DataGridBoolColumn Class
Specifies a column in which each cell contains a check box for representing a Boolean value.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
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 (expressionColumn IsNot 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 (col IsNot 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 = (Me.expressionColumn IsNot Nothing) And (Me.expressionColumn.Expression IsNot 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
System.MarshalByRefObject
System.ComponentModel.Component
System.Windows.Forms.DataGridColumnStyle
System.Windows.Forms.DataGridBoolColumn
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.