IEditableObject 介面
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
對用來做為資料來源的物件,提供進行變更之認可或復原的功能。
public interface class IEditableObject
public interface IEditableObject
type IEditableObject = interface
Public Interface IEditableObject
- 衍生
範例
下列範例提供 介面的簡單實作 IEditableObject 。 類別 Customer
會儲存客戶資訊,並可作為客戶資料庫的集合。 此範例假設您已使用 CustomerList
類別,該類別可在 類別的範例中找到 IBindingList 。
public ref class Customer: public IEditableObject
{
private:
ref struct CustomerData
{
internal:
String^ id;
String^ firstName;
String^ lastName;
};
internal:
CustomersList^ parent;
CustomerData^ custData;
CustomerData^ backupData;
bool inTxn;
// Implements IEditableObject
public:
virtual void BeginEdit()
{
Console::WriteLine( "Start BeginEdit" );
if ( !inTxn )
{
this->backupData = custData;
inTxn = true;
Console::WriteLine( "BeginEdit - {0}", this->backupData->lastName );
}
Console::WriteLine( "End BeginEdit" );
}
virtual void CancelEdit()
{
Console::WriteLine( "Start CancelEdit" );
if ( inTxn )
{
this->custData = backupData;
inTxn = false;
Console::WriteLine( "CancelEdit - {0}", this->custData->lastName );
}
Console::WriteLine( "End CancelEdit" );
}
virtual void EndEdit()
{
Console::WriteLine( "Start EndEdit{0}{1}", this->custData->id, this->custData->lastName );
if ( inTxn )
{
backupData = gcnew CustomerData;
inTxn = false;
Console::WriteLine( "Done EndEdit - {0}{1}", this->custData->id, this->custData->lastName );
}
Console::WriteLine( "End EndEdit" );
}
public:
Customer( String^ ID )
{
this->custData = gcnew CustomerData;
this->custData->id = ID;
this->custData->firstName = "";
this->custData->lastName = "";
inTxn = false;
}
property String^ ID
{
String^ get()
{
return this->custData->id;
}
}
property String^ FirstName
{
String^ get()
{
return this->custData->firstName;
}
void set( String^ value )
{
this->custData->firstName = value;
this->OnCustomerChanged();
}
}
property String^ LastName
{
String^ get()
{
return this->custData->lastName;
}
void set( String^ value )
{
this->custData->lastName = value;
this->OnCustomerChanged();
}
}
internal:
property CustomersList^ Parent
{
CustomersList^ get()
{
return parent;
}
void set( CustomersList^ value )
{
parent = value;
}
}
void OnCustomerChanged()
{
if (!inTxn && Parent != nullptr)
{
Parent->CustomerChanged(this);
}
}
public:
virtual String^ ToString() override
{
StringWriter^ sb = gcnew StringWriter;
sb->Write( this->FirstName );
sb->Write( " " );
sb->Write( this->LastName );
return sb->ToString();
}
};
public class Customer : IEditableObject
{
struct CustomerData
{
internal string id ;
internal string firstName ;
internal string lastName ;
}
private CustomersList parent;
private CustomerData custData;
private CustomerData backupData;
private bool inTxn = false;
// Implements IEditableObject
void IEditableObject.BeginEdit()
{
Console.WriteLine("Start BeginEdit");
if (!inTxn)
{
this.backupData = custData;
inTxn = true;
Console.WriteLine("BeginEdit - " + this.backupData.lastName);
}
Console.WriteLine("End BeginEdit");
}
void IEditableObject.CancelEdit()
{
Console.WriteLine("Start CancelEdit");
if (inTxn)
{
this.custData = backupData;
inTxn = false;
Console.WriteLine("CancelEdit - " + this.custData.lastName);
}
Console.WriteLine("End CancelEdit");
}
void IEditableObject.EndEdit()
{
Console.WriteLine("Start EndEdit" + this.custData.id + this.custData.lastName);
if (inTxn)
{
