Data Bindingとは？ わかりやすく解説

Public NotInheritable Class
 DataBinding

Dim instance As DataBinding

public sealed class DataBinding

public ref class DataBinding sealed

public final class DataBinding

public final class DataBinding

' Create the custom class that accesses the DataBinding and
' DataBindingCollection classes at design time.

Public Class SimpleDesigner
    Inherits System.Web.UI.Design.ControlDesigner
    ' Create a Text property with accessors that obtain 
    ' the property value from and set the property value
    ' to the Text key in the DataBindingCollection class.

    Public Property [Text]() As
 String
        Get
            Dim myBinding As DataBinding =
 DataBindings("Text")
            If Not (myBinding Is
 Nothing) Then
                Return myBinding.Expression
            End If
            Return String.Empty
        End Get
        Set(ByVal value As
 String)

            If value Is Nothing
 OrElse value.Length = 0 Then
                DataBindings.Remove("Text")
            Else

                Dim binding As DataBinding
 = DataBindings("Text")

                If binding Is Nothing
 Then
                    binding = New DataBinding("Text",
 GetType(String), value)
                Else
                    binding.Expression = value
                End If
                ' Call the DataBinding constructor, then add
                ' the initialized DataBinding object to the 
                ' DataBindingCollection for this custom designer.
                Dim binding1 As DataBinding
 = CType(DataBindings.SyncRoot, DataBinding)
                DataBindings.Add(binding)
                DataBindings.Add(binding1)
            End If
            PropertyChanged("Text")
        End Set
    End Property

    Protected Sub PropertyChanged(ByVal
 propName As String)
        Dim myHtmlControlDesignBehavior As
 IControlDesignerTag = Me.Tag
        Dim myDataBindingCollection As DataBindingCollection
        Dim myDataBinding1, myDataBinding2 As
 DataBinding
        Dim myStringReplace1, myDataBindingExpression1, removedBinding,
 removedBindingAfterReplace, myDataBindingExpression2, myStringReplace2 As
 [String]
        Dim removedBindings1(), removedBindings2() As
 String
        Dim temp As Int32

        If myHtmlControlDesignBehavior Is Nothing
 Then
            Return
        End If

        myDataBindingCollection = DataBindings
        ' Use the DataBindingCollection constructor to 
        ' create the myDataBindingCollection1 object.
        ' Then set this object equal to the
        ' DataBindings property of the control created
        ' by this custom designer.
        Dim myDataBindingCollection1 As New
 DataBindingCollection()
        myDataBindingCollection1 = DataBindings
        myDataBindingCollection = DataBindings
        If (myDataBindingCollection.Contains(propName)) Then
            myDataBinding1 = myDataBindingCollection(propName)
            myStringReplace1 = propName.Replace(".",
 "-")
            If myDataBinding1 Is Nothing
 Then
                myHtmlControlDesignBehavior.RemoveAttribute(myStringReplace1)
                Return
            End If
            ' DataBinding is not null.
            myDataBindingExpression1 = [String].Concat("<%#",
 myDataBinding1.Expression, "%>")
            myHtmlControlDesignBehavior.SetAttribute(myStringReplace1, myDataBindingExpression1)
            Dim index As Integer
 = myStringReplace1.IndexOf("-")
        Else
            ' Use the DataBindingCollection.RemovedBindings 
            ' property to set the value of the removedBindings
            ' arrays.
            removedBindings1 = DataBindings.RemovedBindings
            removedBindings2 = DataBindings.RemovedBindings
            temp = 0
            While removedBindings2.Length > temp
                removedBinding = removedBindings2(temp)
                removedBindingAfterReplace = removedBinding.Replace("."c,
 "-"c)
                myHtmlControlDesignBehavior.RemoveAttribute(removedBindingAfterReplace)
                temp = temp & 1
            End While
        End If
        ' Use the DataBindingCollection.GetEnumerator method
        ' to iterate through the myDataBindingCollection object
        ' and write the PropertyName, PropertyType, and Expression
        ' properties to a file for each DataBinding object
        ' in the MyDataBindingCollection object. 
        myDataBindingCollection = DataBindings
        Dim myEnumerator As IEnumerator = myDataBindingCollection.GetEnumerator()

