Gewusst wie: Hosten von Steuerelementen in DataGridView-Zellen in Windows Forms
Aktualisiert: November 2007
Das DataGridView-Steuerelement verfügt über mehrere Spaltentypen, die es den Benutzern ermöglichen, Werte auf verschiedene Weise einzugeben und zu bearbeiten. Wenn diese Spaltentypen Ihre Anforderungen an die Dateneingabe nicht erfüllen, können Sie eigene Spaltentypen mit Zellen, die die gewünschten Steuerelemente hosten, erstellen. Zu diesem Zweck müssen Sie Klassen definieren, die sich von DataGridViewColumn und DataGridViewCell ableiten. Außerdem müssen Sie eine Klasse definieren, die sich von Control ableitet und die IDataGridViewEditingControl-Schnittstelle implementiert.
Im folgenden Codebeispiel wird gezeigt, wie eine Kalenderspalte erstellt wird. In den Zellen dieser Spalte werden Daten in gewöhnlichen Textfeldzellen angezeigt. Wenn der Benutzer eine Zelle bearbeitet, wird jedoch ein DateTimePicker-Steuerelement angezeigt. Damit Sie die Funktionalität für die Textfeldanzeige nicht erneut implementieren müssen, wird die CalendarCell-Klasse von der DataGridViewTextBoxCell-Klasse abgeleitet, anstatt die DataGridViewCell-Klasse direkt zu erben.
.gif "Hinweis") Hinweis: |
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Wenn Sie von DataGridViewCell oder DataGridViewColumn ableiten und der abgeleiteten Klasse neue Eigenschaften hinzufügen, müssen Sie die Clone-Methode überschreiben, um die neuen Eigenschaften bei Klonvorgängen zu kopieren. Sie sollten stets die Clone-Methode der Basisklasse aufrufen, sodass die Eigenschaften der Basisklasse in die neue Zelle oder Spalte kopiert werden. |
Beispiel
Imports System
Imports System.Windows.Forms
Public Class CalendarColumn
Inherits DataGridViewColumn
Public Sub New()
MyBase.New(New CalendarCell())
End Sub
Public Overrides Property CellTemplate() As DataGridViewCell
Get
Return MyBase.CellTemplate
End Get
Set(ByVal value As DataGridViewCell)
' Ensure that the cell used for the template is a CalendarCell.
If (value IsNot Nothing) AndAlso _
Not value.GetType().IsAssignableFrom(GetType(CalendarCell)) _
Then
Throw New InvalidCastException("Must be a CalendarCell")
End If
MyBase.CellTemplate = value
End Set
End Property
End Class
Public Class CalendarCell
Inherits DataGridViewTextBoxCell
Public Sub New()
' Use the short date format.
Me.Style.Format = "d"
End Sub
Public Overrides Sub InitializeEditingControl(ByVal rowIndex As Integer, _
ByVal initialFormattedValue As Object, _
ByVal dataGridViewCellStyle As DataGridViewCellStyle)
' Set the value of the editing control to the current cell value.
MyBase.InitializeEditingControl(rowIndex, initialFormattedValue, _
dataGridViewCellStyle)
Dim ctl As CalendarEditingControl = _
CType(DataGridView.EditingControl, CalendarEditingControl)
ctl.Value = CType(Me.Value, DateTime)
End Sub
Public Overrides ReadOnly Property EditType() As Type
Get
' Return the type of the editing contol that CalendarCell uses.
Return GetType(CalendarEditingControl)
End Get
End Property
Public Overrides ReadOnly Property ValueType() As Type
Get
' Return the type of the value that CalendarCell contains.
Return GetType(DateTime)
End Get
End Property
Public Overrides ReadOnly Property DefaultNewRowValue() As Object
Get
' Use the current date and time as the default value.
