您的位置:首页 > 其它

如何:在 Windows 窗体 DataGridView 单元格中承载控件

2011-07-01 09:56 666 查看
DataGridView 控件提供了多种列类型,使得用户可以通过多种方式输入和编辑值。但是,如果这些列类型无法满足数据输入要求,您也可以使用承载所选控件的单元格创建自己的列类型。要做到这一点,必须定义派生自 DataGridViewColumnDataGridViewCell 的类。您还必须定义派生自 Control 并实现 IDataGridViewEditingControl 接口的类。

下面的代码示例演示如何创建日历列。此列的单元格在普通的文本框单元格中显示日期,但当用户编辑单元格时,就会出现 DateTimePicker 控件。为了避免必须再次实现文本框显示功能,CalendarCell 类从 DataGridViewTextBoxCell 类派生,而不是直接从 DataGridViewCell 类继承。


说明:
当从 DataGridViewCellDataGridViewColumn 派生并向派生类添加新属性时,请确保重写 Clone 方法以便在克隆操作期间复制新属性。还应调用基类的 Clone 方法,以便将基类的属性复制到新的单元格或列中。


示例

Visual Basic


复制代码


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


C#


复制代码


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;
}
}
}


内容来自用户分享和网络整理,不保证内容的准确性,如有侵权内容,可联系管理员处理 点击这里给我发消息
标签: 
相关文章推荐