DesignerDataSourceView 類別
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。
做為設計階段資料來源檢視類別的基底類別。
public ref class DesignerDataSourceView abstract
public abstract class DesignerDataSourceView
type DesignerDataSourceView = class
Public MustInherit Class DesignerDataSourceView
- 繼承
-
DesignerDataSourceView
- 衍生
範例
下列程式代碼範例示範如何建立自定義 DesignerDataSourceView 物件以及自定義 IDataSourceViewSchema 類別和兩個自定義 IDataSourceFieldSchema 類別。
這個範例是 類別較大範例的 DataSourceDesigner 一部分。
// A design-time data source view
public class CustomDesignDataSourceView : DesignerDataSourceView
{
private ArrayList _data = null;
public CustomDesignDataSourceView(
CustomDataSourceDesigner owner, string viewName)
: base(owner, viewName)
{}
// Get data for design-time display
public override IEnumerable GetDesignTimeData(
int minimumRows, out bool isSampleData)
{
if (_data == null)
{
// Create a set of design-time fake data
_data = new ArrayList();
for (int i = 1; i <= minimumRows; i++)
{
_data.Add(new BookItem("ID_" + i.ToString(),
"Design-Time Title 0" + i.ToString()));
}
}
isSampleData = true;
return _data as IEnumerable;
}
public override IDataSourceViewSchema Schema
{
get { return new BookListViewSchema(); }
}
// Allow getting the record count
public override bool CanRetrieveTotalRowCount
{
get { return true; }
}
// Do not allow deletions
public override bool CanDelete
{
get { return false; }
}
// Do not allow insertions
public override bool CanInsert
{
get { return false; }
}
// Do not allow updates
public override bool CanUpdate
{
get { return false; }
}
// Do not allow paging
public override bool CanPage
{
get { return false; }
}
// Do not allow sorting
public override bool CanSort
{
get { return false; }
}
}
' A design-time data source view
Public Class CustomDesignDataSourceView
Inherits DesignerDataSourceView
Private _data As ArrayList = Nothing
Public Sub New(ByVal owner As CustomDataSourceDesigner, ByVal viewName As String)
MyBase.New(owner, viewName)
End Sub
' Get data for design-time display
Public Overrides Function GetDesignTimeData( _
ByVal minimumRows As Integer, _
ByRef isSampleData As Boolean) As IEnumerable
If IsNothing(_data) Then
' Create a set of design-time fake data
_data = New ArrayList()
Dim i As Integer
For i = 1 To minimumRows
_data.Add(New BookItem("ID_" & i.ToString(), _
"Design-Time Title 0" & i.ToString()))
Next
End If
isSampleData = True
Return CType(_data, IEnumerable)
End Function
Public Overrides ReadOnly Property Schema() As IDataSourceViewSchema
Get
Return New BookListViewSchema()
End Get
End Property
' Allow getting the record count
Public Overrides ReadOnly Property CanRetrieveTotalRowCount() As Boolean
Get
Return True
End Get
End Property
' Do not allow deletions
Public Overrides ReadOnly Property CanDelete() As Boolean
Get
Return False
End Get
End Property
' Do not allow insertions
Public Overrides ReadOnly Property CanInsert() As Boolean
Get
Return False
End Get
End Property
' Do not allow updates
Public Overrides ReadOnly Property CanUpdate() As Boolean
Get
Return False
End Get
End Property
' Do not allow paging
Public Overrides ReadOnly Property CanPage() As Boolean
Get
Return False
End Get
End Property
' Do not allow sorting
Public Overrides ReadOnly Property CanSort() As Boolean
Get
Return False
End Get
End Property
End Class
// A custom View Schema class
public class BookListViewSchema : IDataSourceViewSchema
{
public BookListViewSchema()
{ }
// The name of this View Schema
public string Name
{
get { return "BookList"; }
}
// Build a Field Schema array
public IDataSourceFieldSchema[] GetFields()
{
IDataSourceFieldSchema[] fields = new IDataSourceFieldSchema[2];
fields[0] = new CustomIDFieldSchema();