        While myEnumerator.MoveNext()
            myDataBinding2 = CType(myEnumerator.Current, DataBinding)
            Dim dataBindingOutput1, dataBindingOutput2, dataBindingOutput3
 As [String]
            dataBindingOutput1 = [String].Concat("The property
 name is ", myDataBinding2.PropertyName)
            dataBindingOutput2 = [String].Concat("The property
 type is ", myDataBinding2.PropertyType.ToString(), "-",
 dataBindingOutput1)
            dataBindingOutput3 = [String].Concat("The expression
 is ", myDataBinding2.Expression, "-",
 dataBindingOutput2)
            WriteToFile(dataBindingOutput3)

            myDataBindingExpression2 = [String].Concat("<%#",
 myDataBinding2.Expression, "%>")
            myStringReplace2 = myDataBinding2.PropertyName.Replace(".",
 "-")
            myHtmlControlDesignBehavior.SetAttribute(myStringReplace2, myDataBindingExpression2)
            Dim index As Integer
 = myStringReplace2.IndexOf("-"c)
        End While ' while loop
 ends
    End Sub 'OnBindingsCollectionChanged
    Public Sub WriteToFile(ByVal
 input As String)
        ' The WriteToFile custom method writes
        ' the values of the DataBinding properties
        ' to a file on the C drive at design time.
        Dim myFile As StreamWriter = File.AppendText("C:\DataBindingOutput.txt")
        Dim encoder As New
 ASCIIEncoding()
        Dim ByteArray As Byte()
 = encoder.GetBytes(input)
        Dim CharArray As Char()
 = encoder.GetChars(ByteArray)
        myFile.WriteLine(CharArray, 0, input.Length)
        myFile.Close()
    End Sub 'WriteToFile
End Class 'SimpleDesigner

// Create the custom class that accesses the DataBinding and
// DataBindingCollection classes at design time.
public class SimpleDesigner : System.Web.UI.Design.ControlDesigner
{
    // Create a Text property with accessors that obtain 
    // the property value from and set the property value
    // to the Text key in the DataBindingCollection class.
    public string Text
    {
        get
        {
            DataBinding myBinding = DataBindings["Text"];
            if (myBinding != null)
            {
                return myBinding.Expression;
            }
            return String.Empty;
        }
        set
        {

            if ((value == null) || (value.Length
 == 0))
            {
                DataBindings.Remove("Text");
            }
            else
            {

                DataBinding binding = DataBindings["Text"];

                if (binding == null)
                {
                    binding = new DataBinding("Text",
 typeof(string), value);
                }
                else
                {
                    binding.Expression = value;
                }
                // Call the DataBinding constructor, then add
                // the initialized DataBinding object to the 
                // DataBindingCollection for this custom designer.
                DataBinding binding1 = (DataBinding)DataBindings.SyncRoot;
                DataBindings.Add(binding);
                DataBindings.Add(binding1);
            }
            PropertyChanged("Text");
        }
    }
    protected void PropertyChanged(string
 propName)
    {
        IControlDesignerTag myHtmlControlDesignBehavior = this.Tag;
        
        DataBindingCollection myDataBindingCollection;
        DataBinding myDataBinding1, myDataBinding2;
        String myStringReplace1, myDataBindingExpression1, removedBinding, removedBindingAfterReplace,
 myDataBindingExpression2, myStringReplace2;
        string[] removedBindings1, removedBindings2;
        Int32 temp;