Return DateTime.Now
End Get
End Property
End Class
Class CalendarEditingControl
Inherits DateTimePicker
Implements IDataGridViewEditingControl
Private dataGridViewControl As DataGridView
Private valueIsChanged As Boolean = False
Private rowIndexNum As Integer
Public Sub New()
Me.Format = DateTimePickerFormat.Short
End Sub
Public Property EditingControlFormattedValue() As Object _
Implements IDataGridViewEditingControl.EditingControlFormattedValue
Get
Return Me.Value.ToShortDateString()
End Get
Set(ByVal value As Object)
If TypeOf value Is String Then
Me.Value = DateTime.Parse(CStr(value))
End If
End Set
End Property
Public Function GetEditingControlFormattedValue(ByVal context _
As DataGridViewDataErrorContexts) As Object _
Implements IDataGridViewEditingControl.GetEditingControlFormattedValue
Return Me.Value.ToShortDateString()
End Function
Public Sub ApplyCellStyleToEditingControl(ByVal dataGridViewCellStyle As _
DataGridViewCellStyle) _
Implements IDataGridViewEditingControl.ApplyCellStyleToEditingControl
Me.Font = dataGridViewCellStyle.Font
Me.CalendarForeColor = dataGridViewCellStyle.ForeColor
Me.CalendarMonthBackground = dataGridViewCellStyle.BackColor
End Sub
Public Property EditingControlRowIndex() As Integer _
Implements IDataGridViewEditingControl.EditingControlRowIndex
Get
Return rowIndexNum
End Get
Set(ByVal value As Integer)
rowIndexNum = value
End Set
End Property
Public Function EditingControlWantsInputKey(ByVal key As Keys, _
ByVal dataGridViewWantsInputKey As Boolean) As Boolean _
Implements IDataGridViewEditingControl.EditingControlWantsInputKey
' Let the DateTimePicker handle the keys listed.
Select Case key And Keys.KeyCode
Case Keys.Left, Keys.Up, Keys.Down, Keys.Right, _
Keys.Home, Keys.End, Keys.PageDown, Keys.PageUp
Return True
Case Else
Return Not dataGridViewWantsInputKey
End Select
End Function
Public Sub PrepareEditingControlForEdit(ByVal selectAll As Boolean) _
Implements IDataGridViewEditingControl.PrepareEditingControlForEdit
' No preparation needs to be done.
End Sub
Public ReadOnly Property RepositionEditingControlOnValueChange() _
As Boolean Implements _
IDataGridViewEditingControl.RepositionEditingControlOnValueChange
Get
Return False
End Get
End Property
Public Property EditingControlDataGridView() As DataGridView _
Implements IDataGridViewEditingControl.EditingControlDataGridView
Get
Return dataGridViewControl
End Get
Set(ByVal value As DataGridView)
dataGridViewControl = value
End Set
End Property
Public Property EditingControlValueChanged() As Boolean _
Implements IDataGridViewEditingControl.EditingControlValueChanged
Get
Return valueIsChanged
End Get
Set(ByVal value As Boolean)
valueIsChanged = value
End Set
End Property
Public ReadOnly Property EditingControlCursor() As Cursor _
Implements IDataGridViewEditingControl.EditingPanelCursor
Get
Return MyBase.Cursor
End Get
End Property
Protected Overrides Sub OnValueChanged(ByVal eventargs As EventArgs)
' Notify the DataGridView that the contents of the cell have changed.
valueIsChanged = True
Me.EditingControlDataGridView.NotifyCurrentCellDirty(True)
MyBase.OnValueChanged(eventargs)
End Sub
End Class
Public Class Form1
Inherits Form
Private dataGridView1 As New DataGridView()
<STAThreadAttribute()> _
Public Shared Sub Main()
Application.Run(New Form1())
End Sub
Public Sub New()
Me.dataGridView1.Dock = DockStyle.Fill
Me.Controls.Add(Me.dataGridView1)
Me.Text = "DataGridView calendar column demo"
End Sub
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) _
Handles Me.Load
Dim col As New CalendarColumn()
Me.dataGridView1.Columns.Add(col)
Me.dataGridView1.RowCount = 5
Dim row As DataGridViewRow
For Each row In Me.dataGridView1.Rows
row.Cells(0).Value = DateTime.Now
Next row
End Sub
End Class
using System;
using System.Windows.Forms;
public class CalendarColumn : DataGridViewColumn
{
public CalendarColumn() : base(new CalendarCell())
{
}
public override DataGridViewCell CellTemplate
{
get
{
return base.CellTemplate;
}
set
{
// Ensure that the cell used for the template is a CalendarCell.
if (value != null &&
!value.GetType().IsAssignableFrom(typeof(CalendarCell)))
{
throw new InvalidCastException("Must be a CalendarCell");
}
base.CellTemplate = value;
}
}
}
public class CalendarCell : DataGridViewTextBoxCell
{
public CalendarCell()
: base()
{
// Use the short date format.
this.Style.Format = "d";
}
public override void InitializeEditingControl(int rowIndex, object
initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)
{
// Set the value of the editing control to the current cell value.
base.InitializeEditingControl(rowIndex, initialFormattedValue,
dataGridViewCellStyle);
CalendarEditingControl ctl =
DataGridView.EditingControl as CalendarEditingControl;
ctl.Value = (DateTime)this.Value;
}
public override Type EditType
{
get
{
// Return the type of the editing contol that CalendarCell uses.
return typeof(CalendarEditingControl);
}
}
public override Type ValueType
{
get
{
// Return the type of the value that CalendarCell contains.