fields[1] = new CustomTitleFieldSchema();
return fields;
}
// There are no child views, so return null
public IDataSourceViewSchema[] GetChildren()
{
return null;
}
}
// A custom Field Schema class for ID
public class CustomIDFieldSchema : IDataSourceFieldSchema
{
public CustomIDFieldSchema()
{ }
// Name is ID
public string Name
{
get { return "ID"; }
}
// Data type is string
public Type DataType
{
get { return typeof(string); }
}
// This is not an Identity field
public bool Identity
{
get { return false; }
}
// This field is read only
public bool IsReadOnly
{
get { return true; }
}
// This field is unique
public bool IsUnique
{
get { return true; }
}
// This field can't be longer than 20
public int Length
{
get { return 20; }
}
// This field can't be null
public bool Nullable
{
get { return false; }
}
// This is a Primary Key
public bool PrimaryKey
{
get { return true; }
}
// These properties do not apply
public int Precision
{
get { return -1; }
}
public int Scale
{
get { return -1; }
}
}
// A custom Field Schema class for Title
public class CustomTitleFieldSchema : IDataSourceFieldSchema
{
public CustomTitleFieldSchema()
{ }
// Name is Title
public string Name
{
get { return "Title"; }
}
// Type is string
public Type DataType
{
get { return typeof(string); }
}
// This is not an Identity field
public bool Identity
{
get { return false; }
}
// This field is not read only
public bool IsReadOnly
{
get { return false; }
}
// This field is not unique
public bool IsUnique
{
get { return false; }
}
// This field can't be longer than 100
public int Length
{
get { return 100; }
}
// This field can't be null
public bool Nullable
{
get { return false; }
}
// This is not the Primary Key
public bool PrimaryKey
{
get { return false; }
}
// These properties do not apply
public int Precision
{
get { return -1; }
}
public int Scale
{
get { return -1; }
}
}
' A custom View Schema class
Public Class BookListViewSchema
Implements IDataSourceViewSchema
Public Sub New()
End Sub
' The name of this View Schema
Public ReadOnly Property Name() As String Implements IDataSourceViewSchema.Name
Get
Return "BookList"
End Get
End Property
' Build a Field Schema array
Public Function GetFields() As IDataSourceFieldSchema() Implements IDataSourceViewSchema.GetFields
Dim fields(1) As IDataSourceFieldSchema
fields(0) = New CustomIDFieldSchema()
fields(1) = New CustomTitleFieldSchema()
Return fields
End Function
' There are no child views, so return Nothing
Public Function GetChildren() As IDataSourceViewSchema() Implements IDataSourceViewSchema.GetChildren
Return Nothing
End Function
End Class
' A custom Field Schema class for ID
Public Class CustomIDFieldSchema
Implements IDataSourceFieldSchema
Public Sub New()
End Sub
' Name is ID
Public ReadOnly Property Name() As String Implements IDataSourceFieldSchema.Name
Get
Return "ID"
End Get
End Property
' Data type is string
Public ReadOnly Property DataType() As Type Implements IDataSourceFieldSchema.DataType
Get
Return GetType(String)
End Get
End Property
' This is not an Identity field
Public ReadOnly Property Identity() As Boolean Implements IDataSourceFieldSchema.Identity
Get
Return False
End Get
End Property
' This field is read only
Public ReadOnly Property IsReadOnly() As Boolean Implements IDataSourceFieldSchema.IsReadOnly
Get
Return True
End Get
End Property
' This field is unique
Public ReadOnly Property IsUnique() As Boolean Implements IDataSourceFieldSchema.IsUnique
Get
Return True
End Get
End Property
' This field can't be longer than 20
Public ReadOnly Property Length() As Integer Implements IDataSourceFieldSchema.Length
Get
Return 20
End Get
End Property
