IEditableObject 接口
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
提供提交或回滚对用作数据源的对象所做更改的功能。
public interface class IEditableObject
public interface IEditableObject
type IEditableObject = interface
Public Interface IEditableObject
- 派生
示例
以下示例提供了 接口的 IEditableObject 简单实现。 类 Customer
存储客户信息,并可用作客户数据库的集合。 此示例假定你已使用 CustomerList
在 类的 示例中可以找到的 IBindingList 类。
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
注解
此接口通常用于捕获 的 BeginEdit、 EndEdit和 CancelEdit 语义 DataRowView。
方法
BeginEdit() |
开始编辑对象。 |
CancelEdit() |
放弃上一次 BeginEdit() 调用之后的更改。 |
EndEdit() |
将上一次 BeginEdit() 或 AddNew() 调用之后所进行的更改推到基础对象中。 |