumnStyles().Add(dgtbc);

        DataGridBoolColumnInherit db = new DataGridBoolColumnInherit();

        db.set_HeaderText("less than 1000 = blue");
        db.set_Width(150);
        db.set_MappingName("calculatedField");
        dgt.get_GridColumnStyles().Add(db);
        myGrid.get_TableStyles().Add(dgt);

        // This expression instructs the grid to change
        // the color of the inherited DataGridBoolColumn
        // according to the value of the id field. If it's
        // less than 1000, the row is blue. Otherwise,
        // the color is yellow.
        db.set_Expression("id < 1000");
    } //AddTableStyle

    private void AddData()
    {
        // Add data with varying numbers for the id field.
        // If the number is over 1000, the cell will paint
        // yellow. Otherwise, it will be blue.
        DataRow dRow = myTable.NewRow();

        dRow.set_Item("Name", "name 1 ");
        dRow.set_Item("id", (Int32)999);
        myTable.get_Rows().Add(dRow);
        dRow = myTable.NewRow();
        dRow.set_Item("Name", "name 2");
        dRow.set_Item("id", (Int32)2300);
        myTable.get_Rows().Add(dRow);
        dRow = myTable.NewRow();
        dRow.set_Item("Name", "name 3");
        dRow.set_Item("id", (Int32)120);
        myTable.get_Rows().Add(dRow);
        dRow = myTable.NewRow();
        dRow.set_Item("Name", "name 4");
        dRow.set_Item("id", (Int32)4023);
        myTable.get_Rows().Add(dRow);
        dRow = myTable.NewRow();
        dRow.set_Item("Name", "name 5");
        dRow.set_Item("id", (Int32)2345);
        myTable.get_Rows().Add(dRow);
        myTable.AcceptChanges();
    } //AddData

    private void InitializeComponent()
    {
        this.set_Size(new Size(500, 500));
        myGrid.set_Size(new Size(350, 250));
        myGrid.set_TabStop(true);
        myGrid.set_TabIndex(1);
        this.set_StartPosition(FormStartPosition.CenterScreen);
        this.get_Controls().Add(myGrid);
    } //InitializeComponent

    /** @attribute STAThread()
     */
    public static void main(String[] args)
    {
        MyForm myGridForm = new MyForm();
        myGridForm.ShowDialog();
    } //main
} //MyForm

public class DataGridBoolColumnInherit extends DataGridBoolColumn
{
    private SolidBrush trueBrush = (SolidBrush)Brushes.get_Blue();
    private SolidBrush falseBrush = (SolidBrush)Brushes.get_Yellow();
    private DataColumn expressionColumn = null;
    private static int count = 0;

    /** @property 
     */
    public Color get_FalseColor()
    {
        return falseBrush.get_Color();
    } //get_FalseColor

    /** @property 
     */
    public void set_FalseColor(Color value)
    {
        falseBrush = new SolidBrush(value);
        Invalidate();
    } //set_FalseColor

    /** @property 
     */
    public Color get_TrueColor()
    {
        return trueBrush.get_Color();
    } //get_TrueColor

    /** @property 
     */
    public void set_TrueColor(Color value)
    {
        trueBrush = new SolidBrush(value);
        Invalidate();
    } //set_TrueColor

    public DataGridBoolColumnInherit()
    {
        super();
        count++;
    } //DataGridBoolColumnInherit

    // This will work only with a DataSet or DataTable.
    // The code is not compatible with IBindingList implementations.
    /** @property 
     */
    public String get_Expression()
    {
        return (this.expressionColumn == null) 
            ? String.Empty : this.expressionColumn.get_Expression();
    } //get_Expression

    /** @property 
     */
    public void set_Expression(String value)
    {
        if(expressionColumn == null) {
            AddExpressionColumn(value);
        }
        else {
            expressionColumn.set_Expression(value);
        }

        if(expressionColumn != null 
            && expressionColumn.get_Expression().Equals(value)) {
            return;
        }
        Invalidate();
    } //set_Expression

    private void AddExpressionColumn(String value)
    {
        // Get the grid's data source. First check for a null 
        // table or data grid.
        if(this.get_DataGridTableStyle() == null 
            || this.get_DataGridTableStyle().get_DataGrid() == null) {
            return;
        }

        DataGrid myGrid = this.get_DataGridTableStyle().get_DataGrid();
        DataView myDataView = (DataView)(((CurrencyManager)(myGrid.
            get_BindingContext().get_Item(myGrid.get_DataSource(), 
            myGrid.get_DataMember()))).get_List());

        // This works only with System.Data.DataTable.
        if(myDataView == null) {
            return;
        }

        // If the user already added a column with the name 
        // then exit. Otherwise, add the column and set the 
        // expression to the value passed to this function.
        DataColumn col = myDataView.get_Table().get_Columns().
            get_Item("__Computed__Column__");

        if(col != null) {
            return;
        }
        col = new DataColumn("__Computed__Column__" 
            + System.Convert.ToString(count));

        myDataView.get_Table().get_Columns().Add(col);
        col.set_Expression(value);
        expressionColumn = col;
    } //AddExpressionColumn

    // override the OnPaint method to paint the cell based on the expression.
    protected void Paint(Graphics g, Rectangle bounds, CurrencyManager source, 
        int rowNum, Brush backBrush, Brush foreBrush, boolean alignToRight)
    {
        boolean trueExpression = false;
        boolean hasExpression = false;
        DataRowView drv = (DataRowView)source.get_List().get_Item(rowNum);

        hasExpression = this.expressionColumn != null 
            && this.expressionColumn.get_Expression() != null 
            && !(this.expressionColumn.get_Expression().Equals(String.Empty));
        
        Console.WriteLine(String.Format("hasExpressionValue {0}", 
            System.Convert.ToString(hasExpression)));

        // Get the value from the expression column.
        // For simplicity, we assume a True/False value for the 
        // expression column.
        if(hasExpression) {
            Object expr = 
                drv.get_Row().get_Item(expressionColumn.get_ColumnName());
            trueExpression = expr.Equals("True");
        }

        // Let the DataGridBoolColumn do the painting.
        if(!(hasExpression)) {
            super.Paint(g, bounds, source, rowNum, backBrush, foreBrush, 
                alignToRight);
        }

        // Paint using the expression color for true or false, as calculated.
        if(trueExpression) {
            super.Paint(g, bounds, source, rowNum, trueBrush, foreBrush, 
                alignToRight);
        }
        else {
            super.Paint(g, bounds, source, rowNum, falseBrush, foreBrush, 
                alignToRight);
        }
    } //Paint
} //DataGridBoolColumnInherit

System.Object
   System.MarshalByRefObject
     System.ComponentModel.Component
       System.Windows.Forms.DataGridColumnStyle
        System.Windows.Forms.DataGridBoolColumn

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

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