DataGridBoolColumn 类
指定一列，该列中每个单元格均包含一个表示布尔值的复选框。
**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）
语法
声明
Public Class DataGridBoolColumn
Inherits DataGridColumnStyle
用法
Dim instance As DataGridBoolColumn
public class DataGridBoolColumn : DataGridColumnStyle
public ref class DataGridBoolColumn : public DataGridColumnStyle
public class DataGridBoolColumn extends DataGridColumnStyle
public class DataGridBoolColumn extends DataGridColumnStyle
备注
DataGridBoolColumn 从 abstract 类 DataGridColumnStyle 派生。在运行时，默认情况下 DataGridBoolColumn 在每个单元格中均包含具有三个状态的复选框：已选中 (true)、未选中 (false) 和 Value。若要使用两个状态的复选框，请将 AllowNull 属性设置为 false。
添加到该类的属性包括 FalseValue、NullValue 和 TrueValue。这些属性指定各个列状态下的基础值。
示例
下面的代码示例首先创建一个新的 DataGridBoolColumn 并将其添加到 DataGridTableStyle 的 GridColumnStylesCollection 中。
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
using System;
using System.Data;
using System.Windows.Forms;
using System.Drawing;
using System.ComponentModel;
public class MyForm : Form
{
private DataTable myTable;
private DataGrid myGrid = new DataGrid();
public MyForm() : base()
{
try
{
InitializeComponent();
myTable = new DataTable("NamesTable");
myTable.Columns.Add(new DataColumn("Name"));
DataColumn column = new DataColumn
("id", typeof(System.Int32));
myTable.Columns.Add(column);
myTable.Columns.Add(new
DataColumn("calculatedField", typeof(bool)));
DataSet namesDataSet = new DataSet();
namesDataSet.Tables.Add(myTable);
myGrid.SetDataBinding(namesDataSet, "NamesTable");
AddTableStyle();
AddData();
}
catch (System.Exception exc)
{
Console.WriteLine(exc.ToString());
}
}
private void grid_Enter(object sender, EventArgs e)
{
myGrid.CurrentCell = new DataGridCell(2,2);
}
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.MappingName = "NamesTable";
DataGridTextBoxColumn dgtbc = 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);
DataGridBoolColumnInherit db =
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";
}
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["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();
}
private void InitializeComponent()
{
this.Size = new Size(500, 500);
myGrid.Size = new Size(350, 250);
myGrid.TabStop = true;
myGrid.TabIndex = 1;
this.StartPosition = FormStartPosition.CenterScreen;
this.Controls.Add(myGrid);
}
[STAThread]
public static void Main()
{
MyForm myGridForm = new MyForm();
myGridForm.ShowDialog();
}
}
public class DataGridBoolColumnInherit : DataGridBoolColumn
{
private SolidBrush trueBrush = Brushes.Blue as SolidBrush;
private SolidBrush falseBrush = Brushes.Yellow as SolidBrush;
private DataColumn expressionColumn = null;
private static int count = 0;
public Color FalseColor
{
get
{
return falseBrush.Color;
}
set
{
falseBrush = new SolidBrush(value);
Invalidate();
}
}
public Color TrueColor
{
get
{
return trueBrush.Color;
}
set
{
trueBrush = new SolidBrush(value);
Invalidate();
}
}
public DataGridBoolColumnInherit() : base ()
{
count ++;
}
// This will work only with a DataSet or DataTable.
