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DesignerDataSourceView 類別

定義

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)

適用於

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