' This field can't be null
Public ReadOnly Property Nullable() As Boolean Implements IDataSourceFieldSchema.Nullable
Get
Return False
End Get
End Property
' This is a Primary Key
Public ReadOnly Property PrimaryKey() As Boolean Implements IDataSourceFieldSchema.PrimaryKey
Get
Return True
End Get
End Property
' These properties do not apply
Public ReadOnly Property Precision() As Integer Implements IDataSourceFieldSchema.Precision
Get
Return -1
End Get
End Property
Public ReadOnly Property Scale() As Integer Implements IDataSourceFieldSchema.Scale
Get
Return -1
End Get
End Property
End Class
' A custom Field Schema class for Title
Public Class CustomTitleFieldSchema
Implements IDataSourceFieldSchema
Public Sub New()
End Sub
' Name is Title
Public ReadOnly Property Name() As String Implements IDataSourceFieldSchema.Name
Get
Return "Title"
End Get
End Property
' Type is string
Public ReadOnly Property DataType() As Type Implements IDataSourceFieldSchema.DataType
Get
Return GetType(String)
End Get
End Property
' This is not an Identity field
Public ReadOnly Property Identity() As Boolean Implements IDataSourceFieldSchema.Identity
Get
Return False
End Get
End Property
' This field is not read only
Public ReadOnly Property IsReadOnly() As Boolean Implements IDataSourceFieldSchema.IsReadOnly
Get
Return False
End Get
End Property
' This field is not unique
Public ReadOnly Property IsUnique() As Boolean Implements IDataSourceFieldSchema.IsUnique
Get
Return False
End Get
End Property
' This field can't be longer than 100
Public ReadOnly Property Length() As Integer Implements IDataSourceFieldSchema.Length
Get
Return 100
End Get
End Property
' This field can't be null
Public ReadOnly Property Nullable() As Boolean Implements IDataSourceFieldSchema.Nullable
Get
Return False
End Get
End Property
' This is not the Primary Key
Public ReadOnly Property PrimaryKey() As Boolean Implements IDataSourceFieldSchema.PrimaryKey
Get
Return False
End Get
End Property
' These properties do not apply
Public ReadOnly Property Precision() As Integer Implements IDataSourceFieldSchema.Precision
Get
Return -1
End Get
End Property
Public ReadOnly Property Scale() As Integer Implements IDataSourceFieldSchema.Scale
Get
Return -1
End Get
End Property
End Class
給實施者的注意事項
當您繼承自 DesignerDataSourceView 類別時,必須覆寫 GetDesignTimeData(Int32, Boolean) 方法,以建立符合 屬性的 Schema 範例數據,或從數據源傳回實際數據。
建構函式
DesignerDataSourceView(IDataSourceDesigner, String) |
使用指定的資料來源設計工具和檢視名稱,初始化 DesignerDataSourceView 類別的新執行個體。 |
屬性
CanDelete |
取得值,指出與目前 DataSourceControl 物件相關聯的 DataSourceView 物件是否支援 ExecuteDelete(IDictionary, IDictionary) 方法。 |
CanInsert |
取得值,指出與目前 DataSourceControl 物件相關聯的 DataSourceView 物件是否支援 ExecuteInsert(IDictionary) 方法。 |
CanPage |
取得值,指出與目前 DataSourceControl 物件相關聯的 DataSourceView 物件是否支援對 ExecuteSelect(DataSourceSelectArguments) 方法所擷取的資料進行分頁。 |
CanRetrieveTotalRowCount |
取得值,指出與目前 DataSourceControl 物件相關聯的 DataSourceView 物件是否支援擷取資料列總數,而不是資料本身。 |
CanSort |
取得值,其中該值表示與目前 DataSourceControl 物件相關聯的 DataSourceView 物件是否支援基礎資料來源的排序檢視。 |
CanUpdate |
取得值,指出與目前 DataSourceControl 物件相關聯的 DataSourceView 物件是否支援 ExecuteUpdate(IDictionary, IDictionary, IDictionary) 方法。 |
DataSourceDesigner |
取得建立這個 DesignerDataSourceView 控制項之設計工具的參考。 |
Name |
取得建立 DesignerDataSourceView 類別的這個執行個體時所提供檢視的名稱。 |
Schema |
取得結構描述,其描述這個檢視物件所代表的資料來源檢視。 |
方法
Equals(Object) |
判斷指定的物件是否等於目前的物件。 (繼承來源 Object) |
GetDesignTimeData(Int32, Boolean) |
產生設計階段資料,該資料符合使用所指定資料列數之關聯資料來源控制項的結構描述,且指出會傳回範例還是實際資料。 |
GetHashCode() |
做為預設雜湊函式。 (繼承來源 Object) |
GetType() |
取得目前執行個體的 Type。 (繼承來源 Object) |
MemberwiseClone() |
建立目前 Object 的淺層複製。 (繼承來源 Object) |
ToString() |
傳回代表目前物件的字串。 (繼承來源 Object) |