// The code is not compatible with IBindingList implementations.
public string Expression
{
get
{
return this.expressionColumn == null ? String.Empty :
this.expressionColumn.Expression;
}
set
{
if (expressionColumn == null)
AddExpressionColumn(value);
else
expressionColumn.Expression = value;
if (expressionColumn != null &&
expressionColumn.Expression.Equals(value))
return;
Invalidate();
}
}
private void AddExpressionColumn(string value)
{
// Get the grid's data source. First check for a null
// table or data grid.
if (this.DataGridTableStyle == null ||
this.DataGridTableStyle.DataGrid == null)
return;
DataGrid myGrid = this.DataGridTableStyle.DataGrid;
DataView myDataView = ((CurrencyManager)
myGrid.BindingContext[myGrid.DataSource,
myGrid.DataMember]).List
as DataView;
// 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.Table.Columns["__Computed__Column__"];
if (col != null)
return;
col = new DataColumn("__Computed__Column__" + count.ToString());
myDataView.Table.Columns.Add(col);
col.Expression = value;
expressionColumn = col;
}
// override the OnPaint method to paint the cell based on the expression.
protected override void Paint(Graphics g, Rectangle bounds,
CurrencyManager source, int rowNum,
Brush backBrush, Brush foreBrush,
bool alignToRight)
{
bool trueExpression = false;
bool hasExpression = false;
DataRowView drv = source.List[rowNum] as DataRowView;
hasExpression = this.expressionColumn != null &&
this.expressionColumn.Expression != null &&
!this.expressionColumn.Expression.Equals(String.Empty);
Console.WriteLine(string.Format("hasExpressionValue {0}",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.Row[expressionColumn.ColumnName];
trueExpression = expr.Equals("True");
}
// Let the DataGridBoolColumn do the painting.
if (!hasExpression)
base.Paint(g, bounds, source, rowNum,
backBrush, foreBrush, alignToRight);
// Paint using the expression color for true or false, as calculated.
if (trueExpression)
base.Paint(g, bounds, source, rowNum,
trueBrush, foreBrush, alignToRight);
else
base.Paint(g, bounds, source, rowNum,
falseBrush, foreBrush, alignToRight);
}
}
using namespace System;
using namespace System::Data;
using namespace System::Windows::Forms;
using namespace System::Drawing;
using namespace System::ComponentModel;
public ref class DataGridBoolColumnInherit: public DataGridBoolColumn
{
private:
SolidBrush^ trueBrush;
SolidBrush^ falseBrush;
DataColumn^ expressionColumn;
static int count = 0;
public:
DataGridBoolColumnInherit()
: DataGridBoolColumn()
{
trueBrush = dynamic_cast<SolidBrush^>(Brushes::Blue);
falseBrush = dynamic_cast<SolidBrush^>(Brushes::Yellow);
expressionColumn = nullptr;
count++;
}
property Color FalseColor
{
Color get()
{
return falseBrush->Color;
}
void set( Color value )
{
falseBrush = gcnew System::Drawing::SolidBrush( value );
Invalidate();
}
}
property Color TrueColor
{
Color get()
{
return trueBrush->Color;
}
void set( Color value )
{
trueBrush = gcnew System::Drawing::SolidBrush( value );
Invalidate();
}
}
property String^ Expression
{
// This will work only with a DataSet or DataTable.
// The code is not compatible with IBindingList* implementations.
String^ get()
{
return this->expressionColumn == nullptr ? String::Empty : this->expressionColumn->Expression;
}
void set( String^ value )
{
if ( expressionColumn == nullptr )
AddExpressionColumn( value );
else
expressionColumn->Expression = value;
if ( expressionColumn != nullptr && expressionColumn->Expression->Equals( value ) )
return;
Invalidate();
}
}
private:
void AddExpressionColumn( String^ value )
{
// Get the grid's data source. First check for a 0
// table or data grid.
if ( this->DataGridTableStyle == nullptr || this->DataGridTableStyle->DataGrid == nullptr )
return;
DataGrid^ myGrid = this->DataGridTableStyle->DataGrid;
DataView^ myDataView = dynamic_cast<DataView^>((dynamic_cast<CurrencyManager^>(myGrid->BindingContext[ myGrid->DataSource,myGrid->DataMember ]))->List);
// This works only with System::Data::DataTable.
if ( myDataView == nullptr )
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->Table->Columns[ "__Computed__Column__" ];
if ( col != nullptr )
return;
col = gcnew DataColumn( String::Concat( "__Computed__Column__", count ) );
myDataView->Table->Columns->Add( col );
col->Expression = value;
expressionColumn = col;
}
// the OnPaint method to paint the cell based on the expression.