        if (myHtmlControlDesignBehavior == null)
            return;
        // Use the DataBindingCollection constructor to 
        // create the myDataBindingCollection1 object.
        // Then set this object equal to the
        // DataBindings property of the control created
        // by this custom designer.
        DataBindingCollection myDataBindingCollection1 = new DataBindingCollection();
        myDataBindingCollection1 = myDataBindingCollection = DataBindings;
        if (myDataBindingCollection.Contains(propName))
        {
            myDataBinding1 = myDataBindingCollection[propName];
            myStringReplace1 = propName.Replace(".", "-");
            if (myDataBinding1 == null)
            {
                myHtmlControlDesignBehavior.RemoveAttribute(myStringReplace1);
                return;
            }
            // DataBinding is not null.
            myDataBindingExpression1 = String.Concat("<%#", myDataBinding1.Expression,
 "%>");
            myHtmlControlDesignBehavior.SetAttribute(myStringReplace1, myDataBindingExpression1);
            int index = myStringReplace1.IndexOf("-");
        }
        else
        {
            // Use the DataBindingCollection.RemovedBindings 
            // property to set the value of the removedBindings
            // arrays.
            removedBindings2 = removedBindings1 = DataBindings.RemovedBindings;
            temp = 0;
            while (removedBindings2.Length > temp)
            {
                removedBinding = removedBindings2[temp];
                removedBindingAfterReplace = removedBinding.Replace('.', '-');
                myHtmlControlDesignBehavior.RemoveAttribute(removedBindingAfterReplace);
                temp = temp + 1;
            }
        }
        // Use the DataBindingCollection.GetEnumerator method
        // to iterate through the myDataBindingCollection object
        // and write the PropertyName, PropertyType, and Expression
        // properties to a file for each DataBinding object
        // in the MyDataBindingCollection object. 
        myDataBindingCollection = DataBindings;
        IEnumerator myEnumerator = myDataBindingCollection.GetEnumerator();

        while (myEnumerator.MoveNext())
        {
            myDataBinding2 = (DataBinding)myEnumerator.Current;
            String dataBindingOutput1, dataBindingOutput2, dataBindingOutput3;
            dataBindingOutput1 = String.Concat("The property name is ",
 myDataBinding2.PropertyName);
            dataBindingOutput2 = String.Concat("The property type is ",
 myDataBinding2.PropertyType.ToString(), "-", dataBindingOutput1);
            dataBindingOutput3 = String.Concat("The expression is ", myDataBinding2.Expression,
 "-", dataBindingOutput2);
            WriteToFile(dataBindingOutput3);

            myDataBindingExpression2 = String.Concat("<%#", myDataBinding2.Expression,
 "%>");
            myStringReplace2 = myDataBinding2.PropertyName.Replace(".",
 "-");
            myHtmlControlDesignBehavior.SetAttribute(myStringReplace2, myDataBindingExpression2);
            int index = myStringReplace2.IndexOf('-');
        }// while loop ends
    }
    public void WriteToFile(string
 input)
    {
        // The WriteToFile custom method writes
        // the values of the DataBinding properties
        // to a file on the C drive at design time.
        StreamWriter myFile = File.AppendText("C:\\DataBindingOutput.txt");
        ASCIIEncoding encoder = new ASCIIEncoding();
        byte[] ByteArray = encoder.GetBytes(input);
        char[] CharArray = encoder.GetChars(ByteArray);
        myFile.WriteLine(CharArray, 0, input.Length);
        myFile.Close();
    }
}

// Create the custom class that accesses the DataBinding and
// DataBindingCollection classes at design time.
public class SimpleDesigner extends System.Web.UI.Design.ControlDesigner
{
    // Create a Text property with accessors that obtain 
    // the property value from and set the property value
    // to the Text key in the DataBindingCollection class.
    /** @property 
     */
    public String get_Text()
    {
        DataBinding myBinding = get_DataBindings().get_Item("Text");
        if (myBinding != null) {
            return myBinding.get_Expression();
        }
        return("");
    } //get_Text

    /** @property 
     */
    public void set_Text(String value)
    {
        if (value == null || value.get_Length()
 == 0) {
            get_DataBindings().Remove("Text");
        }
        else {
            DataBinding binding = get_DataBindings().get_Item("Text");
            if (binding == null) {
                binding = new DataBinding("Text", String.class.ToType(),
 value);
            }
            else {
                binding.set_Expression(value);
            }

            // Call the DataBinding constructor, then add
            // the initialized DataBinding object to the 
            // DataBindingCollection for this custom designer.
            DataBinding binding1 = (DataBinding)(get_DataBindings().
                get_SyncRoot());
            get_DataBindings().Add(binding);
            get_DataBindings().Add(binding1);
        }
        OnBindingsCollectionChanged("Text");
    } //set_Text