return typeof(DateTime);
}
}
public override object DefaultNewRowValue
{
get
{
// Use the current date and time as the default value.
return DateTime.Now;
}
}
}
class CalendarEditingControl : DateTimePicker, IDataGridViewEditingControl
{
DataGridView dataGridView;
private bool valueChanged = false;
int rowIndex;
public CalendarEditingControl()
{
this.Format = DateTimePickerFormat.Short;
}
// Implements the IDataGridViewEditingControl.EditingControlFormattedValue
// property.
public object EditingControlFormattedValue
{
get
{
return this.Value.ToShortDateString();
}
set
{
if (value is String)
{
this.Value = DateTime.Parse((String)value);
}
}
}
// Implements the
// IDataGridViewEditingControl.GetEditingControlFormattedValue method.
public object GetEditingControlFormattedValue(
DataGridViewDataErrorContexts context)
{
return EditingControlFormattedValue;
}
// Implements the
// IDataGridViewEditingControl.ApplyCellStyleToEditingControl method.
public void ApplyCellStyleToEditingControl(
DataGridViewCellStyle dataGridViewCellStyle)
{
this.Font = dataGridViewCellStyle.Font;
this.CalendarForeColor = dataGridViewCellStyle.ForeColor;
this.CalendarMonthBackground = dataGridViewCellStyle.BackColor;
}
// Implements the IDataGridViewEditingControl.EditingControlRowIndex
// property.
public int EditingControlRowIndex
{
get
{
return rowIndex;
}
set
{
rowIndex = value;
}
}
// Implements the IDataGridViewEditingControl.EditingControlWantsInputKey
// method.
public bool EditingControlWantsInputKey(
Keys key, bool dataGridViewWantsInputKey)
{
// Let the DateTimePicker handle the keys listed.
switch (key & Keys.KeyCode)
{
case Keys.Left:
case Keys.Up:
case Keys.Down:
case Keys.Right:
case Keys.Home:
case Keys.End:
case Keys.PageDown:
case Keys.PageUp:
return true;
default:
return !dataGridViewWantsInputKey;
}
}
// Implements the IDataGridViewEditingControl.PrepareEditingControlForEdit
// method.
public void PrepareEditingControlForEdit(bool selectAll)
{
// No preparation needs to be done.
}
// Implements the IDataGridViewEditingControl
// .RepositionEditingControlOnValueChange property.
public bool RepositionEditingControlOnValueChange
{
get
{
return false;
}
}
// Implements the IDataGridViewEditingControl
// .EditingControlDataGridView property.
public DataGridView EditingControlDataGridView
{
get
{
return dataGridView;
}
set
{
dataGridView = value;
}
}
// Implements the IDataGridViewEditingControl
// .EditingControlValueChanged property.
public bool EditingControlValueChanged
{
get
{
return valueChanged;
}
set
{
valueChanged = value;
}
}
// Implements the IDataGridViewEditingControl
// .EditingPanelCursor property.
public Cursor EditingPanelCursor
{
get
{
return base.Cursor;
}
}
protected override void OnValueChanged(EventArgs eventargs)
{
// Notify the DataGridView that the contents of the cell
// have changed.
valueChanged = true;
this.EditingControlDataGridView.NotifyCurrentCellDirty(true);
base.OnValueChanged(eventargs);
}
}
public class Form1 : Form
{
private DataGridView dataGridView1 = new DataGridView();
[STAThreadAttribute()]
public static void Main()
{
Application.Run(new Form1());
}
public Form1()
{
this.dataGridView1.Dock = DockStyle.Fill;
this.Controls.Add(this.dataGridView1);
this.Load += new EventHandler(Form1_Load);
this.Text = "DataGridView calendar column demo";
}
private void Form1_Load(object sender, EventArgs e)
{
CalendarColumn col = new CalendarColumn();
this.dataGridView1.Columns.Add(col);
this.dataGridView1.RowCount = 5;
foreach (DataGridViewRow row in this.dataGridView1.Rows)
{
row.Cells[0].Value = DateTime.Now;
}
}
}
Kompilieren des Codes
Für dieses Beispiel ist Folgendes erforderlich:
- Verweise auf die Assemblys System und System.Windows.Forms.
Informationen zum Erstellen dieses Beispiels über die Befehlszeile für Visual Basic oder Visual C# finden Sie unter Erstellen von der Befehlszeile aus (Visual Basic) oder Erstellen über die Befehlszeile mit csc.exe. Sie können dieses Beispiel auch in Visual Studio erstellen, indem Sie den Code in ein neues Projekt einfügen.
Siehe auch
Konzepte
Architektur des DataGridView-Steuerelements (Windows Forms)
Spaltentypen im DataGridView-Steuerelement in Windows Forms