protected:
virtual void Paint( Graphics^ g, Rectangle bounds, CurrencyManager^ source, int rowNum, Brush^ backBrush, Brush^ foreBrush, bool alignToRight ) override
{
bool trueExpression = false;
bool hasExpression = false;
DataRowView^ drv = dynamic_cast<DataRowView^>(source->List[ rowNum ]);
hasExpression = this->expressionColumn != nullptr && this->expressionColumn->Expression != nullptr && !this->expressionColumn->Expression->Equals( String::Empty );
Console::WriteLine( String::Format( "hasExpressionValue {0}", 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->Row[ expressionColumn->ColumnName ];
trueExpression = expr->Equals( "True" );
}
// Let the DataGridBoolColumn do the painting.
if ( !hasExpression )
DataGridBoolColumn::Paint( g, bounds, source, rowNum, backBrush, foreBrush, alignToRight );
// Paint using the expression color for true or false, as calculated.
if ( trueExpression )
DataGridBoolColumn::Paint( g, bounds, source, rowNum, trueBrush, foreBrush, alignToRight );
else
DataGridBoolColumn::Paint( g, bounds, source, rowNum, falseBrush, foreBrush, alignToRight );
}
};
public ref class MyForm: public Form
{
private:
DataTable^ myTable;
DataGrid^ myGrid;
public:
MyForm()
{
myGrid = gcnew DataGrid;
try
{
InitializeComponent();
myTable = gcnew DataTable( "NamesTable" );
myTable->Columns->Add( gcnew DataColumn( "Name" ) );
DataColumn^ column = gcnew DataColumn( "id",Int32::typeid );
myTable->Columns->Add( column );
myTable->Columns->Add( gcnew DataColumn( "calculatedField",bool::typeid ) );
DataSet^ namesDataSet = gcnew DataSet;
namesDataSet->Tables->Add( myTable );
myGrid->SetDataBinding( namesDataSet, "NamesTable" );
AddTableStyle();
AddData();
}
catch ( System::Exception^ exc )
{
Console::WriteLine( exc );
}
}
private:
void grid_Enter( Object^ sender, EventArgs^ e )
{
myGrid->CurrentCell = DataGridCell(2,2);
}
void AddTableStyle()
{
// Map a new TableStyle to the DataTable. Then
// add DataGridColumnStyle objects to the collection
// of column styles with appropriate mappings.
DataGridTableStyle^ dgt = gcnew DataGridTableStyle;
dgt->MappingName = "NamesTable";
DataGridTextBoxColumn^ dgtbc = gcnew DataGridTextBoxColumn;
dgtbc->MappingName = "Name";
dgtbc->HeaderText = "Name";
dgt->GridColumnStyles->Add( dgtbc );
dgtbc = gcnew DataGridTextBoxColumn;
dgtbc->MappingName = "id";
dgtbc->HeaderText = "id";
dgt->GridColumnStyles->Add( dgtbc );
DataGridBoolColumnInherit^ db = gcnew 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";
}
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[ "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();
}
void InitializeComponent()
{
this->Size = System::Drawing::Size( 500, 500 );
myGrid->Size = System::Drawing::Size( 350, 250 );
myGrid->TabStop = true;
myGrid->TabIndex = 1;
this->StartPosition = FormStartPosition::CenterScreen;
this->Controls->Add( myGrid );
}
};
[STAThread]
int main()
{
MyForm^ myGridForm = gcnew MyForm;
myGridForm->ShowDialog();
}
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
继承层次结构
System.Object
System.MarshalByRefObject
System.ComponentModel.Component
System.Windows.Forms.DataGridColumnStyle
System.Windows.Forms.DataGridBoolColumn
线程安全
此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。
平台
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
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0
请参见
参考
DataGridBoolColumn 成员
System.Windows.Forms 命名空间
DataColumn
DataGrid 类
DataGridColumnStyle
GridColumnStylesCollection
GetType
Type