DataGridBoolColumn-Klasse
Gibt eine Spalte an, in der jede Zelle ein Kontrollkästchen zur Darstellung eines booleschen Werts enthält.
Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)
Syntax
'Declaration
Public Class DataGridBoolColumn
Inherits DataGridColumnStyle
'Usage
Dim instance As DataGridBoolColumn
public class DataGridBoolColumn : DataGridColumnStyle
public ref class DataGridBoolColumn : public DataGridColumnStyle
public class DataGridBoolColumn extends DataGridColumnStyle
public class DataGridBoolColumn extends DataGridColumnStyle
Hinweise
Die DataGridBoolColumn wird von der abstract Klasse DataGridColumnStyle abgeleitet. Zur Laufzeit enthält DataGridBoolColumn standardmäßig in jeder Zelle Kontrollkästchen mit drei Zuständen: aktiviert (true), deaktiviert (false) und Value. Um Kontrollkästchen mit zwei Zuständen zu verwenden, legen Sie die AllowNull-Eigenschaft auf false fest.
Zu den der Klasse hinzugefügten Eigenschaften gehören u. a. FalseValue, NullValue und TrueValue. Diese Eigenschaften geben den Wert an, der den einzelnen Zuständen der Spalte zugrunde liegt.
Beispiel
Im folgenden Codebeispiel wird zunächst eine neue DataGridBoolColumn erstellt und der GridColumnStylesCollection eines DataGridTableStyle hinzugefügt.
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
Vererbungshierarchie
System.Object
System.MarshalByRefObject
System.ComponentModel.Component
System.Windows.Forms.DataGridColumnStyle
System.Windows.Forms.DataGridBoolColumn
Threadsicherheit
Alle öffentlichen statischen (Shared in Visual Basic) Member dieses Typs sind threadsicher. Bei Instanzmembern ist die Threadsicherheit nicht gewährleistet.
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
Siehe auch
Referenz
DataGridBoolColumn-Member
System.Windows.Forms-Namespace
DataColumn
DataGrid-Klasse
DataGridColumnStyle
GridColumnStylesCollection
GetType
Type