    // Override the OnBindingsCollectionChanged class to create
    // the data-binding expression and associate it with 
    // a property on the control created by the designer.
    protected void OnBindingsCollectionChanged(String
 propName)
    {
        IHtmlControlDesignerBehavior myHtmlControlDesignBehavior = 
            get_Behavior();
        DataBindingCollection myDataBindingCollection;
        DataBinding myDataBinding1, myDataBinding2;
        String myStringReplace1, myDataBindingExpression1, removedBinding, 
        removedBindingAfterReplace, myDataBindingExpression2, myStringReplace2;
        String removedBindings1[], removedBindings2[];
        int temp;

        if (myHtmlControlDesignBehavior == null)
 {
            return;
        }

        // Use the DataBindingCollection constructor to 
        // create the myDataBindingCollection1 object.
        // Then set this object equal to the
        // DataBindings property of the control created
        // by this custom designer.
        DataBindingCollection myDataBindingCollection1 = 
            new DataBindingCollection();
        myDataBindingCollection1 = (myDataBindingCollection = 
            get_DataBindings());

        if (propName != null) {
            myDataBinding1 = myDataBindingCollection.get_Item(propName);
            myStringReplace1 = propName.Replace(".", "-");
            if (myDataBinding1 == null) {
                myHtmlControlDesignBehavior.RemoveAttribute(myStringReplace1, 
                    true);
                return;
            }

            // DataBinding is not null.
            myDataBindingExpression1 = String.Concat("<%#", myDataBinding1.
                get_Expression(), "%>");
            myHtmlControlDesignBehavior.SetAttribute(myStringReplace1, 
                myDataBindingExpression1, true);
            int index = myStringReplace1.IndexOf("-");
        }
        else {
            // Use the DataBindingCollection.RemovedBindings 
            // property to set the value of the removedBindings
            // arrays.
            removedBindings2 = (removedBindings1 = get_DataBindings().
                get_RemovedBindings());

            temp = 0;
            while (removedBindings2.length > temp) {
                removedBinding = removedBindings2[temp];
                removedBindingAfterReplace = removedBinding.Replace('.', '-');
                myHtmlControlDesignBehavior.RemoveAttribute(
                    removedBindingAfterReplace, true);
                temp = temp + 1;
            }
        }

        // Use the DataBindingCollection.GetEnumerator method
        // to iterate through the myDataBindingCollection object
        // and write the PropertyName, PropertyType, and Expression
        // properties to a file for each DataBinding object
        // in the MyDataBindingCollection object. 
        myDataBindingCollection = get_DataBindings();
        IEnumerator myEnumerator = myDataBindingCollection.GetEnumerator();
        while (myEnumerator.MoveNext()) {
            myDataBinding2 = (DataBinding)(myEnumerator.get_Current());
            String dataBindingOutput1, dataBindingOutput2, dataBindingOutput3;
            dataBindingOutput1 = String.Concat("The property name is ",
 
                myDataBinding2.get_PropertyName());
            dataBindingOutput2 = String.Concat("The property type is ",
 
                myDataBinding2.get_PropertyType().ToString(), "-", 
                dataBindingOutput1);
            dataBindingOutput3 = String.Concat("The expression is ", 
                myDataBinding2.get_Expression(), "-", dataBindingOutput2);
            WriteToFile(dataBindingOutput3);
            myDataBindingExpression2 = String.Concat("<%#", myDataBinding2.
                get_Expression(), "%>");
            myStringReplace2 = myDataBinding2.get_PropertyName().
                Replace(".", "-");
            myHtmlControlDesignBehavior.SetAttribute(myStringReplace2, 
                myDataBindingExpression2, true);
            int index = myStringReplace2.IndexOf("-");
        } // while loop ends
    } //OnBindingsCollectionChanged
    
    public void WriteToFile(String input)
    {
        // The WriteToFile custom method writes
        // the values of the DataBinding properties
        // to a file on the C drive at design time.
        StreamWriter myFile = File.AppendText("C:\\DataBindingOutput.txt");
        ASCIIEncoding encoder = new ASCIIEncoding();
        ubyte byteArray[] = encoder.GetBytes(input);
        char charArray[] = encoder.GetChars(byteArray);
        myFile.WriteLine(charArray, 0, input.get_Length());
        myFile.Close();
    } //WriteToFile