backupData = new CustomerData();
inTxn = false;
Console.WriteLine("Done EndEdit - " + this.custData.id + this.custData.lastName);
}
Console.WriteLine("End EndEdit");
}
public Customer(string ID) : base()
{
this.custData = new CustomerData();
this.custData.id = ID;
this.custData.firstName = "";
this.custData.lastName = "";
}
public string ID
{
get
{
return this.custData.id;
}
}
public string FirstName
{
get
{
return this.custData.firstName;
}
set
{
this.custData.firstName = value;
this.OnCustomerChanged();
}
}
public string LastName
{
get
{
return this.custData.lastName;
}
set
{
this.custData.lastName = value;
this.OnCustomerChanged();
}
}
internal CustomersList Parent
{
get
{
return parent;
}
set
{
parent = value ;
}
}
private void OnCustomerChanged()
{
if (!inTxn && Parent != null)
{
Parent.CustomerChanged(this);
}
}
public override string ToString()
{
StringWriter sb = new StringWriter();
sb.Write(this.FirstName);
sb.Write(" ");
sb.Write(this.LastName);
return sb.ToString();
}
}
Public Class Customer
Implements IEditableObject
Structure CustomerData
Friend id As String
Friend firstName As String
Friend lastName As String
End Structure
Public parent As CustomersList
Private custData As CustomerData
Private backupData As CustomerData
Private inTxn As Boolean = False
' Implements IEditableObject
Sub BeginEdit() Implements IEditableObject.BeginEdit
Console.WriteLine("Start BeginEdit")
If Not inTxn Then
Me.backupData = custData
inTxn = True
Console.WriteLine(("BeginEdit - " + Me.backupData.lastName))
End If
Console.WriteLine("End BeginEdit")
End Sub
Sub CancelEdit() Implements IEditableObject.CancelEdit
Console.WriteLine("Start CancelEdit")
If inTxn Then
Me.custData = backupData
inTxn = False
Console.WriteLine(("CancelEdit - " + Me.custData.lastName))
End If
Console.WriteLine("End CancelEdit")
End Sub
Sub EndEdit() Implements IEditableObject.EndEdit
Console.WriteLine(("Start EndEdit" + Me.custData.id + Me.custData.lastName))
If inTxn Then
backupData = New CustomerData()
inTxn = False
Console.WriteLine(("Done EndEdit - " + Me.custData.id + Me.custData.lastName))
End If
Console.WriteLine("End EndEdit")
End Sub
Public Sub New(ByVal ID As String)
Me.custData = New CustomerData()
Me.custData.id = ID
Me.custData.firstName = ""
Me.custData.lastName = ""
End Sub
Public ReadOnly Property ID() As String
Get
Return Me.custData.id
End Get
End Property
Public Property FirstName() As String
Get
Return Me.custData.firstName
End Get
Set(ByVal Value As String)
Me.custData.firstName = Value
Me.OnCustomerChanged()
End Set
End Property
Public Property LastName() As String
Get
Return Me.custData.lastName
End Get
Set(ByVal Value As String)
Me.custData.lastName = Value
Me.OnCustomerChanged()
End Set
End Property
Friend Property Parents() As CustomersList
Get
Return Parent
End Get
Set(ByVal Value As CustomersList)
parent = Value
End Set
End Property
Private Sub OnCustomerChanged()
If Not inTxn And (Parent IsNot Nothing) Then
Parent.CustomerChanged(Me)
End If
End Sub
Public Overrides Function ToString() As String
Dim sb As New StringWriter()
sb.Write(Me.FirstName)
sb.Write(" ")
sb.Write(Me.LastName)
Return sb.ToString()
End Function
End Class
備註
這個介面通常用來擷取 BeginEdit的、 EndEdit和 CancelEdit 語意 DataRowView。
方法
BeginEdit() |
開始對物件進行編輯。 |
CancelEdit() |
捨棄從上次 BeginEdit() 呼叫以來所做的變更。 |
EndEdit() |
推入自從上次對基礎物件的 BeginEdit() 或 AddNew() 呼叫所做的變更。 |