Public Sub New ( _
    propertyName As String, _
    propertyType As Type, _
    expression As String _
)

Dim propertyName As String
Dim propertyType As Type
Dim expression As String

Dim instance As New DataBinding(propertyName,
 propertyType, expression)

public DataBinding (
    string propertyName,
    Type propertyType,
    string expression
)

public:
DataBinding (
    String^ propertyName, 
    Type^ propertyType, 
    String^ expression
)

public DataBinding (
    String propertyName, 
    Type propertyType, 
    String expression
)

public function DataBinding (
    propertyName : String, 
    propertyType : Type, 
    expression : String
)

' Create a Text property with accessors that obtain 
' the property value from and set the property value
' to the Text key in the DataBindingCollection class.

Public Property [Text]() As
 String
    Get
        Dim myBinding As DataBinding = DataBindings("Text")
        If Not (myBinding Is
 Nothing) Then
            Return myBinding.Expression
        End If
        Return String.Empty
    End Get
    Set(ByVal value As String)

        If value Is Nothing
 OrElse value.Length = 0 Then
            DataBindings.Remove("Text")
        Else

            Dim binding As DataBinding = DataBindings("Text")

            If binding Is Nothing
 Then
                binding = New DataBinding("Text",
 GetType(String), value)
            Else
                binding.Expression = value
            End If
            ' Call the DataBinding constructor, then add
            ' the initialized DataBinding object to the 
            ' DataBindingCollection for this custom designer.
            Dim binding1 As DataBinding = CType(DataBindings.SyncRoot,
 DataBinding)
            DataBindings.Add(binding)
            DataBindings.Add(binding1)
        End If
        PropertyChanged("Text")
    End Set
End Property

// Create a Text property with accessors that obtain 
// the property value from and set the property value
// to the Text key in the DataBindingCollection class.
public string Text
{
    get
    {
        DataBinding myBinding = DataBindings["Text"];
        if (myBinding != null)
        {
            return myBinding.Expression;
        }
        return String.Empty;
    }
    set
    {

        if ((value == null) || (value.Length
 == 0))
        {
            DataBindings.Remove("Text");
        }
        else
        {

            DataBinding binding = DataBindings["Text"];

            if (binding == null)
            {
                binding = new DataBinding("Text", typeof(string),
 value);
            }
            else
            {
                binding.Expression = value;
            }
            // Call the DataBinding constructor, then add
            // the initialized DataBinding object to the 
            // DataBindingCollection for this custom designer.
            DataBinding binding1 = (DataBinding)DataBindings.SyncRoot;
            DataBindings.Add(binding);
            DataBindings.Add(binding1);
        }
        PropertyChanged("Text");
    }
}

// Create a Text property with accessors that obtain 
// the property value from and set the property value
// to the Text key in the DataBindingCollection class.
/** @property 
 */
public String get_Text()
{
    DataBinding myBinding = get_DataBindings().get_Item("Text");
    if (myBinding != null) {
        return myBinding.get_Expression();
    }
    return("");
} //get_Text

/** @property 
 */
public void set_Text(String value)
{
    if (value == null || value.get_Length()
 == 0) {
        get_DataBindings().Remove("Text");
    }
    else {
        DataBinding binding = get_DataBindings().get_Item("Text");
        if (binding == null) {
            binding = new DataBinding("Text", String.class.ToType(),
 value);
        }
        else {
            binding.set_Expression(value);
        }

        // Call the DataBinding constructor, then add
        // the initialized DataBinding object to the 
        // DataBindingCollection for this custom designer.
        DataBinding binding1 = (DataBinding)(get_DataBindings().
            get_SyncRoot());
        get_DataBindings().Add(binding);
        get_DataBindings().Add(binding1);
    }
    OnBindingsCollectionChanged("Text");
} //set_Text